Bempegaldesleukin Plus Nivolumab in Untreated Advanced Melanoma: The Open-Label, Phase III PIVOT IO 001 Trial Results

PURPOSE

Despite marked advances in the treatment of unresectable or metastatic melanoma, the need for novel therapies remains. Bempegaldesleukin (BEMPEG), a pegylated interleukin-2 (IL-2) cytokine prodrug, demonstrated efficacy in the phase II PIVOT-02 trial. PIVOT IO 001 (ClinicalTrials.gov identifier: NCT03635983) is a phase III, randomized, open-label study that builds on the PIVOT-02 results in first-line melanoma.

METHODS

Patients with previously untreated, unresectable, or metastatic melanoma were randomly assigned 1:1 to receive BEMPEG plus nivolumab (NIVO) or NIVO monotherapy. Primary end points were objective response rate (ORR) and progression-free survival (PFS) by blinded independent central review and overall survival (OS). Secondary and exploratory end points included additional efficacy measures, safety, and pharmacokinetics (PKs) and pharmacodynamics analyses.

RESULTS

In 783 patients (n = 391, BEMPEG plus NIVO; n = 392, NIVO monotherapy), the median follow-up was 11.6 months in the intent-to-treat population. The ORR with BEMPEG plus NIVO was 27.7% versus 36.0% with NIVO (two-sided P = .0311). The median PFS with BEMPEG plus NIVO was 4.17 months (95% CI, 3.52 to 5.55) versus 4.99 months (95% CI, 4.14 to 7.82) with NIVO (hazard ratio [HR], 1.09; 97% CI, 0.88 to 1.35; P = .3988). The median OS was 29.67 months (95% CI, 22.14 to not reached [NR]) with BEMPEG plus NIVO versus 28.88 months (95% CI, 21.32 to NR) with NIVO (HR, 0.94; 99.929% CI, 0.59 to 1.48; P = .6361). Grade 3-4 treatment-related adverse events (AEs) and serious AE rates were higher with the combination (21.7% and 10.1%, respectively) versus NIVO (11.5% and 5.5%, respectively). BEMPEG PK exposure and absolute lymphocyte count changes after BEMPEG plus NIVO were comparable between PIVOT IO 001 and PIVOT-02.

CONCLUSION

The PIVOT IO 001 study did not meet its primary end points of ORR, PFS, and OS. Increased toxicity was observed with BEMPEG plus NIVO versus NIVO.

Outcome and Immune Correlates of a Phase II Trial of High-Dose Interleukin-2 and Stereotactic Ablative Radiotherapy for Metastatic Renal Cell Carcinoma

PURPOSE

This phase II clinical trial evaluated whether the addition of stereotactic ablative radiotherapy (SAbR), which may promote tumor antigen presentation, improves the overall response rate (ORR) to high-dose IL2 (HD IL2) in metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

Patients with pathologic evidence of clear cell renal cell carcinoma (RCC) and radiographic evidence of metastasis were enrolled in this single-arm trial and were treated with SAbR, followed by HD IL2. ORR was assessed based on nonirradiated metastases. Secondary endpoints included overall survival (OS), progression-free survival (PFS), toxicity, and treatment-related tumor-specific immune response. Correlative studies involved whole-exome and transcriptome sequencing, T-cell receptor sequencing, cytokine analysis, and mass cytometry on patient samples.

RESULTS

Thirty ethnically diverse mRCC patients were enrolled. A median of two metastases were treated with SAbR. Among 25 patients evaluable by RECIST v1.1, ORR was 16% with 8% complete responses. Median OS was 37 months. Treatment-related adverse events (AE) included 22 grade ≥3 events that were not dissimilar from HD IL2 alone. There were no grade 5 AEs. A correlation was observed between SAbR to lung metastases and improved PFS (P = 0.0165). Clinical benefit correlated with frameshift mutational load, mast cell tumor infiltration, decreased circulating tumor-associated T-cell clones, and T-cell clonal expansion. Higher regulatory/CD8⁺ T-cell ratios at baseline in the tumor and periphery correlated with no clinical benefit.

CONCLUSIONS

Adding SAbR did not improve the response rate to HD IL2 in patients with mRCC in this study. Tissue analyses suggest a possible correlation between frameshift mutation load as well as tumor immune infiltrates and clinical outcomes.

Comparison of an oncology clinical decision-support system's recommendations with actual treatment decisions

Objective

IBM^(R) Watson for Oncology (WfO) is a clinical decision-support system (CDSS) that provides evidence-informed therapeutic options to cancer-treating clinicians. A panel of experienced oncologists compared CDSS treatment options to treatment decisions made by clinicians to characterize the quality of CDSS therapeutic options and decisions made in practice.

