A General Approach to Patients Presenting With Locally Advanced or Distant Metastatic Disease

ABSTRACT

The widespread adoption of immune checkpoint inhibitors and small molecule inhibitors of the MAP kinase pathway has transformed the management of locally advanced and metastatic melanoma. Here, we provide a broad overview on the use of these agents in the first-line setting, incorporating a review of the clinical literature as well as the practice patterns of our respective melanoma groups. Throughout, we highlight areas of uncertainty that provide opportunities for future clinical investigation and additional improvement in outcomes for patients with melanoma.

Phase Ib Trial of Phenformin in Patients with V600-mutated Melanoma Receiving Dabrafenib and Trametinib

PURPOSE

Preclinical studies show that activation of AMP kinase by phenformin can augment the cytotoxic effect and RAF inhibitors in BRAF V600-mutated melanoma. We conducted a phase Ib dose-escalation trial of phenformin with standard dose dabrafenib/trametinib in patients with metastatic BRAF V600-mutated melanoma.

EXPERIMENTAL DESIGN

We used a 3+3 dose-escalation design which explored phenformin doses between 50 and 200 mg twice daily. Patients also received standard dose dabrafenib/trametinib. We measured phenformin pharmacokinetics and assessed the effect of treatment on circulating myeloid-derived suppressor cells (MDSC).

RESULTS

A total of 18 patients were treated at dose levels ranging from 50 to 200 mg twice daily. The planned dose-escalation phase had to be cancelled because of the COVID 19 pandemic. The most common toxicities were nausea/vomiting; there were two cases of reversible lactic acidosis. Responses were seen in 10 of 18 patients overall (56%) and in 2 of 8 patients who had received prior therapy with RAF inhibitor. Pharmacokinetic data confirmed drug bioavailability. MDSCs were measured in 7 patients treated at the highest dose levels and showed MDSC levels declined on study drug in 6 of 7 patients.

CONCLUSIONS

We identified the recommended phase II dose of phenformin as 50 mg twice daily when administered with dabrafenib/trametinib, although some patients will require short drug holidays. We observed a decrease in MDSCs, as predicted by preclinical studies, and may enhance immune recognition of melanoma cells.

SIGNIFICANCE

This is the first trial using phenformin in combination with RAF/MEK inhibition in patients with BRAF V600-mutated melanoma. This is a novel strategy, based on preclinical data, to increase pAMPK while blocking the MAPK pathway in melanoma. Our data provide justification and a recommended dose for a phase II trial.

Beyond the 5-year milestone: Long-term survivorship of melanoma patients treated off-trial with anti-PD-1

Little is known about the long-term outcomes of anti-PD-1 treated patients with melanoma beyond 5 years, especially for patients treated off clinical trials. This retrospective cohort study includes patients with unresectable stage III/IV nonuveal melanoma treated with anti-PD-1 off-trial at Memorial Sloan Kettering Cancer Center between 2014 and 2017 who survived at least 5 years following their first anti-PD-1 dose (N = 139). We characterized overall survival (OS), melanoma-specific survival (MSS) estimates, treatment-free survival rates, and subsequent treatment courses. Median follow-up among 5-plus year survivors (N = 125) was 78.4 months (range 60.0-96.3). OS at year 7 (2 years post 5-year landmark) was 90.1% (95% CI: 83.0%-94.3%). Fourteen deaths occurred, seven due to melanoma. MSS at year 7 (2 years post 5-year landmark) was 95.0% (95% CI: 33.5%-95.2%). In patients who completed anti-PD-1 based therapy and did not require subsequent treatment by 5 years (N = 80), the probability of not requiring additional treatment for an additional 2 years was 95.7% (95% CI: 91.0%-100%). Patients treated with anti-PD-1 regimens off clinical trials who survive at least 5 years from initial anti-PD-1 treatment can be reassured of their excellent long-term prognosis, particularly if they did not require additional melanoma treatment during the first 5 years.

Decision-Making and Health-Related Quality of Life in Patients with Melanoma Considering Adjuvant Immunotherapy

BACKGROUND

Adjuvant anti-PD1 treatment improves relapse-free survival (RFS) but has not been shown to improve overall survival (OS) in melanoma and is associated with risks of immune-related adverse events (irAEs), some permanent. We identified factors patients consider in deciding whether to undergo adjuvant anti-PD1 treatment and assessed prospective health-related quality of life (HRQoL), treatment satisfaction, and decisional regret.

PATIENTS AND METHODS

Patients with stage IIIB-IV cutaneous melanoma and free of disease, were candidates for adjuvant anti-PD1 immunotherapy, and had not yet discussed adjuvant treatment options with their oncologist were eligible. Participants viewed a 4-minute informational video tailored to their disease stage which communicated comprehensive, quantitative information about the risk of relapse both with and without adjuvant treatment, and risks of each irAE before deciding whether or not to opt for adjuvant therapy. We collected data on demographics, HRQoL, and attitudes toward adjuvant treatment over 1 year.

RESULTS

14/34 patients (41%) opted for adjuvant anti-PD1 immunotherapy, 20/34 (59%) opted for observation. Patients choosing adjuvant immunotherapy scored higher on HRQoL social well-being at pre-treatment, were more likely to endorse positive statements about adjuvant immunotherapy, and to perceive that their physician preferred adjuvant therapy. They had lower decisional regret and higher satisfaction, even if they experienced toxicity or recurrence.

CONCLUSIONS

When provided with comprehensive quantitative information about risks and benefits of adjuvant anti-PD1 immunotherapy, 20/34 (59%) of patients opted for observation. Patients choosing adjuvant immunotherapy had lower decisional regret and higher satisfaction over time even if they had poorer outcomes in treatment.

