SALVO: Single-Arm Trial of Ipilimumab and Nivolumab as Adjuvant Therapy for Resected Mucosal Melanoma

PURPOSE

Mucosal melanoma is a rare, aggressive form of melanoma with extremely high recurrence rates despite definitive surgical resection with curative intent. Currently there is no consensus on adjuvant therapy. Data on checkpoint inhibitors for adjuvant therapy are lacking.

PATIENTS AND METHODS

We performed a single-arm, multicenter clinical trial using "flip dose" ipilimumab (1 mg/kg q3w × 4 cycles), and nivolumab (3 mg/kg q3w × 4 cycles), then nivolumab 480 mg q4w × 11 cycles to complete a year of adjuvant therapy. Participants must have had R0/R1 resection ≤90 days before registration, no prior systemic therapy (adjuvant radiotherapy allowed), ECOG 0/1, and no uncontrolled autoimmune disease or other invasive cancer. Patients were recruited through the Midwest Melanoma Partnership/Hoosier Oncology Network.

RESULTS

From September 2017 to August 2021, 35 patients were enrolled. Of these, 29 (83%) had R0 resections, and 7 (20%) received adjuvant radiotherapy. Median age was 67 years, 21 (60.0%) female. Recurrence-free survival (RFS) rates at 1 and 2 years were 50% [95% confidence interval (CI), 31%-66%] and 37% (95% CI, 19%-55%), respectively. Overall survival rates at 1 and 2 years were 87% (95% CI, 68%-95%) and 68% (95% CI, 46%-83%), respectively. Median RFS was 10.3 months (95% CI, 5.7-25.8). Most common grade 3 toxicities were diarrhea (14%), hypertension (14%), and hyponatremia (11%), with no grade 4/5 toxicities.

CONCLUSIONS

Flip-dose ipilimumab and nivolumab after resection of mucosal melanoma is associated with outcomes improved over that of surgical resection alone. Long-term follow-up, subgroup analyses and correlative studies are ongoing.

Safety and efficacy of immune checkpoint inhibitors (ICI) in advanced penile squamous cell carcinoma (PeCa): An international study from the Global Society of Rare Genitourinary Tumors (GSRGT)

5

Background: Management options for patients (pts) with advanced (locally advanced or metastatic) PeCa are limited. The GSRGT assembled an international cohort of pts with advanced PeCa treated with ICI to evaluate toxicity and clinical outcomes. Methods: We retrospectively collected data on pts with advanced PeCa receiving ≥1 cycle of ICI between 2015-2022 at 18 medical centers in the US, Europe, and Asia. Immune-related adverse events (irAE) were graded per the Common Terminology Criteria for Adverse Events v5.0. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Objective response rate (ORR) was determined by the clinical investigator per RECIST 1.1 criteria, whenever feasible. Results: Among 72 pts with advanced PeCa treated with ICI, 24 (33%) were Hispanic and 7 (10%) were Black. 60 (83%) pts had metastases while the remainder had locally advanced disease. The median age was 64 (inter-quartile range (IQR): 54,70) years and 48 (67%) had ECOG performance status ≥1. Most pts (n=60, 83%) were treated in the ≥2nd line setting and received pembrolizumab (n=23), nivolumab (n=15), cemiplimab (n=15), nivolumab and ipilimumab (n=7), or other anti-PD1/L1-based therapies (n=12). Among 37 pts with available data on HPV status, 24 (65%) were HPV+. 3 (4%) pts were HIV+. irAE of any grade occurred in 18 (25%) pts, 7 (10%) were grade ≥3, 7 (10%) required steroids, 6 (9%) required hospitalization, and 8 (11%) led to treatment discontinuation. The median OS and 24-month OS and median PFS and 24-month PFS were 9.4 (95%CI: 6.8, 12.8) months and 19.3% (95%CI: 9.2, 32.1) and 2.8 (95%CI: 2.1, 3.9) months and 11.2 % (95%CI: 4.9, 20.2), respectively. Among 66 pts evaluable for response, ORR was 7/66 (11%) (2 with complete response, 5 with partial response), and 16 (24%) pts had stable disease for a disease control rate of 35%. The median duration of response was 7.9 (IQR: 3, not reached) months. Conclusions: In the largest retrospective cohort of ICI-treated advanced PeCa, ICI showed no new safety signals, however, overall anti-tumor activity was limited. Future translational studies are needed to identify pts that are more likely to derive clinical benefit from ICI.

Phase II trial of cytoreductive stereotactic hypofractionated radiotherapy with combination ipilimumab/nivolumab for metastatic kidney cancer (CYTOSHRINK)

TPS750

Background: Randomized data from the interferon era demonstrated survival benefits of cytoreductive nephrectomy (CN) in patients with metastatic renal cell carcinoma (mRCC). Results from SURTIME and CARMENA, conducted in the VEGF-targeted therapy era, have challenged the routine use of upfront CN in most IMDC intermediate and poor risk patients. Furthermore, the treatment landscape in mRCC now includes multiple first-line doublet combination immunotherapy approvals. The Checkmate-214 trial showed that intermediate/poor risk patients have improved overall survival and durable objective responses with ipilimumab and nivolumab (I/N) compared to sunitinib. However, patients with a primary kidney lesion in situ appeared to have less benefit than patients with prior nephrectomy. Stereotactic body radiation therapy (SBRT) provides a convenient method for cytoreduction of the primary kidney lesion and may induce an enhanced systemic anti-tumor immune response. We hypothesize that SBRT to the primary kidney mass will enhance the efficacy of I/N compared to standard of care I/N alone in this unique subset of de novo mRCC patients. We also hypothesize that the combination of SBRT and I/N will lead to upregulation of key components of immune modulation as well as unique perturbation of the host gut microbiome compared to I/N alone. Methods: This phase II trial randomizes untreated mRCC patients in a 2:1 fashion to I/N plus SBRT (30-40 Gy in 5 fractions) to the primary kidney mass between cycles 1 and 2 (experimental arm, E), versus standard of care I/N alone (standard arm, S). Eligible patients have biopsy-proven mRCC (any histology) and IMDC intermediate/poor risk disease. Patients with a primary kidney lesion ≥ 20cm, previous abdominal radiation precluding SBRT, or who have a contraindication to I/N are excluded. The primary objective is to compare the efficacy of I/N plus SBRT versus I/N alone, as determined by the hazard ratio for progression free survival (PFS). Secondary objectives include evaluation of safety, overall survival, objective response rate, and health-related quality of life. Exploratory analyses include: (1) immune and genomic profiling of liquid biopsies; (2) transcriptional profiling of baseline tumor biopsies; and (3) interrogation of the gut microbiome and bacterial functionality. Blood and fecal samples will be prospectively collected at baseline, prior to cycle 2 of each arm, and at time of disease progression or the 12-month mark, whichever comes first. Up to 78 patients will be enrolled under the assumption of an improved 12-month PFS from 50% (S) to 75% (E), using a two-sided α=0.1, power=80%, and accounting for loss-to-follow-up and stratification using IMDC criteria 1-2 vs 3-6. Trial is enrolling in Canada and Australia. Clinical trial information: NCT04090710 .

FDG PET-CT imaging in assessing interim response to neoadjuvant cisplatin-based chemotherapy (NAC) in muscle invasive bladder cancer (MIBC): A prospective study

460

Background: Muscle invasive bladder cancer (MIBC) is an aggressive local disease where initial staging with conventional CT imaging is often suboptimal. To explore the role of PET-CT in both staging MIBC and assessing response to neoadjuvant chemotherapy (NAC), we conducted a prospective multicentre, randomized trial known as PETMUSE. We report here the first results from the neoadjuvant substudy which assessed interim PET-CT response after 2-3 cycles of NAC and how this correlated with disease free survival (DFS) and overall survival (OS). Methods: Patients with MIBC (T2a-4a, N0-3, M0) based on transurethral resection of their bladder tumor and CT staging were randomized 2:1 to PET-CT or no PET-CT. All PET-CT patients, receiving cisplatin-based NAC underwent a second PET-CT after 2 cycles of gemcitabine and cisplatin (GC) or 3 cycles of dose dense methotrexate, vinblastine, adriamycin, cisplatin (ddMVAC) to assess for interim response. Patients were scored (1-5) by 2 independent reviewers according to the extent of metabolic response on PET-CT. Disease-free survival (DFS) and overall survival (OS) were collected. Results: Between 2016 and 2021, 291 patients were enrolled on PETMUSE of which 46 participated in the neoadjuvant substudy. Median age was 68 (51-86); 36 (78%) were male; 26 were ECOG 0 (57%); 31 (68%) were T2, 13 (28%) were T3/T4; and 35 (76%) were node negative. In terms of NAC regimens: 22 (48%) received GC, 17 (37%) split dose GC, 6 (13%) ddMVAC, and 1 (2%) MVAC. On PET-CT, 23 (50%) had a complete metabolic response, 14 (30%) had a partial metabolic response, 5 (11%) had no change or mixed response and 4 (9%) had progressive disease or new lesion on PET scan. Metabolic response on PET-CT was a statistically significant prognostic factor for both DFS and OS (see Table). Conclusions: In MIBC patients receiving cisplatin-based NAC, metabolic response seen on interim PET-CT was correlated with DFS and OS. PET-CT warrants further study in this setting as a potential early indicator of response to NAC. Clinical trial information: NCT02462239 . [Table: see text][Table: see text]

Cardiac Morbidity Following Chemoradiation in Stage III Non-small Cell Lung Cancer Patients: A Population-Based Cohort Study

AIMS

To assess the risk of cardiac toxicity following radical radiotherapy in advanced lung cancer patients.

MATERIALS AND METHODS

Patients with a diagnosis of stage III non-small cell lung cancer (NSCLC) receiving chemoradiotherapy were extracted from a population-based cohort in Ontario, Canada. The primary outcome of cardiac toxicity, defined as cardiac events or congestive heart failure, was assessed at 1 and 5 years following chemoradiotherapy. Secondary outcomes included overall survival, survival in relationship to post-treatment cardiac events and the effect of radiotherapy technique on cardiac toxicity.

RESULTS

In total, 2031 NSCLC patients were included. The cumulative incidence of cardiac toxicity at 5 years was 20.3% (18.4-22.3). The median survival was 13.7 months in NSCLC patients who had a cardiac event post-chemoradiotherapy compared with 23.4 months in those who did not (P = 0.012). There was a trend towards increased cumulative cardiac toxicity (hazard ratio 3.37, P = 0.14) with three-dimensional conformal radiotherapy compared with intensity-modulated or volumetric arc radiotherapy techniques.

CONCLUSION

The risk of cardiac events and congestive heart failure 5 years after radical thoracic radiotherapy appears high and survival is inferior at 1 year in those patients who experience a cardiac event post-treatment. More conformal radiotherapy techniques may help reduce cardiac toxicity. Further studies should investigate adaptive treatment planning and close monitoring and intervention in this high-risk group after chemoradiotherapy.

Hepatitis B screening to reduce the risk of viral reactivation in gynecologic oncology patients receiving chemotherapy at a regional tertiary cancer center: A quality improvement initiative

332

Background: In 2020, ASCO released a Provisional Clinical Opinion recommending universal hepatitis B virus (HBV) screening prior to systemic chemotherapy to reduce the risk of reactivation and associated morbidities. There is limited data for HBV prevalence and risk factors in gynecologic oncology. In gynecologic oncology patients at the Juravinski Cancer Centre, median baseline screening rate over 6 months was 0%. Our aim was to increase the rate of HBV screening to 70% in gynecologic oncology patients initiating chemotherapy over 6 months and compare real-world efficacy of risk factor-based vs. universal screening. Methods: We performed an interrupted time series study using the Model for Improvement methodology. Four interventions were introduced to address identified screening barriers: provider education, standardization of a testing protocol, integration with existing clinical workflow, and biweekly feedback reports. These were modified in response to outcomes and stakeholder feedback in Plan-Do-Study-Act cycles. Process and outcome measures data were collected by chart review and analyzed on statistical process control and run charts. Retrospective chart review collected demographic and disease data including Centers for Disease Control (CDC) hepatitis risk factors. Results: From Dec 1/20 to Nov 30/21, there were 381 new chemotherapy initiations in gynecology patients. The proportion of physicians screening increased significantly from 0% to 85%, and HBV monthly screening rates increased significantly from 0% to 72.2% by month 8 and were sustained for 4 months at last analysis. The integrated clinic screening protocol and feedback report interventions were each associated with increased screening rates. Of 330 unique patients initiating chemotherapy, 175 were screened (53%). Although ≥95% lacked data for 4 CDC hepatitis risk factors, 60.9% had ≥1 risk factor, and 11.2% had ≥2. HBV surface antigen (HBSAg) was non-reactive in all screened patients, but anti-HBV core (HBc) antibody was reactive in 5 (2.9%), indicative of prior infection. Real world risk factor-based screening in those with ≥1 CDC risk factor would have only identified 3/5 seropositive patients. In the screened population, risk-factor based screening had sensitivity 60%, specificity 38.8%, PPV 2.8%, NPV 97.1%. There were no HBV reactivations. Conclusions: Implementation of 4 interventions to increase HBV screening in gynecologic oncology patients receiving chemotherapy significantly improved screening rates, achieving our target at 8 months with sustained improvement. Risk-factor based screening lacks sensitivity compared to universal screening which may impact management. Lessons learned from this initiative may be applicable to other interventions to reduce infectious morbidity in oncologic populations.