Methods

This study included patients treated between 1/2017 and 7/2018 for breast, colon, lung, and rectal cancers at Bumrungrad International Hospital (BIH), Thailand. Treatments selected by clinicians were paired with therapeutic options presented by the CDSS and coded to mask the origin of options presented. The panel rated the acceptability of each treatment in the pair by consensus, with acceptability defined as compliant with BIH’s institutional practices. Descriptive statistics characterized the study population and treatment-decision evaluations by cancer type and stage.

Results

Nearly 60% (187) of 313 treatment pairs for breast, lung, colon, and rectal cancers were identical or equally acceptable, with 70% (219) of WfO therapeutic options identical to, or acceptable alternatives to, BIH therapy. In 30% of cases (94), 1 or both treatment options were rated as unacceptable. Of 32 cases where both WfO and BIH options were acceptable, WfO was preferred in 18 cases and BIH in 14 cases. Colorectal cancers exhibited the highest proportion of identical or equally acceptable treatments; stage IV cancers demonstrated the lowest.

Conclusion

This study demonstrates that a system designed in the US to support, rather than replace, cancer-treating clinicians provides therapeutic options which are generally consistent with recommendations from oncologists outside the US.

Abstract 2617: Factors associated with utilization of post-mastectomy adjuvant therapies in privately insured female patients with early-stage invasive breast cancer

Background: In a commercially insured cohort of female patients with early-stage invasive breast cancer we examined geographic and clinical factors associated with variation in uptake of post-mastectomy adjuvant endocrine therapy (AET), cytotoxic chemotherapy (ACT) and biologic therapy (ABT).

Methods: Retrospective observational study of the IBM® MarketScan® claims data from 01/01/2012-03/31/2018. Eligibility criteria included: 1) diagnosis of non-metastatic invasive breast cancer in female patients 18 years old or older, 2) mastectomy within 6 months of initial diagnosis. Patients with breast carcinoma in situ only and those who received neoadjuvant therapies were excluded. Multivariate logistic regression was used to identify factors associated with receipt of adjuvant therapy, including: 1) age, insurance plan type, and select chronic comorbid conditions, 2) sociodemographic, community-level (ZIP3) measures obtained from the 2019 Area Health Resource Files, and 3) time effects. Analyses were conducted at the patient level with standard errors clustered by ZIP3.

Results: Of the 16,680 patients identified, 5,341 (32%) received AET only, 2,290 (14%) received ACT only and 729 (4%) received ABT. 7,911 (47%) did not have any claims for adjuvant therapy. 3% received adjuvant combinations, mostly post-radiation treatment (2%). We observed the following statistically significant associations (p<.001 to p<.05) between selected variables and adjuvant therapy use:- Increasing age and higher likelihood of AET (1.2-1.8) but decreased likelihood of ACT (.8-.03) and ABT (.98-.24).- Primary health policy holders were 13% more likely to receive ACT compared to a spouse or other dependent.- Patients residing in the Midwest and higher likelihood of receiving AET (OR=1.15), ACT (OR=1.14), and ABT (OR=1.44) compared to those in the Northeast whereas those in the West and South had higher likelihood of receiving ACT (OR=1.31; OR=1.21), and ABT (OR=1.66; OR=1.36).- Patients residing in areas with increased Black resident density (ZIP3 level) and lower likelihood of receiving AET (OR=.58), ACT (OR=.61), and ABT (OR=.45).- Percentage population with a 4-year college degree and decreased likelihood of ACT (OR=.33).- Genetic testing and increased likelihood of AET (OR=1.92), ACT (OR=2.72), and ABT (OR=1.91).- Breast carcinoma in situ diagnosis preceding invasive disease diagnosis and decreased likelihood of receiving AET (OR=.56), ACT (OR=.2) and ABT (OR=.65).

Conclusions: In a large cohort of commercially insured patients with early-stage invasive breast cancer, uptake of post-mastectomy adjuvant therapies varied and was influenced by several non-clinical factors. Results of real-world evidence cancer studies may support treatment-decision making, guide adoption of value-based care models and reduce treatment disparities.

Citation Format: Yull Arriaga, Joseph Tkacz, M Christopher Roebuck, Judy George, Van Willis, Irene Dankwa-mullan. Factors associated with utilization of post-mastectomy adjuvant therapies in privately insured female patients with early-stage invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2617.

A Narrative Review of Emerging Therapeutics for COVID-19

The novel severe acute respiratory syndrome coronavirus 2, the causal agent of coronavirus disease 2019 (COVID-19), quickly spread around the world, resulting in the most aggressive pandemic experienced in more than 100 years. Research on targeted therapies and vaccines has been initiated on an unprecedented scale and speed but will take months and even years to come to fruition. Meanwhile, the efficacy of emerging therapeutics for use in treating COVID-19 is feverishly being investigated to identify the best available treatment options for dealing with the current wave of disease. This review of publications with a "treatment" tag through June 29, 2020 in the National Library of Medicine's LitCovid literature hub, provides frontline clinicians with a pragmatic summary of the current state of the rapidly evolving evidence supporting emerging candidate therapeutics for COVID-19. Two main categories of pharmaceutical therapeutics are showing promise: those with antiviral activity directly addressing infection and those that counteract the inflammatory cytokine storm induced by severe disease. Preliminary results suggest that other approaches such as convalescent plasma therapy and lung radiation therapy may have some efficacy. The current clinical evidence for potential treatments is preliminary-often small retrospective series or early results of randomized trials-and the science is evolving rapidly. The long-term results from large, well-designed randomized controlled trials will provide definitive evidence for therapeutic effectiveness and are likely months away. The trial landscape for promising therapies is described.

