Patient-Reported Outcomes in Patients With Advanced Urothelial Cancer Who Are Ineligible for Cisplatin and Treated With First-Line Enfortumab Vedotin Alone or With Pembrolizumab

PURPOSE

Locally advanced/metastatic urothelial cancer (la/mUC) affects patients' quality of life (QOL) and functioning. We describe the impact of first-line (1L) enfortumab vedotin (EV) alone or with pembrolizumab (P) on QOL/functioning/symptoms in patients with la/mUC who were cisplatin-ineligible from EV-103 Cohort K.

METHODS

In this phase Ib/II trial, patients were randomly assigned 1:1 to EV + P or EV monotherapy (mono). Exploratory patient-reported outcomes (PROs) were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core Questionnaire (EORTC QLQ-C30) and Brief Pain Inventory Short Form (BPI-SF) at baseline, once per week for cycles 1-3, and then in every cycle through the end of treatment. Changes in scores from baseline to week 24, reported as least squares mean (standard error), were assessed by mixed models for repeated measures. There were no formal statistical comparisons between treatment arms.

RESULTS

Of 149 patients treated, 65 (EV + P) and 63 (EV mono) comprised the PRO analysis set. For EV + P, EORTC QLQ-C30 QOL was maintained through week 24 with improvements in emotional functioning, pain, and insomnia. Clinically meaningful improvements were seen in EORTC QLQ-C30 pain after EV + P at weeks 12 (-14.41 [3.14]) and 24 (-14.99 [3.56]) and BPI-SF worst pain at week 24 (-2.07 [0.37]). For EV mono, EORTC QLQ-C30 QOL remained stable with clinically meaningful improvements in EORTC QLQ-C30 pain (-12.55 [4.27]), insomnia (-14.46 [4.69]), and constipation (-10.09 [4.35]) at week 24. There were small-to-moderate improvements in BPI-SF worst pain at week 24.

CONCLUSION

EV + P in patients with la/mUC who were cisplatin-ineligible was associated with preservation or improvement of QOL/functioning/symptoms. Improvement in pain was seen in both PRO instruments and treatment arms. These data complement clinical outcomes of 1L EV + P.

Therapy With Metronomic Cyclophosphamide (mCyc) for Previously-Treated Metastatic Castrate-Resistant Prostate Cancer (mCRPC)

INTRODUCTION

Despite the introduction of various novel therapies for management of metastatic castrate resistant prostate cancer (mCRPC) in recent decades, available treatment options are finite and remain limited. Multiple historical studies have demonstrated activity and a favorable toxicity profile of oral metronomic cyclophosphamide (mCyc) in prostate cancer (PCa). Unlike the cytotoxic immunosuppressive effects of high-dose intravenously-administered cyclophosphamide, continuous low doses of oral mCyc have a unique immune-stimulatory mechanism of action.

MATERIALS AND METHODS

This is a retrospective, multi-institution study of men with 43 patients with mCRPC treated mCyc. Patient demographic information as well as clinical, pathologic, and genomic characteristics of their PCa were extracted. The primary endpoint was the rate of PSA decline by ≥ 50% (ie, PSA50). Additional efficacy and toxicity data as well as cost analysis compared to other commonly used agents in mCRPC was obtained.

RESULTS

PSA50 was noted in 20.9% of patients, while an additional 25.6% patients achieved < PSA50 and 6.9% reported improvement in prostate cancer-related symptoms without any PSA reduction. Meanwhile, 9.3% of patients required mCyc dose reduction, 11.6% needed dose interruption due to toxicity, and no treatment discontinuations due to toxicity were observed. mCyc was also cost effective compared to other agents commonly used in mCRPC.

CONCLUSIONS

Despite the small sample size and retrospective nature of this dataset, mCyc demonstrated promising rapid activity and a tolerable toxicity profile in a heavily pretreated mCRPC population with aggressive clinical, pathologic, and genomic disease features.

Enfortumab Vedotin and Pembrolizumab in Untreated Advanced Urothelial Cancer

BACKGROUND

No treatment has surpassed platinum-based chemotherapy in improving overall survival in patients with previously untreated locally advanced or metastatic urothelial carcinoma.

METHODS

We conducted a phase 3, global, open-label, randomized trial to compare the efficacy and safety of enfortumab vedotin and pembrolizumab with the efficacy and safety of platinum-based chemotherapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma. Patients were randomly assigned in a 1:1 ratio to receive 3-week cycles of enfortumab vedotin (at a dose of 1.25 mg per kilogram of body weight intravenously on days 1 and 8) and pembrolizumab (at a dose of 200 mg intravenously on day 1) (enfortumab vedotin-pembrolizumab group) or gemcitabine and either cisplatin or carboplatin (determined on the basis of eligibility to receive cisplatin) (chemotherapy group). The primary end points were progression-free survival as assessed by blinded independent central review and overall survival.

RESULTS

A total of 886 patients underwent randomization: 442 to the enfortumab vedotin-pembrolizumab group and 444 to the chemotherapy group. As of August 8, 2023, the median duration of follow-up for survival was 17.2 months. Progression-free survival was longer in the enfortumab vedotin-pembrolizumab group than in the chemotherapy group (median, 12.5 months vs. 6.3 months; hazard ratio for disease progression or death, 0.45; 95% confidence interval [CI], 0.38 to 0.54; P<0.001), as was overall survival (median, 31.5 months vs. 16.1 months; hazard ratio for death, 0.47; 95% CI, 0.38 to 0.58; P<0.001). The median number of cycles was 12 (range, 1 to 46) in the enfortumab vedotin-pembrolizumab group and 6 (range, 1 to 6) in the chemotherapy group. Treatment-related adverse events of grade 3 or higher occurred in 55.9% of the patients in the enfortumab vedotin-pembrolizumab group and in 69.5% of those in the chemotherapy group.

CONCLUSIONS

Treatment with enfortumab vedotin and pembrolizumab resulted in significantly better outcomes than chemotherapy in patients with untreated locally advanced or metastatic urothelial carcinoma, with a safety profile consistent with that in previous reports. (Funded by Astellas Pharma US and others; EV-302 ClinicalTrials.gov number, NCT04223856.).

A case report of challenges in distinguishing gastroesophageal junction hepatoid adenocarcinoma from testicular germ cell tumor: Insights for improved diagnosis with gene expression profiling

Gastroesophageal junction hepatoid adenocarcinoma is a rare form of gastroesophageal cancer. We present a case of a 38-year-old man with no significant medical history who was diagnosed with gastroesophageal junction hepatoid adenocarcinoma but initially misdiagnosed with a testicular germ cell tumor, given the elevated alpha-feto protein and poorly differentiated pathology. We will elaborate on the importance of gene expression profiling in modern oncology to better define the tumor of origin in patients with cancer of unknown primary origin, how it helped us to diagnose gastroesophageal junction hepatoid adenocarcinoma and how it can help identify potential additional therapeutic targets in some cases. Due to the rarity of this subtype of gastroesophageal junction cancer there is a lack of standard therapeutic options, and we will discuss the most commonly used treatment regimens. The patient underwent three lines of antineoplastic therapy and unfortunately passed after 51 weeks of follow-up.

Development of a Screening Nomogram for Regional Lymph Node Metastasis Development in Muscle Invasive Bladder Cancer after Multiagent Systemic Therapy

PURPOSE/OBJECTIVE(S)

A reliable method of identifying clinically node negative bladder cancer patients at greater risk of developing lymph node metastasis and may require intensified therapy is needed. The purpose of this study was to create a nomogram to quantify the risk for regional lymphatic involvement in non-metastatic muscle invasive bladder cancer.

MATERIALS/METHODS

Usingthe National Cancer Database, patients with clinical T2-4N0M0 urothelial carcinoma of the bladder between the years of 2004 - 2020 were selected. All patients completed multiagent chemotherapy followed by surgery for pathologic nodal staging to determine presence or absence of nodal disease. No neoadjuvant radiation therapy was allowed and patients with history of prior malignancies were excluded. Following a 70:30 training to testing data split, baseline variables were assessed using univariate logistic regression. Variables were selected for inclusion in the multivariate logistic regression model using a combination of previously reported findings in the literature and/or if found to have a p-value < 0.05 on univariate analysis. A nomogram was constructed using this final model with assessment using calibration plots and the area under the receiver operating characteristics curve (AUC), respectively. An empiric cut point was chosen at 95% sensitivity to identify patients at "high" and "low" risk for pathologic nodal disease with overall assessment in both cohorts using chi-square.

RESULTS

A total of 6194patients were identified for study with a median age of 65 years (IQR = 58 - 71 years). Most patients were male (68.0%) with T2 disease (81.2%). The final multivariate model included age at time of diagnosis (OR = 0.99; 95% CI = 0.99 - 1.00; p = 0.172), time from diagnosis to initiation of chemotherapy (OR = 1.00; 95% CI = 1.00 - 1.01; p = 0.005), papillary histology (OR = 0.85; 95% CI = 0.72 - 1.01; p = 0.068), and clinical T stage (Table 1). Model calibration demonstrated excellent goodness-of-fit with good discrimination (AUC = 0.644). Within the training data, high risk patients were seen to have a twofold increase in pathologic nodal disease (N = 835/3924, 21.2%) when compared to those identified as low risk (N = 38/347, 9.9%) (p < 0.001). Validation within the testing data set demonstrated similar results with pathologic node rates of 22.8% and 7.8% for high- and low-risk patients, respectively (AUC = 0.645, p < 0.001).

CONCLUSION

This study demonstrates a clinically applicable risk stratification tool for identifying patients at risk for developing lymphadenopathy in T2-4 bladder cancer and may help guide future research in selecting patients eligible for escalation of therapy. Future studies should aim to externally validate this tool within prospective cohorts, and seek to determine if this nomogram may provide further prognostic utility.