LUMINA: A prospective trial omitting radiotherapy (RT) following breast conserving surgery (BCS) in T1N0 luminal A breast cancer (BC)

LBA501

Background: Adjuvant breast RT is usually prescribed following BCS to reduce the risk of local recurrence (LR). However, this treatment is inconvenient, costly, and associated with acute and late toxicity. Traditional clinical pathological factors (CPFs) alone are limited in their ability to identify women with a low enough risk of LR to omit RT. Molecular defined intrinsic subtypes of BC provide additional prognostic information with luminal A having the lowest risk of recurrence. A retrospective analysis of a previous trial suggested that women >60 years with luminal A grade 1-2 T1N0 BC treated by BCS and endocrine therapy alone had a low rate of LR ( JCO 2015; 33:2035). The utility of identifying luminal A subtype combined with CPFs has not been prospectively evaluated for its ability to guide RT decision-making. Methods: A prospective multicenter cohort study was performed. Eligibility criteria were: women ≥ 55 years; having undergone BCS for grade 1-2 T1N0 BC; ≥ 1mm margins of excision; luminal A subtype (defined as: ER ≥ 1%, PR>20%, HER2 negative and Ki67 ≤ 13.25%); and treated with adjuvant endocrine therapy. ER, PR and HER2 were performed locally as per ASCO guidelines. Patients meeting clinical eligibility with ER ≥ 1%, PR>20%, HER2 negative BC were registered and had Ki67 immunohistochemistry performed centrally in one of three Canadian laboratories using International Ki67 Working Group methods. Proficiency testing between laboratories was performed yearly. Patients with Ki67 ≤ 13.25% were enrolled in the trial and were assigned to not receive RT. The primary outcome was LR defined as time from enrollment to any invasive or non-invasive cancer in the ipsilateral breast. Assuming a 5-year LR rate of 3.5%, 500 patients were required to show that the upper bound of a two sided 90% (one-sided 95%) confidence interval (CI) was <5%. Patients were followed every six months for the first two years and then yearly. The probability of LR was estimated using the cumulative incidence function with death as a competing risk. Secondary outcomes were contralateral BC; relapse free survival (RFS) based on any recurrence; disease free survival (DFS) based on any recurrence, second cancer or death; and overall survival (OS). Results: From August 2013 to July 2017, 501 of 727 registered patients from 26 centers had a Ki67 ≤ 13.25% and were enrolled. Median follow-up was 5 years. Median age was 67 and 442 (88%) patients were <75 years. Median tumor size was 1.1 cm. The 5-year rate of LR satisfied our pre-specified boundary (see Table). Conclusions: Women ≥ 55 years with grade 1-2 T1N0 luminal A BC following BCS treated with endocrine therapy alone had very low rates of LR at 5 years and are candidates for omission of RT. Clinical trial information: NCT01791829. [Table: see text]

Intratumoral (IT) INT230-6 can cause tumor necrosis in vivo: Preliminary results of a phase II randomized presurgical window-of-opportunity study in early breast cancers (the INVINCIBLE study)

605

Background: The INVINCIBLE study is a randomized, Phase 2 presurgical Window-Of-Opportunity trial for IT INT230-6 (comprising VINblastine (VIN) Cisplatin (VIN)) evaluating clinical and BioLogical Effects in patients with early-stage operable Breast Cancer. INT230-6 also contains a dispersion enhancer molecule designed to facilitate diffusion of the cytotoxic agents into cancer cells and cause tumor necrosis. We have previously demonstrated that INT230-6 halts cancer cell replication and induces apoptosis while maturing dendritic cells and recruiting T-cells to the tumor microenvironment. In this trial, IT injections of INT230-6 are conducted to 1) exploit the potential of regional cytotoxic chemotherapy on breast cancer in vivo and 2) assess the potential for an immune response in the tumor microenvironment and host prior to surgical resection. Methods: Up to 90 women with newly diagnosed operable early-stage intermediate or high-grade T1-T2 invasive breast cancers are randomly allocated (2:1) prior to resection to IT injections of INT230-6, no treatment or saline sham. This study has two parts. Part I (N=29) was a randomized trial comparing 1-3 doses of INT230-6 injected weekly vs no treatment prior to surgery to evaluate safety, feasibility, and optimal drug dosing. Part II is a double-blinded randomized trial of up to 60 patients where patients will receive one IT dose of INT230-6 vs saline injection (2:1). The primary endpoint is to estimate the proportion of patients who achieve a complete cell cycle arrest post-surgery compared to the diagnosis biopsy. Secondary endpoints include an evaluation of the rate of pathological complete response, the percent of residual cancer, and safety. The study will also profile changes in CD4/CD8 and the T-cell repertoire. Results: Part I demonstrated feasibility, safety and tolerability of presurgical IT injections in breast cancer patients. Twenty patients with tumors ranging from 1-4.4cm were injected with at least one dose up to 48 hours prior to surgery. No surgeries were delayed or altered and the most common (>10%) AEs were injection site pain (100%), infusion site extravasation, injection site reaction and vomiting (10% each). Preliminary data show histologic evidence of up to 95% tumor necrosis in varying biologic subtypes and an increase in intratumoral TILs in injected tumors compared to controls. Part II is ongoing. Conclusions: Preliminary evidence shows that a single dose of INT230-6 can cause intratumoral necrosis and stimulate an immune response in breast cancers prior to surgery with minimal adverse effects and good tolerability. The results of Part II of the study will further evaluate the potential cytotoxic, immunomodulatory and other biologic effects of INT230-6 and its role as a potential cancer therapy in breast cancer patients awaiting surgery. Clinical trial information: NCT04781725.

Overall survival of patients with chronic obstructive pulmonary disease receiving immunotherapy for non-small cell lung cancer: A population-based analysis in Ontario, Canada

e21172

Background: Outside of clinical trial eligibility criteria, there is limited data to guide the selection of patients with non-small cell lung cancer (NSCLC) for immune checkpoint inhibitor (ICI) therapy. Chronic obstructive pulmonary disease (COPD) and lung cancer are associated, independent of smoking history, with a common background of chronic inflammation. Previous studies have demonstrated that COPD is a negative prognostic marker for NSCLC, but the clinical benefit of ICI in patients with NSCLC and COPD is unknown. Methods: A population-level administrative data analysis of Ontario patients was performed through the Institute of Clinical Evaluative Sciences (ICES) Data Analytic Services. All patients with NSCLC diagnosed between Jan 2010 and Dec 2020 and treated with immune-checkpoint inhibitors (pembrolizumab, nivolumab, atezolizumab) were included. Demographics, comorbidity and marginalization scores, and COPD status were extracted along with outcome information. Overall survival (OS) was estimated using the Kaplan-Meier method, and compared between patients with or without COPD using Cox proportional hazards regression. The frequency of patients requiring hospitalization and duration of treatment was also estimated and compared using the chi-square and Wilcoxon rank-sum test. Results: 73331 NSCLC patients were identified, of which 4.5% (n = 3285) patients received ICI. COPD patients were less likely to receive immunotherapy (3.8% vs. 5.1%, p < 0.001). Among those receiving an ICI, 41% (n = 1362) of patients had a diagnosis of COPD prior to NSCLC diagnosis. Median (95% CI) OS was 17.3 (16.6 to 18.2) months for patients with COPD and 16.9 (16.2 to 17.8) for patients with no known COPD, which was not significantly different in univariate (hazard ratio = 0.96, 95% CI = 0.89 to 1.04, p = 0.35) or multivariate analysis (HR = 0.96, 95% CI = 0.89 to 1.05, p = 0.40). The 5-year survival was also similar between both groups (6.7% vs. 6.5%). The rate of hospitalization within 6 months (18.4% vs 18.0%, p = 0.82) and the duration of immunotherapy treatment (median = 80 vs 71 days p = 0.23) did not differ for the COPD vs. non-COPD groups. Conclusions: Despite an expectation of frailty, our data suggest that NSCLC patients with COPD receiving ICI maintained similar durations of treatment and similar rates of hospitalization, with no significant difference in survival time, compared with those without COPD. While a treatment selection bias cannot be excluded in this non-randomized dataset, our data suggest that a diagnosis of COPD itself should not be considered a contraindication to immune checkpoint inhibitor use in NSCLC.

The RADIO trial: Randomized assessment of cisplatin dosing interval for ototoxicity with curative concurrent chemo-radiation for locally advanced head and neck squamous cell carcinoma

TPS12144

Background: Patients with locally advanced squamous cell carcinoma of the head and neck (LASCCHN) receive curative chemoradiation (CRT) with Cisplatin, as a standard of care. A meta-analysis of 52 randomized trials comparing Low Dose (LD) and High Dose (HD) schedules demonstrated differing toxicity profiles but hearing effects were not rigorously studied. Hearing loss associated with HD Cisplatin can result in survivorship challenges. A local study suggested a protective effect for LD Cisplatin in relation to ototoxicity and pharmacogenomic markers, MATE1 and COMT, to be associated with risk for ototoxicity. We hypothesize that LD cisplatin is associated with reduced frequency of hearing loss when compared to the standard HD cisplatin in LASCCHN patients on CRT and that differences in MATE1/COMT can predict for cisplatin-related ototoxicity and be identified prior to treatment. Our goal is to develop an innovative personalized treatment pathway incorporating predictive pharmacogenomics markers to improve the tolerability and survivorship outcomes of curative CRT for LASCCHN. Methods: This is a prospective, open-label, randomized clinical trial. Following informed consent, eligible LASCCHN patients planned for primary CRT will be stratified by tumor p16 status and then randomized in 1:1 fashion to either concurrent LD Cisplatin (40mg/m2 every week) or HD cisplatin (100mg/m2 every 3 weeks). The primary outcome is to measure the change in incidence of CTCAE grade ≥2 hearing loss and hearing-related quality of life (QOL) at 1 year. As part of secondary and exploratory outcomes, differences in survival, loco-regional control, global QOL and other toxicities (e.g. nephrotoxicity, neurotoxicity) will be assessed. The relationship between MATE1 and COMT, as predictors for cisplatin-related ototoxicity will be evaluated. Cost-effectiveness analyses comparing the two regimens will be assessed. Statistical plan: Based on rates of CTCAE grade ≥2 hearing loss in an earlier study (Winquist et al., 2016), assuming a conservative rate of hearing loss, amongst treated patients, of 60% with HD cisplatin and 30% with LD cisplatin, a total sample size of 92 patients would achieve > 80% statistical power, (two-sided, alpha = 0.05 test of two proportions) to detect these differences. 100 patients would be targeted to accrual for an assumed 5% noncompliance rate. For hearing related QOL, a two-sided, alpha = 0.05, two-sample t-test with 50 patients per group would achieve > 80% statistical power to detect an effect size of 0.60 and > 95% power to detect an effect size of 0.75. All analyses will be based primarily on the intent-to-treat population. An arms-length data and safety monitoring committee (DSMC) will review safety data bi-annually. Trial accrual status: 60 participants have been accrued. Clinical trial information: NCT03649048.

Will COVID-19 directives to reduce regularly scheduled physical examinations affect recurrence detection in patients with early breast cancer?

1532

Background: The COVID-19 pandemic has significantly reduced routinely scheduled in person assessment and examination of early breast cancer patients (EBC). To assess if this is likely to impact the detection of recurrent disease, we reviewed recurrence patterns of EBC patients enrolled in a survivorship program that adheres to ASCO guidelines. Methods: Charts of EBC patients transferred through a single center Wellness Beyond Cancer Program (WBCP) and who subsequently had a breast cancer recurrence between February 1, 2013 and January 1, 2019 were reviewed. Patient, tumor and treatment characteristics were evaluated. Results: Of 206 patients eligible for the current study, 41 patients had ipsilateral breast recurrences (19.9%), 135 had distant recurrences (65.5%) and 30 had contralateral new breast cancers (14.6%). Ipsilateral breast recurrences were detected by the patient in 53.7% (22/41) and by routine imaging in 41.5% (17/21). The majority of distant recurrences (125/135, 92.6%) were detected via patient-reported symptoms. Contralateral breast primaries were detected by patients 16.7% (5/30) or by routine imaging (83.3%, 25/30). Only 2/206 (1.14%) recurrences/new primaries were detected by healthcare providers at routinely scheduled follow-up visits. There was a statistical difference in recurrence detection between image detected vs. self-detected in the following factors: grade 3 (26.5% vs 51%, p < 0.007), triple negative breast cancer (3.9% vs. 15.1%, p = 0.03), HER2 disease (18.4% vs. 9.8%, p = 0.04). Conclusions: Despite following ASCO follow-up guidelines for routinely scheduled follow-up appointments with physical examination, healthcare providers rarely detect recurrence disease. While reduced in person visits may affect other aspects of follow-up (e.g., toxicity management), it appears unlikely, provided patients attend regular screening tests, that reduced in-person follow-up is associated with worse breast cancer-related outcomes during the COVID-19 pandemic. [Table: see text]

Hepatitis B screening to reduce the risk of viral reactivation in gynecologic oncology patients receiving chemotherapy at a regional tertiary cancer center: A quality improvement initiative

e18628

Background: In 2020, ASCO released a Provisional Clinical Opinion recommending universal hepatitis B virus (HBV) screening prior to systemic chemotherapy to reduce the risk of reactivation and associated morbidities. There is limited data for HBV prevalence and risk factors in gynecologic oncology. In gynecologic oncology patients at the Juravinski Cancer Centre, median baseline screening rate over 6 months was 0%. Our aim was to increase the rate of HBV screening to 70% in gynecologic oncology patients initiating chemotherapy over 6 months and compare real-world efficacy of risk factor-based vs. universal screening. Methods: We performed an interrupted time series study using the Model for Improvement methodology. Four interventions were introduced to address identified screening barriers: provider education, standardization of a testing protocol, integration with existing clinical workflow, and biweekly feedback reports. These were modified in response to outcomes and stakeholder feedback in Plan-Do-Study-Act cycles. Process and outcome measures data were collected by chart review and analyzed on statistical process control and run charts. Retrospective chart review collected demographic and disease data including Centers for Disease Control (CDC) hepatitis risk factors. Results: From Dec 1/20 to Nov 30/21, there were 381 new chemotherapy initiations in gynecology patients. The proportion of physicians screening increased significantly from 0% to 85%, and HBV monthly screening rates increased significantly from 0% to 72.2% by month 8 and were sustained for 4 months at last analysis. The integrated clinic screening protocol and feedback report interventions were each associated with increased screening rates. Of 330 unique patients initiating chemotherapy, 175 were screened (53%). Although ≥95% lacked data for 4 CDC hepatitis risk factors, 60.9% had ≥1 risk factor, and 11.2% had ≥2. HBV surface antigen (HBSAg) was non-reactive in all screened patients, but anti-HBV core (HBc) antibody was reactive in 5 (2.9%), indicative of prior infection. Real world risk factor-based screening in those with ≥1 CDC risk factor would have only identified 3/5 seropositive patients. In the screened population, risk-factor based screening had sensitivity 60%, specificity 38.8%, PPV 2.8%, NPV 97.1%. There were no HBV reactivations. Conclusions: Implementation of 4 interventions to increase HBV screening in gynecologic oncology patients receiving chemotherapy significantly improved screening rates, achieving our target at 8 months with sustained improvement. Risk-factor based screening lacks sensitivity compared to universal screening which may impact management. Lessons learned from this initiative may be applicable to other interventions to reduce infectious morbidity in oncologic populations.