Abstract 6579: Clinical utility of comprehensive genomic testing with artificial-intelligence-based analysis to identify targetable sub-clonal events in relapsed acute myeloid leukemia (AML)

Next-generation sequencing (NGS) is increasingly used to inform diagnostic, therapeutic, and prognostic decisions in AML at the time of first presentation. We highlight the utility of NGS combined with Watson™ for Genomics (WfG), an artificial-intelligence-based decision-support system, in identifying new clinically actionable alterations as a result of clonal evolution in the relapsed disease setting. In less than 3 minutes, WfG identified an IDH1 R132H pathogenic mutation in the relapsed sample sequenced with the Illumina TruSight Tumor 170-gene panel leading to the compassionate use of ivosidenib. In addition, mutations in two genes resulting in increased sensitivity to PARP inhibitors and mutations in PTEN resulting in activation of the MTOR/PI3K signaling pathway were detected by WfG. In February 2018, a previously healthy 23-year old Caucasian female presented with AML consisting of 80% blasts with positive FLT3 mutation. She received induction cytarabine plus daunorubicin (7+3) followed by multikinase inhibitor therapy with midostaurin on days 8 to 21. A 28-day bone marrow biopsy showed persistent disease with 40% blasts. In March 2018, the patient underwent re-induction chemotherapy with mitoxantrone, etoposide, and cytarabine (MEC) followed by midostaurin on days 8 to 21. A bone marrow biopsy after completion of re-induction therapy showed complete remission with < 5% blasts (CR1). In May 2018, a matched donor was not found on a bone marrow registry, and the patient underwent a post-remission dual unrelated umbilical cord blood (UCB) hematopoietic stem cell transplantation (HSCT). Engraftment was not achieved. In July 2018, the patient had disease relapse with the presence of circulating blasts and 7% of blasts in the bone marrow. While NGS is typically not performed on relapsed samples, WfG identified IDH1 R132H and PTEN C78T pathogenic mutations using the 170-gene panel. Based on these results, the patient initiated azacytidine plus the IDH1 inhibitor ivosidenib. In August 2018, a bone marrow biopsy showed less than 5% blasts positive for a FLT3-ITD mutation. In September 2018, the patient underwent reduced-intensity conditioning with fludarabine, cyclophosphamide, and total body irradiation followed by haploidentical allogeneic HSCT from her mother. Maintenance therapy with azacytidine plus ivosidenib was continued until the present time. Currently, the patient is in remission for over 15 months without evidence of AML minimal residual disease. She has developed mild skin chronic graft-versus-host disease that is controlled with standard treatment. She works on a full-time basis and has excellent functional status. The combination of CGP, artificial intelligence, and expert care has resulted in an excellent outcome in a patient with relapsed AML. In conclusion, our experience suggests that CGP testing should be considered at different time points, at least in the relapsed setting, to help treating physicians alter or help improve clinical outcome. CGP testing in a relapsed setting is precluded because it is not covered by payers. In support of optimal care, we have initiated a new program for compassionate use of genomic testing, where such testing is medically necessary, but not covered by insurance or payer supported.

Citation Format: Ravindra Kolhe, Ashis Mondal, Vamsi Kota, Nkhil Sahajpal, Meenakshi Ahluwalia, Allan Njau, Dilhan Weeraratne, Yull Arriaga, David Brotman, Gretchen Jackson, Jane Snowdon. Clinical utility of comprehensive genomic testing with artificial-intelligence-based analysis to identify targetable sub-clonal events in relapsed acute myeloid leukemia (AML) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6579.

Abstract P4-14-05: A systematic review of concordance studies using Watson for Oncology (WfO) to support breast cancer treatment decisions: A four-year global experience

Background: Watson for Oncology (WfO) is an artificial intelligence (AI)-based clinical decision-support system (CDSS) that presents personalized therapeutic options to support cancer-treating physicians in making treatment decisions for cancer patients. WfO was released in 2015, and it has been deployed in over 200 institutions across the world. Many academic centers have examined WfO’s performance by measuring concordance between WfO therapeutic options and treatment recommendations by multidisciplinary tumor boards (MTBs) or individual clinicians (ICs). This study systematically reviewed the results of such concordance studies for breast cancer.