Adaptive Dosing of Nivolumab + Ipilimumab Immunotherapy Based Upon Early, Interim Radiographic Assessment in Advanced Melanoma (The ADAPT-IT Study)

PURPOSE

Nivolumab + ipilimumab (nivo + ipi) is highly efficacious but has high toxicity. Standard treatment in advanced melanoma is four doses of nivo + ipi followed by nivo alone. Whether four doses of nivo + ipi are needed is unclear.

METHODS

The Adaptively Dosed ImmunoTherapy Trial (ADAPT-IT) study (NCT03122522) is a multicenter, single-arm phase II clinical trial. Patients received two doses of nivo (1 mg/kg) + ipi (3 mg/kg) followed by a computed tomography scan at week 6. Patients without new lesions or index lesion tumor growth of > 4% had protocol-defined early favorable antitumor effect (FATE) and ceased nivo + ipi, transitioning to nivo monotherapy. Patients without FATE at week 6 received the standard third and fourth doses of nivo + ipi followed by nivo monotherapy. The primary end point was response rate by RECIST 1.1 at week 12. Secondary end points included additional efficacy assessments and safety.

RESULTS

Sixty patients were enrolled; 41 patients (68%) had FATE at week 6 and met criteria for stopping nivo + ipi. Best overall response rates by RECIST at week 12 or any time afterward were 48% (95% CI, 35 to 62) and 58% (95% CI, 45 to 71), respectively. With a median follow-up of 25 months, the estimated 18-month progression-free survival and overall survival are 52% and 80%, respectively. Fifty seven percent of patients had grade 3-5 treatment-related toxicity.

CONCLUSION

The efficacy and toxicity of standard four dose nivo + ipi induction therapy in melanoma is likely driven by the first two doses. An interim computed tomography scan after two doses guided cessation of combination dosing and identified almost all responders. Longer follow-up and further study are needed to fully understand the implications of a shortened induction course of nivo + ipi.

Risks and benefits of reinduction ipilimumab/nivolumab in melanoma patients previously treated with ipilimumab/nivolumab

BACKGROUND

In melanoma patients who progress after prior ipilimumab/nivolumab (ipi/nivo) combination immunotherapy, there is no information regarding the risks and benefits of reinduction ipi/nivo.

METHODS

This was a retrospective review of 26 melanoma patients treated at Memorial Sloan Kettering Cancer Center (MSKCC) since 2012 who received reinduction ipi/nivo at least 6 months following completion of an initial course of ipi/nivo. We collected data on demographics, genetics, immune-related adverse events (irAEs), best overall responses (BORs), time to treatment failure (TTF) and overall survival (OS).

RESULTS

The BOR rate (complete response+partial response) was 74% (95% CI 52% to 90%) after the first course of ipi/nivo but only 23% (95% CI 8% to 45%)) after reinduction. Response to reinduction did not correlate with response to the initial course. Among the 16 patients who had an objective response to the first course, only four (25%) responded to reinduction. Of five patients who did not respond to the first course, one responded to reinduction. For all patients, median TTF was 5.3 months after reinduction; TTF was shorter for reinduction than for the first course in 85% of patients. Median OS from reinduction was 8.4 months; estimated 2-year OS was 18%. Although reinduction was associated with fewer irAEs than the initial course of ipi/nivo (58% of patients vs 85% of patients in the initial course), eight (31%) patients experienced at least one new irAE after the second course.

CONCLUSIONS

BOR rate and TTF were markedly less favorable after reinduction with ipi/nivo than after the initial course of ipi/nivo. Reinduction ipi/nivo was associated with frequent irAEs although less frequent than for the initial course.

LAG-3 expression on peripheral blood cells identifies patients with poorer outcomes after immune checkpoint blockade

Immune checkpoint blocking antibodies are a cornerstone in cancer treatment; however, they benefit only a subset of patients and biomarkers to guide immune checkpoint blockade (ICB) treatment choices are lacking. We designed this study to identify blood-based correlates of clinical outcome in ICB-treated patients. We performed immune profiling of 188 ICB-treated patients with melanoma using multiparametric flow cytometry to characterize immune cells in pretreatment peripheral blood. A supervised statistical learning approach was applied to a discovery cohort to classify phenotypes and determine their association with survival and treatment response. We identified three distinct immune phenotypes (immunotypes), defined in part by the presence of a LAG-3⁺CD8⁺ T cell population. Patients with melanoma with a LAG⁺ immunotype had poorer outcomes after ICB with a median survival of 22.2 months compared to 75.8 months for those with the LAG^- immunotype (P = 0.031). An independent cohort of 94 ICB-treated patients with urothelial carcinoma was used for validation where LAG⁺ immunotype was significantly associated with response (P = 0.007), survival (P < 0.001), and progression-free survival (P = 0.004). Multivariate Cox regression and stratified analyses further showed that the LAG⁺ immunotype was an independent marker of outcome when compared to known clinical prognostic markers and previously described markers for the clinical activity of ICB, PD-L1, and tumor mutation burden. The pretreatment peripheral blood LAG⁺ immunotype detects patients who are less likely to benefit from ICB and suggests a strategy for identifying actionable immune targets for further investigation.