Nivolumab in squamous cell carcinomas of the head and neck (SCCHN): A real-world outcome study in Ontario, Canada

e18017

Background: The CheckMate-141 trial led to the approval of nivolumab in platinum-resistant metastatic squamous cell carcinomas of the head and neck (SCCHN). We evaluated outcomes of SCCHN patients in Ontario, Canada treated with nivolumab since its funding through the New Drug Funding Program (NDFP) of Cancer Care Ontario (CCO). Methods: Retrospective review using the provincial treatment registry (CCO NDFP) was undertaken. Patient characteristics, reason for treatment, treatment length, and date of death were collected. Kaplan-Meier method was used to estimate overall survival and Cox regression to evaluate prognostic effect of selected factors. Results: 134 patients with SCCHN received nivolumab between March 2017 and March 2019. Median patient age was 63 years with 80.6% male. Nivolumab was used as second-line therapy after disease relapse within 6 months of curative-intent platinum chemotherapy (PC) in 39.6% of patients (Indication 1 – I1), used as second-line therapy post PC in non-curative intent in 42.6% of patients (Indication 2 – I2), and used as first-line therapy in non-curative intent due to contraindication for PC in 17.2% of patients (Indication 3 – I3). Median overall survival (mOS) was 5.8 months (95% confidence intervals (CI) 4.5-7.3), and one-year OS was 28.4% (CI 2.10-36.1). HPV status had no statistically significant impact on OS (p = 0.12). Patients with a lower BSA (< 1.81) had median OS of 3.9 months (CI 3.1-6.7) versus 9.0 months (CI 6.5-14.8) in those with higher BSA, HR = 0.12 (CI 0.04-0.39, p < 0.001). Differences between indications was statistically significant (p < 0.001). Patients who received nivolumab for I1 had mOS 7.2 months (CI 3.8-9.8) versus 11.9 months (CI 6.2-not reached) for I3, HR = 1.73(CI 0.94-3.16). Patients who received nivolumab for I2 had mOS 3.9 months (CI 2.9-5.4) as compared to I3, HR = 3.27(CI 1.80-5.94). Patients who received nivolumab for I2 had poorer mOS as compared to I1 HR = 1.90(CI 1.23-2.92). Conclusions: Real world data in Ontario demonstrates poorer mOS, but similar 1-year survival compared to CheckMate-141 trial. HPV status had no significant impact on mOS. Patients who received nivolumab as first-line therapy in the non-curative setting appeared to have longer mOS than those who received initial PC for non-curative intent followed by nivolumab. Patients who received nivolumab as second-line therapy post PC in non-curative intent setting as compared to within 6 months of curative-intent therapy had poorer mOS.

SALVO: Single-arm trial of ipilimumab and nivolumab as adjuvant therapy for resected mucosal melanoma

9573

Background: Mucosal melanoma is a rare, highly aggressive form of melanoma with extremely high recurrence rates, despite definitive surgical resection. Median RFS has been reported to be 5.4m, with RFS rates at 1 and 2 years of 10%, and 0%, respectively (Lian B, Si L, Cui C, et al. Phase II Randomized Trial Comparing High-Dose IFN-α2b with Temozolomide Plus Cisplatin as Systemic Adjuvant Therapy for Resected Mucosal Melanoma. Clinical Cancer Research 2013, 19(16):4488-4498). Currently there is no consensus on recommendations for adjuvant therapy. Data on the use of immune checkpoint inhibitors (ICI) adjuvantly is lacking. Methods: We performed a single arm, multicenter clinical trial using “flip dose” ipilimumab (1mg/kg q3w x4 cycles),and nivolumab (3 mg.kg q3w x4 cycles), then Nivolumab 480 mg q4w x 11 cycles to complete a year of adjuvant therapy. The primary endpoint was recurrence-free survival (RFS), and the study had 85% power to detect an improvement in RFS between 5.5 and 9.5 months using a one-sided log rank test. Participants must have had R0/R1 resection <90 days prior to registration, and no prior systemic therapy (adjuvant radiation allowed), ECOG 0/1, no uncontrolled significant autoimmune disease or other invasive cancer. Patients were recruited through the Midwest Melanoma Partnership/Hoosier Oncology Network. Results: From 9/17 to 8/21, 44 patients were approached at 6 centers. Of these 9 were ineligible, and 35 were enrolled. Of these, 29 (83%) had R0 resections, and 7 (20%) had adjuvant radiation prior to enrollment. As of Dec 2021, 31 patients have completed the treatment phase. Of the 35 patients treated on study, 20 patients have recurred (7 local, 5 distant, 3 regional, 5 sites unconfirmed), 6 stopped therapy due to adverse effects, and 8 have died. The mean age of patients was 65.8 years and 21 (60.0%) were female. The primary site of disease was vulvovaginal N=12 (32.4%) patients, sinonasal N= 11 (29.7%), anorectal N= 9 (24.3%) and other site N= 5 (13.5%). Adjuvant radiation had been given in 7 pts. Driver mutations were rare, with only 3 (8.6%) patients having a KIT mutation, and one patient (2.9%) each having a NRAS or BRAF mutation. RFS rates at 1 and 2 years were 50% (95% CI 31-66%) and 37% (95% CI 19-55%), with OS rates at 1 and 2 years of 87% (95% CI 68-95%) and 68% (95% CI 46-83%). Median RFS was 10.3 m (95% CI5.7-25.8). Most common grade 3 adverse events were diarrhea (14%), hypertension (14%), hyponatremia (11%), with no grade 4/5 toxicities. Conclusions: Flip dose ipilimumab and nivolumab after resection is associated with outcomes improved over previously reported outcomes in the absence of therapy. Long term follow up is ongoing as are subgroup analyses and correlative studies. Clinical trial information: NCT03241186.

Phase II trial of cytoreductive stereotactic hypofractionated radiotherapy with combination ipilimumab/nivolumab for metastatic kidney cancer (CYTOSHRINK)

TPS398

Background: Randomized data from the interferon era demonstrated survival benefits of cytoreductive nephrectomy (CN) in patients with metastatic renal cell carcinoma (mRCC). Results from SURTIME and CARMENA, conducted in the VEGF-targeted therapy era, have challenged the routine use of upfront CN in most IMDC intermediate and poor risk patients. Furthermore, the treatment landscape in mRCC now includes multiple first-line combination immunotherapy approvals. Five-year follow-up from the Checkmate-214 trial showed that intermediate/poor risk patients have improved overall survival and durable objective responses with ipilimumab and nivolumab (I/N) compared to sunitinib. However, patients with a primary kidney lesion in situ appeared to have less benefit than patients with prior nephrectomy. Stereotactic body radiation therapy (SBRT) provides a convenient method for cytoreduction of the primary kidney lesion and may induce an enhanced systemic anti-tumor immune response. We hypothesize that SBRT to the primary kidney mass will enhance the efficacy of I/N compared to standard of care I/N alone in this unique subset of de novo mRCC patients. We also hypothesize that the combination of SBRT and I/N will lead to upregulation of key components of immune modulation as well as unique perturbation of the host gut microbiome compared to I/N alone. Methods: This phase II trial randomizes untreated mRCC patients in a 2:1 fashion to I/N plus SBRT (30-40 Gy in 5 fractions) to the primary kidney mass between cycles 1 and 2 (experimental arm, E), versus standard of care I/N alone (standard arm, S). Eligible patients have biopsy-proven mRCC (any histology) and IMDC intermediate/poor risk disease. Patients with a primary kidney lesion ≥ 20cm, previous abdominal radiation precluding SBRT, or who have a contraindication to I/N are excluded. The primary objective is to compare the efficacy of I/N plus SBRT versus I/N alone, as determined by the hazard ratio for progression free survival (PFS). Secondary objectives include evaluation of safety, overall survival, objective response rate, and health-related quality of life. Exploratory analyses include: (1) immune and genomic profiling of liquid biopsies; (2) transcriptional profiling of baseline tumor biopsies; and (3) interrogation of the gut microbiome and bacterial functionality. Blood and fecal samples will be prospectively collected at baseline, prior to cycle 2 of each arm, and at time of disease progression or the 12-month mark, whichever comes first. Up to 78 patients will be enrolled under the assumption of an improved 12-month PFS from 50% (S) to 75% (E), using a two-sided α = 0.1, power = 80%, and accounting for loss-to-follow-up and stratification using IMDC criteria 1-2 vs 3-6. Trial is enrolling in Canada and Australia. Clinical trial information: NCT04090710.

Impact of angiotensin-converting enzyme inhibitors (ACEi) on pathologic complete response with neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC)

485

Background: The renin-angiotensin system (RAS) has been demonstrated to modulate cell proliferation, desmoplasia, angiogenesis and immunosuppression. Angiotensin pathway inhibitors are postulated to favorably reprogram the stroma in part by inhibition of transforming growth factor-β, a major mechanism of resistance, and have been previously reported to be associated with improved outcomes in the setting of immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (Jain R, Clin Genitourin Cancer 2021). In this analysis, we examined the association of angiotensin inhibitors in the setting of NAC for MIBC preceding radical cystectomy (RC). Methods: Pts with MIBC who received NAC preceding radical cystectomy were assembled from 3 institutions: Dana-Farber Cancer Institute (DFCI), Moffitt Cancer Center (MCC) and McGill University Health Center (MUHC). Pts were retrospectively assessed for the association of concurrent ACEi/angiotensin receptor blockers (ARB) use at initiation of NAC on pathologic complete response (pCR), defined as pT0N0, and overall survival (OS). Pathologic features, performance status (PS), clinical stage, type/number of cycles of NAC, and toxicities were collected. The Kaplan-Meier method was used to estimate OS. Logistic and Cox regression were used to explore factors potentially prognostic for pCR and OS respectively. Results: 302 MIBC pts who received NAC preceding RC were available from 3 institutions: DFCI (n = 187), MCC (n = 50) and MUHC (n = 65). Overall, 141 pts (46.7%) received Cisplatin/Gemcitabine, 130 (43.1%) received dose dense MVAC and the remaining received other regimens. The overall pCR rate was 26.2%. The 5-year OS was 62%. 63 (20.9%) pts were receiving an ACEi and 41 (13.6%) were receiving an ARB. ACEi prior to NAC approached significance for association with pCR (odds ratio = 1.71 (95% CI = 0.94-3.11) p = 0.077). Pts with cT3/4N0-N1 disease receiving ACEi had higher pCR rates (30.8% (8/26) vs 17.7% (14/98), p = 0.056) than those not on ACEi; no difference was observed for pts with cT2N0 tumors (31.1% vs 31.3%, p = 0.99). pCR, ECOG-PS and clinical stage were significantly associated with improved OS. ARB intake was not associated with pCR or OS. Conclusions: ACEi intake appeared potentially associated with increased pCR in pts with MIBC receiving NAC, which was more pronounced in those with higher clinical stages cT3/4N0-1. Given the association of pCR with OS, our data suggest the potential relevance of angiotensin as a therapeutic target in aggressive MIBC. Future prospective validation is warranted to repurpose angiotensin inhibitors in this setting, given their excellent toxicity profile and low costs.

Angiotensin Blockade Modulates the Activity of PD1/L1 Inhibitors in Metastatic Urothelial Carcinoma

BACKGROUND

The renin-angiotensin system is involved in the regulation of angiogenesis and cell proliferation. Angiotensin inhibition may improve drug delivery by enhancing tumor perfusion partly by downregulating transforming growth factor (TGF)-β. Because TGF-β is associated with resistance in patients with metastatic urothelial carcinoma (mUC) receiving programmed cell death protein 1/programmed cell death ligand 1 (PD1/L1) inhibitors, we hypothesized that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may enhance the outcomes of patients with mUC who receive PD1/L1 inhibitors.

PATIENTS AND METHODS

Data from patients with mUC who received PD1/L1 inhibitors as monotherapy were obtained; patients from the Dana-Farber Cancer Institute constituted the discovery dataset, and data from Moffitt Cancer Center served as the validation dataset. A logistic regression investigated the impact of concurrent ACEI/ARB primarily on any regression of tumor (ART) after controlling for prognostic factors.

RESULTS

Data were available for 178 patients from the discovery dataset, of whom 153 (86%) had received prior platinum and 33 (18.5%) concurrent ACEIs/ARBs. Multivariable logistic regression analysis revealed that ACEIs/ARBs were associated with greater probability of ART (odds ratio [OR] = 2.69; 95% confidence interval [CI], 1.15-6.30; P = .022). In the validation dataset, 101 patients were available, of whom 59 (58.4%) had received prior platinum and 22 (21.8%) concurrent ACEIs/ARBs. ACEI/ARB demonstrated a trend for association with ART (OR = 3.28; 95% CI, 0.98-10.99; P = .054) on multivariable analysis of the validation dataset.

