Faculty Bibliography

BACKGROUND:CAPRA (NCT02565992) evaluated Coxsackievirus A21 (V937) + pembrolizumab for metastatic/unresectable stage IIIB-IV melanoma. METHODS:Patients received intratumoral V937 on days 1, 3, 5, and 8 (then every 3 weeks [Q3W]) and intravenous pembrolizumab 2 mg/kg Q3W from day 8. Primary endpoint was safety. RESULTS:T cells in the tumor microenvironment was significantly lower in responders compared with nonresponders (P = 0.0179). CONCLUSIONS:These findings suggest responses to this combination may be seen even in patients without a typical "immune-active" microenvironment. TRIAL REGISTRATION NUMBER/BACKGROUND:NCT02565992.

The Great Debate session at the 2022 Melanoma Bridge congress (December 1-3) featured counterpoint views from leading experts on five contemporary topics of debate in the management of melanoma. The debates considered the choice of anti-lymphocyte-activation gene (LAG)-3 therapy or ipilimumab in combination with anti-programmed death (PD)-1 therapy, whether anti-PD-1 monotherapy is still acceptable as a comparator arm in clinical trials, whether adjuvant treatment of melanoma is still a useful treatment option, the role of adjuvant therapy in stage II melanoma, what role surgery will continue to have in the treatment of melanoma. As is customary in the Melanoma Bridge Great Debates, the speakers are invited by the meeting Chairs to express one side of the assigned debate and the opinions given may not fully reflect personal views. Audiences voted in favour of either side of the argument both before and after each debate.

BACKGROUND:Overexpression of metabotropic glutamate receptor 1 (GRM1) has been implicated in the pathogenesis of multiple cancers. Riluzole, an inhibitor of glutamate release, showed synergistic antitumor activity in combination with the multi-kinase inhibitor sorafenib in preclinical models. This phase I trial identified the toxicity profile, dose-limiting toxicities, maximum tolerated dose (MTD), and pharmacokinetic and pharmacodynamic properties of riluzole combined with sorafenib in patients with advanced cancers. PATIENTS AND METHODS:Patients with refractory solid tumors were enrolled utilizing a 3+3 dose-escalation design. Riluzole was given at 100 mg PO BID in combination with sorafenib, beginning at 200 mg PO daily and escalating in 200 mg increments per level in 28-day cycles. Restaging evaluations were performed every 2 cycles. RESULTS:35 patients were enrolled over 4 dose levels. The MTD was declared at dose level 3 (riluzole: 100 mg PO BID; sorafenib: 400 mg AM/200 mg PM). Pharmacokinetic analyses did not reveal definitive evidence of drug-drug interactions. Consistent decreases in phospho-forms of ERK and AKT in tumor tissue analyses with accompanying decrease in GRM1 expression and increase in pro-apoptotic BIM suggest target engagement by the combination. Best responses included a partial response in 1 (2.9%) patient with pancreatic acinar cell carcinoma with a KANK4-RAF1 fusion, and stable disease in 11 (36%) patients. CONCLUSION:Combination therapy with riluzole and sorafenib was safe and tolerable in patients with advanced solid tumors. The partial response in a patient with a RAF1 fusion suggests that further exploration in a genomically selected cohort may be warranted.

There is currently no targeted therapy to treat NF1-mutant melanomas. Herein, we compared the genomic and transcriptomic signatures of NF1-mutant and NF1-WT melanoma to reveal potential treatment targets for this subset of patients. Genomic alterations were verified using qPCR, and differentially expressed genes were independently validated using TCGA data, and immunohistochemistry (IHC). Digital spatial profiling (DSP) with multiplex IHC and immunofluorescence (IF) were used to validate the signatures. The efficacy of combinational regimens driven by these signatures was tested through in vitro assays using low-passage cell lines. Pathogenic NF1 mutations were identified in 27% cases. NF1-mutant melanoma expressed higher proliferative markers MK167 and CDC20 compared to NF1-WT (P=0.008), which was independently validated both in the TCGA dataset (P=0.01, P=0.03) and with IHC (P=0.013, P=0.036), respectively. DSP analysis showed upregulation of LY6E within the tumor cells [FDR<0.01, lg2FC>1], confirmed with multiplex IF showing co-localization of LY6E in melanoma cells. The combination of MEK and CDC20 co-inhibition induced both cytotoxic and cytostatic effects, decreasing CDC20 expression in multiple NF1-MUT cell lines. In conclusion, NF1-mutant melanoma is associated with a distinct genomic and transcriptomic profile. Our data support investigating CDC20 inhibition with MAPK pathway inhibitors as a targeted regimen in this melanoma subtype.