Prognostication of Overall Survival in Muscle Invasive Bladder Cancer: An Application of a Lymph Node Metastasis Nomogram

PURPOSE/OBJECTIVE(S)

The purpose of this study was to determine if a previously developed nomogram predictive of developing pathologic lymph node metastasis after multiagent chemotherapy for clinical node-negative muscle invasive bladder cancer may also prognosticate overall survival (OS) in patients treated with definitive chemoradiotherapy (CRT).

MATERIALS/METHODS

Using the National Cancer Database, we identified all patients with cN0 muscle invasive urothelial carcinoma of the bladder treated with definitive CRT from 2004 to 2020. Patient probability of occult nodal disease was assessed using a previous nomogram developed from those treated with multiagent chemotherapy alone followed by pathologic nodal assessment. Following a 70:30 training and testing data split, variables were assessed for association with OS using the log-rank test, with those with p < 0.05 deemed eligible for inclusion within a multivariate Cox proportional hazards model. Patients were then stratified as high-, medium-, or low-risk for death using the hazard function's prognostic index. The proportional hazards assumption was checked using Schoenfeld residuals and discrimination assessed using dynamic area under the receiver operating characteristics curves (AUC). Validation was assessed within the testing and a retrospectively collected institutional cohort of 15 patients treated from 2014 - 2020 with CRT.

RESULTS

A total of 1047 patients were identified for this study with median age of 78 years (IQR = 70-83 years) and follow-up of 31.3 months (IQR = 16.0 - 56.6 months). Cox analysis revealed patient age (HR = 1.03; 95% CI = 1.02 - 1.04; p < 0.001), Charlson-Deyo Score, and predicted probability of developing future lymphadenopathy (HR = 4.47; 95% CI = 1.83 - 10.93; p = 0.001) were significantly associated with OS. Median OS for those identified as high, medium, and low risk for death on Cox analysis was 34.2 months (IQR = 21.3 - 40.6 months), 38.9 months (IQR = 31.4 - 47.2 months), and 77.8 months (IQR = 56.1 - 100.3 months), respectively (AUC range = 0.615 - 0.870) (p < 0.001). Similar discrimination was seen within the testing cohort as well with significant differences between median OS across each group (AUC range = 0.580 - 0.726) (p < 0.001). Notably, among patients within the institutional cohort, only one patient stratified as high (N = 1/2; 50.0%) or medium risk (N = 0/5; 0.0%) remained alive at time of final follow-up, whereas 88.9% (N = 7/8) of low-risk patients survived (p = 0.051). Similarly, significant differences in OS were again seen between risk groups, with a median OS of 51.3 months and 19.9 months for high- and medium-risk patients, respectively, while median OS for low-risk patients was not reached (p = 0.006).

CONCLUSION

This study demonstrates the prognostic utility of a previously reported nomogram in predictions of OS. Investigation is warranted to explore how radiation and chemotherapy may offset worse OS in those at high risk for occult nodal disease progression.

Drug extravasation with Enfortumab vedotin

INTRODUCTION

Enfortumab vedotin is an antibody drug conjugate approved for management of pretreated locally advanced or metastatic urothelial carcinoma, which is associated with a rare risk of drug extravasation and soft tissue reactions.

CASE REPORT

We report two cases of EV extravasation with subsequent development of bullae and cellulitis.

MANAGEMENT AND OUTCOME

They were both treated for cellulitis and had conservative management without surgical intervention and were able to resume treatment with Enfortumab vedotin without subsequent adverse events.

DISCUSSION

We propose that EV acts as a vesicant upon extravasation, highlight measures to prevent extravasation events, and encourage appropriate measures when dealing such as attempt of aspiration, removal of catheter, application of compresses, and thorough documentation with photographic evidence.

Enfortumab Vedotin With or Without Pembrolizumab in Cisplatin-Ineligible Patients With Previously Untreated Locally Advanced or Metastatic Urothelial Cancer

PURPOSE

Patients with locally advanced or metastatic urothelial cancer (la/mUC) who are ineligible for cisplatin-based therapy have limited first-line (1L) treatment options and significant need for improved therapies. Enfortumab vedotin (EV) and pembrolizumab (Pembro) individually have shown a survival benefit in urothelial cancer in second-line + la/mUC settings. Here, we present data from the pivotal trial of EV plus Pembro (EV + Pembro) in the 1L setting.

PATIENTS AND METHODS

In Cohort K of the EV-103 phase Ib/II study, cisplatin-ineligible patients with previously untreated la/mUC were randomly assigned 1:1 to receive EV as monotherapy or in combination with Pembro. The primary end point was confirmed objective response rate (cORR) per blinded independent central review. Secondary end points included duration of response (DOR) and safety. There were no formal statistical comparisons between treatment arms.

RESULTS

The cORR was 64.5% (95% CI, 52.7 to 75.1) and 45.2% (95% CI, 33.5 to 57.3) for patients treated with EV + Pembro (N = 76) and EV monotherapy (N = 73), respectively. The median DOR was not reached for the combination and was 13.2 months for monotherapy; 65.4% and 56.3% of patients who responded to the combination and monotherapy, respectively, maintained a response at 12 months. The most common grade 3 or higher treatment-related adverse events (TRAEs) in patients treated with the combination were maculopapular rash (17.1%), fatigue (9.2%), and neutropenia (9.2%). EV TRAEs of special interest (any grade) in the combination arm included skin reactions (67.1%) and peripheral neuropathy (60.5%).

CONCLUSION

EV + Pembro showed a high cORR with durable responses as 1L treatment in cisplatin-ineligible patients with la/mUC. Patients who received EV monotherapy had a response and safety profile consistent with previous studies. Adverse events for EV + Pembro were manageable, with no new safety signals observed.

Results from a Phase 1b/2 Study of Ibrutinib Combination Therapy in Advanced Urothelial Carcinoma

Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. We evaluated the safety and efficacy of ibrutinib, alone or combined with standard-of-care regimens, in adults with advanced urothelial carcinoma (UC). Once-daily ibrutinib was administered orally at 840 mg (single-agent or with paclitaxel) or at 560 mg (with pembrolizumab). Phase 1b determined the recommended phase 2 dose (RP2D) of ibrutinib, and phase 2 assessed progression-free survival (PFS), overall response rate (ORR), and safety. Thirty-five, eighteen, and fifty-nine patients received ibrutinib, ibrutinib plus pembrolizumab, and ibrutinib plus paclitaxel at the RP2D, respectively. Safety profiles were consistent with those of the individual agents. The best-confirmed ORRs were 7% (two partial responses) with single-agent ibrutinib and 36% (five partial responses) with ibrutinib plus pembrolizumab. Median PFS was 4.1 months (range, 1.0-37.4+) with ibrutinib plus paclitaxel. The best-confirmed ORR was 26% (two complete responses). In previously treated patients with UC, ORR was higher with ibrutinib plus pembrolizumab than with either agent alone (historical data in the intent-to-treat population). ORR with ibrutinib plus paclitaxel was greater than historical values for single-agent paclitaxel or ibrutinib. These data warrant further evaluation of ibrutinib combinations in UC.

Optimal treatment by invoking biologic clusters in renal cell carcinoma (OPTIC RCC)

TPS742

Background: The first-line treatment for metastatic clear cell renal cell carcinoma (mccRCC) includes an immuno-oncology (IO) based combination. The current standard regimens include a PD-1 inhibitor plus either (1) an anti-CTLA-4 inhibitor (IO/IO), or (2) an anti-vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) (IO/TKI). Currently, there is no level 1 evidence to guide physician’s choice between an IO/IO versus IO/TKI combination. The phase III IMmotion 151 trial performed RNA-seq from 823 ccRCC tumors and established seven biologically distinct gene expression clusters of ccRCC (Motzer and Rini et al., Cancer Cell 2020). The seven clusters showed differential responses to immune checkpoint inhibitor and may serve as a predictive biomarker to select frontline treatment. Methods: This trial is a phase II, multicenter study using the established biologic clusters to assign patients with mccRCC to either an IO/IO (ipilimumab/nivolumab) or an IO/TKI (nivolumab/cabozantinib) regimen. Patients diagnosed with mccRCC without prior systemic therapy (including in the neoadjuvant or adjuvant setting) and at least one measurable lesion as defined by RECIST 1.1 are eligible for enrollment. RNA-seq will be performed on metastatic tumor specimens and used to assign tumor clusters. Patients with cluster 1/2 tumors will be assigned to the nivolumab/cabozantinib arm; patients with cluster 4/5 tumors will be assigned to the ipilimumab/nivolumab arm. Cluster 3/6/7 will be excluded. The primary endpoint is overall response rate (ORR) per RECIST 1.1. The hypothesis is that use of tumor clusters to assign front-line therapy to either nivolumab/cabozantinib or ipilimumab/nivolumab will lead to a 20% greater ORR compared to unselected historical controls in CheckMate 9ER (ORR: 55%) or CheckMate 214 (ORR: 40%). This trial adopts Simon’s MiniMax two-stage design (power: 80%, one-sided α: 0.1). For the nivolumab/cabozantinib arm, stage I will enroll 12 eligible patients. If there are 7 or more responders in the first 12 patients, the trial will continue for stage II to enroll additional 14 patients (total n=26). The primary endpoint will be met if there are 18 or more responders (ORR ≥75%). For the ipilimumab/nivolumab arm, stage I will enroll 16 eligible patients. If there are 7 or more responders in the first 16 patients, the trial will continue for stage II to enroll additional 12 patients (total n=28). The primary endpoint will be met if there are 15 or more responders (ORR ≥60%). Key secondary endpoints include progression-free survival (PFS), depth of response>80%, and rate of immune-related adverse events (irAEs). This trial is funded by the Department of Defense Kidney Cancer Research Program Clinical Trial Award (W81XWH-22-1-1033) (NCT05361720). Clinical trial information: NCT05361720 .