CONCLUSIONS

Concurrent angiotensin blockade was associated with a higher rate of tumor regression in patients with mUC receiving PD1/L1 inhibitors. Validation is warranted in a prospective trial, especially given the cost efficacy of ACEIs/ARBs.

Impact of angiotensin inhibitors on pathologic complete response with neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC)

432

Background: The renin-angiotensin system (RAS) is involved in regulation of angiogenesis, cell proliferation, desmoplasia and immunosuppression. Angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) may have antitumor effects partly by inhibiting transforming growth factor (TGF)-β, a major resistance mechanism in bladder cancer. Methods: Patients (pts) with muscle invasive bladder cancer (MIBC) treated or not treated with ACEi/ARB while receiving preceding radical cystectomy (RC) were assessed for pathologic complete response (pCR) defined as pT0N0 and overall survival (OS). Pathologic features, performance status, clinical stage, type and number of cycles of NAC, and presence of grade ≥3 toxicities were collected retrospectively. The Kaplan-Meier method was used to estimate overall survival (OS). Logistic and Cox regression was used to explore factors potentially prognostic for pCR and OS respectively. Results: 187 patients received NAC followed by RC. The mean age at the time of NAC was 65. 71% were male and 29% were female. Of the 187 patients, 61% received Cisplatin/Gemcitabine and 28.3% received dose dense MVAC. Of patients receiving NAC, 53 (28%) had a pCR. The 5-year OS was 64%. There were 41 (21.9%) patients taking an ACEi and 24 (12.8%) patients taking an ARB at the start of NAC. Of the 41 patients who took an ACEi, 17 (41.5%) had a pCR; of the 146 patients who did not take an ACEi, 36 (24.7%) had a pCR. ACEi intake during NAC was the only factor associated with pCR on multivariable analysis (odds ratio of 2.17 [95% CI 1.05-4.48] p = 0.037). pCR was the only factor shown to be associated with significantly improved OS (Hazard Ratio 0.18 [95% CI 0.07-0.45] p = < 0.001). After adjusting for pCR, ACEi was not significantly prognostic of OS (HR = 1.12, 95% CI = 0.60 to 2.09, p = 0.72). ARB intake while receiving NAC was not associated with pCR or OS. Conclusions: ACEi intake was associated with significantly increased pCR in patients with MIBC receiving NAC, and pCR was the only significant factor associated with OS. We hypothesize that ACEi may augment the activity of NAC and increase pCR, which translates to improved OS. ACEi intake was not associated with improvement in OS potentially due to competing causes of mortality in patients requiring ACEi. Our data requires validation.

Impact of angiotensin blockade on response to PD1/L1 inhibitors for patients with metastatic urothelial carcinoma (mUC)

453

Background: The renin-angiotensin system (RAS) is involved in regulation of angiogenesis and cell proliferation. Preclinical data also indicate that angiotensin inhibition may improve drug delivery by enhancing tumor perfusion partly by downregulating transforming growth factor (TGF)-β. Since (TGF)-β appears to be associated with resistance in patients (pts) with metastatic urothelial carcinoma (mUC) receiving PD1/L1 inhibitors, we hypothesized that angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARBs) may enhance the outcomes of mUC pts receiving PD1/L1 inhibitors. Methods: Data from mUC pts who received PD1/L1 inhibitors as monotherapy were obtained: pts from the Dana-Farber Cancer Institute (DFCI) served as the discovery dataset, while data from Moffitt Cancer Center (MCC) served as the validation dataset. Data for ACEI and ARB administration was collected with concurrent administration defined as ongoing therapy from the time of starting PD1/L1 inhibitor treatment. A logistic regression was used to investigate the impact of concurrent ACEI/ARB on any regression of tumor (ART, any decrease in size of tumor on scan) as the primary endpoint defined as any tumor regression after controlling for known prognostic factors (performance status, sites of metastasis, neutrophil/lymphocyte ratio, platelet count, hemoglobin). Overall survival (OS), the secondary endpoint, was analyzed using Cox proportional hazards regression. Results: Data was available for 178 pts from DFCI (discovery dataset) with mUC who received a PD1/L1 inhibitor of whom 153 (86%) had received prior platinum and 33 pts (18.5%) received concurrent AECI/ARBs. Multivariable analysis controlling for known prognostic factors revealed that patients who received ACEIs or ARBs had greater ART (HR 3.0 [95% CI 1.25-7.17], p = 0.014) and improved OS, (HR 0.49 [95% CI 0.28-0.88] p = 0.016). In the MCC validation dataset, 101 pts were available of whom 59 (58.4%) had received prior platinum and 22 pts (21.8%) received concurrent ACEI/ARBs. Univariate analysis showed that those patients who were treated with ACEI/ARB had an improved ART (OR 3.32 [95% CI 1.22-9.06] p = 0.019). On multivariable analysis, there was a borderline significant association of ACEI/ARB with ART (OR = 3.03, p = 0.075), but no association was observed with OS. Conclusions: In this hypothesis-generating study, concurrent angiotensin inhibitors including ACEI or ARBs were associated with tumor regression in mUC pts receiving PD-1/L1 inhibitors. The inconsistent association with OS may be partly due to modest sample size and comorbidities associated with the need for ACEI/ARBs. These results require validation in a prospective study.

Dissecting outcomes of patients (pts) with <ypT2N0 disease after neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer (MIBC): Results from a large, international, multicenter collaboration

5043

Background: Pathologic complete response (pCR) after NAC for MIBC is strongly correlated with long-term overall survival. However, there are sparse data on the risk of recurrence based on depth of pathologic response (pT0, pTa, pTis, pT1), and the differential impact of clinicopathologic factors and NAC regimen on recurrence. Methods: Baseline data on all pts with cT2-4N0-1 MIBC receiving NAC and who achieved < ypT2N0 disease at radical cystectomy (RC) from 9 international centers were obtained. The key outcome was time to recurrence (TTR) – defined as the time to any recurrence in the urinary tract or regional/distant metastasis, with death (in the absence of recurrence) considered a competing risk. Cox regression analysis was used to analyze the impact of clinical factors on recurrence. Results: A total of 506 pts were available. Median age was 66 years (range 33-86) and 78% (n = 396) were male; median follow-up after RC was 2.6 years. The majority of patients had pure urothelial histology (n = 371, 73%), and baseline stage was cT2N0 (n = 368, 73%), cT3-4N0 (n = 95, 19%) and TanyN1 (n = 43, 9%). NAC regimens were gemcitabine-cisplatin (GC, n = 296, 59%), dose-dense methotrexate-vinblastine-doxorubicin-cisplatin (ddMVAC, n = 141, 28%), split-dose GC (n = 29, 6%), MVAC (n = 29, 6%) and non-cisplatin based regimens (n = 11, 2%). At RC, 304 patients (60%) had ypT0N0 disease, 32 (6%) had ypTaN0, 107 (21%) had ypTisN0 and 63 (13%) had ypT1N0. Overall, 43 patients (8%) recurred with a median TTR of 56 weeks (range 7-251); 5-year freedom from recurrence was 87% (95% CI 83-91). The majority (n = 38) recurred outside the urinary tract. On multivariable analysis, ypTa (HR = 3.36 [1.24-9.11]) and ypT1 (HR = 2.88 [1.33-6.22], p = 0.013) disease at RC were predictors of shorter TTR, while female sex was associated with longer TTR (HR = 0.52 [0.27-0.98], p = 0.043). The type of NAC was not predictive of TTR (GC vs. other, HR = 1.49 [0.75-2.97], p = 0.26). Conclusions: To our knowledge, this is the largest study to quantify the risk of recurrence in pts achieving pathologic response after NAC and RC for MIBC. 8% of patients undergoing NAC and achieving < ypT2N0 at RC recurred. Residual ypTa and ypT1 disease conferred a significantly higher risk of recurrence, while ypTis did not; female sex was associated with a lower risk of recurrence. Importantly, the type of cisplatin-based NAC regimen used was not an independent predictor of recurrence.

Outcomes of patients (pts) with metastatic urothelial carcinoma (mUC) following discontinuation of enfortumab-vedotin (EV): Emergence of a new unmet need

5048

Background: Enfortumab vedotin (EV) is an antibody drug conjugate recently approved to treat mUC following prior platinum and PD1/L1 inhibitors. The outcomes and patterns of therapy of pts following discontinuation of EV has yet to be studied. We investigated outcomes of pts who completed EV treatment for mUC at multiple institutions in order to identify benchmarks for evaluation of new agents following EV. Methods: Clinical data were obtained from mUC patients who had completed EV treatment from collaborating academic institutions. Descriptive stats were performed to describe the overall dataset and compare patient characteristics and outcomes of those who went on to receive further treatment post-EV and those who did not. Results: Data were available for 63 patients from 6 collaborating institutions: DFCI, University of Michigan, University of Washington, Moffitt Cancer Center, INT Milan and University of Miami. 17 (27%) were female and 46(73%) were male. The median age was 68 (range 43-83. The primary site of malignancy included bladder, upper tract, and other in 43 (68%), 19 (30%), and 1pt (.02%), respectively. The histologies included pure UC and mixed predominant UC in 49 (78%), and 14 pts (22%), respectively. 32 pts (51%) received further therapy after EV and 31pts (49%) did not. Longer duration of prior EV therapy was associated with receipt of post-EV therapy (p=0.0437). Treatments received post-EV were: trial therapy (n=14), PD1/L1 inhibitor (n=7), pemetrexed (n=4), taxane (n=3), carboplatin (n=2) and unknown in 2 pts. Objective response was observed in 3 of 32 pts (9.4%) who received therapy post-EV. The median duration of time from end of EV to death was 24 weeks. The median overall survival (OS) of those who received post-EV therapy and did not receive post-EV therapy was 37.5 weeks and 12 weeks, respectively. Conclusions: Outcomes of mUC following discontinuation of EV are dismal with only 51% receiving subsequent therapy. This study identifies an unmet need setting and establishes benchmarks for the interpretation of activity of new agents evaluated following EV.

Impact of concurrent angiotensin inhibitors on outcomes with PD1/L1 inhibitors for patients (pts) with metastatic urothelial carcinoma (mUC)

e17044

Background: Preclinical data indicate that angiotensin inhibition may improve drug delivery by enhancing tumor perfusion partly by downregulating transforming growth factor (TGF)-β. Since (TGF)-β appears to be associated with resistance in patients with mUC receiving PD1/L1 inhibitors, we investigated whether angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARBs) may enhance the outcomes of mUC pts receiving PD1/L1 inhibitors. Methods: Data from mUC pts who received PD1/L1 inhibitors at the Dana-Farber Cancer Institute (DFCI) was obtained. Data for ACEI and ARB administration was collected with concurrent administration defined as ongoing therapy from the time of starting PD1/L1 inhibitor treatment. A Cox logistic regression was used to investigate the impact of concurrent ACEI/ARB on any regression of tumor (ART, any decrease in size of tumor on scan) defined as any tumor regression after controlling for known prognostic factors (performance status, sites of metastasis, neutrophil/lymphocyte ratio, platelet count, hemoglobin). Results: Data was available for 178 pts with mUC who received pembrolizumab (79), atezolizumab (83), nivolumab (15), and durvalumab (1). Prior platinum chemotherapy was administered in 153 pts (86%). 33 pts (18.5%) received AECI/ARBs: 24 pts (13.5%) received ACEI and 9 pts (5.1%) received ARBs. Of 145 patients who did not receive an ACE-inhibitor nor an ARB, 49 (33.8%) patients experienced ART and their median overall survival (OS) was 9.1 months. Among/33 patients who did receive an ACEI or an ARB, 17 (51.5%) exhibited ARTand their median OS was 17.0 months. Multivariable analysis controlling for known prognostic factors revealed that patients who received ACE inhibitors or ARBs had greater ART (HR 3.0 [95% CI 1.25-7.17], p = 0.014) and improved OS, (HR 0.49 [95% CI 0.28-0.88] p = 0.016). Conclusions: In this hypothesis-generating study, concurrent angiotensin inhibitors including ACEI or ARBs were associated with significantly better outcomes in mUC pts receiving PD-1/L1 inhibitors. These results require validation in a larger mUC dataset in conjunction with probing the effect in other malignancies.

A multicenter study comparing granulocyte-colony stimulating factors to antibiotics for primary prophylaxis of taxotere/cyclophosphamide-induced febrile neutropenia in patients with early-stage breast cancer

7001

Background: Docetaxel-cyclophosphamide (TC) adjuvant chemotherapy is commonly used in patients with early stage breast cancer (EBC). Due to the risk of febrile neutropenia (FN) with TC, primary prophylaxis with either ciprofloxacin (cipro) or granulocyte-colony stimulating factors (G-CSF) is recommended. Despite significant differences in costs (7-120 $US/course [cipro] vs. 2100-7000 $US/dose [G-CSF]) and toxicity profiles, optimal primary FN prophylaxis is unknown. We performed a pragmatic randomised trial comparing the superiority of G-CSF to cipro. Methods: EBC patients receiving TC chemo were randomized to receive cipro or G-CSF as primary FN prophylaxis. The primary outcome is a composite of either treatment-related hospitalisations or FN. Secondary outcomes included: chemo dose reductions, delays, discontinuations and incidence of C. difficile infections. Primary analysis was performed with the intention to treat (ITT) population. Results: 455 eligible patients were randomized to cipro (227) or G-CSF (228). 37/227 (16.3%) patients on cipro had a hospitalization, compared with 25/228 (11.0%) on G-CSF (Fisher’s exact test p-value=0.10). Relative risk (RR) of hospitalization for patients on G-CSF:0.68, 95%CI=0.42 to 1.09. Patients on cipro were statistically significantly more likely to be hospitalized for FN (30/227, 13.2%) vs 9/228 (4.0%) patients on G-CSF(p<0.001). RR of developing FN and being hospitalized for patients on G-CSF: 0.44, 95%CI=0.26 to 0.76. There was no significant difference between groups for chemo dose reductions, delays, and C. difficile rates. Twenty patients on cipro (8.8%) and 9 on G-CSF (3.9%) discontinued chemo early (p=0.036). RR of discontinuing chemo: 0.43, 95%CI=0.19 to 0.96. Conclusion: G-CSF was superior to cipro at reducing FN. While a trend towards reduced hospitalizations was also observed with G-CSF, it did not attain statistical significance. However, as 18 patients would need to be treated with G-CSF to prevent one hospitalization compared to cipro, this would suggest a cost of over $100000 $US to prevent a hospitalization. A formal cost-effectiveness analysis will be performed. Clinical trial information: NCT02173262, NCT02816112 .