Methods: We conducted a review of the WfO publication database and a PubMed search to identify WfO concordance studies in breast cancer patients, published from 01/01/2015 to 06/30/2019. Studies were excluded if they measured concordance for multiple cancer types but did not include individual concordance for breast cancer. Concordance was defined as agreement between WfO “Recommended” and “For Consideration” treatment options and treatments prescribed by MTBs or ICs. Mean concordance rates were calculated as an average, weighted by the number of patients in each study. Concordance rates between MTBs and ICs were compared with z-test of two proportions. Subgroup analyses for larger studies were summarized.

Results: Table 1 presents the results of nine identified breast cancer concordance studies (4,427 patients) from China, India, and Thailand. Five studies (1,528 patients) determined concordance with MTB and 4 (2,899 patients) with ICs. WfO treatment options were compared to historical treatment recommendations by MTBs and ICs. Mean concordance for all studies was 70.8% (range 55 - 98%). Mean concordance with MTBs of 90.7% (range 79 - 98%) was significantly higher than the concordance between WfO and ICs of 59.9% (range 55-76%) p<0.0001.

Table 1Study/LocationNumber of patientsConcordance Multidisciplinary Tumor Board Studies (MTBs)Zhang XC, et al. Ann Oncol 2017;28:x170 / China11979%Yue L, Yang L. Ann Oncol 2017;28:x162 / China3198%Somashekhar SP, et al. Ann Oncol 2018 1; 29(2):418-423 / India63893%Zhou N, et al. The Oncologist 2018;23:1-8 / China12082%Somashekhar SP, et al. J Clin Oncol 2019; 37 (suppl; abstr 6533) / India62092%MTB subtotals152890.7%Individual Clinicians Studies (ICs)Suwanvecho S, et al. J Clin Oncol 2017;35 (suppl; abstr 6589) / Thailand21176%Jiang Z, et al. J Clin Oncol 2018;36 (suppl; abstr 18566) / China1,99755%Suwanrusme H, et al. J Clin Oncol 2018;36 (suppl; abstr 18584) / Thailand26470%32672%Suwanvecho S et al. J Clin Oncol 2019; 37 (suppl; abstr 6553) / Thailand10160%ICs subtotals289959.9%

Mean concordance in China, Thailand and India were 78.5%, 69.5%, and 92.5%, respectively. A large IC study from China including 1,997 patients found concordance in triple negative, high risk non-metastatic, and metastatic breast cancers of 69%, 66%, and 50%, respectively. A MTB study from China in 120 patients found concordance for luminal A, luminal B and triple negative breast cancers of 63%, 87% and 79%, respectively. Reported reasons for discordance varied among studies and included locally unavailable treatments, individual physician or MTB management preferences, and age older than 75 years.

Conclusions

Overall concordance between the WfO therapeutic options and decisions of both MTBs and ICs was high, demonstrating performance comparable with experts across the world. Higher concordance was observed between WfO and MTBs versus WfO and ICs, likely reflecting the multidisciplinary expertise having greater agreement with evidence and guideline-based recommendations of WfO than decisions of individual clinicians. This finding illustrates a role for clinical decision support in practice. Concordance varied across countries, reflecting the need for localization to address regional differences in practice.

Citation Format: Yull Arriaga, Rezzan Hekmat, Karlis Draulis, Suwei Wang, Winnie Felix, Irene Dankwa-mullan, Kyu Rhee, Gretchen Jackson. A systematic review of concordance studies using Watson for Oncology (WfO) to support breast cancer treatment decisions: A four-year global experience [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-14-05.

HIF-2 Complex Dissociation, Target Inhibition, and Acquired Resistance with PT2385, a First-in-Class HIF-2 Inhibitor, in Patients with Clear Cell Renal Cell Carcinoma

PURPOSE

The heterodimeric transcription factor HIF-2 is arguably the most important driver of clear cell renal cell carcinoma (ccRCC). Although considered undruggable, structural analyses at the University of Texas Southwestern Medical Center (UTSW, Dallas, TX) identified a vulnerability in the α subunit, which heterodimerizes with HIF1β, ultimately leading to the development of PT2385, a first-in-class inhibitor. PT2385 was safe and active in a first-in-human phase I clinical trial of patients with extensively pretreated ccRCC at UTSW and elsewhere. There were no dose-limiting toxicities, and disease control ≥4 months was achieved in 42% of patients.

PATIENTS AND METHODS

We conducted a prospective companion substudy involving a subset of patients enrolled in the phase I clinical trial at UTSW (n = 10), who were treated at the phase II dose or above, involving multiparametric MRI, blood draws, and serial biopsies for biochemical, whole exome, and RNA-sequencing studies.