Management disparities in metastatic castrate-sensitive prostate cancer (mCSPC)

79

Background: Recent approvals in management of high-volume mCSPC offer major improvements in patient outcomes. Triplet therapy combining androgen deprivation therapy (ADT) with docetaxel (D) and novel hormonal therapy (NHT) is the new standard of care in this patient population. Patients ineligible for triplet therapy should receive doublet therapy with ADT plus D or NHT based on category 1 evidence. Multiple retrospective datasets examining the “real-world” mCSPC treatment landscape note significant underutilization of therapies beyond ADT and discordance with treatment guidelines. Methods: A 15-question survey to assess management patterns was electronically distributed to various mCSPC providers in California and Washington. Results: A total of 40 responses were received, with 62.5% identifying as medical oncologists (MO), 20.0% as urologists, 5.0% as radiation oncologists, and 12.5% as advanced practitioners/other. Out of physician responders, 48.6% were academic and 51.4% were community-based. When treating newly diagnosed fit mCSPC patients, 20.0% would prescribe triplet therapy, 42.5% ADT/NHT, 5.0% ADT/D, 5.0% ADT/bicalutamide, 0% ADT alone, 10.0% other therapies, and 17.5% would refer out for therapies beyond ADT. When comparing academic versus community oncologists, 66.7% versus 0% would prescribe triplet therapy, while 22.2% versus 68.8% would prescribe ADT/NHT. Some perceived barriers to following mCSPC treatment guidelines included difficulty keeping up with rapidly evolving data/too many treatment options in 27.5%, insurance coverage concerns in 22.5%, difficulty obtaining early referrals for these therapies in 12.5%, patient factors in 10.0%, and toxicity concerns in 2.5%. When making referrals to MO, 37.5% of non-MO responders would do so at development of mCSPC and 6.3% at mCRPC. Conversely, 24.2% of MO perceived receiving referrals at development of mCSPC and 33.3% at mCRPC. Patterns of ordering genomic testing are listed, with biggest perceived barriers being cost, inadequate access to sequencing platforms and genetic counselors, lack of confidence in counseling about results, and patient refusal. Upon progression from mCSPC to mCRPC, ordering of repeat tumor biopsies would occur “sometimes” by 40.0% of providers, “rarely” by 20.0%, and “never” by 20.0%. Conclusions: Multiple provider disparities when managing mCSPC patients still exist. Our survey demonstrated higher compliance with treatment guidelines than in previous retrospective datasets, possibly due to higher proportion of academic providers. Increased provider awareness of genomic testing recommendations is also needed. [Table: see text]

Enfortumab vedotin (EV) alone or in combination with pembrolizumab (P) in previously untreated cisplatin-ineligible patients with locally advanced or metastatic urothelial cancer (la/mUC): Subgroup analyses of confirmed objective response rate (cORR) from EV-103 cohort K

499

Background: In EV-103 Cohort K (NCT03288545), EV and P in combination (EV+P) showed encouraging antitumor activity and a manageable safety profile when used as 1L therapy in patients (pts) w/ la/mUC who are ineligible for cisplatin, a population w/ high unmet need. Here we report results of an analysis of prespecified Cohort K subgroups known to be associated w/ poor outcomes. Methods: Pts who are cisplatin-ineligible w/ previously untreated la/mUC were randomized 1:1 to EV (1.25 mg/kg) as monotherapy on Days 1 and 8 or in combination w/ P (200 mg) on Day 1 of 3-week cycles. Primary endpoint is cORR per RECIST v1.1 by blinded independent central review w/ no formal statistical comparison between arms. Secondary endpoints included duration of response and safety (e.g. treatment-related adverse events, TRAEs). The cORR analysis was performed in prespecified subgroups including age, ECOG PS, liver metastasis, PD-L1 expression status, metastatic disease site at baseline, and primary disease site of origin. Results: 149 pts were treated: EV+P n=76; EV n=73; cORRs across key subgroups for both EV+P and EV monotherapy are shown in the table. For EV+P overall cohort, cORR (95%CI): 64.5% (52.7, 75.1); median DOR was not reached. cORRs were consistent across subgroups for EV+P including those w/ ECOG PS score of 1-2: 62.8% (46.7, 77.0) and presence of liver metastasis: 53.8% (25.1, 80.8). Among TRAEs of special interest in the EV+P arm, skin reactions occurred in n=51 (67.1%); peripheral neuropathy occurred in n=46 (60.5%). For EV+P, 68.4% of pts had TRAEs leading to interruption of either EV or P; 48.7% of pts had TRAEs leading to EV dose reduction. Median duration of EV+P treatment was 11 cycles. Conclusions: EV+P showed promising cORR in 1L cisplatin-ineligible pts w/ la/mUC; activity was consistently observed across a range of pre-specified subgroups including those with poor prognosis. EV+P TRAEs were manageable w/ close monitoring and appropriate dose modifications w/ a meaningful duration of treatment. EV+P has the potential to address high unmet needs in 1L la/mUC and MIBC and is being further evaluated in 3 Phase 3 trials (NCT04223856, NCT04700124, NCT03924895). Clinical trial information: NCT03288545 . [Table: see text]

Exploratory analysis of predictive biomarkers for immune-related adverse events (irAEs) due to checkpoint inhibitors (CPIs) in patients with genitourinary (GU) cancers

569

Background: CPIs targeting PD-1/PD-L1 and CTLA-4 have transformed management of GU cancers. These agents are associated with a unique type of immune-mediated toxicities that may affect any organ, which may be severe or life-threatening. Development of irAEs may in part depend on type of CPI used, type of solid tumor, and individual patient factors including presence of subclinical inflammatory states. However, distinct biomarkers predictive of irAE development are poorly defined. This study aimed to examine possible associations between tumor mutation burden (TMB) and PD-L1 expression with occurrence of irAEs. Methods: A retrospective chart review was performed of all patients with urothelial carcinoma (UC) and renal cell carcinoma (RCC), who received therapy with CPIs from 1/2019 to 9/2022 at our institution and developed associated irAEs. Severe irAEs were defined as those necessitating initiation of immunosuppressive therapies or other supportive therapies. TMB and PDL-1 expression patterns were analyzed, if available. Given lack of standardized cutoffs for PD-L1 positivity across different GU cancer types, tumors were considered positive if a combined positive score of greater than 10 was present in UC or a total positive score of greater than 1% was present in RCC. Results: A total of 60 patients were included in this analysis - 33 with UC and 27 with RCC. Severe irAEs occurred in 19 patients with UC and 25 patients with RCC. Median TMB was 8.7 in patients with UC, while it was 2.5 in patients with RCC. PD-L1 positivity was seen in 39.3% (13/33) of UC patients and 40.7% (11/27) of RCC patients. In the UC cohort, 57.8% (11/19) had severe irAEs and TMB less than 10, while 36.8% (7/19) had severe irAEs and TMB greater than 10. Further, 47.3% (9/19) of UC patients had severe irAEs and positive PD-L1, while 42.1% (8/19) had severe irAEs and negative PD-L1. In the RCC cohort, 88% (22/25) had severe irAEs and TMB less than 10, while 8% (2/25) had severe irAEs and TMB greater than 10. Additionally, 40% (10/25) RCC patients had severe irAEs and positive PD-L1, while 56% (14/25) had severe irAEs and negative PD-L1. The incidence of TERT promoter mutations and TMB is noted in the table. Conclusions: Identification of predictive biomarkers of irAEs from CPIs is a major area of need in GU malignancies. Definitive conclusions from this dataset are limited by its small sample size. Interestingly, there appear to be differences in baseline expression of traditional immune biomarkers between UC and RCC, with lower prevalence of TMB greater than 10 and positive PD-L1 noted in the RCC cohort. As such, their utility when making treatment decisions in clinical practice may be of limited value. [Table: see text]

Molecular characteristics of advanced clear cell renal cell carcinoma (ccRCC) harboring TERTmutations

706

Background: There is a large unmet need for identifying prognostic and predictive biomarkers in advanced RCC. TERT is a catalytic subunit of the telomerase enzyme and TERT promoter mutations lead to increased telomerase activity, which promotes tumorigenesis by preventing telomere shortening. Emerging data suggests a correlation between TERT promoter mutations (pTERTmut) and improved responses to immune checkpoint inhibitors in urothelial carcinoma (UC), while there is paucity of such data in RCC. This study aims to analyze the immune biomarker environment and co-mutational landscape in TERT mutated versus wild-type RCC. Methods: A retrospective analysis of patients with advanced ccRCC who completed sequencing with the Tempus xT assay (DNA-seq of 648 genes at 500x coverage, full transcriptome RNA-seq) was performed. De-identified data was analyzed for presence of pTERTmut, all other TERT mutations (otherTERT), and TERT wildtype (wtTERT). Companion alterations and immune biomarkers were compared between these three groups. Results: A total of 866 samples was analyzed, with 58% from primary renal lesions and 42% from a metastatic site. The frequency of all TERT mutations was 8.2% (71/866). pTERTmut was present in 5.6% (28/502) of primary and 5.5% (20/364) of metastatic sites, while otherTERT was present in 3.0% (15/502) of primary and 2.2% (8/364) of metastatic sites. Tumor mutational burden (TMB) was performed in 764 samples and only 0.4% had TMB greater than 10 m/MB, all of which were wtTERT. Median TMB was 2.08 m/MB across all samples, with 1.91 m/MB in pTERTmut, 1.72 m/MB in otherTERT, and 2.31 m/MB in wtTERT. Only 0.2% of 834 samples harbored MSI-high and 1.4% of 295 samples were mismatch repair deficient (dMMR), all of which were wtTERT. PD-L1 status was available in 439 samples, with 14% scored as positive (PD-L1+) with a combined positive score >10. Of PD-L1+, 4.8% was in pTERTmut, 3.2% in otherTERT, and 92.1% in wtTERT. Neoantigen tumor burden of all non-silent mutations was evaluated in 698 samples, with a median value of 2.11 in pTERTmut, 1.58 in otherTERT, and 2.11 in wtTERT. PBRM1 co-mutations were noted in 22.9% of samples with pTERTmut, 21.7% in otherTERT, and 33.2% in wtTERT. Additional RCC co-mutations are listed in the table. RCC mRNA and UC cohort data analysis is in progress. Conclusions: This is the largest analysis of the molecular and immune landscape of TERT mutated ccRCC. Interestingly, this dataset showcases that traditional immune biomarkers (TMB, MSI, dMMR, and PD-L1) do not appear to be highly prevalent in RCC and their use in clinical practice may be limited. Further investigation into the TERT biomarker candidate is warranted. [Table: see text]