A multicentre, randomised trial comparing schedules of G-CSF (filgrastim) administration for primary prophylaxis of chemotherapy-induced febrile neutropenia in early stage breast cancer

BACKGROUND

The optimal duration of filgrastim as primary febrile neutropenia (FN) prophylaxis in early breast cancer patients is unknown, with 5, 7 or 10 days being commonly prescribed. This trial evaluates whether 5 days of filgrastim was non-inferior to 7/10 days.

PATIENTS AND METHODS

In this randomised, open-label trial, early breast cancer patients who were to receive filgrastim as primary FN prophylaxis were randomly allocated to 5 versus 7 versus 10 days of filgrastim for all chemotherapy cycles. A protocol amendment in November 2017 allowed subsequent patients (N = 324) to be randomised to either 5 or 7/10 days. The primary outcome was a composite of either FN or treatment-related hospitalisations. Secondary outcomes included chemotherapy dose reductions, delays and discontinuations. Analyses were carried out by per protocol (primary) and intention-to-treat, and the non-inferiority margin was set at 3% for the risk of having FN and/or hospitalisation per cycle of chemotherapy.

RESULTS

Patients (N = 466) were randomised to receive 5 (184, 39.5%), or 7/10 (282, 60.5%) days of filgrastim. In our primary analysis, the difference in risk of either FN or treatment-related hospitalisation per cycle was -1.52% [95% confidence interval (CI): -3.22% to 0.19%] suggesting non-inferiority of a 5-day filgrastim schedule compared with 7/10-days. The difference in events per cycle for FN was 0.11% (95% CI: -1.05 to 1.27) while for treatment-related hospitalisations it was -1.68% (95% CI: -2.73% to -0.63%). The overall proportions of patients having at least one occurrence of either FN or treatment-related hospitalisation were 11.8% and 14.96% for the 5- and 7/10-day groups, respectively (risk difference: -3.17%, 95% CI: -9.51% to 3.18%).

CONCLUSION

Five days of filgrastim was non-inferior to 7/10 days. Given the cost and toxicity of this agent, 5 days should be considered standard of care. CLINICALTRIALS.

GOV REGISTRATION

NCT02428114 and NCT02816164.

Phase II trial of cytoreductive stereotactic hypofractionated radiotherapy with combination ipilimumab/nivolumab for metastatic kidney cancer (CYTOSHRINK)

TPS761

Background: Randomized data from the interferon era demonstrated modest survival benefits of cytoreductive nephrectomy (CN) in patients with advanced renal cell carcinoma (aRCC). Results from SURTIME and CARMENA, conducted in the VEGF-targeted therapy era, have challenged the routine use of upfront CN especially in IMDC intermediate and poor risk patients. Furthermore, the treatment landscape in aRCC now includes first-line combination immunotherapy. Data from the Checkmate-214 trial showed that intermediate/poor risk patients have improved overall survival and objective response rate with ipilimumab and nivolumab (I/N) compared to sunitinib. Stereotactic body radiation therapy (SBRT) provides a convenient method for cytoreduction of the primary kidney lesion and may induce an ‘abscopal effect’, leading to enhanced systemic anti-tumour immune response. We hypothesize that SBRT to the primary kidney mass in aRCC patients will enhance the efficacy of I/N compared to standard of care I/N alone. Methods: This phase II trial randomizes untreated aRCC patients in a 2:1 fashion to I/N plus SBRT (30-40 Gy in 5 fractions) to the primary kidney mass between cycles 1 and 2 (experimental arm, E), versus standard of care I/N alone (standard arm, S). Eligible patients have biopsy-proven aRCC (any histology), IMDC intermediate/poor risk disease, and who decline or are unsuitable for CN. Patients with a primary kidney lesion ≥ 20cm, previous abdominal radiation precluding SBRT, or who have a contraindication to I/N are excluded. The primary objective is to compare the efficacy of I/N plus SBRT versus I/N alone, as determined by the hazard ratio for progression free survival (PFS). Secondary objectives include evaluation of safety, overall survival, objective response rate, and health-related quality of life. Exploratory analyses include blood immune signatures and stool microbiome. Up to 78 patients will be enrolled under the assumption of an improved 12-month PFS from 50% (S) to 75% (E), using a two-sided α=0.1, power=80%, and accounting for loss-to-follow-up and stratification using IMDC criteria 1-2 vs 3-6. Clinical trial information: NCT04090710.

Conditional immune adverse event rate in urothelial and renal cell carcinoma patients treated with immune checkpoint inhibitors

481

Background: Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs). While the incidence and prevalence of irAEs have been well characterized in the literature, much less is known about the cumulative incidence (CI) rate of irAEs. We sought to evaluate the CI of irAEs in metastatic urothelial carcinoma (mUC) and metastatic renal cell carcinoma (mRCC) patients (pts) treated with ICIs. Methods: We identified a cohort of mUC and mRCC pts who received ICIs at DFCI. irAEs were classified using CTCAE v.5.0 guidelines. The CI rate was a defined measure that accounted for elapsed time since treatment initiation and estimated the risk of irAE development conditioned on time elapsed without experiencing an irAE, accounting for the competing risk of death. Incidence and CI of irAEs at each monthly landmark time was calculated. Prognostic factors of irAE were assessed using the Fine and Gray method. Results: A total of 470 pts was treated with ICIs between July 2013 and October 2018 [mUC: 199 (42.3%); mRCC: 271 (57.7%)]. 341 (72.6%) pts received ICI monotherapy, 86 (18.3%) received ICIs in combination with targeted therapies, and 43 (9.2%) received a combination of two ICIs. Overall, 186 pts (39.5%) experienced any irAE at any time point. Common irAEs included hypothyroidism (n=42 [22.6%]), skin (n=36 [19.4%]), colitis (n=35 [18.8%]), transaminitis (n=32 [17.2%]), and pneumonitis (n=14 [7.5%]). The risk of developing an irAE over time was as follows: 33.5% if no irAE within the 1st month(mo), 27.3% if no irAE in 3mo, 18.8% if no irAE in 6mo, and 16.4% if no irAE by 12mo. No difference was observed in CI based on type of cancer (mUC vs mRCC) or agent (PD1 vs. PD-L1). Multivariable analysis showed that ICI combined with ICI or other agents vs. ICI monotherapy (p<0.001), firstline therapy (p=0.013) and PD-1 vs. PD-L1 inhibitors (p=0.008) were statistically correlated with the development of irAEs. Conclusions: This study quantitates the incidence of developing irAEs with ICI conditioned on time elapsed without irAE development. Although the incidence of irAEs decreased over time on therapy, irAEs require continuous vigilant monitoring because of the long tail in its incidence.

Impact of histology and toxicities on outcomes of patients with muscle invasive bladder cancer receiving neoadjuvant chemotherapy

540

Background: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) extends survival in muscle invasive bladder cancer (MIBC) patients (pts). Pathologic complete response (pCR) is associated with survival. We conducted a retrospective study to examine the prognostic impact of other variables including histologic subtype, location, multifocality, margins, size of tumor and toxicities. Methods: Pts who underwent RC at Dana-Farber for MIBC stage T2-T4N0-1 were studied. Data were collected for demographics, clinical and pathologic variables. Descriptive stats were reported, and Cox proportional hazards regression analyses were conducted to examine the association with recurrence-free survival (RFS) and overall survival (OS). Results: From 2002 to 2018, 150 patients were available. The median age was 66 (range 36-89) and 102 (68%) were male. MVAC/dose dense MVAC, GC and other non-standard regimens were given in 42 (28%), 85 (56.7%) and 23 (15.3%) pts, respectively. The 2-yr RFS was 63.6%, the 5-yr OS was 68.7% and pCR occurred in 38 pts (25.3%). Multivariable analysis identified pure urothelial carcinoma in the residual tumor and absence of pathologic response to be associated with poor RFS and OS. Positive margins were associated with poor RFS, while grade ≥3 toxicities were associated with poor OS. Conclusions: Pure urothelial carcinoma histology was associated with worse RFS and OS following RC after NAC for MIBC, suggesting molecular studies may be useful in these cases. The association of severe toxicities with poor OS suggests that optimal pt selection for NAC and early recognition of toxicities is important.[Table: see text]

A comparison of combined immune checkpoint inhibitors (IO) versus vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI) in the treatment of advanced clear cell renal cell carcinoma

692

Background: IO and VEGFR/TKI are approved treatment options, either alone or combination, in advanced clear cell RCC. Currently, there is a lack of evidence comparing efficacy and safety outcomes amongst these therapies. We sought to compare the published data for the various options with respect to efficacy and safety. Methods: A literature search using PubMed, clinicaltrials.gov, ASCO and ESMO meeting abstract databases from January 1, 2015 to June 30, 2019 to identify eligible clinical trials in advanced clear cell RCC involving at least one immunotherapy agent was performed. Due to small sample sizes in the various cohorts, descriptive statistics were provided. Weighting of estimates was based on sample size of the intervention arms. Results: 14 studies involving 6,197 pts were identified. The median age was 62 years (54.8, 64), men constituting median of 75%, and prior TKI receipt in 63%. There were 7 studies in each treatment arm. The efficacy outcomes did not demonstrate statistical differences. In the safety analyses, IO + VEGFR/TKI demonstrated the highest serious adverse event rate, correlating with treatment discontinuation rates. Conclusions: IO + IO and IO + VEGFR/TKI showed comparable efficacy and toxicity outcomes in the treatment of advanced clear cell RCC. There is a non-significant trend towards increased efficacy in some outcomes with IO + VEGFR/TKI, with possibly increased adverse events. Further studies with patient level data, cross-comparative trials, and predictive biomarkers are needed to establish a therapeutic matrix for RCC pts.[Table: see text]

FDG and PSMA PET in metastatic castration-resistant prostate cancer (mCRPC)

23

Background: We hypothesized 18F-DCFPyL (PSMA-based tracer) and/ or 18F-FDG (glucose metabolism-based tracer) PET/CT might provide different/complementary molecular imaging information in men with mCRPC treated with abiraterone (A) or enzalutamide (E). Methods: In this prospective cohort study (MISTER trial) mCRPC patients (pts) had conventional imaging and both PSMA and FDG PET/CT prior to standard treatment with A or E, repeated after ~10 weeks on treatment. The main objective was to compare changes in PET/CT findings with conventional imaging. Median of PET maximum standardized uptake value (SUVmax) was measured across all PET avid disease sites and change in SUVmax was evaluated in the 5 hottest sites per patient. Review of PET/CT was performed by 3 experts based on consensus. Results: 36 men were enrolled between 2/2017-12/2018, of whom 28 had treatment and followup imaging. To date, 13 cases have been reviewed: mean age 71.2 years, 7 (53.9%) were ECOG=0, median duration since diagnosis of initial cancer 7.5 months and 8 (61.5%) were stage II/III. PSMA detected more skeletal metastases, positive nodes and non-skeletal, non-nodal metastases in 5/5/3 (39%/39%/23%) men, while FDG detected more non-skeletal, non-nodal metastases in 1 man. Following treatment, new lesions were seen in 3 men on both PSMA and FDG, 3 with PSMA only, and 1 with FDG only. 12 men had baseline FDG-avid disease with median SUVmax 6.5 pre-treatment and 3.8 following therapy (all men had lower SUVmax post-treatment). All 13 men had PSMA-avid disease with median SUVmax 17.6 at baseline and 18.7 post-therapy. Following treatment, 8/12 men (67%) had SUV declines ≥30% (2 had new lesions), 4 had declines of 0-30% (2 had new lesions) using FDG; at followup, 1/13 men had PSMA SUVmax declines ≥30% or more, 6 had declines of 0-30% (2 had new lesions), 5 had SUV increases of 0-30% (4 had new lesions) and 1 had >30% increase. Conclusions: In early analyses, PSMA identified more disease burden in mCRPC pts and was more avid than FDG. SUVmax for FDG declined following treatment in all men, while PSMA changes were heterogeneous. Potential prognostic value of early PSMA and FDG imaging changes on clinical outcomes will be correlated with conventional imaging along with review of remaining cases. Clinical trial information: NCT02813226.