Characteristics and probability of survival for patients with advanced melanoma who live five or more years after initial treatment with immune checkpoint blockade (ICB)

9534

Background: A subset of melanoma patients treated with ICB (ipilimumab [ipi], nivolumab [nivo], pembrolizumab [pembro] or nivo+ipi) will experience durable responses. While five-year survival rates have been reported for patients treated with ICB on clinical trials, little is known about the clinical characteristics, survival past five years, and patterns of late relapse of long-term survivors. Methods: We retrospectively reviewed all patients treated at Memorial Sloan Kettering for unresectable stage III/IV melanoma who survived at least five years following their first dose of ICB (N = 151). Demographics, disease characteristics, and nature of progression were examined. Overall survival (OS) was calculated from 5 years post-ICB. Time to Treatment failure (TTF) was calculated conditionally from 5 years out until next therapy, progression, or death. Results: Of the 151 long-term survivors, median age at first ICB treatment was 62 years (range 22-83), with 101 (66.9%) male and 50 (33.1%) female patients. Stage at first ICB treatment was unresectable stage III (26, 17.2%), M1a (21,13.9%), M1b (39, 25.8%), M1c (52, 34.4%), M1d (13, 8.6%). Melanoma subtype was cutaneous (122, 80.8%), unknown primary (24, 15.9%), mucosal (3, 2%), and acral (2, 1.3%). First ICB was ipi (108, 71.5%), PD-1 (nivo or pembro) (5, 3.3%), and nivo+ipi (37, 24.5%). The best overall response to first ICB was CR (76, 50.3%), PR (27, 17.9%), SD (16, 10.6%) and PD (32, 21.2%). Of the patients who progressed after initial ICB, 38 received subsequent systemic treatment as follows: PD-(L)1 in 20 (53%), BRAF ± MEK in 9 (23.7%), ipi in 7 (18.4%), and chemotherapy in 2 (5.3%). Median duration of follow-up among survivors (N = 138) was 93 months (range 60-192). From 5 years post-ICB, 85% (95% CI: 73-92%) survived an additional 5 years. In those who made it to 5 years without treatment failure (N = 72), the probability of remaining failure-free was 92% (95% CI: 86-99%) at 7 years. Of the 151 patients, only 4 patients (2.6%) experienced disease progression after 5 years. Three patients had radiographic or pathologic disease progression in the lymph nodes and one in the subcutaneous tissue. No patients progressed in the lungs, visceral organs, or CNS after 5 years. At time of analysis, 13 (8.6%) patients died after 5 years post ICB, none died of progressive melanoma. 6 patients died of unknown causes, 2 died of other causes, and 5 died of other non-melanoma cancer-related causes. Conclusions: Patients who survive five years after their initial immunotherapy have excellent overall survival and treatment failure-free survival. Given the anxiety surrounding survivorship and late progression, long-term survivors should be reassured of their excellent prognosis. These data suggest that aggressive follow-up schedules and imaging of melanoma patients after 5 years of survival may not be required.

The Genetic Evolution of Treatment-Resistant Cutaneous, Acral, and Uveal Melanomas

PURPOSE

Melanoma is a biologically heterogeneous disease composed of distinct clinicopathologic subtypes that frequently resist treatment. To explore the evolution of treatment resistance and metastasis, we used a combination of temporal and multilesional tumor sampling in conjunction with whole-exome sequencing of 110 tumors collected from 7 patients with cutaneous (n = 3), uveal (n = 2), and acral (n = 2) melanoma subtypes.

EXPERIMENTAL DESIGN

Primary tumors, metastases collected longitudinally, and autopsy tissues were interrogated. All but 1 patient died because of melanoma progression.

RESULTS

For each patient, we generated phylogenies and quantified the extent of genetic diversity among tumors, specifically among putative somatic alterations affecting therapeutic resistance.

CONCLUSIONS

In 4 patients who received immunotherapy, we found 1-3 putative acquired and intrinsic resistance mechanisms coexisting in the same patient, including mechanisms that were shared by all tumors within each patient, suggesting that future therapies directed at overcoming intrinsic resistance mechanisms may be broadly effective.

Safety and efficacy of combination nivolumab plus ipilimumab in patients with advanced melanoma: results from a North American expanded access program (CheckMate 218)

CheckMate 218, a North American expanded access program (EAP), investigated nivolumab plus ipilimumab in patients with advanced melanoma. Safety and efficacy, including 2-year survival in clinically relevant patient subgroups, are reported. Eligible patients were aged ≥18 years with unresectable stage III/IV melanoma, an Eastern Cooperative Oncology Group performance status of 0/1, and no prior checkpoint inhibitors. Patients received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for 4 cycles (induction) followed by nivolumab 3 mg/kg every 2 weeks (maintenance) until progression or unacceptable toxicity or a maximum of 48 weeks. Safety and overall survival (OS) data were collected. This EAP included 754 treated patients from the USA (n = 580) and Canada (n = 174). Median follow-up time was 17.8 months. All-grade and grade 3-4 treatment-related adverse events were reported in 96% and 53% of patients and led to treatment discontinuation in 36% and 26% of patients, respectively. OS rates at 12 and 24 months were 82% [95% confidence interval (CI) 79-84] and 70% (95% CI 66-74), respectively. Twenty-four-month OS rates were 63% in patients aged ≥75 years, 56% in patients with elevated lactate dehydrogenase levels, 73% in patients with BRAF wild-type tumors, 70% in patients with BRAF mutant tumors, and 56% in patients with mucosal melanoma. In this EAP, nivolumab plus ipilimumab demonstrated high survival rates and safety outcomes consistent with those from randomized clinical trials, further supporting the use of this combination for advanced melanoma across multiple subgroups.

Therapeutic Implications of Detecting MAPK-Activating Alterations in Cutaneous and Unknown Primary Melanomas

PURPOSE

Cutaneous and unknown primary melanomas frequently harbor alterations that activate the MAPK pathway. Whether MAPK driver detection beyond BRAF V600 is clinically relevant in the checkpoint inhibitor era is unknown.

EXPERIMENTAL DESIGN

Patients with melanoma were prospectively offered tumor sequencing of 341-468 genes. Oncogenic alterations in 28 RTK-RAS-MAPK pathway genes were used to construct MAPK driver groups. Time to treatment failure (TTF) was determined for patients who received first-line programmed cell death protein 1 (PD-1) monotherapy, nivolumab plus ipilimumab, or subsequent genomically matched targeted therapies. A Cox proportional hazards model was constructed for TTF using driver group and clinical variables.