Patient-reported outcomes (PROs) in cisplatin-ineligible patients (pts) with locally advanced or metastatic urothelial cancer (la/mUC) treated with enfortumab vedotin (EV) alone or in combination with pembrolizumab (P) in the phase 1b/2 EV-103 Cohort K study

439

Background: The EV-103 Cohort K trial evaluated 1L EV+P or EV alone (NCT03288545) in pts with la/mUC who were cisplatin-ineligible. EV+P showed a clinically meaningful objective response rate (64.5%; 95% CI, 52.7–75.1) with a manageable safety profile. Because la/mUC is associated with symptoms with a frequent impact on quality of life (QOL) and functioning (Mamtani et al. JCO 2021), we describe the impact of EV+P or EV alone on QOL and symptoms. Methods: In this open-label, Phase 1b/2 trial, cisplatin-ineligible pts with la/mUC were randomized 1:1 to EV+P or EV alone. For exploratory PRO endpoints, pts completed EORTC QLQ-C30 and the BPI-SF at baseline, weekly for cycles 1–3, and once every cycle for the remainder of treatment period. The PRO analysis set included only pts who were treated and completed the questionnaire at baseline. Mixed effect models for repeated measures (MMRM; least squares [LS] mean, standard error [SE]) not adjusted for multiplicity, estimated change vs baseline until Week 24; established thresholds (EORTC QLQ-C30: 10-point change; BPI-SF: 2-point change) were applied to determine clinically meaningful change. Results: Of the 76 pts treated with EV+P, 65 were included in the PRO analysis set. EORTC QLQ-C30 and BPI-SF were completed by 100% and 95%, respectively, at baseline; compliance rates were ≥84% for both instruments through Week 24. In the EORTC QLQ-C30 MMRM analyses, QOL was maintained through Week 24 for EV+P; functioning and symptom scores remained stable over time, with improvements in emotional functioning, pain and sleep disturbance vs observed baseline. In the EV+P arm, clinically meaningful reductions in pain were seen at Week 12 (-12.64 [3.208]) vs baseline and persisted through Week 24 (-13.20 [3.406]). In the BPI-SF MMRM analyses, worst and average pain, pain interference and severity consistently showed improved scores from Week 4–24 for EV+P; clinically meaningful change in worst pain was seen at Week 21 (-2.08 [0.361]). Similar completion and compliance rates were seen for the EV alone PRO analysis set (n=63). EV alone demonstrated clinically meaningful improvements in pain at Week 24 in the EORTC QLQ-C30 (-10.63 [4.110]) and consistent small-to-moderate improvements in the BPI worst and average pain, and pain severity (0.5–1.0 points). Sleep disturbances demonstrated improvement, and other symptom scales, QOL and functional domains remained stable. Conclusions: PRO data showed that EV+P in cisplatin-ineligible pts with la/mUC was associated with preservation or improvement of QOL, functioning, and symptoms. Improvement in pain was demonstrated consistently in both PRO instruments and treatment arms. These PRO data complement the clinical outcomes of EV+P in 1L cisplatin-ineligible pts with la/mUC. Clinical trial information: NCT03288545 .

Immunotherapy With Checkpoint Inhibitors in FGFR-Altered Urothelial Carcinoma

The treatment landscape of metastatic urothelial cancer (mUC) remained unchanged for over 30 years until the approval of immune checkpoint inhibitors (ICIs) in 2016. Since then, several ICIs have been approved for the treatment of mUC. In addition, recent molecular characterization of bladder cancer has revealed several subtypes, including those harboring fibroblast growth factor receptor (FGFR) mutations and fusion proteins. Erdafitinib, a pan-FGFR inhibitor, was approved for the treatment of metastatic/advanced UC in 2019. Some available evidence suggests ICI may have inferior response in advanced FGFR+ UC for unclear reasons, but may possibly be related to the tumor microenvironment. Several ongoing trials are evaluating erdafitinib in metastatic/advanced UC including the ongoing phase IB/II NORSE trial combining erdafitinib plus ICI, which may prove to offer a more robust and durable response in patients with FGFR+ metastatic/advanced UC.

Landscape analysis of urothelial carcinoma (UC) by telomerase reverse transcriptase (TERT) alterations

4524

Background: TERT is a catalytic subunit of telomerase, the unique enzyme that confers immortality to cells and is expressed in >90% of cancer cells. Mutations in the TERT promoter region (pTERTmut) are the most prevalent noncoding mutations in cancer. Recent data suggest pTERTmut are associated with improved outcomes in patients with UC treated with immune checkpoint inhibitors. We evaluated the molecular and immune landscape of UC with and without pTERTmut. Methods: UC tissue samples were analyzed for DNA alterations (NextSeq, 592 Genes; NovaSeq, WES) and mRNA expression (NovaSeq, WTS). Immune cell fraction was calculated by QuantiSeq (Finotello 2019, Genome Medicine). PD-L1 expression was assessed by immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ). MSI/MMR was tested by fragment analysis, IHC and NGS. TMB-H was based on a cut-off of > 10 mut/MB. We compared alterations between samples with and without detected pathogenic pTERTmut. Significance was determined by Mann–Whitney U, X2, and Fischer-Exact and p adjusted for multiple comparisons (q) was < 0.05 using Benjamini-Hochberg. Results: Overall, 1686 UC samples were analyzed, 1166 from primary lesions and 499 from a lymph node or metastatic site. pTERTmut was present in 68% of primary and 61% of metastatic tumors, and correlated with modest increase of TERT expression (1.18 fold, p=0.015). pTERTmut was associated with less frequent alterations in TP53, KMT2D, CCND1, MYC, KEAP1 and less MSI/dMMR. By contrast, pTERTmut was associated with more frequent alterations in ARID1A, TSC1, PIK3CA and TMB-H (all q<0.05). Over 41% of pTERTmut were TMB-H. TERTp mutations were not associated with FGFR alterations. The frequency of co-occurring mutations was similar by specimen site. In evaluating the immune landscape (Table), pTERTmut was associated with higher expression of PD-L1 (IHC, mRNA), PD-L2 (mRNA) and TIM3 (mRNA) in tumors from primary sites (all p and q<0.05), but not in metastatic sites. Investigation of tumor-associated immune cells demonstrated that pTERTmut correlated with higher percentage of M1-macrophages and CD8+ T cells in primary tumors, and was inversely-correlated with NK cells in metastatic sites (all q<0.05). Conclusions: This is the largest analysis looking at the molecular and immune landscape of pTERTmut UC tumors. We observed differential patterns of DNA alterations and tumor immune microenvironment based on pTERTmut status. Further work is needed to understand differences in these molecular cohorts and the association of these data with clinical outcomes. [Table: see text]

Study EV-103 Cohort H: Antitumor activity of neoadjuvant treatment with enfortumab vedotin monotherapy in patients with muscle-invasive bladder cancer who are cisplatin-ineligible

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Background: Up to 25% of all patients (pts) diagnosed with urothelial cancer present with muscle-invasive disease for whom the risk of progression or metastasis is substantial. Neoadjuvant chemotherapy prior to radical cystectomy and pelvic lymph node dissection (RC+PLND) has been shown to prolong overall survival for patients who are cisplatin (cis) eligible. The standard of care for cis-ineligible pts undergoing surgery does not include neoadjuvant therapy. Therefore, safe and effective neoadjuvant therapies are an unmet need for cis-ineligible pts with muscle invasive bladder cancer (MIBC). Enfortumab vedotin (EV) is an antibody-drug conjugate directed to Nectin-4, which is highly expressed in urothelial cancer, and has been shown to benefit previously treated locally advanced or metastatic urothelial cancer pts in phase 2 and 3 trials, including cis-ineligible pts. Methods: Cohort H of the EV-103 phase 1b/2 trial (NCT03288545) enrolled pts with cis-ineligible cT2-T4aN0M0 MIBC who were eligible for RC+PLND and had an ECOG of 0-2. Pts received 3 cycles of neoadjuvant EV (1.25 mg/kg) on Days 1 and 8 of every 3-week cycle prior to RC+PLND. The primary endpoint of the study was pathological complete response rate (pCRR; ypT0N0) by central review. Key secondary endpoints included pathological downstaging (pDS) rate (ypT0,Tis,Ta,T1,N0) and safety. Results from a preliminary analysis are presented. Results: 22 pts were treated. Pts had cT2 (68.2%), cT3 (27.3%), and cT4 (4.5%) tumors. 68.2% pts had predominant urothelial cancer; 31.8% had a mixed histology. 19 pts completed all 3 cycles of EV. 21 underwent RC+PLND, and 1 had a partial cystectomy. 36.4% pts had a pCR. pDS was seen in 50.0% pts. The most common EV treatment-related adverse events (TRAEs) were fatigue (45.5%), alopecia (36.4%), and dysgeusia (36.4%). 18.2% pts had Grade ≥3 EV TRAEs. No surgeries were delayed due to EV administration. 3 pts had Grade 5 AEs while on study that were unrelated to EV; in 2 pts these AEs occurred > 30 days after RC+PLND. Conclusions: Observed pCRR after neoadjuvant EV showed promising activity in cis-ineligible pts with MIBC who have a high unmet need. Adverse events were consistent with the known safety profile of EV. This first disclosure of data supports the ongoing phase 2 and 3 programs evaluating EV in MIBC. Clinical trial information: NCT03288545.