Any regression of tumor (ART) within 12 weeks versus RECIST 1.1 response category as an intermediate endpoint to assess the activity of immune checkpoint inhibitors (ICIs) for metastatic urothelial carcinoma (mUC)

473

Background: Many ICIs are approved to treat mUC following platinum-based chemo and as 1st-line therapy for selected patients (pts). While RECIST 1.1 responses are generally durable and associated with prolonged survival, the benefit of ICIs extends beyond this group of pts. Stable disease (SD) consists of a heterogeneous population of pts with both increase and decrease in tumor size and is confounded by the impact of pre-ICI disease pace. We hypothesized that in the setting of ICIs, any regression of tumor (ART) within 12 weeks may capture early benefit and correlate with survival more comprehensively than RECIST 1.1. Methods: mUC pts who received an ICI following platinum-based chemo at DFCI were eligible for analysis. Pts were required to have tumor size changes, RECIST 1.1 response by week 12 and survival data available. Demographics and prognostic factors were collected. Descriptive stats were calculated, and univariable Cox proportional hazards regression analysis was conducted to examine the prognostic effect of ART and RECIST 1.1 with overall survival (OS). Results: 104 pts were evaluable. The median age was 66 (range 34-89). 71% were male. The numbers of pts with ART and RECIST1.1 partial response (PR) were 45 (43.3%) and 32 (30.1%), respectively. Univariable analyses identified an association between ART and RECIST 1.1 response with OS (p<0.001). The 1-year OS (95% CI) for ART vs. no ART was 83.6 % (68.7, 91.8) and 35.9 % (23.1, 48.8), while the 1-year OS (95% CI) for RECIST 1.1 response vs. no response was 81.3% (62.9, 91.1) and 45.6% (32.9, 57.4), respectively. RECIST 1.1 category was not significantly associated with OS (p-value=0.68) after adjusting for ART; however, statistically, ART associated with OS (p=0.002) after adjusting for RECIST 1.1 category. The modest size of this cohort is a limitation. Conclusions: ART within 12 weeks is identified early and is robustly associated with OS in pts with mUC receiving post-platinum ICIs. ART may serve as a more optimal intermediate endpoint for survival compared to RECIST 1.1 in the setting of ICIs. Evaluating this endpoint in other malignancies is warranted.

SALVO: Single-arm phase II study of ipilimumab and nivolumab as adjuvant therapy for resected mucosal melanoma

TPS65

Background: Mucosal melanoma is a rare and, therefore, poorly studied malignancy. Patients with resected primary tumors have a median time to recurrence of 5.5 months. While no one adjuvant therapy is of proven benefit for patients, immunotherapy has shown activity in metastatic mucosal melanoma. Methods: We are performing a single arm, phase II clinical trial through the Midwest Melanoma Partnership/Hoosier Cancer Research Network (6 sites) for resected mucosal melanoma. The primary endpoint is recurrence free survival (RFS), and it will include 36 subjects. Patients must have had an R0 or R1 resection of a mucosal melanoma (sinonasal, anorectal, vulvar, or other), and register within 90 days of surgery. Adjuvant radiation is allowed prior to registration but not required. Therapy consists of ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) IV q3w x 4, then 480 mg nivolumab x 1 year. Statistical power is calculated to be 85% to detect a change in RFS from 5.5 months to 9.5 months, with a one sided alpha of 0.05. Enrollment began Sept 2017, with current participation from 6 large volume centers in the United States, with 17 patients enrolled as of Sept 2019. Full accrual is anticipated to complete by year end 2020. Patients will be followed for RFS and OS. Translational studies will include mutational burden, c-kit, BRAF, NRAS status, and serum markers of immunity -- including soluble PD-L1 and Bim. Clinical trial information: NCT03241186.

Association of immune-related adverse events (irAEs) with clinical benefit in patients with metastatic urothelial carcinoma (mUC) treated with immune-checkpoint inhibitors (ICIs)

e16038

Background: In other cancers such as metastatic lung and melanoma, pts who experience irAEs may have a greater degree of clinical benefit. We sought to evaluate whether the development of irAEs correlates with clinical benefits in mUC pts. Methods: We identified mUC pts who received PD-1/L1 inhibitors at the Dana-Farber Cancer Institute (DFCI). The severity of irAEs was graded using CTCAE v.5.0. Clinical benefit was defined as any objective reduction (complete- or partial- response) in tumor burden. Fisher’s exact test was used to evaluate for differences in the proportion of pts experiencing clinical benefit between pts experiencing an irAEs within 90 days after starting therapy and those who did not experience an irAEs. The log-rank test assessed differences in progression-free survival (PFS) and overall survival (OS) between cohorts. Results: A total of 199 mUC pts were enrolled between July 2013 and October 2018 [median (range) age, 69.6 (26.6-89.0) years; 141 men (70.9%), 58 women (29.1%)]. 114 (57.3%) pts were treated with anti-PD-1 and 85 (42.7%) with anti-PD-L1. irAEs were observed in 67 pts (33.7%), of which 34 (17.1%) < 90 days from start of therapy. Common irAEs included 20 (29.9%) hypothyroidism, 17 (25.4%) colitis, 12 (17.9%) rash/pruritus, and 10 (14.9%) transaminitis. Grade ≥3 irAEs were observed in 14 pts (20.9%).13 (40.6%) pts with irAE < 90 days experienced clinical benefit compared with 21 (17.8%) of pts with no irAE (p-value = 0.008). No difference (p = 0.26 and 0.18) was observed for either PFS (6-month PFS = 19.2% vs 35.3% for no irAE and irAE < 90 days) or OS (1-year OS = 41.8% vs 57.7% for no irAE vs irAE < 90 days). Conclusions: The development of irAEs within 90 days from starting therapy in mUC pts may herald clinical benefit in pts with mUC. Further evaluation of this potential relationship in a large prospective study is warranted.

A randomized study comparing physician-directed or fixed-dose dexamethasone replacement following incomplete steroid premedication for docetaxel chemotherapy

6610

Background: Prior to receiving docetaxel-based chemotherapy patients often incorrectly take all or part of their steroid-premedication. The lack of standardised steroid-replacement strategies can lead to variability in care and delays in starting chemotherapy while nursing/pharmacy/physicians establish an individualized patient plan, which can use up valuable chemotherapy chair time. A randomised controlled trial comparing a fixed-oral dose of dexamethasone and physician-directed replacement was performed. Methods: Patients who missed at least one dose of steroid-premedication were randomised to either standard replacement with dexamethasone 8mg orally or physician-directed replacement (any steroid, dose or route). The primary outcome was time from randomisation to starting docetaxel. Secondary outcomes included rates of acute and delayed hypersensitivity reactions, fluid retention and skin rashes. Results: Sixty patients were randomized. Most patients were enrolled during cycle 1 (47.5%) and cycle 2 (22%) of docetaxel. The most frequent total doses of dexamethasone omitted were 24 mg (27%), 12 mg (20%), and 8 mg (19%). There were 7 different replacement strategies used by physicians. The most frequently used strategies were: dexamethasone 8mg IV (34.5%), 12mg IV (17.2%) and 20mg IV (13.8%). Patients in the fixed-dose arm received docetaxel earlier than patients in the physician-choice arm, at a median of 47.5 and 61 minutes after randomization (mean = 62.2 vs 83.4 minutes) (p = 0.033). No significant difference in rates of acute (0 vs 2)/delayed allergic reactions (1 vs 0), fluid retention (2 vs 1), or skin rashes (1 vs 0) was observed between the fixed-dose and physician-choice arms respectively. Conclusions: This is the first randomised trial to compare steroid-replacement strategies in this patient population. Fixed-dose replacement with dexamethasone 8 mg PO should be the preferred standard of care, as it reduces both the time to starting docetaxel and treatment variability, with no apparent increase in toxicity. Clinical trial information: NCT02815319.

Cost disparities with age in the treatment of advanced non-small cell lung cancer (NSCLC) in Ontario, Canada

6629

Background: Previous studies noted an association between age and cost of care in NSCLC. The drivers of these cost disparities have not yet been fully examined. We conducted a cost analysis study examining the differences in, and drivers of, costs of NSCLC care across age groups in Ontario, Canada. Methods: We conducted a retrospective cohort study of patients diagnosed in Ontario from Apr 1, 2007 to Mar 30, 2014, who received palliative chemotherapy for stage IV NSCLC. Variables of interest were extracted from registry data linked by the Institute for Clinical Evaluative Sciences (ICES). The mean total cost of care including systemic therapy and supportive care, was calculated in 2015 CAD dollars by fiscal year of diagnosis. Results: Of all NSCLC cases diagnosed in Ontario (n = 37,786), 17,203 (45.5%) were de novo stage IV, of which 29.7% of patients received any chemotherapy for their disease (n = 5,113), and 281 patients are presumed alive. In this population, median age was 65 to 69 years, 51.9% were male, 43.5% were adenocarcinomas, and 25.1% received second line chemotherapy. After adjusting for comorbidities, income, gender, year of diagnosis, and rural versus urban living, the average lifetime costs per patient remains significantly inversely related to age (p < 0.001). Belonging to the highest income quintile (p = 0.006) and being diagnosed in more recent years (p < 0.001) contributes significantly to increasing overall healthcare costs. Elderly patients (80+) cost less (71%) and have shorter survival time (HR of death 1.28, 95% C.I. 1.10 to 1.50) compared to younger patients (≤45 years old). Accounting for longer survival in younger patients, the youngest group still incur a higher cost per day alive than other age groups ($471/day in ≤45 group, $301/day in > 85 group). Hospitalization accounts for ~30% of total cost in both age groups. Chemotherapy accounts for 1% of total health care costs amongst the elderly (80+) age group and 10% of costs in ≤45 group. Conclusions: Our study shows that, despite everyone receiving systemic therapy in this patient population, younger patients incur significantly higher costs than elderly patients with advanced NSCLC, both before and after adjusting for survival. While hospitalization accounts for the biggest component of total costs, patients with high income and more recent years of diagnosis drive the higher costs of care, and chemotherapy remains a driver of higher costs amongst younger patients.

5-factor prognostic model for survival of patients with metastatic urothelial carcinoma receiving three different post-platinum PD-L1 inhibitors

4552

Background: A prognostic model for overall survival (OS) of metastatic urothelial carcinoma (mUC) was previously reported in the setting of post-platinum atezolizumab (Pond GR, GU ASCO 2018). This model was limited by employing only atezolizumab treated patients (pts), small size of the validation dataset and unclear applicability to other PD-1/L1 inhibitors. Hence, we constructed a robust prognostic model utilizing the combined atezolizumab cohort as the discovery dataset and used 2 separate validation datasets comprised of post-platinum avelumab or durvalumab treated pts. Methods: The discovery dataset consisted of pt level data from 2 phase I/II trials (IMvigor210 and PCD4989g) evaluating atezolizumab (n = 405). Pts enrolled on 2 separate phase I/II trials, EMR 100070-001 that evaluated post-platinum avelumab (n = 242) and CD1108 that evaluated durvalumab (n = 189) comprised the validation datasets. Cox regression analyses evaluated the association of candidate prognostic factors with OS. Factors were dichotomized and laboratory values were normalized by logarithmic transformation. Stepwise selection was employed to propose an optimal model using the discovery dataset. Discrimination and calibration were assessed in the avelumab and durvalumab datasets following the validation procedure by Royston and Altman (2013). Results: The 5 factors included in the optimal prognostic model in the discovery dataset were ECOG-PS (1 vs. 0; HR 1.80; 95% CI [1.36-2.36]), presence/absence of liver metastasis (HR 1.55; 95% CI [1.20-2.00]), number of platelets (HR 2.22; 95% CI [1.54-3.18]), neutrophil-lymphocyte ratio (NLR; HR 1.94; 95% CI [1.57-2.40]) and lactate dehydrogenase (LDH; HR 1.60; 95% CI [1.28-1.99]). There was robust discrimination of survival between low, intermediate and high-risk groups based on 0-1, 2-3 and 4 factors. The concordance of survival was 0.692 in the discovery and 0.671 and 0.775 in the avelumab and durvalumab validation datasets, respectively. Acceptable or good calibration of expected 1-year survival rate was observed. Conclusions: A 5-factor prognostic model is prognostic for survival across 3 different PD-L1 inhibitors (atezolizumab, avelumab, durvalumab) in this large study totaling 836 pts overall in the setting of post-platinum therapy for mUC. This model may assist in prognostic stratification and interpreting nonrandomized trials of post-platinum PD1/L1 inhibitors.

The ESCAPADE Study: Early supportive care for advanced cancer patients, assessing care delivery and provider engagement

e23142

Background: Advanced cancer patients benefit from early integration of palliative care (EIPC) with usual care. A proposed model of EIPC reserves specialized palliative care (SPC) for complex patients, while primary care providers (PCP) and oncologists oversee basic palliative care (PC). We studied the attitudes among patients and their healthcare providers regarding delivery of EIPC. Methods: A cross-sectional study at a tertiary cancer centre in Ontario. Patients with newly diagnosed incurable gastrointestinal (GI) cancer were surveyed using a study specific instrument for the outcomes of interest: importance of and preferences for accessing support across 8 domains of PC (disease management, physical, psychological, social, spiritual, practical, end of life care, loss and grief). Healthcare providers within the circle of care completed a parallel survey for each recruited patient. Primary analysis involved use of descriptive statistics to summarize survey results and concordance between patient and provider responses. Results: From Oct 2017 - Nov 2018, 67 patients were surveyed (median age 69, 34% female). 90% had an identified medical oncologist, and 19% had SPC. 97% had a PCP, but only 42% listed a PCP as part of the care team. Median time from first oncology assessment for advanced cancer to patient survey completion was 52.5 days. 85 providers responded (oncologist = 59, PCP = 20, SPC = 6; response rate 92%; 1-3 physician responses per patient). Disease management and physical concerns were most important to patients. In these domains, 67% and 81% of patients endorsed receiving care from the preferred provider, but concordance between patient and physician responses regarding most responsible provider was only 58% and 38%. For all other domains, 87 – 100% of patients attributed primary responsibility to self or family rather than any healthcare provider. Conclusions: Respondents did not assign responsibility to physicians early in the disease trajectory for many domains of PC. Our findings suggest that incorporating patient activation and empowerment into EIPC requires further study. PCPs appeared to have limited involvement in PC for newly diagnosed advanced GI cancer patients.