RESULTS

PT2385 inhibited HIF-2 in nontumor tissues, as determined by a reduction in erythropoietin levels (a pharmacodynamic marker), in all but one patient, who had the lowest drug concentrations. PT2385 dissociated HIF-2 complexes in ccRCC metastases, and inhibited HIF-2 target gene expression. In contrast, HIF-1 complexes were unaffected. Prolonged PT2385 treatment resulted in the acquisition of resistance, and we identified a gatekeeper mutation (G323E) in HIF2α, which interferes with drug binding and precluded HIF-2 complex dissociation. In addition, we identified an acquired TP53 mutation elsewhere, suggesting a possible alternate mechanism of resistance.

CONCLUSIONS

These findings demonstrate a core dependency on HIF-2 in metastatic ccRCC and establish PT2385 as a highly specific HIF-2 inhibitor in humans. New approaches will be required to target mutant HIF-2 beyond PT2385 or the closely related PT2977 (MK-6482).

Blocking Monocytic Myeloid-Derived Suppressor Cell Function via Anti-DC-HIL/GPNMB Antibody Restores the In Vitro Integrity of T Cells from Cancer Patients

PURPOSE

Blocking the function of myeloid-derived suppressor cells (MDSC) is an attractive approach for cancer immunotherapy. Having shown DC-HIL/GPNMB to be the T-cell-inhibitory receptor mediating the suppressor function of MDSCs, we evaluated the potential of anti-DC-HIL mAb as an MDSC-targeting cancer treatment.

EXPERIMENTAL DESIGN

Patients with metastatic cancer (n = 198) were analyzed by flow cytometry for DC-HIL or PDL1 expression on blood CD14+HLA-DRno/lo MDSCs. Their suppressor function was assessed by in vitro coculture with autologous T cells, and the ability of anti-DC-HIL or anti-PDL1 mAb to reverse such function was determined. Tumor expression of these receptors was examined histologically, and the antitumor activity of the mAb was evaluated by attenuated growth of colon cancers in mice.

RESULTS

Patients with metastatic cancer had high blood levels of DC-HIL+ MDSCs compared with healthy controls. Anti-DC-HIL mAb reversed the in vitro function in ∼80% of cancer patients tested, particularly for colon cancer. Despite very low expression on blood MDSCs, anti-PDL1 mAb was as effective as anti-DC-HIL mAb in reversing MDSC function, a paradoxical phenomenon we found to be due to upregulated expression of PDL1 by T-cell-derived IFNγ in cocultures. DC-HIL is not expressed by colorectal cancer cells but by CD14+ cells infiltrating the tumor. Finally, anti-DC-HIL mAb attenuated growth of preestablished colon tumors by reducing MDSCs and increasing IFNγ-secreting T cells in the tumor microenvironment, with similar outcomes to anti-PDL1 mAb.

CONCLUSIONS

Blocking DC-HIL function is a potentially useful treatment for at least colorectal cancer with high blood levels of DC-HIL+ MDSCs.See related commentary by Colombo, p. 453.

Improved Survival Outcomes for Kidney Cancer Patients With Brain Metastases

BACKGROUND

Brain metastases (BM) occur frequently in patients with metastatic kidney cancer and are a significant source of morbidity and mortality. Although historically associated with a poor prognosis, survival outcomes for patients in the modern era are incompletely characterized. In particular, outcomes after adjusting for systemic therapy administration and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk factors are not well-known.

PATIENTS AND METHODS

A retrospective database of patients with metastatic renal cell carcinoma (RCC) treated at University of Texas Southwestern Medical Center between 2006 and 2015 was created. Data relevant to their diagnosis, treatment course, and outcomes were systematically collected. Survival was analyzed by the Kaplan-Meier method. Patients with BM were compared with patients without BM after adjusting for the timing of BM diagnosis, either prior to or during first-line systemic therapy. The impact of stratification according to IMDC risk group was assessed.

RESULTS

A total of 56 (28.4%) of 268 patients with metastatic RCC were diagnosed with BM prior to or during first-line systemic therapy. Median overall survival (OS) for systemic therapy-naive patients with BM compared with matched patients without BM was 19.5 versus 28.7 months (P = .0117). When analyzed according to IMDC risk group, the median OS for patients with BM was similar for favorable- and intermediate-risk patients (not reached vs. not reached; and 29.0 vs. 36.7 months; P = .5254), and inferior for poor-risk patients (3.5 vs. 9.4 months; P = .0462). For patients developing BM while on first-line systemic therapy, survival from the time of progression did not significantly differ by presence or absence of BM (11.8 vs. 17.8 months; P = .6658).

CONCLUSIONS

Survival rates for patients with BM are significantly better than historical reports. After adjusting for systemic therapy, the survival rates of patients with BM in favorable- and intermediate-risk groups were remarkably better than expected and not statistically different from patients without BM, though this represents a single institution experience, and numbers are modest.

Phase 1 study of ARQ 761, a β-lapachone analogue that promotes NQO1-mediated programmed cancer cell necrosis

BACKGROUND

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase expressed in multiple tumour types. ARQ 761 is a β-lapachone (β-lap) analogue that exploits the unique elevation of NQO1 found in solid tumours to cause tumour-specific cell death.