RESULTS

A total of 670 of 696 sequenced melanomas (96%) harbored an oncogenic RTK-RAS-MAPK pathway alteration; 33% had ≥1 driver. Nine driver groups varied by clinical presentation and mutational burden. TTF of PD-1 monotherapy (N = 181) varied by driver, with worse outcomes for NRAS Q61 and BRAF V600 versus NF1 or other alterations (median 4.2, 7.5, 22, and not reached; P < 0.0001). Driver group remained significant, independent of tumor mutational burden and clinical features. TTF did not vary by driver for nivolumab plus ipilimumab (N = 141). Among 172 patients with BRAF V600 wild-type melanoma who progressed on checkpoint blockade, 27 were treated with genomically matched therapy, and eight (30%) derived clinical benefit lasting ≥6 months.

CONCLUSIONS

Targeted capture multigene sequencing can detect oncogenic RTK-RAS-MAPK pathway alterations in almost all cutaneous and unknown primary melanomas. TTF of PD-1 monotherapy varies by mechanism of ERK activation. Oncogenic kinase fusions can be successfully targeted in immune checkpoint inhibitor-refractory melanoma.

The State of Melanoma: Emergent Challenges and Opportunities

Five years ago, the Melanoma Research Foundation (MRF) conducted an assessment of the challenges and opportunities facing the melanoma research community and patients with melanoma. Since then, remarkable progress has been made on both the basic and clinical research fronts. However, the incidence, recurrence, and death rates for melanoma remain unacceptably high and significant challenges remain. Hence, the MRF Scientific Advisory Council and Breakthrough Consortium, a group that includes clinicians and scientists, reconvened to facilitate intensive discussions on thematic areas essential to melanoma researchers and patients alike, prevention, detection, diagnosis, metastatic dormancy and progression, response and resistance to targeted and immune-based therapy, and the clinical consequences of COVID-19 for patients with melanoma and providers. These extensive discussions helped to crystalize our understanding of the challenges and opportunities facing the broader melanoma community today. In this report, we discuss the progress made since the last MRF assessment, comment on what remains to be overcome, and offer recommendations for the best path forward.

Checkpoint Blockade in Melanoma Patients With Underlying Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is associated with immune dysfunction and an increased risk of melanoma. For patients with metastatic melanoma, immunotherapy with checkpoint blocking antibodies is a standard of care. In patients with concomitant CLL and metastatic melanoma, it is not known whether CLL might influence the antimelanoma efficacy or immune-related toxicities of immune checkpoint blockade. Fifteen patients with locally advanced or metastatic melanoma and a concomitant diagnosis of CLL who received pembrolizumab or ipilimumab with or without nivolumab for the treatment of their melanoma at Memorial Sloan Kettering Cancer Center between January 1, 2010, and January 1, 2017, were retrospectively identified. Clinical characteristics including absolute lymphocyte counts during therapy were recorded along with a response to treatment (objective radiographic response, progression-free survival, and adverse events) for each patient. Of 9 response-evaluable patients treated with ipilimumab, 3 (33%) had a partial response, 1 (11%) had stable disease, and 5 (56%) developed progressive disease. Objective tumor responses were also observed with single-agent therapy pembrolizumab and with combination therapy of nivolumab and ipilimumab. Grade 3 or 4 toxicity was observed in 6 of 15 patients (40%), including diarrhea, transaminitis, rash, and hemolytic anemia. Although our retrospective assessment was limited, there was no evidence that CLL responded to the checkpoint blockade. This case series demonstrates that ipilimumab, pembrolizumab, and combined ipilimumab and nivolumab therapies show clinical activity in patients with melanoma and concomitant CLL, at rates consistent with those previously reported. This population may warrant closer surveillance for hematologic immune-related toxicities such as autoimmune hemolytic anemia.

Abstract IA10: Targeting melanoma metabolism to overcome resistance to treatment

Despite adequate oxygen levels, cancer cells undergo anaerobic glycolysis converting glucose to lactate (the Warburg effect). It is now thought that the advantage of this for the cancer cell is that it provides the carbon and nitrogen precursors critical for macromolecule synthesis (amino acids, nucleotides, fatty acids) while still providing an adequate supply of ATP needed for growth. Understanding this metabolic landscape may provide strategies to overcome mechanisms of resistance to therapy in melanoma. AMP-activated protein kinase (AMPK) has been shown to inactivate BRAF by phosphorylating Ser 729, and in preclinical models, this can be used to enhance inhibitors of BRAFV600E. In the high ATP environment of a melanoma cell, AMPK is typically low but inducers of AMPK, such as biguanides, increase AMPK. The biguanide metformin does not enter melanoma cells efficiently due to the lack of organic cation transporter (OCT) expression on melanoma cells. However, phenformin does not require OCT for uptake. We are conducting a phase I trial in BRAF V600E-mutated melanoma patients using dabrafenib/trametinib and escalating doses of phenformin. One of the pharmacodynamic effects of phenformin is weight loss, which we are measuring. Interestingly, obesity has been associated with improved outcome in male melanoma patients treated with anti-PD1 antibodies. In contrast, our data in melanoma patients treated with anti-PD1 antibody immunotherapy do not show an association between outcome and obesity. Another consequence of anaerobic glycolysis is generation and excretion of large amounts of lactate. There is evidence that lactate can inhibit T-cell function, and we will discuss strategies to block lactate transport to enhance immunotherapy.

Citation Format: Allison Betoff, Jonathan Zippin, Taha Merghoub, Paul B. Chapman, Jedd Wolchok. Targeting melanoma metabolism to overcome resistance to treatment [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr IA10.

Long-term outcomes in patients with BRAF V600-mutant metastatic melanoma receiving dabrafenib monotherapy: Analysis from phase 2 and 3 clinical trials

BACKGROUND

Previous analyses of BREAK-2 and BREAK-3 showed that durable outcomes lasting ≥3 years are achievable with dabrafenib in some patients with BRAF V600-mutant metastatic melanoma (MM); however, additional follow-up is needed to fully characterise the long-term impact of dabrafenib in these patients.