Use of immunotherapy in clinical management of genitourinary cancers - a review

Checkpoint inhibitors targeting PD-1/PD-L1 and CTLA-4 have revolutionized oncologic care delivery, including clinical management of genitourinary malignancies. Despite significant associated improvement in patient outcomes, molecular heterogeneity of tumors, variable tumor engagement with the immune response, and unique patient factors likely account for different clinical responses to immunotherapy agents. A search for predictive biomarkers of treatment response to checkpoint inhibitors is underway and several candidates, although imperfect, have been identified. Multiple checkpoint inhibitors have received approval as monotherapies or in combination with other agents in genitourinary cancers and clinical trial data continues to rapidly evolve. This review summarizes key published evidence involving use of checkpoint inhibitors in management of urothelial carcinoma, renal cell carcinoma, prostate adenocarcinoma, and penile squamous cell carcinoma. This review aims to help oncology practitioners develop an up-to-date, evidence-based approach to using these agents when managing patients with genitourinary cancers in clinical practice.

Study EV-103 Cohort H: Antitumor activity of neoadjuvant treatment with enfortumab vedotin monotherapy in patients (pts) with muscle invasive bladder cancer (MIBC) who are cisplatin-ineligible

435

Background: Up to 25% of all pts diagnosed with urothelial cancer present with muscle-invasive disease for whom the risk of progression or metastasis is substantial. Neoadjuvant chemotherapy prior to radical cystectomy and pelvic lymph node dissection (RC+PLND) has been shown to prolong overall survival for patients who are cisplatin (cis) eligible. The standard of care for cis-ineligible pts undergoing surgery does not include neoadjuvant therapy. Therefore, safe, and effective neoadjuvant therapies are an unmet need for cis-ineligible pts with MIBC. Enfortumab vedotin (EV) is an antibody-drug conjugate directed to Nectin-4, which is highly expressed in urothelial cancer, and has been shown to benefit locally advanced or metastatic urothelial cancer pts in Phase II and III trials, including cis-ineligible pts. Methods: Cohort H of the EV-103 phase 1b/2 trial (NCT03288545) enrolled pts with cis-ineligible cT2-T4aN0M0 MIBC who were eligible for RC+PLND and had an ECOG of 0-2. Pts received 3 cycles of neoadjuvant EV (1.25 mg/kg) on Days 1 and 8 of every 3-week cycle prior to RC+PLND. The primary endpoint of the study was pathological complete response rate (pCRR; ypT0N0) by central review. Key secondary endpoints included pathological downstaging (pDS) rate (yp T0,Tis,Ta,T1,N0) and safety. Results from a preliminary analysis are presented. Results: 22 pts were treated. Pts had cT2 (68.2%), cT3 (27.3%), and cT4 (4.5%) tumors. 68.2% pts had predominant urothelial cancer; 31.8% had a mixed histology. 19 pts completed all 3 cycles of EV. 21 underwent RC+PLND, and 1 had a partial cystectomy. 36.4% pts had a pCR. pDS was seen in 50.0% pts, with 1 case pending central pathology review. The most common EV treatment-related adverse events (TRAEs) were fatigue (45.5%), alopecia (36.4%), and dysgeusia (36.4%). 18.2% pts had Grade ≥3 EV TRAEs. No surgeries were delayed due to EV administration. 3 pts had Grade 5 AEs while on study that were unrelated to EV; in 2 pts these AEs occurred > 30 days after RC+PLND. Conclusions: Observed pCRR after neoadjuvant EV showed promising activity in cis-ineligible pts with MIBC who have a high unmet need. Adverse events were consistent with the known safety profile of EV. This first disclosure of data supports the ongoing Phase II and III programs evaluating EV in MIBC. Clinical trial information: NCT03288545.

Pembrolizumab (pembro) plus abiraterone acetate (abi) and prednisone (p) in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC): Results from KEYNOTE-365 cohort D

118

Background: Abi + p is a standard of care for mCRPC. Cohort D of the phase 1b/2 KEYNOTE-365 study (NCT02861573) was used to evaluate safety and efficacy of the PD-1 inhibitor pembro + abi and p in patients (pts) who had not received chemotherapy for mCRPC. Methods: Chemotherapy-naive pts who had not previously used next-generation hormonal agents (NHAs) for mCRPC or were intolerant to enzalutamide or for whom enzalutamide was ineffective for mCRPC, whose disease progressed ≤6 months before screening, and who had ECOG PS score 0/1 were eligible. Enrolled pts received pembro 200 mg IV Q3W + abi 1000 mg PO QD and p 5 mg PO BID. Primary end points were PSA response rate (PSA decrease ≥50% from baseline), confirmed ORR per RECIST v1.1 by blinded independent central review, and safety. Secondary end points included rPFS per PCWG3-modified RECIST v1.1, DCR (CR + PR + SD or non-CR/non-PD ≥6 mo), DOR, OS, time to symptomatic skeletal-related event, radiographic bone progression, and radiographic soft tissue progression. Results: Of 103 treated pts, 35.9% had RECIST-measurable disease and 26.2% had previously received enzalutamide. Median (range) time from enrollment to data cutoff was 17.6 (9.7-27.0) months. Confirmed PSA response rate in all 103 pts was 56.3%. Overall, 78.6% of pts had a reduction in PSA level from baseline (confirmed and unconfirmed). For 37 pts with RECIST-measurable disease, ORR was 16.2% (1 CR; 5 PRs) overall, 7.7% for those who previously received enzalutamide (n = 13) and 21.7% for those who had not previously received NHAs (n = 23). Two pts with RECIST-nonmeasurable disease had a CR. DOR was not reached (NR; range, 2.1+ to 19.4+ mo); 4 pts had a response ≥12 months. DCR was 44.7% overall, 11.1% in pts who previously received enzalutamide (n = 27), and 57.3% in pts who had not previously used NHAs (n = 75). Additional analyses are listed in the table. Treatment-related AEs (TRAEs) were experienced by 90.3% of pts; 36.9% experienced grade 3-5 TRAEs. Overall, 18.4% of pts had a grade 3/4 ALT laboratory elevation and 12.6% had a grade 3/4 AST elevation. Five pts died of AEs; 1 was treatment-related (myasthenic syndrome). Conclusions: Pembro + abi and p showed antitumor activity in chemotherapy-naive pts with mCRPC. Safety was generally consistent with individual profiles of each agent, although there was an increased incidence of grade 3/4 ALT/AST laboratory elevations than reported for the individual treatments. Clinical trial information: NCT02861573. [Table: see text]

Study EV-103 cohort L: Evaluating perioperative enfortumab vedotin monotherapy in cis-ineligible muscle invasive bladder cancer (MIBC) (trial in progress)

TPS587

Background: The current standard of care for patients (pts) with newly diagnosed MIBC is neoadjuvant cisplatin (cis)-based chemotherapy followed by radical cystectomy and pelvic lymph node dissection (RC+PLND). For the 20-50% pts who are cis-ineligible, the current standard of care is RC+PLND alone (Galsky Future Oncol 2021). Adjuvant therapy is currently recommended for cis-ineligible patients with high-risk features at cystectomy. Due to the high rates of recurrence in cis-ineligible pts with RC+PLND alone, there is a need to develop new therapies in this setting. Enfortumab vedotin (EV), an antibody-drug conjugate, delivers the microtubule-disrupting agent monomethyl auristatin E to cells expressing Nectin-4, which is highly expressed in urothelial cancer. In EV-301, a phase 3 study, EV showed an overall survival (OS) benefit vs chemotherapy in pts with locally advanced (la) or metastatic urothelial carcinoma (mUC) who had previously received platinum-based therapy and a PD-1 or PD-L1 inhibitor (Powles NEJM 2021). EV has also demonstrated activity and a tolerable safety profile in cis-ineligible pts with la/mUC (Yu Lancet Oncol 2021). Given the efficacy of EV in la/mUC, it is being evaluated as perioperative therapy in cis-ineligible MIBC in EV-103 cohort L. Methods: Study EV-103 (NCT03288545) la/mUC and MIBC cohorts were described previously (Hoimes ASCO 2019; Hoimes ASCO-GU 2020). Cohort L was added to evaluate EV monotherapy (n = 50) as perioperative therapy in cis-ineligible pts with MIBC (cT2-T4aN0M0 or cT1-T4aN1M0). Eligible pts are previously untreated for MIBC, ECOG 0-2, have CrCl ≥30 mL/min, and are medically fit for and agree to undergo curative intent RC+PLND. Pts with pT1 disease are eligible only if they have N1 disease. Pts receive 3 cycles of neoadjuvant EV (1.25 mg/kg IV) on Days 1 and 8 of each 3-week cycle, followed by RC+PLND and then 6 cycles of adjuvant EV starting 8 weeks post-RC on the same schedule. Pathological complete response rate per central pathology review is the primary endpoint. Secondary endpoints include event-free survival and disease-free survival by blinded independent central review and investigator, pathological downstaging rate per central pathology review, OS, safety and tolerability. Cohort L is currently enrolling pts in the US and Canada. Clinical trial information: NCT03288545.