BACKGROUND:Disparities in cancer outcomes persist for underserved populations; one important aspect of this is limited access to promising early phase clinical trials. To address this, the National Cancer Institute (NCI) funded Create Access to Targeted Cancer Therapy for Underserved Populations (CATCH-UP.2020). We report the tools developed and accrual metrics of the initial year of CATCH-UP.2020 with a focus on racial, ethnic, geographic and socioeconomically underserved populations. METHODS:CATCH-UP.2020 is a P30 supplement awarded to eight NCI designated cancer centers with existing resources to rapidly open and accrue to Experimental Therapeutics Clinical Trials Network (ETCTN) trials with emphasis on engaging patients from underserved populations. Sites utilized patient-based, community-based, investigator-based, and program-based tools to meet specific program goals. RESULTS:From September 2020 to August 2021, CATCH-UP.2020 sites opened 45 ETCTN trials. Weighted average trial activation time for the 7 sites reporting this was 107 days. In the initial year, sites enrolled 145 patients in CATCH-UP.2020 with 68 (46.9%) representing racial, ethnic, rural and socioeconomically underserved populations using the broader definition of underserved encompassed in the grant charge. During the initial year of CATCH-UP.2020, a time impacted by the COVID-19 pandemic, 15.8% (66/417) and 21.4% (31/145) of patients enrolled to ETCTN trials at network and at CATCH-UP sites respectively, were from racial/ethnic minority groups, a more limited definition of underserved for which comparable data are available. CONCLUSION/CONCLUSIONS:Targeted funding accelerated activation and accrual of early phase trials and expanded access to this therapeutic option for underserved populations.

INTRODUCTION/UNASSIGNED:High-dose interleukin-2 (HD IL-2) and pembrolizumab are each approved as single agents by the U.S. F.D.A. for the treatment of metastatic melanoma. There is limited data using the agents concurrently. The objectives of this study were to characterize the safety profile of IL-2 in combination with pembrolizumab in patients with unresectable or metastatic melanoma. METHODS/UNASSIGNED:In this Phase Ib study, patients received pembrolizumab (200 mg IV every 3 weeks) and escalating doses of IL-2 (6,000 or 60,000 or 600,000 IU/kg IV bolus every 8 hours up to 14 doses per cycle) in cohorts of 3 patients. Prior treatment with a PD-1 blocking antibody was allowed. The primary endpoint was the maximum tolerated dose (MTD) of IL-2 when co-administered with pembrolizumab. RESULTS/UNASSIGNED:Ten participants were enrolled, and 9 participants were evaluable for safety and efficacy. The majority of the evaluable participants (8/9) had been treated with PD-1 blocking antibody prior to enrollment. Patients received a median of 42, 22, and 9 doses of IL-2 in the low, intermediate, and high dose cohorts, respectively. Adverse events were more frequent with increasing doses of IL-2. No dose limiting toxicities were observed. The MTD of IL-2 was not reached. One partial response occurred in 9 patients (11%). The responding patient, who had received treatment with an anti-PD-1 prior to study entry, was treated in the HD IL-2 cohort. DISCUSSION/UNASSIGNED:Although the sample size was small, HD IL-2 therapy in combination with pembrolizumab appears feasible and tolerable. CLINICAL TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov, identifier NCT02748564.