First-line PD(L)1 inhibitors for platinum-ineligible advanced urothelial carcinoma (aUC)

e16024

Background: FDA modified the label for 1st-line pembrolizumab or atezolizumab to PD-L1 high cisplatin-ineligible or platinum-ineligible aUC patients (pts) regardless of PD-L1 expression. However, the outcomes when using PD-(L)1 inhibitors for platinum-ineligible pts are unclear. We hypothesized that treatment response and outcomes are comparable to data reported in trials in the 1st line setting of aUC, and conducted a retrospective study to test this hypothesis using data outside the clinical trial setting. Methods: We collected data from 8 institutions for aUC pts with locally advanced unresectable or metastatic UC. The following criteria were used to define pts platinum-ineligible while comorbidities, age and physician discretion were also allowed: Cr Cl < 30 ml/min, ECOG PS 3, Cr Cl 30-59 ml/min and ECOG PS 2. Demographic & clinical variables and outcomes (overall response rate [ORR], overall survival [OS]) were collected. A Cox regression analysis was used to explore associations of baseline variables with response and outcomes. Results: Data were available for 79 pts. Pts received atezolizumab [n = 41], pembrolizumab [n = 28], nivolumab [n = 7] or durvalumab [n = 3]. Median age was 74 years (45-93). Reasons for platinum-ineligibility were: Cr Cl < 30 ml/min (n = 26), ECOG PS 3 (n = 8), ECOG-PS 2 and Cr Cl < 30-59ml/min (n = 14), elderly/co-morbidities (n = 17), and ‘unavailable’ (n = 14). Median OS was 45 weeks (CI 32-80) and ORR was 27.9%: Complete response in 4 pts [5.1%], partial response in 18 pts [22.8%], stable disease in 19 pts [24.1%], progressive disease in 34 pts [43 %]; data for 4 pts [5.1%] was unavailable for best response. Toxicity of any grade and Grade ≥3 was seen in 41.8% and 31.7% of pts, respectively. Hemoglobin (HR = 0.78, 95% CI 0.68 - 0.90, P = 0.001) and liver metastasis (HR = 1.13, 95% CI 0.51 - 2.53, P = 0.036) correlated with OS. Conclusions: The efficacy and toxicities of 1st-line PD-(L)1 inhibitors for platinum-ineligible pts outside clinical trials appear comparable to those reported in trials for unselected cisplatin-ineligible pts. Further validation is required including data based on PD-L1 status and other biomarkers. Platinum-ineligible pts with aUC warrant evaluation of novel safe and effective agents.

A randomized trial comparing four-weekly versus 12-weekly administration of bone-targeted agents (denosumab, zoledronate, or pamidronate) in patients with bone metastases from either breast or castration-resistant prostate cancer

11501

Background: Defining the optimal dosing interval of commonly used bone-targeted agents (BTAs), such as denosumab and bisphosphonates, for patients with bone metastases remains an important clinical question. We performed a pragmatic randomised trial comparing the non-inferiority of 12- versus 4-weekly BTAs in patients with bone metastases from breast and prostate cancer. Methods: Patients with bone metastases, who were either BTA-naïve, or already receiving, denosumab, pamidronate or zoledronate were eligible. They were randomised to receive their chosen BTA every 12- or 4-weeks for one year. The primary endpoint was Health related quality of life (HRQL) (EORTC-QLQ-C30 Functional Domain - Physical Subdomain). Secondary endpoints included: pain (EORTC-QLQ-BM22 - pain domain), Global Health Status (EORTC-QLQ-C30), symptomatic skeletal events (SSE) rates and time to SSEs. Adverse events and toxicity profiles were also compared. Results: Of 263 patients (60.8% breast and 39.2% prostate), 130 (49.4%) were randomised to 12-weekly and 133 (50.6%) to 4-weekly therapy. 138 (52.5%) were bone-agent naïve. The BTAs included; denosumab (n=148, 56.3%), zoledronate (n=63, 24.0%) and pamidronate (n=52, 19.8%). Study-reported outcomes showed no significant difference in; HRQL-physical domain (median [range]: 0 [-86, 40] vs. 0 [-66, 53.3]), pain (median [range]: 0 [-66, 72] vs. 0 [-100, 88]), Global Health Status (median [range]: 0 [-100, 66.7] vs. 0 [-83, 33.3]), SSE rates (N [%]: 24 [18.5%] vs. 22 [16.5%]), 1-year SSE-free rate (median, range; 73.2% [63.6, 80.7] vs. 77.9% [69.1, 84.4]) between the 12- and 4-weekly arms, respectively. Subgroup analyses for BTA naïve and pre-treated patients, and for patients receiving denosumab, zoledronate and pamidronate, showed no significant difference between the 12- and 4-weekly arms. There was no significant difference in reported rates of renal impairment (2.3% vs. 3.0%), symptomatic hypocalcaemia (1.5% vs. 1.5%) or osteonecrosis of the jaw (0.8% vs. 0.8%). Conclusion: The findings of this trial are consistent with those previously reported for de-escalating zoledronate. This trial also included patients receiving de-escalated denosumab and pamidronate. While the results of the Swiss REDUSE trial are awaited, the data presented would suggest that de-escalation of all commonly used BTAs is a reasonable treatment option. Clinical trial information: NCT02721433.

Validated five-factor prognostic model for survival of patients (pts) with metastatic urothelial carcinoma (mUC) receiving different post-platinum PD-L1 inhibitors

476

Background: A prognostic model for overall survival (OS) of mUC was previously reported in the setting of post-platinum atezolizumab (Pond GR, GU ASCO 2018). This model was limited by employing only atezolizumab treated pts, small size of the validation dataset and unclear applicability to other PD-1/L1 inhibitors. Hence, we constructed a robust prognostic model utilizing the combined atezolizumab cohort as the discovery dataset and used a validation dataset comprised of post-platinum avelumab-treated pts. Methods: The discovery dataset consisted of pt level data from 2 phase I/II trials (IMvigor210 and PCD4989g) evaluating atezolizumab (n = 405). Pts enrolled on a phase I/II trial that received post-platinum avelumab (n = 242) comprised the validation dataset (EMR 100070-001). Cox regression analyses evaluated the association of candidate prognostic factors with OS. Factors were dichotomized and laboratory values were normalized by logarithmic transformation. Stepwise selection was employed to propose an optimal model using the discovery dataset. Discrimination (via c-statistic) and calibration were assessed in the avelumab dataset following the validation procedure by Royston and Altman (2013). Results: The 5 factors included in the optimal prognostic model in the discovery dataset were ECOG-PS (1 vs. 0; HR 1.80; 95% CI [1.36-2.36]), presence/absence of liver metastasis (HR 1.55; 95% CI [1.20-2.00]), number of platelets (HR 2.22; 95% CI [1.54-3.18]), neutrophil-lymphocyte ratio (NLR; HR 1.94; 95% CI [1.57-2.40]) and lactate dehydrogenase (LDH; HR 1.60; 95% CI [1.28-1.99]). The c-statistic for prediction of survival was 0.692 and 0.671 in the discovery and validation datasets, respectively. Acceptable or good calibration of expected 1-year survival was observed. Conclusions: A 5-factor externally validated prognostic model for OS is proposed employing a large dataset of 647 pts overall in the setting of post-platinum PD-L1 inhibitors for mUC. This model may assist in prognostic stratification and interpreting nonrandomized trials of post-platinum PD1/L1 inhibitors.

First-line PD1/PD-L1 inhibitors for platinum-ineligible advanced urothelial carcinoma (UC)

432

Background: FDA modified the label for the use of 1st-line pembrolizumab or atezolizumab therapy to PD-L1 high cisplatin-ineligible or platinum-ineligible UC patients (pts) regardless of PD-L1 expression. However, the outcomes when using PD1/PD-L1 inhibitors for platinum-ineligible pts are unclear. We conducted a retrospective study to evaluate clinical outcomes with first-line PD1/PD-L1 inhibitors for platinum-ineligible pts with advanced UC in a real-world setting. Methods: We collected data retrospectively from 6 institutions. The following criteria were deemed to render pts platinum-ineligible although physician discretion was also allowed: Cr Cl < 30 ml/min, ECOG-PS 3, Both Cr Cl 30 to < 60 AND ECOG-PS 2. Demographic and clinical variables and outcomes (overall response rate [ORR], overall survival [OS]) were collected. A Cox regression analysis was done to study the association of baseline variables with response and survival. Results: Data were available for 45 pts. Pts received atezolizumab [n = 24], pembrolizumab [n = 11], nivolumab [n = 7] and durvalumab [n = 3]. The mean age was 72.2 (range 45-90) years. The reasons for platinum-ineligibility were: Cr Cl < 30 ml/min (n = 17), ECOG-PS 3 (n = 3), ECOG-PS 2 plus Cr Cl < 60 ml/min (n = 7), elderly with co-morbidities (n = 12), and reason was unavailable for 6 pts. The median OS was 37 weeks (CI 30-80). ORR was 27.3%: Complete response in 3 pts [6.8%], partial response in 9 pts [20.5%], stable disease in 11 pts [25%] and progressive disease in 21 pts [47.7%] and data for 1 patient was unavailable. Toxicity of any grade were seen in 42.2% of pts and Grade ≥3 toxicity in 9 pts’ [20%]. There were no treatment-related deaths. Anemia (HR = 0.75, 95% CI 0.62 - 0.92, P = 0.005) and liver metastasis (HR = 1.17, 95% CI 0.47 - 2.93, P = 0.017) correlated with shorter OS. Conclusions: To our knowledge, this is the 1st report of efficacy and toxicity of PD1/PD-L1 inhibitors as1st-line therapy for platinum ineligible UC. Data appear comparable to those reported previously in unselected cisplatin-ineligible pts receiving pembrolizumab or atezolizumab in phase II trials. Validation is needed in larger datasets and prospective trials.

Impact of concurrent medications on outcomes with PD1/PD-L1 inhibitors for metastatic urothelial carcinoma

435

Background: The impact of concurrent medications (meds) on outcomes with PD1/PD-L1 inhibitors in metastatic urothelial carcinoma (mUC) is unclear. We investigated whether candidate concurrent meds (NSAIDS [N], metformin [M], antibiotics [A], statins [S] and corticosteroids [C]) have an association with outcomes in mUC patients (pts) receiving a PD1/PD-L1 inhibitor. We hypothesized that A and C compromise outcomes, while N, M and S improve outcomes. Methods: Data from mUC pts who received PD1/PD-L1 inhibitors at the Dana-Farber Cancer Institute (DFCI) was obtained. The concurrent medication was required to be administered within 1 month before starting to anytime during PD1/PD-L1 inhibitor therapy. A Cox regression analysis was done to study the association of variables with response and survival. Results: Data was available for 101 pts with mUC who received atezolizumab [n = 52], pembrolizumab [n = 39], nivolumab [n = 9] and durvalumab [n = 1]. Prior platinum had been administered in 74 pts (73.2%), 25 were chemonaive (24.8%) and prior therapy status was unknown in 2 pts (2%). The concurrent meds were N (n = 30), M (n = 7), A (n = 26), S (n = 33) and C (n = 12). The median survival was 57.9 weeks. Response was seen in 26 pts [25.7%]. A was associated with a lower probability of response (11.5%) than those not on A (30.7%), and worse survival (HR = 1.93, 95% CI 1.93 – 3.42, P = 0.024). Pts who received neither A nor C, one of them or both had a response rate (RR) of 30.6%, 20% and 0%, and median survival of 65.3, 53.1 and 14.9 weeks, respectively (HR = 3.02, 95% CI = 1.34-6.83, p = 0.027). Pts who did not receive N, M and S (n = 52) exhibited a median OS of 39.6 weeks, while those who received ≥1 of these meds (n = 49) exhibited a median survival of 160.3 weeks (p = NS). The study is limited by the retrospective design and modest sample size. Conclusions: In this hypothesis-generating study, concurrent antibiotics or corticosteroids compromised outcomes in mUC pts receiving a PD1/PD-L1 inhibitor and receiving both further compromised outcomes. The numerically higher survival with concurrent N, M or S did not attain statistical significance, but requires further study in larger datasets.

Impact of pure versus mixed metastatic urothelial carcinoma (mUC) histology on response with immune checkpoint inhibitors (ICIs)

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Background: PD1/PD-L1 inhibitors have been evaluated in trials enrolling patients (pts) with pure urothelial or mixed urothelial histology containing non-urothelial components. However, any differential impact of pure vs. mixed urothelial histology on ICI benefit is unclear. We conducted a retrospective study to evaluate the impact of pure vs. mixed urothelial carcinoma histology on outcomes with ICIs in pts with metastatic urothelial carcinoma (mUC). Methods: We obtained data from 120 pts with mUC from a single institution (DFCI) who received ICI therapy. Demographic, clinical variables and outcomes (overall response rate [ORR], overall survival [OS]) were collected. Histology was reviewed at DFCI for all pts and recorded as pure urothelial if only urothelial carcinoma was seen or mixed urothelial if components of any other histology were observed in addition to urothelial. A Cox regression analysis was done to study the association of prognostic variables and histology with objective response. Results: Data was obtained from 120 pts, of whom 110 (91.7%) received a single agent PD1/PD-L1 inhibitor (pembrolizumab=58, atezolizumab=52, nivolumab=4, nivolumab + ipilimumab=3, nivolumab + vaccine=2, durvalumab+tremelimumab=1). The median age was 66, 70.8% were male and 72.5% had received prior chemotherapy. 79 (65.8%) tumors originated from the bladder, 39 (32.5%) from the upper tract, 2 (1.67%) had unknown site of origin. 91 (76.6%) had pure urothelial and 28 (23.3%) had mixed urothelial histology. On univariable analysis, pure vs. mixed urothelial histology was not associated with response (HR 1.52 [95% CI 0.59-3.98, p=0.39]). On multivariable analysis, upper tract vs. bladder primary (HR 3.06 [95% CI 1.10-8.49], p=0.032) and higher blood neutrophil to lymphocyte ratio (HR 0.35 [95% CI 0.17-0.72], p=0.004) were associated with lower response rate. Conclusions: In this hypothesis-generating study, pure vs. mixed urothelial carcinoma histology did not appear to significantly impact response to ICI therapy for mUC. The impact of proportion of non-urothelial histology, pure non-urothelial histology and site of primary on response warrants further study.