METHODS

BREAK-2 was a single-arm phase 2 study evaluating dabrafenib in treatment-naive or previously treated BRAF V600E/K-mutant MM. BREAK-3, a randomised (3:1) phase 3 study, assessed dabrafenib versus dacarbazine in previously untreated unresectable or metastatic BRAF V600E-mutant melanoma. Five-year analyses were performed.

RESULTS

All BREAK-2 patients (N = 92 [V600E, n = 76; V600K, n = 16]) discontinued treatment by the data cutoff. Median follow-up was 13.0 months. In BRAF V600E patients, 5-year progression-free survival (PFS) and overall survival (OS) were 11% and 20%, respectively. Subsequent immunotherapy was received by 22% of patients. In BREAK-3, median follow-up was 17.0 and 12.0 months in the dabrafenib (n = 187) and dacarbazine (n = 63) arms, respectively. Thirty-seven patients (59%) receiving dacarbazine crossed over to dabrafenib following disease progression as per protocol. Five-year PFS was 12% in the dabrafenib arm; all dacarbazine-arm patients progressed or were censored by 5 years. Dabrafenib improved PFS versus dacarbazine, regardless of baseline lactate dehydrogenase levels. Five-year OS rates were 24% and 22% in the dabrafenib and dacarbazine arms, respectively. Subsequent therapy in each arm included anti-CTLA-4 (dabrafenib [24%] and dacarbazine [24%]) and/or anti-PD-1 (8% and 2%) treatment. No new safety signals were observed.

CONCLUSIONS AND RELEVANCE

These data, representing extended follow-up for dabrafenib monotherapy, demonstrate that durable benefit lasting ≥5 years is achievable in a subset of patients.

TRIAL REGISTRATION

ClinicalTrials.gov (BREAK-2, NCT01153763; BREAK-3, NCT01227889).

A phase II study to evaluate the need for > two doses of nivolumab + ipilimumab combination (combo) immunotherapy

10003

Background: Standard of care nivolumab (nivo) + ipilimumab (ipi) combo immunotherapy is given for 4 doses in patients (pts) with unresectable stage III/IV melanoma. Whether 4 doses are needed is questionable as retrospective data suggest pts treated with <4 doses of combo due to toxicity can have durable benefit. No prospective trials have evaluated the efficacy of intentionally giving <4 doses of combo in unresectable stage III/IV melanoma. Methods: In this phase 2, multicenter clinical trial (n=60), pts with unresectable stage III/IV melanoma received 2 doses of nivo (1mg/kg) + ipi (3mg/kg) followed by a CT scan at week 6. Pts with complete (CR) or partial responses (PR) by RECIST 1.1 or stable disease without an increase in total measurable tumor burden had protocol defined early favorable anti-tumor effect (FATE) and ceased combo, transitioning to maintenance nivo. Pts without FATE at week 6 received the standard third and fourth doses of combo followed by maintenance nivo. The primary endpoint was response rate by RECIST 1.1 at week 12. Secondary endpoints included additional efficacy assessments and safety. Results: 41 pts (68%) had FATE at week 6. The best overall response rates (CR + PR) by RECIST at week 12 or any time afterwards were 48% (95% CI: 35.2-61.6%) and 53% (95% CI: 40.0-66.3%), respectively. 18%, 58%, 12%, 10% had 1, 2, 3, 4 doses of combo, respectively. With a median follow-up of 11 months, any grade treatment-related toxicity occurred in 100% (57% grade 3-4) of pts. Three pts died due to treatment-related toxicity (2 myocarditis, 1 possible adrenal insufficiency). Among the 19 pts without FATE at week 6 and not selected to de-escalate combo after dose 2, no pts ultimately responded with ongoing combo dosing. Conclusions: The first 2 doses of nivo + ipi appear to drive combo’s response efficacy and toxicity. Early radiographic imaging at week 6 may be able to identify pts who do not respond to combo dosing beyond dose 2. Randomized studies are planned to evaluate 1 dose of combo to see if efficacy is maintained with reduced toxicity. Clinical trial information: NCT03122522.

A Prospective, Phase 1 Trial of Nivolumab, Ipilimumab, and Radiotherapy in Patients with Advanced Melanoma

PURPOSE

Preclinical data suggest that radiotherapy (RT) is beneficial in combination with immune checkpoint blockade. Clinical trials have explored RT with single-agent immune checkpoint blockade, but no trials have reported RT with the combination of nivolumab and ipilimumab.

PATIENTS AND METHODS

We conducted a phase 1 study of patients with stage IV melanoma receiving nivolumab and ipilimumab with two different dose-fractionation schemes of RT. Patients had at least one melanoma metastasis that would benefit from palliative RT and one metastasis that would not be irradiated. Nivolumab 1 mg/kg + ipilimumab 3 mg/kg and extracranial RT with a dose of 30 Gy in 10 fractions was administered in Cohort A, and then 27 Gy in 3 fractions was administered in Cohort B. The primary outcome was safety.

RESULTS

Twenty patients were treated (10 in each cohort). The rates of treatment-related grade 3-4 adverse events in Cohort A and B were 40% and 30%, respectively. There were no grade ≥3 adverse events attributed to RT. Patients responded to treatment outside of the irradiated volume (Cohort A 5/10; Cohort B 1/9). No evaluable patients had progression of irradiated metastases. Immunologic changes were seen in the peripheral blood with increases in T-cell receptor diversity in some responding patients.

CONCLUSIONS

RT with nivolumab and ipilimumab was safe compared with historical data of nivolumab and ipilimumab alone. Immunologic effects were observed in the peripheral blood. Randomized studies are ongoing to assess whether RT increases the efficacy of nivolumab and ipilimumab.