METHODS

We performed a 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ 761 in patients with refractory advanced solid tumours. Tumour tissue was analysed for NQO1 expression. After 20 patients were analysed, enrolment was restricted to patients with NQO1-high tumours (H-score ≥ 200).

RESULTS

A total of 42 patients were treated. Median number of prior lines of therapy was 4. Maximum tolerated dose was 390 mg/m² as a 2-h infusion every other week. Dose-limiting toxicity was anaemia. The most common treatment-related adverse events were anaemia (79%), fatigue (45%), hypoxia (33%), nausea (17%), and vomiting (17%). Transient grade 3 hypoxia, reflecting possible methemoglobinaemia, occurred in 26% of patients. Among 32 evaluable patients, best response was stable disease (n = 12); 6 patients had tumour shrinkage. There was a trend towards improved efficacy in NQO1-high tumours (P = 0.06).

CONCLUSIONS

ARQ 761 has modest single-agent activity, which appears associated with tumour NQO1 expression. Principal toxicities include anaemia and possible methemoglobinaemia.

Practice Patterns and Impact of Postchemotherapy Retroperitoneal Lymph Node Dissection on Testicular Cancer Outcomes

Background

Owing to surgical complexity and controversy regarding indications, there are wide practice variations in the use of postchemotherapy retroperitoneal lymph node dissection (PC-RPLND).

Objective

To evaluate patterns of PC-RPLND use in the USA and evaluate the association between PC-RPLND and survival in advanced nonseminomatous germ cell tumors (NSGCTs).

Design setting and participants

A retrospective, observational study using National Cancer Data Base (NCDB) data from 2004-2014 for 5062 men diagnosed with stage II/III NSGCT.

Outcome measurements and statistical analysis

In a comparative analysis based on receipt of PC-RPLND, the primary outcome of interest was factors associated with omission of PC-RPLND as explored via logistic regression. As a secondary outcome, we evaluated the association between PC-RPLND and overall survival (OS) via multivariable Cox regression and propensity score matching (PSM).

Results and limitations

Patients undergoing PC-RPLND were more likely to be younger, white, privately insured, and reside in more educated/wealthier regions (p < 0.001). Insurance status was independently associated with receipt of PC-RPLND; compared to patients with private insurance, those without insurance were significantly less likely to receive PC-RPLND (odds ratio 0.49; p < 0.001). After multivariate adjustment, age, comorbidity, non-private insurance, distance from hospital, clinical stage, and risk group were independently associated with all-cause mortality. In addition, omission of PC-RPLND remained associated with all-cause mortality (hazard ratio 1.98; p < 0.001). After PSM, the 5-yr OS was significantly lower among those not undergoing PC-RPLND (72% vs 77%; p = 0.007).

Conclusions

PC-RPLND represents a critical part of the multidisciplinary management of NSGCT. Patients with non-private insurance are less likely to undergo PC-RPLND, and omission of PC-RPLND is associated with lower OS.

Patient summary

We evaluated the practice patterns for advanced testicular cancer management and found that patients who did not undergo a postchemotherapy retroperitoneal lymph node dissection were more likely to have worse survival outcomes. Patients with unfavorable insurance were less likely to receive this surgical treatment.

Safety and efficacy of concurrent immune checkpoint inhibitors and hypofractionated body radiotherapy

Integration of hypofractionated body radiotherapy (H-RT) into immune checkpoint inhibitor (ICI) therapy may be a promising strategy to improve the outcomes of ICIs, although sufficient data is lacking regarding the safety and efficacy of this regimen. We, hereby, reviewed the safety and efficacy of this combination in 59 patients treated with H-RT during or within 8 weeks of ICI infusion and compared results with historical reports of ICI treatment alone. Most patients had RCC or melanoma. Median follow-up was 11 months. Most patients received either Nivolumab alone or with Ipilimumab; 83% received stereotactic RT and 17% received conformal H-RT. Any grade adverse events (AEs) were reported in 46 patients, and grade 3-4 in 12 patients without any treatment-related grade 5 toxicity. The most common grade 3 AEs were fatigue and pneumonitis. Grade 3-4 toxicities were higher with ICI combination and with simultaneous ICIs. Overall, most any-grade or grade ≥3 AE rates did not differ significantly from historically reported rates with single-agent or multi-agent ICIs. Toxicity did not correlate with H-RT site, dose, fraction number, tumor type, or ICI and H-RT sequencing. Median progression-free survival was 6.5 months. Objective response rate (ORR) was 26%; 10% had complete response (CR). Median duration of response was 9.4 ± 4.6 months. H-RT of lung lesions was more likely to achieve CR than other sites. H-RT of bone lesions had a lower ORR than non-bone H-RT. In conclusion, combining body H-RT with ICIs is safe and promising. Prospective validation is warranted.