Distribution of immune-related adverse events (irAEs) across genitourinary (GU) malignancies

480

Background: Checkpoint inhibitors (CPIs) targeting PD-1/PD-L1 and CTLA-4 have revolutionized management of GU malignancies. These agents are associated with a unique subset of toxicities that are immune-mediated, with a broad clinical spectrum that may affect any organ. Patients can also experience ³1 irAE involving multiple organ systems. Individual patient susceptibilities and type of CPI used may influence the incidence and type of irAEs that may develop. Wehypothesize that there are also differences in irAEs based on the histologic malignancy subtype. Methods: We performed a retrospective analysis of all patients with GU malignancies who received CPIs at the University of California Irvine using an outpatient oncology pharmacy database. Data was collected from 1/1/2020 to 6/30/2021. Patients were aged ³18 years and had a diagnosis of urothelial carcinoma (UC), renal cell carcinoma (RCC), prostate adenocarcinoma, or penile squamous cell carcinoma. Patients must have received ³1 dose of a CPI agent including ipilimumab (I), nivolumab (N), pembrolizumab (P), atezolizumab (At), avelumab (Av), durvalumab (D), and cemiplimab (C). Results: A total of 128 patients who received 141 unique CPI regimens were included. Documented irAEs were noted in 50.0% of patients and 18.4% had ³1 irAE. A total of 99 unique irAEs were recorded. In those who experienced irAEs, 92.2% of patients received CPIs in the metastatic setting and 7.8% in the adjuvant setting. In those who experienced irAEs, 12.5% of patients received combination CPIs with I+N, while 87.5% received single-agent CPI. In those who experienced irAEs, 46.8% of patients had UC, 50.0% had RCC, 1.6% had prostate cancer, and 1.6% had penile cancer. In those who experienced irAEs, 24.2% had skin rash or pruritis, 23.2% had endocrinopathies, 14.1% had colitis, 13.1% had other toxicity including arthritis, 12.0% had hepatitis, 3.9% had myositis, 2.9% had pneumonitis, 1.9% had neurologic toxicity including myasthenia gravis and encephalitis, 1.9% had carpal tunnel syndrome, 1.9% had nephritis, and 0.9% had autoimmune thrombocytopenia. Various irAEs for UC and RCC are summarized in Table. Conclusions: In this dataset, there were differences in type and incidence of irAEs in patients with UC and RCC, while the sample size was too small to draw conclusions about patients with prostate and penile cancer. Further investigation is needed involving other solid tumor types, including non-GU malignancies, to definitively answer this question.[Table: see text]

Late recurrence of localized pure seminoma in prostate gland: A case report

BACKGROUND

Late relapses of early-stage germ cell tumors are rare. Most patients (-85%) with stage I seminoma are cured by radical orchiectomy. The detection of late relapse is challenging given the relative rarity of this phenomenon, and the fact that patients who have completed surveillance are usually not undergoing regular oncologic workup nor imaging. While many treatment options do exist for a patient with late relapse of seminoma, surgery is typically the mainstay as these tumors are generally thought to be more chemo-resistant.

CASE SUMMARY

In this article, we describe the management of a patient with an early-stage pure seminoma who was subsequently identified to have a recurrence two decades later. We provide a review of the literature not only focused on clinical factors and biology, but also the management of late recurrences specifically in pure seminoma and in prostate gland.

CONCLUSION

There is a paucity of data and treatment recommendations for this clinical entity, and a multidisciplinary approach emphasizing subspecialty expert consultation and patient education is imperative.

Use of enfortumab vedotin in an HIV-positive patient with urothelial carcinoma

Introduction: Enfortumab vedotin is an antibody-drug conjugate used in patients with pretreated advanced urothelial carcinoma. Patients with human immunodeficiency virus were excluded from clinical trials conducted with this agent. Efficacy and safety of enfortumab vedotin has not been established in this patient population. Case report: A patient with a long-standing diagnosis of human immunodeficiency virus and an undetectable viral load on antiretroviral therapy was diagnosed with metastatic upper tract urothelial carcinoma. Following disease progression on platinum-based chemotherapy and pembrolizumab, he was initiated on therapy with enfortumab vedotin. Management & outcome: The patient developed significant toxicity shortly after initiation of enfortumab vedotin. His treatment was subsequently changed to docetaxel chemotherapy and he developed similar significant toxicity. Upon changing his antiretroviral therapy regimen, he was rechallenged with enfortumab vedotin and was able to tolerate it without dose-limiting toxicity, ultimately achieving a partial treatment response. Discussion: This case describes use of enfortumab vedotin in a patient with human immunodeficiency virus, which has not previously been reported. It also underscores the importance of careful medication reconciliation in patients receiving enfortumab vedotin and antiretroviral therapy.

351 KEYNOTE-365 cohort D: pembrolizumab plus abiraterone acetate and prednisone in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC)

Background

Treatment with abiraterone acetate + prednisone can improve outcomes in mCRPC patients with or without prior chemotherapy. Cohort D of phase 1b/2 study KEYNOTE-365 (NCT02861573) evaluated safety and efficacy of PD-1 inhibitor pembrolizumab + abiraterone acetate and prednisone in patients who had not received chemotherapy for mCRPC.

Methods

Patients were enrolled who had not received second-generation hormonal manipulation for mCRPC or failed/were intolerant to enzalutamide for mCRPC; had progressive disease ≤6 months before screening; and had ECOG PS 0/1. Patients received pembrolizumab 200 mg IV Q3W + abiraterone acetate 1000 mg orally QD and prednisone 5 mg orally BID. Primary end points: safety, PSA response rate (PSA decrease ≥50% from baseline), and confirmed ORR per RECIST v1.1 by blinded independent central review (BICR). Secondary end points: rPFS per PCWG3-modified RECIST v1.1, DCR, DOR, and OS.

Results

One hundred three patients were treated. Median (range) age was 70.0 (46–89) years, 30.1% were PD-L1+, 35.9% had RECIST-measurable disease, 18.4% had visceral disease, and 26.2% had previously received enzalutamide only. Median (range) time from enrollment to data cutoff was 17.6 (9.7–27.0) months. Confirmed PSA response rate in patients with PSA measurement at baseline (n=103) was 56.3%. For 37 patients with RECIST-measurable disease, ORR was 16.2% (1 CR; 5 PRs); 2 patients with RECIST-nonmeasurable disease had CR. In total population, 5 patients had a response ≥6 months; DCR was 44.7%. ORR for RECIST-measurable patients was 7.7% for those who previously received enzalutamide only (n=13) and 21.7% for those who had not previously received NHAs (n=23); DCR was 11.1% in all patients who previously received enzalutamide (n=27) and 57.3% in all patients who had not received NHAs (n=75). Median (95% CI) rPFS was 15.1 (9.2-NR) months; rPFS at 12 months was 54.9%. Median (95% CI) OS was NR (23.3 months-NR); OS at 12 months was 82.9%. Sixty-nine patients (67.0%) discontinued treatment, mostly because of progressive disease (37.9%). Treatment-related AEs (TRAEs) were experienced by 90.3% of patients and most common (≥15%) were ALT increase (22.3%), AST increase (17.5%), asthenia (16.5%), and diarrhea (16.5%); 36.9% experienced grade 3–5 TRAEs. There were 18.4%/12.5% grade 3 or 4 ALT/AST laboratory elevations. Five patients died of AEs; 1 was treatment related (myasthenic syndrome).

Conclusions

Pembrolizumab + abiraterone acetate and prednisone demonstrated antitumor activity in patients with chemotherapy-naive mCRPC. Safety was generally consistent with individual profiles of each agent. There was an increased incidence of grade 3–4 ALT/AST laboratory elevations.

Acknowledgements

Medical writing and/or editorial assistance was provided by Matthew Grzywacz, PhD, of ApotheCom (Yardley, PA, USA). This assistance was funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Funding for this research was provided by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.

Trial Registration

ClinicalTrials

gov, identifier: NCT02861573

Ethics Approval

The study and the protocol were approved by the Institutional Review Board or ethics committee at each site.

Immune-Related Meningoencephalitis following Nivolumab in Metastatic Renal Cell Carcinoma

While immunotherapy with nivolumab is promising for patients with renal cell carcinoma (RCC), overactivation of the immune system can lead to serious side effects. Immune-related meningoencephalitis without a viral or microbial etiology is a rare complication that may occur in patients treated with checkpoint inhibitors (CPI). Herein, we report a 66-year-old man who underwent a partial nephrectomy which revealed a papillary RCC with clear cell component. Three years later, an abdomen and pelvic CT revealed metastatic lesions in the left psoas muscle and in the left 12th rib. The patient was treated with pazopanib which was discontinued after 2 weeks due to significant hepatic and renal toxicity. He subsequently started sunitinib. Two months later, a chest, abdomen, and pelvic CT demonstrated progressive metastatic RCC in the retroperitoneal mass of the left psoas muscle and paraspinal musculature as well as a left renal mass. The patient was treated with 7 cycles of the CPI nivolumab. He was subsequently hospitalized for 3 weeks after experiencing bilateral lower extremity weakness, lethargy, several falls, hyperthermia, confusion, and gait abnormalities. A CSF analysis demonstrated a lymphocyte pleocytosis with elevated protein and no bacterial or viral growth. The patient was treated with high-dose steroids after which his symptoms resolved. Chest, abdomen, and pelvic CT scans over the next 3 years revealed no evidence of metastatic disease, reflecting a progression-free survival of 40 months. We highlight the unique case of a patient with metastatic RCC who experienced immune-related meningoencephalitis following immunotherapy with nivolumab. Medical oncologists should be alert to the potential development of immune-related encephalitis in patients treated with nivolumab and should promptly diagnose and treat this concerning condition. The excellent oncologic outcome of this case emphasizes the need for continued aggressive measures for management of CNS toxicity resulting from CPI therapy.

Adjuvant pembrolizumab in genomically selected high-risk patients with muscle-invasive bladder cancer

INTRODUCTION

Patients with muscle-invasive urothelial bladder cancer post neoadjuvant cisplatin-based chemotherapy with pathologic advanced disease (ypT3, ypT4, ypN+) at radical cystectomy have a significantly worse five-year overall survival. There is currently no preferred adjuvant therapy to reduce risk of cancer recurrence in this high-risk patient cohort and surveillance remains the standard-of-care.

CASE REPORT

We present a case series of two patients who received cisplatin-based neoadjuvant chemotherapy and had pathologic node-positive urothelial carcinoma at the time of radical cystectomy. Tumor next generation sequencing revealed high mutational burden in both patients and positive PD-L1 in one patient.Management and outcome: Patients were treated with adjuvant pembrolizumab and experienced long-term disease free intervals.

DISCUSSION

Use of adjuvant checkpoint inhibitors in patients post neoadjuvant cisplatin-based chemotherapy with pathologic advanced disease at the time of radical cystectomy at high-risk of cancer recurrence sounds appealing. Careful patient selection based on tumor-specific genomic alterations may be key. Large trials addressing this question are ongoing.