Long-Term Outcomes and Responses to Retreatment in Patients With Melanoma Treated With PD-1 Blockade

PURPOSE

To analyze long-term outcomes after treatment discontinuation of anti-programmed death-1 (anti-PD-1) therapy in a cohort of patients with melanoma with the longest follow-up yet available to our knowledge, including a majority of patients treated outside of a clinical trial. We also assessed efficacy of retreatment with anti-PD-1 therapy with or without ipilimumab in relapsing patients.

METHODS

We retrospectively analyzed all patients with nonuveal, unresectable stage III/IV melanoma treated with single-agent anti-PD-1 therapy at Memorial Sloan Kettering from 2009-2018 who had discontinued treatment and had at least 3 months of follow-up after discontinuation (n = 396). Overall survival for patients with complete response (CR) was calculated from time of CR. Time to treatment failure for patients with CR was time from CR to the next melanoma treatment or death.

RESULTS

CRs were seen in 102 of 396 patients (25.8%). The median number of months of treatment after CR was zero (range, stopped before CR to 26 months after CR). With a median follow-up of 21.1 months from time of CR in patients who did not relapse, the probability of being alive and not needing additional melanoma therapy at 3 years was 72.1%. There was no significant association between treatment duration and relapse risk. In multivariable analysis, CR was associated with M1b disease and cutaneous versus mucosal or acral primaries. Among the 78 patients (of 396) retreated after disease progression, response was seen in 5 of 34 retreated patients with single-agent anti-PD-1 therapy and 11 of 44 patients escalated to anti-PD-1 plus ipilimumab.

CONCLUSION

In our cohort, most patients discontinued treatment at the time of CR. Most CRs were durable but the probability of treatment failure was 27% at 3 years. Responses to retreatment were infrequent. The optimal duration of treatment after CR is not yet established.

Survival Outcomes After Metastasectomy in Melanoma Patients Categorized by Response to Checkpoint Blockade

INTRODUCTION

Checkpoint inhibitors have improved outcomes in metastatic melanoma, with 4-year overall survival (OS) of 46% for anti-PD-1 alone or 53% in combination with anti-CTLA-4. However, the median progression free survival is 6.9 and 11.5 months, respectively. Many who progress have gone on to alternative treatments, including surgery, yet the outcome of patients selected for surgery after checkpoint blockade remains unclear.

METHODS

Patients who were treated with checkpoint blockade from 2003 to 2017, followed by metastasectomy, were identified from a prospectively maintained institutional melanoma database. Response to immunotherapy was assessed at the time of surgery. Patients were categorized as having responding, isolated progressing, or multiple progressing lesions.

RESULTS

Of the 237 total patients identified, 208 (88%) had stage IV disease, and 29 (12%) had unresectable stage III disease at the start of immunotherapy. Median OS following first resection was 21 months. Median follow-up among survivors was 23 months. Complete resection at the first operation (n = 87, 37%) was associated with improved survival compared with patients with incomplete resection (n = 150, 63%) [median OS not reached (NR) vs. 10.8 months, respectively; 95% CI: 7.3, 14.8; p < 0.0001]. Patients resected for an isolated progressing or responding tumor had a longer median survival compared with those with multiple progressing lesions (NR vs. 7.8 months, 95% CI: 6.2, 11.2; p < 0.0001).

CONCLUSIONS

Patients selected for surgical resection following checkpoint blockade have a relatively favorable survival, especially if they had a response to immunotherapy and undergo complete resection of isolated progressing or responding disease.

Treatment Outcomes of Immune-Related Cutaneous Adverse Events

PURPOSE

The aim of the current study was to report the efficacy of topical and systemic treatments for immune-related cutaneous adverse events (ircAEs) attributed to checkpoint inhibitors in an uncontrolled cohort of patients referred to oncodermatology clinics.

METHODS

A retrospective analysis of patients with ircAEs evaluated by dermatologists from January 1, 2014, to December 31, 2017, at three tertiary care hospitals and cancer centers were identified through electronic medical records. Clinicopathologic characteristics, dermatologic therapy outcome, and laboratory data were analyzed.

RESULTS

A total of 285 patients (median age, 65 years [range, 17 to 89 years]) with 427 ircAEs were included: pruritus (n = 138; 32%), maculopapular rash (n = 120; 28%), psoriasiform rash (n = 22; 5%), and others (n = 147; 34%). Immune checkpoint inhibitor class was associated with ircAE phenotype (P = .007), where maculopapular rash was predominant in patients who received combination therapy. Severity of ircAEs was significantly reduced (mean Common Terminology Criteria for Adverse Events grade: 1.74 v 0.71; P < .001) with dermatologic interventions, including topical corticosteroids, oral antipruritics, and systemic immunomodulators. A total of 88 ircAEs (20%) were managed with systemic immunomodulators. Of these, 22 (25%) of 88 persisted or worsened. In seven patients with corticosteroid-refractory ircAEs, improvement resulted from targeted biologic immunomodulatory therapies that included rituximab and dupilumab. Serum interleukin-6 (IL-6) was elevated in 34 (52%) of 65 patients; grade 3 or greater ircAEs were associated with increased absolute eosinophils (odds ratio, 4.1; 95% CI, 1.3 to 13.4) and IL-10 (odds ratio, 23.8; 95% CI, 2.1 to 262.5); mean immunoglobulin E serum levels were greater in higher-grade ircAEs: 1,093 kU/L (grade 3), 245 kU/L (grade 2), and 112 kU/L (grade 1; P = .043).

CONCLUSION

Most ircAEs responded to symptom- and phenotype-directed dermatologic therapies, whereas biologic therapies were effective in patients with corticosteroid-refractory disease. Increased eosinophils, IL-6, IL-10, and immunoglobulin E were associated with ircAEs, and they may represent actionable therapeutic targets for immune-related skin toxicities.