Abstract 3660: Blocking the DC-HIL receptor reverses the T-cell suppression induced by proliferating myeloid-derived suppressor cells in common cancer types

Myeloid-derived suppressor cells (MDSC) are the most potent suppressors of T-cell function, and their exponential proliferation in cancer states counteracts the benefits of immunotherapy given to these patients. Having discovered the T cell-inhibitory DC-HIL receptor, we showed that DC-HIL is responsible for MDSC’s T-cell suppressive function. We found that melanoma patients (but not healthy controls) harbor in the blood an expanded population of DC-HIL+ MDSC, whose suppressor effects in vitro can be blocked by our 3D5 anti-DC-HIL mAb. To determine whether similar outcomes apply to non-melanoma cancers, we recruited patients with metastases from bladder (BL, n=4), breast (BR, n=11), colon (CO, n=44), kidney (KI, n=6), lung (LU, n=20), pancreatic (PA, n=17), and prostate (PR, n=9) cancer. FACS analysis of blood samples showed all cancer types (except LU) were associated with elevated blood HLA-DRno/low CD14+ MDSC vs. age-matched controls (n=21, median of 0.5%). % DC-HIL+ MDSC in PBMC was also significantly high in all cancer types; median of 2.5% for BL; 1.7% for BR; 3.5% for CO; 3.6% for KI; 0.3% for LU; 1.8% for PA; and 4.8% for PR, vs. 0.04% for healthy controls. MDSC in all cancer types showed high DC-HIL-positivity (20-90% vs. 8% for controls). We assayed T-cell suppressor activity by purifying MDSC and T-cells from the same patient and co-culturing them at varying cell ratios, with co-stimulators. Activity was determined by % suppression in IFN-γ secretion, which was correlated with % DC-HIL-positivity of MDSC. MDSC from KI (n=3) were more suppressive than those from CO and PA, with suppressor activity correlating with DC-HIL-positivity: Pearson’s r for 0.5 for CO (n=13) and 0.73 for PA (n=8). We evaluated effects of anti-DC-HIL mAb on co-cultures of MDSC/ T-cells from cancer patients (n=25). The mAb restored IFN-γ secretion by &gt;30% in 8/15 cases of CO; 4/8 of PA, and 2/2 of KI. To determine whether DC-HIL+ MDSC migrate into cancer sites, lesional specimens from CO patients (n=5) with high blood counts of DC-HIL+ MDSC were immunohistochemically stained for CD14 and DC-HIL expression: DC-HIL was absent from all cancer cells, but present strongly in many CD14+ cells surrounding the cancers. This outcome contrasts starkly with melanoma, in which DC-HIL was expressed highly by the cancer cells surrounded by only a few DC-HIL+ CD14+ cells. Finally we evaluated in vivo effects of blocking DC-HIL using a mouse model of MC38 colon cancer, which is DC-HILneg. MC38 tumor challenge induced DC-HIL+ Gr1lowLy6Chigh MDSC in the tumor site. Intravenous infusion of anti-DC-HIL mAb into mice with pre-established MC38 tumor significantly inhibited tumor growth by 50-70%, reduced blood levels of MDSC, and enhanced cytotoxic T-lymphocyte response. Our findings support DC-HIL blockade as a potential treatment for metastatic cancers, with high blood levels of DC-HIL+ MDSC as a prognostic marker for the best responders.

Citation Format: Masato Kobayashi, Jin-Sung Chung, Muhammad Beg, Yull Arriaga, Udit Verma, Kevin Courtney, John Mansour, Barbara Haley, Saad Khan, Yutaka Horiuchi, David Harker, Purva Gopal, Ponciano D. Cruz, Kiyoshi Ariizumi. Blocking the DC-HIL receptor reverses the T-cell suppression induced by proliferating myeloid-derived suppressor cells in common cancer types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3660. doi:10.1158/1538-7445.AM2017-3660

Changing trends in utilization of neoadjuvant chemotherapy in muscle-invasive bladder cancer

INTRODUCTION

To reassess use of perioperative chemotherapy in muscle-invasive bladder cancer (MIBC) following implementation of monthly multidisciplinary meetings to facilitate optimal oncologic treatment. We previously reported from 2003 to 2008 17% of eligible patients with bladder cancer received cisplatin-based neoadjuvant chemotherapy (NAC) at our institution.

MATERIALS AND METHODS

A retrospective review of all patients who underwent radical cystectomy (RC) between 2008 and 2012 was performed. Information on clinical and pathologic stage, renal function, perioperative chemotherapy (CTX) use and oncologic outcomes was collected. Rationale for utilization decisions was obtained from physician encounter notes. Primary outcome was use of CTX among eligible patients. Secondary measures were type of CTX, pathologic and survival outcomes.