Thromboembolic events in metastatic testicular cancer treated with cisplatin-based chemotherapy

BACKGROUND

Testicular germ cell tumor (TGCT) is the most curable solid tumor and most common cancer among men 18-39 years. While cisplatin-based chemotherapy has significantly lengthened the survival of patients with TGCT, it is associated with a high rate of thromboembolic events (TEE).

AIM

To summarize our single-center experience highlighting patients who were diagnosed with TGCT and received platinum-based chemotherapy, with special attention to those patients who suffered a TEE.

METHODS

A retrospective analysis of the medical records and imaging studies of 68 consecutive individuals who were diagnosed with TGCT and received platinum-based chemotherapy at our Institution in a metropolitan community between January 1, 2014 and December 31, 2019.

RESULTS

A total of 19 (28%) patients experienced a TEE following orchiectomy which occurred during chemotherapy in 13 (68%) of these patients. Patients with a higher pathologic stage (stage III) were significantly (P = 0.023) more likely to experience a TEE compared to patients who had a lower stage. Additionally, patients who were treated with 3 cycles of bleomycine, etoposide, and cisplatin and 1 cycle of etoposide and cisplatin or 4 cycles of etoposide and cisplatin were significantly 5 (P = 0.02) times more likely to experience a TEE compared to patients who were treated with only 3 cycles of bleomycine, etoposide, and cisplatin.

CONCLUSION

Due to numerous factors that predispose to a TEE such as large retroperitoneal disease, higher clinical stage, greater number of chemotherapy cycle, central venous catheter, cigarette smoking, and possible cannabis use, high-risk ambulatory patients with TGCT treated with cisplatin-based chemotherapy may benefit from prophylactic anticoagulation. Randomized studies to evaluate the safety and efficacy of prophylactic anticoagulants are warranted in this young patient population generally devoid of medical co-morbidities.

Prescribing patterns in patients with metastatic castrate-sensitive prostate cancer (mCSPC)

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Background: Recent advances and approvals in mCSPC treatment offer improved outcomes. Docetaxel chemotherapy as well as novel hormonal therapies (NHT) including abiraterone, apalutamide and enzalumide are preferred regimens in addition to androgen deprivation therapy (ADT), with category 1 evidence supporting their use. Despite lack of consensus regarding use of first-generation anti-androgens (fgAI) aside from tumor flare prevention, they are still frequently prescribed. This multitude of options may lead to disparities in prescribing patterns. Methods: Retrospective analysis of pharmacy and medical claims data from the IQVIA database was performed. Patients were aged >18 years and had an ICD 9/10 diagnosis of metastatic prostate cancer (PCa) with >1 treatment claim. Patients on active therapy for another primary malignancy as well as those with <12 months of data pre- and <9 months post-first PCa-related event were excluded. Data was collected from 1/1/2015 to 6/30/2020. Treatment categories were classified as NHT, fgAI, chemotherapy, or ADT monotherapy. Results: National (N) and state of California (S) prescribing patterns are provided in Table. Nationally, Medicare reimbursed 16% NHT, 30% fgAI, 2% chemotherapy and 52% ADT, while third-party payers reimbursed 18% NHT, 20% fgAI, 3% chemotherapy and 59% ADT in 2020. State of California 2020 data yielded similar reimbursement patterns. In Southern California, academic centers prescribed 31% NHT, 23% fgAI and 46% ADT, while community-based practices prescribed 7% NHT, 36% fgAI and 57% ADT in 2020. In Southern California, community oncology practices prescribed 12% NHT, 40% fgAI, 2% chemotherapy and 44% ADT, while community urology practices prescribed 2% NHT, 38% fgAI, and 59% ADT in 2020. Data from 2015-2019 was similar. Conclusions: Although NHT utilization is increasing while chemotherapy utilization is declining, only a minority of mCSPC men received these therapies in 2020. Most of mCSPC men still receive ADT monotherapy or fgAI. Type of insurance carrier does not appear to affect prescribing patterns. Dramatic variations across treatment settings and different specialties exist, with academic centers prescribing more NHT than community-based practices and oncology practices prescribing more NHT than urology practices. These disparities should be addressed with provider education to standardize care delivery for mCSPC patients. [Table: see text]

Management of Advanced Prostate Cancer in Clinical Practice: Real-World Answers to Challenging Dilemmas

Advanced prostate cancer is a continuum of states distinguished by the presence or absence of metastasis and sensitivity or resistance to androgen deprivation therapy (ADT). Therapeutic options for this disease continue to rapidly evolve, making it a challenge to apply results of clinical trial data to daily patient management. One question relevant to providers is whether molecular biomarkers predictive of response or resistance to therapies are available to guide clinical treatment decisions. Other salient topics include the timing of therapy initiation in patients with biochemical recurrence, treatment approach in low-volume versus high-volume metastatic castrate-sensitive prostate cancer, types of agents available beyond ADT, and timing of their use in men with nonmetastatic castrate-resistant prostate cancer as well as whether sequencing of therapies in metastatic castrate-resistant prostate cancer matters. Additionally, familiarity with emerging treatment strategies is important. This review addresses the gray areas and challenging questions in advanced prostate cancer management that frequently arise in clinical practice.

Development of carpal tunnel syndrome in association with checkpoint inhibitors

INTRODUCTION

The incidence of neuropathy with checkpoint inhibitors is 0.3-1%, typically occurring 2-12 weeks after treatment initiation. Common neuropathy phenotypes include inflammatory myopathies, myasthenia gravis, acute and chronic demyelinating polyradiculopathies, vasculitic neuropathies, isolated cranial neuropathies, aseptic meningitis, autoimmune encephalitis, multiple sclerosis and hypophysitis. Carpal tunnel syndrome is the most common entrapment neuropathy in the general population; however, the association of carpal tunnel syndrome with checkpoint inhibitors is exceedingly rare.

CASE REPORT

We report two cases of patients with no prior history of carpal tunnel syndrome treated with checkpoint inhibitors that developed de novo bilateral carpal tunnel syndrome.Management & Outcome: For both patients, the neurologic symptoms improved with cessation of the checkpoint inhibitor and initiation of corticosteroids.

DISCUSSION

Given the prevalence of carpal tunnel syndrome in the general population, a high index of suspicion for carpal tunnel in patients receiving checkpoint inhibitors and prompt treatment with corticosteroids is essential.

Management of Urothelial Bladder Cancer in Clinical Practice: Real-World Answers to Difficult Questions

Management of urothelial bladder cancer has historically been challenging as a result of a limited grasp of disease biology and few available systemic therapy options, mainly consisting of platinum-based chemotherapy. Improved understanding of molecular mechanisms underlying pathogenesis of muscle-invasive bladder cancer as well as their correlation with tumor behavior and response to treatment has emerged over the past few years. Remarkable therapeutic advances have been made with the introduction of checkpoint inhibitors, which have changed the course of this disease. Multiple agents with novel mechanisms of action are also actively being explored in ongoing clinical trials. These advances are exciting but may prove challenging in terms of how to apply this constantly evolving plethora of data to actual patients. This review addresses the gray areas and challenging questions that frequently arise in clinical practice.

Pembrolizumab (pembro) plus olaparib in patients (pts) with docetaxel-pretreated metastatic castration-resistant prostate cancer (mCRPC): KEYNOTE-365 cohort A efficacy, safety, and biomarker results

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Background: Pembro + olaparib has shown antitumor activity and acceptable safety in docetaxel-pretreated pts with mCRPC enrolled in cohort A of the phase I/II KEYNOTE-365 study (NCT02861573). Updated results with new biomarker data are reported. Methods: Pts with docetaxel-pretreated mCRPC who progressed within 6 mo of screening received pembro 200 mg IV Q3W + olaparib 400-mg capsule or 300-mg tablet PO BID. Pts might have received 1 other chemotherapy and ≤2 second-generation androgen-receptor targeted therapies. Primary end points: PSA response rate (decrease ≥50% from baseline, confirmed by a second value ≥3 wks later), ORR per RECIST v1.1, and safety. Key secondary end points: DCR, DOR, rPFS, and OS. Biospecimens (eg, blood, tissue) were collected for biomarker analysis (tissue PD-L1 expression, androgen receptor variant 7 [AR-v7] expression in circulating tumor cells [CTCs], and a T-cell–inflamed gene expression profile [GEP]). ctDNA was analyzed by Guardant Health 360 (GH360) and Omni (GH Omni) assays. FFPE tissue was analyzed by FoundationOne CDx (F1CDx) assay. Results: 84 of 87 enrolled pts were treated; 48/84 (57.1%) had measurable disease. Median (range) time from enrollment to data cutoff was 3.6 mo (0.0-29.2) for all pts and 26.7 mo (21.2-29.2) for 41 pts with ≥27 wks’ follow-up. Confirmed PSA response rate was 9% (95% CI, 3.5-16.8) in 82 pts with a baseline PSA assessment. Median time to PSA progression: 3.8 mo (95% CI, 2.9-4.4). In 24 pts with measurable disease and ≥27 wks’ follow-up, ORR was 8.3% (95% CI, 1.0-27.0; 2 PRs) and DCR ≥6 mo was 20.8% (95% CI, 7.1-42.2). Median (range) DOR was NR (12.0+ to 21.4+ mo); 2 pts had DOR ≥12 mo. In all pts, median rPFS was 4.3 mo (95% CI, 3.4-7.7) and median OS was 14.4 mo (95% CI, 8.1-18.5). Grade ≥3 TRAEs occurred in 29 pts (35%); 2 pts died of TRAEs (1 myocardial infarction, 1 unknown). Overall, 26% had PD-L1+ tumors (combined positive score ≥1). Of 31 pts with CTC data, 12.9% were AR-v7+. No BRCA1/2 mutation was detected by GH360 (n=42). Of 57 pts analyzed by GH Omni, 2 had BRCA2 mutations, 1 had a BRCA1 mutation, 4 had ATM mutations, 1 had a CHEK1 mutation, and 6 had CDK12 mutations. Of 49 pts analyzed by F1CDx, 4 had BRCA mutations; 1 pt had a copy number loss mutation not detected by ctDNA analysis. GEP was not associated with ORR or PSA response. Conclusions: Pembro + olaparib continued to show activity and acceptable safety in pts with docetaxel-pretreated mCRPC. A phase III study of this combination is ongoing (KEYLYNK-010, NCT03834519). Clinical trial information: NCT02861573 .