Responders to anti-PD1 therapy: Long-term outcomes and responses to retreatment in melanoma (mel)

9513

Background: Little is known about patients (pts) who discontinue anti-PD1 therapy after a complete response (CR) outside of clinical trials. There are also limited data about retreatment with a second course of anti-PD1 upon disease progression. Methods: We retrospectively studied pts (n = 398) at MSKCC with unresectable mel (non-uveal) who received ≥1 dose of single-agent anti-PD1 and were followed ≥3 months (mos) after treatment cessation. CR was defined radiographically or by a negative biopsy of residual tissue. Overall survival (OS) and time to treatment failure (TTF, time until next therapy or death) were calculated from time of CR. When to stop therapy and whether to retreat after progressive disease (PD) were at the discretion of the treating oncologist. A subset of pts received a second course of single-agent anti-PD1 ≥3 months after initial discontinuation; retreated pts were evaluable if they had radiographic or clinical evaluation to assess retreatment efficacy. Results: 102 pts (25.6%) achieved CR (n = 89 radiographic, n = 13 pathologic). Median follow-up was 22.6 mos for survivors who had a CR. Estimated 3-year OS from time of CR was 82.5% (95% CI 67.4-91.0). For pts who had a CR, therapy was discontinued due to CR (n = 72), toxicity (n = 24), or other reasons (n = 6). The median duration of treatment for CR pts was 9.4 mos (range 1.6-36.1). 20 CR pts later had progressive disease (PD). Median TTF has not been reached; at 3-years the estimated treatment-free survival for CR pts was 72.3% (95% CI 60.2-81.3). 34 pts received a second course of anti-PD1 for PD after a median of 11.6 mos off treatment (range 3.5-28.6). Best responses to the second course of treatment were: 2 CRs (5.9%), 3 with tumor shrinkage (8.8%), 9 (26.5%) with SD, and 20 with PD (58.8%). Of these pts who had had a CR (n = 8) or some lesser degree of tumor shrinkage (n = 13) to the initial course of anti-PD1 treatment, only 1 and 2 pts responded, respectively, to retreatment. Median duration of retreatment was 10.9 wks. Conclusions: In this largest dataset to knowledge of mel pts treated with a second course of anti-PD1, response rate was low, even in pts who had achieved a response initially. Further study is needed into the necessary duration of initial anti-PD1 treatment and optimal strategies for initial responders who discontinue and later develop PD.

Therapeutic implications of a novel driver classification system for cutaneous and unknown primary melanomas

9539

Background: Cutaneous and “unknown primary” melanomas frequently harbor alterations that activate the Mitogen Activated Protein Kinase (MAPK) pathway, and are often classified as BRAF, NRAS, NF1 mutant, or “triple wild type.” Multigene sequencing may identify additional oncogenic drivers, but the clinical impact of this information is unknown. Methods: Patients with BRAF inhibitor naïve melanoma underwent prospective tumor molecular profiling using a targeted capture-based assay (MSK-IMPACT), and demographic and treatment data were collected. Time to treatment failure was assessed for patients who received frontline PD-1 monotherapy or nivolumab plus ipilimumab. Results: 576 patients were successfully sequenced. 533 samples (96%) harbored a known or presumed oncogenic mutation in 1 of 28 genes in the RTK-RAS-MAPK pathway. 187 tumors (32%) had two or more drivers in this pathway, and the rates of driver co-alterations varied widely by specific driver. A hierarchical classification of 9 driver groups (BRAF V600E; V600K/R/M; BRAF non-V600; NRAS Q61; Other RAS; NF1; KIT; Other driver; Unknown driver) was significantly associated with tumor mutational burden, primary melanoma site, and patient age. Time to treatment failure varied by driver class and site of primary melanoma for PD-1 monotherapy but not nivolumab plus ipilimumab. 150 patients with BRAF V600 wild-type melanoma required systemic therapy after progression on checkpoint blockade. 21 were given genomically matched therapy, and 5/21 had clinical benefit for ≥6 months. Complete and durable responses were observed with TRK and ROS1 inhibitors in patients with NTRK1/2/3 and ROS1 fusion positive tumors. Conclusions: Oncogenic alterations in the RTK-RAS-MAPK pathway can be detected using targeted capture NGS in the vast majority of cutaneous and unknown primary melanomas. A hierarchical classification of 9 driver groups revealed clinically relevant melanoma subsets with varying clinical outcomes to PD-1 monotherapy. Select patients with oncogenic kinase fusions can achieve durable therapeutic benefit with targeted inhibitors of these rare drivers.

Myocarditis Surveillance in Patients with Advanced Melanoma on Combination Immune Checkpoint Inhibitor Therapy: The Memorial Sloan Kettering Cancer Center Experience

This letter to the editor describes myocarditis screening among patients undergoing combination immune checkpoint inhibitor therapy, in light of the consensus document from the Checkpoint Inhibitor Safety Working Group.

Genomic Features of Exceptional Response in Vemurafenib ± Cobimetinib-treated Patients with BRAF V600-mutated Metastatic Melanoma

PURPOSE

Previous investigations identified transcriptional signatures associated with innate resistance to anti-programmed cell death protein 1 therapy in melanoma. This analysis aimed to increase understanding of the role of baseline genetic features in the variability of response to BRAF and MEK inhibitor therapy for BRAF ^V600-mutated metastatic melanoma.

PATIENTS AND METHODS

This exploratory analysis compared genomic features, using whole-exome and RNA sequencing, of baseline tumors from patients who had complete response versus rapid progression (disease progression at first postbaseline assessment) on treatment with cobimetinib combined with vemurafenib or vemurafenib alone. Associations of gene expression with progression-free survival or overall survival were assessed by Cox proportional hazards modeling.