Abstract PD6-04: Lifestyle intervention study (LISA) in early breast cancer (BC): An RCT of the effects of a telephone-based weight loss intervention (with educational materials) vs educational materials alone on disease-free survival (DFS)

Background: Obesity has been associated with poor BC outcomes. We investigated whether a standardized, telephone-based weight loss lifestyle intervention in recently diagnosed BC patients would lower recurrence and death rates.

Methods: We conducted a multicenter RCT comparing mail-based educational material alone (control arm) or combined with a standardized, telephone-based lifestyle intervention (19 calls over 2 years, (intervention arm) that focused on diet (500-100 kcal/day deficit), physical activity (150-200 minutes of moderate-intensity activity per week) and behavior (compliance, relapse prevention) to achieve up to 10% weight loss. 338 (of 2150 planned) T1-3, N0-3, M0 ER/PgR+ BC patients with body mass index (BMI) ≥ 24 kg/m2 receiving adjuvant letrozole were randomized Aug 2007 to Jan 2010 (enrolment ended due to funding loss). Primary outcome was DFS; secondary outcome OS. Weight loss (5.3 vs 0.7% at 6 months and 3.6 vs 0.4% at 24 months in the intervention vs control arms, respectively) has been reported (JCO 2014;32:2331). At 8 years median follow-up (May 2018), DFS and OS were compared using Cox proportional hazards regression.

Results: Mean age was 61.6 vs 60.4 years, mean BMI 31.4 vs 31.0 kg/m2 and adjuvant chemotherapy was received by 56.1 vs 57.5% in intervention vs controls arms respectively. T1/T2/T3 66.7/27.5/5.9% vs 61.7/33.5/3.6% and N0/1/2+ 62.6/28.7/8.8 vs 63.5/32.3/4.2% in intervention vs controls arms respectively. HER2+ in 8.8 vs 15.0% (intervention vs control). 20 of 171 (11.7%) in the lifestyle intervention arm vs 30 of 167 (18.0%) in the mail-based arm had DFS events, HR 0.71, 95%CI 0.41-1.24, p=0.23). DFS curves separated at 2 yrs; beyond 3-3.5 yrs separation approximated 5%. In a landmark DFS analysis of women alive at 24 months, DFS HR=0.68 (0.34-1.37, p=0.28).

Conclusions: We identified fewer DFS events in the lifestyle intervention arm. Although loss of funding reduced sample size and lowered power, these results are consistent with a potential beneficial effect of a lifestyle intervention on DFS in postmenopausal ER/PgR+ BC patients. They provide strong support for completion of ongoing RCTs (e.g. BWEL) that will provide definitive evidence regarding the effect of lifestyle based weight loss on BC outcomes.

Funded by Novartis Pharmaceuticals Inc.; Sponsored by the Ontario Clinical Oncology Group

Citation Format: Goodwin PJ, Segal R, Vallis M, Ligibel JA, Pond GR, Robidoux A, Findlay BP, Gralow JR, Mukherjee SD, Levine MN, Pritchard KI. Lifestyle intervention study (LISA) in early breast cancer (BC): An RCT of the effects of a telephone-based weight loss intervention (with educational materials) vs educational materials alone on disease-free survival (DFS) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-04.

Circulating tumor DNA alterations in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Because cell-free DNA (cfDNA) analysis facilitates the noninvasive genomic profiling of metastatic castration-resistant prostate cancer (mCRPC), the authors evaluated the association between cfDNA alterations and outcomes and evolution with therapy.

METHODS

Patients with mCRPC underwent cfDNA genomic profiling using Guardant360, which examines major cancer-associated genes. Clinical factors, therapy information, failure-free survival, and overall survival (OS) were obtained for select patients. The association between genomic alterations and outcomes was investigated.

RESULTS

Of 514 men with mCRPC, 482 (94%) had ≥1 circulating tumor DNA (ctDNA) alteration. The most common recurrent somatic mutations were in TP53 (36%), androgen receptor (AR) (22%), adenomatous polyposis coli (APC) (10%), neurofibromin 1 (NF1) (9%), epidermal growth factor receptor (EGFR), catenin beta-1 (CTNNB1), and AT-rich interactive domain-containing protein 1A (ARID1A) (6% each); and BRCA1, BRCA2, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (5% each) The most common genes with increased copy numbers were AR (30%), MYC (20%), and BRAF (18%). Clinical outcomes were available for 163 patients, 46 of whom (28.8%) were untreated for mCRPC. A higher number of ctDNA alterations, AR alterations, and amplifications of MYC and BRAF were associated with worse failure-free survival and/or OS. On multivariable analysis, MYC amplification remained significantly associated with OS. Prior therapy and serial profiling demonstrated the evolution of alterations in AR and other genes.

CONCLUSIONS

ctDNA frequently was detected in this large cohort of "real-world" patients with mCRPC, and the alterations appeared to be similar to previously reported tumor tissue alterations. A higher number of alterations, and AR and MYC alterations, appear to compromise clinical outcomes, suggesting a role for immune checkpoint inhibitors and novel AR and BET inhibitors in selected patients.

Oncologists and medical assistance in dying: Where do we stand?

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Background: With the passage of Bill C-14 in June 2016, medical assistance in dying (MAiD) was formally enacted into Canadian law. Since then, approximately 2,000 patients have died with medical assistance across the country, with cancer being the most common qualifying condition. We aimed to understand the views of oncology providers (OPs) regarding MAiD. Methods: We designed and administered an online survey to Canadian OPs’ to assess experience with MAiD, self-perceived knowledge, willingness to participate, and perception of the role of OPs in introducing MAiD as an end-of-life care option. We used complete sampling via the Canadian Association of Medical Oncologists (CAMO) and the Canadian Association of Radiation Oncologists (CARO) membership email lists. The survey was sent to 366 Radiation Oncologists, and 325 Medical Oncologists. Data was collected from April-June 2018. Results were analyzed using descriptive statistics as well as univariate and multivariate analysis. Results: We received 224 responses (response rate 32.4%). 70% of OPs have been approached by patients requesting MAiD. OPs were confident in their knowledge of the eligibility criteria, and previous exposure to MAiD was associated with confidence in this domain (odds ratio [OR]=3.77, 95% CI=2.05-6.94, p value<0.001). OPs were most willing to engage in MAiD with an assessment for eligibility, yet most refer to specialized teams for assessments. A majority of physicians (52.8%) would initiate a conversation of MAiD with a patient under certain circumstances, most commonly the absence of viable therapeutic options, coupled with unmanageable patient distress. Conclusions: In this first national survey of Canadian OP’s regarding MAiD, we found that most OP’s encounter patient requests for MAiD, are confident in knowledge of eligibility, and are willing to act as assessors of eligibility. Many OP’s believe that it is appropriate to present MAiD as a therapeutic option at the end of life under some circumstances. This finding warrants further deliberation amongst national/regional bodies for the development of consensus guidelines in order to ensure equitable access to MAiD for patients who wish to pursue it.

Taxane acute pain syndrome (TAPS) in patients receiving chemotherapy for breast or prostate cancer: a prospective multi-center study

BACKGROUND

Taxane acute pain syndrome (TAPS) is characterized by myalgias and arthralgias starting 2-3 days after taxane-based chemotherapy and lasting up to 7 days. In the absence of validated tools, many studies use the presence of both the myalgia and arthralgia components of the Common Terminology Criteria for Adverse Events (CTCAE) to define TAPS. The present study prospectively evaluated the frequency, severity, and impact of TAPS in patients with breast or prostate cancer.

PATIENTS AND METHODS

In this prospective, non-randomized study, patients with breast or prostate cancer commencing taxane-based chemotherapy completed the CTCAE (version 4.03), the Functional Assessment of Cancer Therapy-Taxane (FACT-T), and Brief Pain Inventory (BPI) questionnaires at baseline and once between days 5 and 7 of each chemotherapy cycle.

RESULTS

From March 2015 to April 1, 2016, 75 patients (breast n = 66, prostate n = 9) were enrolled; 83% received docetaxel and 16% paclitaxel and 1% withdrew. After the first cycle of taxane, TAPS was reported by 25/69 (36.2%) patients; a further 8/69 (18.2%) reporting TAPS after a subsequent chemotherapy treatment. Overall incidence of TAPS was 33/75 (44%). While associated with detrimental scores on FACT-T and BPI as well as increased use of analgesics in 63% (21/33) of patients with TAPS, TAPS did not lead to alterations in chemotherapy dosing.

CONCLUSIONS

TAPS is common after taxane-based chemotherapy, and its presence is associated with reduced quality of life and increased analgesic requirements. Prospective patient-reported outcome assessments are crucial to help individualize treatment strategies and improve management of TAPS.

New 6-factor prognostic model for patients (pts) with advanced urothelial carcinoma (UC) receiving post-platinum atezolizumab

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Background: Prognostic factors for overall survival (OS) have been identified in pts receiving post-platinum chemotherapy for advanced UC, but it is unknown whether these factors and/or others optimally predict OS for pts treated with PD1/PD-L1 inhibitor therapy. Methods: Pt level data from two UC salvage trials evaluating atezolizumab were used: IMvigor210 (n = 310) for training and PCD4989g (n = 95) for validation. Univariable and multivariable Cox regression analyses were performed to evaluate the association of the prognostic factors recognized in the chemotherapy setting (ECOG performance status [ECOG-PS], liver metastasis (LM), anemia, treatment-free interval, albumin), neutrophil-lymphocyte ratio (NLR), eosinophil count, platelet count (PLT), site of primary/metastases, stage at diagnosis, smoking, LDH, prior therapies and immune cell PD-L1 status by IHC with OS. Clinical factors were dichotomous and lab values normalized by logarithmic transformation as needed. Stepwise selection was employed to propose an optimal model using the training dataset; pts were then categorized by number of risk factors. Concordance, discrimination (c-statistic) and calibration were assessed in the validation dataset using bootstrap analyses. Results: The factors included in the optimal prognostic model for OS were: ECOG-PS 1 vs. 0 (HR 1.64 [95% CI: 1.20, 2.24], p = 0.002), LM (1.45 [1.08, 1.94], p = 0.014), PLT (1.73 [1.14, 2.61], p = 0.010), NLR (1.84 [1.45, 2.34], p < 0.001), LDH (1.54 [1.19, 1.99], p = < 0.001) and anemia (HR = 1.60 [1.17, 2.21] p = 0.004). The c-statistic was 0.690 (95% CI = 0.649-0.715) and 0.759 (0.694-0.795) in the training and validation datasets, respectively. 1-year OS of pts in the training and the validation cohorts were similar. PD-L1 score was statistically significant when adjusted for the optimal model, but did not improve clinical interpretability (c-statistic = 0.698). Conclusions: A new validated 6-factor prognostic model for OS including ECOG-PS, LM, PLT, NLR, LDH and anemia is proposed in the setting of post-platinum atezolizumab for advanced UC. Applicability of the model to other PD1/PD-L1 inhibitors and PD-L1 IHC assays warrant investigation.

Nivolumab demonstrates benefit over nomogram-predicted 12-month survival as salvage therapy for metastatic urothelial carcinoma

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Background: Intermediate endpoints of benefit in metastatic urothelial carcinoma (mUC) nonrandomized trials are necessary to identify promising drugs, particularly for checkpoint inhibitors, where response and progression-free survival remain suboptimal. We previously reported a nomogram (Pond GR et al, 2017 GU Cancers Symposium) using 5 prognostic factors (hemoglobin < 10 g/dL, Eastern Cooperative Oncology Group performance status ≥1, presence of liver metastasis, time from last treatment ≤3 months, and albumin < lower limit of normal) from phase 2 trials of historical agents (eg, taxanes) to estimate 12-month overall survival (OS), against which observed survival could be compared. Nivolumab was granted approval as salvage therapy for patients with mUC, based on the CheckMate (CM) 275 trial; it is thus of interest to compare the nivolumab observed survival versus nomogram-predicted survival results. Methods: Data were obtained from CM 275, including survival and all 5 prognostic factors. Nomogram points were calculated and the expected 12-month OS was estimated. Bootstrap analyses based on 2000 replications were used to estimate 95% confidence intervals (CIs) for the median expected, observed, and difference between the expected and observed 12-month OS values. All tests were 2-sided, with statistical significance defined as P≤0.05. Results: Data were available from 270 patients from CM 275. Fifteen patients did not have albumin recorded and were excluded. Among the 255 evaluable patients, 46 (18.0%) patients had 0 adverse prognostic factors, 85 (33.3%) had 1, and 124 (48.6%) had 2 or more. The observed nivolumab 12-month OS from CM 275 (43.3% [95% CI, 37.0%-50.5%]) was 19.8% higher (95% CI, 13.6%-26.4%) when compared with the nomogram-predicted 12-month OS (23.5%; [95% CI, 22.5%-25.5%]) if patients received historical chemotherapy. Across all 2000 bootstrap samples, the observed nivolumab 12-month OS exceeded the nomogram-predicted 12-month OS. Conclusions: Nivolumab was associated with a significantly improved 12-month OS compared with historical chemotherapy based on the value predicted by the validated nomogram incorporating baseline prognostic factors. Clinical trial information: NCT02387996.