Study EV-103: New randomized cohort testing enfortumab vedotin as monotherapy or in combination with pembrolizumab in locally advanced or metastatic urothelial cancer

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Background: Cisplatin-based chemotherapy is the standard for first-line (1L) patients (pts) with locally advanced/metastatic urothelial cancer (LA/mUC). PD-1/PD-L1 inhibitors have promising durability of responses but 1L use is restricted to pts ineligible for cisplatin-containing therapy and whose tumors express PD-L1 (CPS ≥10) or pts ineligible for platinum-containing chemotherapy regardless of PD-L1 status. Enfortumab vedotin (EV), an antibody-drug conjugate, delivers the microtubule-disrupting agent monomethyl auristatin E to cells expressing Nectin-4, which is highly expressed in UC. EV recently received FDA accelerated approval based on tumor response rates for adults with LA/mUC who have previously received a PD-1/PD-L1 inhibitor and a platinum-containing chemotherapy. In the ongoing phase 1b/2 study EV-103/KEYNOTE-869 (NCT03288545), the safety and antitumor activity of EV are investigated as monotherapy (mono) (for the first time in the 1L setting) and in combination with PD-1 inhibitor pembrolizumab (P) +/- chemotherapy in UC. An initial analysis of EV (1.25 mg/kg) + P (200 mg) (both drugs in investigational use here) in this study showed a 73.3% confirmed ORR in 45 1L cisplatin-ineligible LA/mUC pts (dose-escalation + expansion Cohort A) (Rosenberg ASCO 2020). Methods: A new Cohort K randomized 1:1 to 1.25 mg/kg EV mono or 1.25 mg/kg EV + 200 mg P provides additional information on EV + P and the contribution of activity from EV in cisplatin-ineligible pts with LA/mUC in the 1L setting. This cohort will enroll 150 adults (≥18 years) with LA/mUC and measurable disease per RECIST v1.1, and exclude pts with prior systemic treatment for LA/mUC, active CNS metastases, ongoing sensory or motor neuropathy (Grade ≥2), or uncontrolled diabetes. Cisplatin-ineligibility in this study is based on ≥1 of the following: ECOG of 2, creatinine clearance of ≥30 and < 60 mL/min, or hearing loss/dysfunction. In each 3-week cycle of this study, EV is administered on days 1 and 8, and P on day 1. The primary endpoint is ORR per RECIST v1.1 by BICR. Secondary endpoints include ORR per RECIST v1.1 by investigator assessment, DOR, DCR, PFS per RECIST v1.1 by BICR and investigator assessment, OS, safety, and tolerability. Sample size is not based on power calculation for formal hypothesis testing but is selected based on ORR estimate precision based on 95% CIs. Efficacy is summarized by treatment arm with no formal statistical comparisons between arms. The study opened in Oct 2017. Cohort K opened in Jan 2020. Clinical trial information: NCT03288545 .

Metastatic penile squamous cell carcinoma with dramatic response to combined checkpoint blockade with ipilimumab and nivolumab

INTRODUCTION

Prognosis for patients with lymph node positive or metastatic penile squamous cell carcinoma remains poor. Chemotherapy with paclitaxel, ifosfamide, and cisplatin (TIP regimen) is recommended as a first-line option in this cohort of patients. No standard preferred subsequent-line therapy exists for patients with relapsed or refractory penile carcinoma following TIP chemotherapy. Molecular pathogenesis of penile cancer can be subdivided into human papilloma virus-dependent and human papilloma virus-independent pathways. Recent studies have demonstrated increased expression of programmed death ligand-1 in some penile tumors, commonly those that are human papilloma virus-negative. Given the rarity of penile carcinoma in industrialized countries and lack of effective therapies, checkpoint inhibitors may be an attractive treatment option for this subset of patients.

CASE REPORT

We report a case of metastatic penile cancer refractory to TIP chemotherapy, with a dramatic treatment response to ipilimumab and nivolumab. Molecular profiling of this tumor showed a high programmed death ligand-1 expression, high tumor mutational burden, high microsatellite instability, and alterations in DNA mismatch repair genes.

DISCUSSION

This case highlights another dimension of information that may be gained with molecular genomic profiling of penile tumors, providing insight into the biologic behavior of this neoplasm and assessing for predictive biomarkers of response to immune checkpoint inhibitors.

KEYNOTE-365 cohort A updated results: Pembrolizumab (pembro) plus olaparib in docetaxel-pretreated patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: KEYNOTE-365 (NCT02861573) is a phase 1b/2 study evaluating pembro + other agents in mCRPC. Updated results from cohort A (pembro + olaparib) are reported. Methods: Docetaxel-pretreated, molecularly unselected pts with mCRPC with progression within 6 mo of screening per PSA or radiologic bone/soft tissue progression enrolled. Pts may have received 1 other chemotherapy and ≤2 2nd-generation hormone therapy (HT). Pts received pembro 200 mg IV Q3W + olaparib 400 mg PO BID. Primary end points: safety, PSA response rate (confirmed PSA decline ≥50%), and ORR per blinded independent central review. Results: Of 84 treated pts, 42 discontinued, primarily due to progression (n=29). Median age was 71 y (range, 47-83); 26% were PD-L1+, 26% had visceral disease, and 57% had RECIST-measurable disease. Median follow-up was 3 mo for all pts (n=81) and 14 mo for pts with ≥27 wks’ follow-up (n=41). See Table for efficacy outcomes. Treatment-related AEs occurred in 70 (83%) pts. Most frequent (≥30%) were nausea (33%) and anemia (31%). Grade 3-5 treatment-related AEs occurred in 29 (35%) pts. Three pts died of AEs (2 treatment related [l myocardial infarction, 1 unknown cause]). Conclusions: With additional follow-up, pembro + olaparib continued to show activity in docetaxel-pretreated, molecularly unselected pts who previously received HT for mCRPC. Safety of the combination was consistent with individual profiles of each agent. Clinical trial information: NCT02861573. [Table: see text]

CCR 20th Anniversary Commentary: Bevacizumab in the Treatment of Glioblastoma--The Progress and the Limitations

Vredenburgh and colleagues conducted the first phase II study of bevacizumab plus irinotecan in recurrent malignant glioma, confirming the safety and efficacy of bevacizumab. This study, which was published in the February 15, 2007, issue of Clinical Cancer Research, was a stepping stone for subsequent research, leading to regulatory approval of bevacizumab for recurrent glioblastoma.

Dual HER2 Blockade in Non-Small Cell Lung Cancer Harboring a HER2 Mutation

Identification of targetable oncogenic mutations in non-small cell lung cancer (NSCLC) has been a major advance in cancer treatment. Laboratory techniques to assess human epidermal growth factor receptor 2 (HER2) positivity in NSCLC include immunohistochemistry (IHC) for protein overexpression, fluorescent in situ hybridization (FISH) for gene amplification, and next generation sequencing (NGS) for HER2 gene mutations. These tests have a controversial prognostic and predictive value, with an emerging association between HER2 gene mutations and treatment response to HER2 targeted therapy. We present a case of a woman with metastatic lung adenocarcinoma with HER2 positivity assessed by IHC and FISH, as well as a high gene copy number noted on NGS. She was observed to have significant disease progression following standard first-line platinum doublet chemotherapy. She was started on dual HER2 blockade in the second-line setting, which yielded a great response in the liver with stable disease elsewhere. To our knowledge, this is the first report describing successful use of dual HER2 blockade in metastatic HER2 positive NSCLC. We also review common laboratory techniques for determining HER2 positivity in NSCLC and their clinical applications.

Recurrent thrombosis prevention with intravenous immunoglobulin and hydroxychloroquine during pregnancy in a patient with history of catastrophic antiphospholipid syndrome and pregnancy loss

We report a case of a 36-year old patient with prior history of thrombosis in a setting of antiphospholipid antibody syndrome (APS) as well as pregnancy-associated catastrophic antiphospholipid syndrome (CAPS), resulting in multi-organ infarction and pregnancy loss. The episode of CAPS occurred while she was receiving antepartum low-dose aspirin and therapeutic-dose enoxaparin. This patient presented again at 6 weeks gestation and ultrasounds were consistent with fetal growth restriction, concerning for placental insufficiency and thrombosis. This time, hydroxychloroquine and monthly intravenous immunoglobulin (IVIG) infusions were added to her prophylaxis regimen, resulting in a successful delivery. Platelet count and antiphospholipid antibody titers were routinely monitored throughout pregnancy as markers of disease activity for APS. Current thromboprophylaxis guidelines do not address therapeutic options to prevent further pregnancy morbidity in women who develop recurrent episodes of thrombosis or CAPS despite receiving adequate anti-thrombotic treatment. Use of hydroxychloroquine and IVIG has been associated with good outcomes in this subset of patients.

Targeting HER2 in the treatment of non-small cell lung cancer

Oncogenic driver mutations have emerged as major treatment targets for molecular therapies in a variety of cancers. HER2 positivity has been well-studied in breast cancer, but its importance is still being explored in non-small cell lung cancer (NSCLC). Laboratory methods for assessment of HER2 positivity in NSCLC include immunohistochemistry (IHC) for protein overexpression, fluorescent in situ hybridization (FISH) for gene amplification, and next generation sequencing (NGS) for gene mutations. The prognostic and predictive significance of these tests remain to be validated, with an emerging association between HER2 gene mutations and response to HER2 targeted therapies. Despite the assay used to determine the HER2 status of lung tumors, all patients with advanced HER2 positive lung adenocarcinoma should be evaluated for treatment with targeted agents. Several clinical approaches for inclusion of these drugs into patient treatment plans exist, but there is no defined algorithm specific to NSCLC.