BACKGROUND:Inhibitors of poly(ADP-ribose) polymerase (PARP) proteins potentiate antitumor activity of platinum chemotherapy. This study sought to determine the safety and tolerability of PARP inhibitor talazoparib with carboplatin and paclitaxel. METHODS: days 1, 8, 15 of 21-day cycles in patients with advanced solid tumors. Patients enrolled using a 3 + 3 design in two cohorts with talazoparib for 7 (schedule A) or 3 days (schedule B). After induction with 4-6 cycles of triplet therapy, patients received one of three maintenance options: (a) continuation of triplet (b) carboplatin/talazoparib, or (c) talazoparib monotherapy. RESULTS:Forty-three patients were treated. The MTD for both schedules was talazoparib 250mcg daily. The main toxicity was myelosuppression including grade 3/4 hematologic treatment-related adverse events (TRAEs). Dose modification occurred in 87% and 100% of patients for schedules A and B, respectively. Discontinuation due to TRAEs was 13% in schedule A and 10% in B. Ten out of 22 evaluable patients in schedule A and 5/16 patients in schedule B had a complete or partial response. Twelve out of 43 patients received ≥6 cycles of talazoparib after induction, with a 13-month median duration of maintenance. CONCLUSION/CONCLUSIONS:on days 1, 8, 15 of 21-day cycles. This regimen is associated with significant myelosuppression, and in addition to maximizing supportive care, modification of the chemotherapy component would be a consideration for further development of this combination with the schedules investigated in this study.

Brain metastases are the most common brain malignancy. This review discusses the studies presented at the third annual meeting of the Melanoma Research Foundation in the context of other recent reports on the biology and treatment of melanoma brain metastases (MBM). Although symptomatic MBM patients were historically excluded from immunotherapy trials, efforts from clinicians and patient advocates have resulted in more inclusive and even dedicated clinical trials for MBM patients. The results of checkpoint inhibitor trials were discussed in conversation with current standards of care for MBM patients, including steroids, radiotherapy and targeted therapy. Advances in the basic scientific understanding of melanoma brain metastases, including the role of astrocytes and metabolic adaptations to the brain microenvironment are exposing new vulnerabilities which could be exploited for therapeutic purposes. Technical advances including single cell omics and multiplex imaging are expanding our understanding of the MBM ecosystem and its response to therapy. This unprecedented level of spatial and temporal resolution is expected to dramatically advance the field in coming years and render novel treatment approaches that might improve the MBM patient outcomes.

BACKGROUND:Recent data suggest that patients with stage III melanoma are at high risk for developing central nervous system (CNS) metastases. Because a subset of patients with stage II melanoma experiences worse survival outcomes than some patients with stage III disease, the authors investigated the risk of CNS metastasis in stage II melanoma to inform surveillance guidelines for this population. METHODS:test, the cumulative incidence, and Cox multivariable regression analyses were performed to evaluate the association between baseline characteristics and the development of CNS metastases. RESULTS:Patients with stage III melanoma had a higher rate of developing brain metastases than those with stage II melanoma (100 of 468 patients [21.4%] vs. 82 of 586 patients [14.0%], respectively; p = .002). However, patients who had stage IIC melanoma had a significantly higher rate of isolated first recurrences in the CNS compared with those who had stage III disease (12.1% vs. 3.6%; p = .002). The risk of ever developing brain metastases was similarly elevated for patients who had stage IIC disease (hazard ratio [HR], 3.16; 95% CI, 1.77-5.66), stage IIIB disease (HR, 2.83; 95% CI, 1.63-4.91), and stage IIIC disease (HR, 2.93; 95% CI, 1.81-4.74), and the risk was highest in patients who had stage IIID disease (HR, 8.59; 95% CI: 4.11-17.97). CONCLUSIONS:Patients with stage IIC melanoma are at elevated risk for first recurrence in the CNS. Surveillance strategies that incorporate serial neuroimaging should be considered for these individuals until more accurate predictive markers can be identified.