RESULTS

Among 261 patients undergoing RC for bladder cancer, 162 were eligible for NAC. Overall 40.7% (n = 66) received NAC, and 86.4% were given platinum. Patients given NAC were younger and had more advanced clinical stage. The degree of chronic kidney disease (CKD) (0-3) did not impact likelihood of receiving NAC. NAC patients were more likely to be downstaged to non-muscle-invasive disease (21.2% versus 7.3% p < 0.01) or have a complete pathologic response (12.1% versus 3.1% p = 0.025). Receipt of NAC did not affect oncologic outcomes. Following RC 22.3% of high risk patients (n = 112) received adjuvant chemotherapy (AC).

CONCLUSIONS

Our use of cisplatin-based NAC improved from 17% to 35% and overall utilization of NAC increased from 22% to 41%. NAC led to improved pT0 rates and increased pathologic downstaging. The degree of CKD (0-3) did not impact likelihood of receiving NAC. AC use decreased in part due to higher utilization of NAC.

Shorter bevacizumab infusions do not increase the incidence of proteinuria and hypertension

BACKGROUND

A previous study has shown that shorter bevacizumab infusions (0.5 mg/kg/min) can be safely administered without increasing the risk of infusion-related hypersensitivity reactions (HSRs). However, the risk of proteinuria and hypertension in patients receiving shorter infusions of bevacizumab is undetermined.

PATIENTS AND METHODS

This was a multicenter, prospective, observational study in patients receiving <10 mg/kg of bevacizumab infused over 0.5 mg/kg/min. Patients were observed until discontinuation of bevacizumab for progression of cancer or toxicity. The incidence of hypertension and proteinuria was compared with a prior cohort of patients who had received standard duration infusions of bevacizumab.

RESULTS

Sixty-three patients received a total of 392 doses of shorter bevacizumab infusions. Nineteen (30.2%) patients experienced proteinuria while receiving bevacizumab. Out of 19 patients, 13 had grade 1 and 6 had grade 2 proteinuria. None of the patients experienced grade 3 or 4 proteinuria. Hypertension was reported in 32 (50.8%) patients receiving bevacizumab. Twelve (19%) patients developed grade 3 or greater hypertension on bevacizumab. The incidence of proteinuria and hypertension was 38.3% and 56.6%, respectively, in patients (N = 120, 1347 infusions) receiving standard duration infusions of bevacizumab.

CONCLUSIONS

Shorter bevacizumab infusions (0.5 mg/kg/min) do not increase the risk of proteinuria and hypertension.

Adverse effects of bevacizumab and their management in solid tumors

Bevacizumab is the first successful example of targeting the vasculature for the treatment of solid tumors. Although generally well tolerated in combination with different chemotherapy regimens, bevacizumab has side effects that are unique to this class of agents. In this review, we discuss the side effects associated with bevacizumab and potential treatments to ameliorate these toxicities.

Conservative management in selected patients with upper tract urothelial carcinoma compares favourably with early radical surgery

OBJECTIVE

To compare the outcomes of patients treated for upper tract urothelial carcinoma with either immediate nephroureterectomy (NU) or initial endoscopic management.

PATIENTS AND METHODS

The treatments of 108 patients (120 renal units) at the authors' institution were retrospectively reviewed and divided into two groups, i.e. those who received immediate NU and those who had conservative initial therapy, which included renal units solely treated with endoscopy with or without delayed NU. Overall and disease-specific survival (DSS) were compared between the treatment groups.

RESULTS

There were 48 low-grade tumours, of which 27 (56%) were managed conservatively and 21 (44%) by immediate NU. Seven patients treated conservatively had stage or grade progression and had delayed NU. The mean (sd) DSS at 5 years in patients with low-grade disease was equally good for conservative treatment and immediate NU, at 86.2 (9.1)% vs 87.4 (8.4)% (P = 0.909). There were 68 high-grade tumours, of which 12 (18%) patients had conservative management and 56 (82%) had immediate NU. Among the former, seven of 12 had a solitary kidney and three had bilateral disease. In patients managed endoscopically, four of 30 (13%) required delayed NU. The DSS for the conservative and immediate NU groups were 68.6 (18.6)% vs 75.0 (8.1)% (P = 0.528).

CONCLUSION

Management with a conservative approach in selected patients provides comparable outcomes to immediate NU in patients with low-grade disease.

Influence of the suture in the propagation of tears in calf pericardium employed in the construction of cardiac bioprostheses

The tearing of the fibers of biomaterials employed in implants or bioprostheses leads to early the failure of these devices. The purpose of this study was to determine the force necessary to propagate a tear in a biological tissue, calf pericardium, when sutured. We analyzed the outcome of 230 trials. There was a loss of resistance to tearing in samples sutured edge-to-edge as compared to unsutured control samples. This loss was not observed when the suture was preceded by an intact or protective zone. The values corresponding to the tearing force for an overlapping suture, especially when sewn with Gore-Tex(R), were higher than those obtained in controls. This study confirms the deleterious effect of the edge-to-edge suture, which can be minimized by protecting the suture, and the excellent behavior of the overlapping suture.