RESULTS

Whole-exome sequencing showed that MITF and TP53 alterations were more frequent in tumors from patients with rapid progression, while NF1 alterations were more frequent in tumors from patients with complete response. However, the low frequency of alterations in any one gene precluded their characterization as drivers of response/resistance. Analysis of RNA profiles showed that expression of immune response-related genes was enriched in tumors from patients with complete response, while expression of keratinization-related genes was enriched in tumors from patients who experienced rapid progression.

CONCLUSIONS

These findings suggest that enriched immune infiltration might be a shared feature favoring response to both targeted and immune therapies, while features of innate resistance to targeted and immune therapies were distinct.

Widespread Selection for Oncogenic Mutant Allele Imbalance in Cancer

Driver mutations in oncogenes encode proteins with gain-of-function properties that enhance fitness. Heterozygous mutations are thus viewed as sufficient for tumorigenesis. We describe widespread oncogenic mutant allele imbalance in 13,448 prospectively characterized cancers. Imbalance was selected for through modest dosage increases of gain-of-fitness mutations. Negative selection targeted haplo-essential effectors of the spliceosome. Loss of the normal allele comprised a distinct class of imbalance driven by competitive fitness, which correlated with enhanced response to targeted therapies. In many cancers, an antecedent oncogenic mutation drove evolutionarily dependent allele-specific imbalance. In other instances, oncogenic mutations co-opted independent copy-number changes via the evolutionary process of exaptation. Oncogenic allele imbalance is a pervasive evolutionary innovation that enhances fitness and modulates sensitivity to targeted therapy.

Elevated Levels of BRAFV600 Mutant Circulating Tumor DNA and Circulating Hepatocyte Growth Factor Are Associated With Poor Prognosis in Patients With Metastatic Melanoma

Purpose

We performed a retrospective exploratory analysis to evaluate the prognostic and predictive effect of two circulating biomarkers, BRAFV600 mutant circulating tumor DNA (ctDNA) and circulating hepatocyte growth factor (cHGF), in metastatic melanoma.

Materials and Methods

This study evaluated patients from BRIM-3, a phase III trial comparing vemurafenib and dacarbazine in 675 patients with BRAFV600 mutated advanced melanoma. ctDNA was measured using droplet digital polymerase chain reaction, and cHGF was measured by enzyme-linked immunosorbent assay. Overall survival (OS) was estimated using the Kaplan-Meier method, and hazard ratios (HRs) were estimated using Cox proportional hazards modeling. Partitioning analysis was used to group patients into risk categories.

Results

Patients with elevated levels of baseline BRAFV600 ctDNA had significantly shorter median OS than those with undetectable levels of ctDNA (vemurafenib arm, 9.9 v 21.4 months, respectively, and dacarbazine arm: 6.1 v 21.0 months, respectively). Median OS was also shorter in patients with high levels of cHGF compared with those with low cHGF (vemurafenib arm, 11.9 v 17.3 months, respectively, and dacarbazine arm, 6.1 v 14.4 months, respectively). In a multivariable proportional hazards model with adjustment for lactate dehydrogenase, Eastern Cooperative Oncology Group status, disease stage, and treatment, ctDNA and cHGF were both independent prognostic factors for OS, (HR, 1.75; 95% CI, 1.35 to 2.28 for high v undetectable ctDNA; HR, 1.24; 95% CI, 1.00 to 1.53 for high v low cHGF). Using partitioning analysis, we found that patients with elevated ctDNA combined with elevated cHGF constituted the highest risk group with significantly shorter OS.

Conclusion

Here, we report that BRIM-3 patients with high levels of ctDNA and cHGF have worse OS regardless of treatment and that these factors are independent prognostic markers for metastatic melanoma.

Vemurafenib in patients with BRAFV600 mutation-positive metastatic melanoma: final overall survival results of the randomized BRIM-3 study

Background

The BRIM-3 trial showed improved progression-free survival (PFS) and overall survival (OS) for vemurafenib compared with dacarbazine in treatment-naive patients with BRAFV600 mutation-positive metastatic melanoma. We present final OS data from BRIM-3.

Patients and methods

Patients were randomly assigned in a 1 : 1 ratio to receive vemurafenib (960 mg twice daily) or dacarbazine (1000 mg/m2 every 3 weeks). OS and PFS were co-primary end points. OS was assessed in the intention-to-treat population, with and without censoring of data for dacarbazine patients who crossed over to vemurafenib.

Results

Between 4 January 2010 and 16 December 2010, a total of 675 patients were randomized to vemurafenib (n = 337) or dacarbazine (n = 338, of whom 84 crossed over to vemurafenib). At the time of database lock (14 August 2015), median OS, censored at crossover, was significantly longer for vemurafenib than for dacarbazine {13.6 months [95% confidence interval (CI) 12.0-15.4] versus 9.7 months [95% CI 7.9-12.8; hazard ratio (HR) 0.81 [95% CI 0.67-0.98]; P = 0.03}, as was median OS without censoring at crossover [13.6 months (95% CI 12.0-15.4) versus 10.3 months (95% CI 9.1-12.8); HR 0.81 (95% CI 0.68-0.96); P = 0.01]. Kaplan-Meier estimates of OS rates for vemurafenib versus dacarbazine were 56% versus 46%, 30% versus 24%, 21% versus 19% and 17% versus 16% at 1, 2, 3 and 4 years, respectively. Overall, 173 of the 338 patients (51%) in the dacarbazine arm and 175 of the 337 (52%) of those in the vemurafenib arm received subsequent anticancer therapies, most commonly ipilimumab. Safety data were consistent with the primary analysis.

Conclusions

Vemurafenib continues to be associated with improved median OS in the BRIM-3 trial after extended follow-up. OS curves converged after ≈3 years, likely as a result of crossover from dacarbazine to vemurafenib and receipt of subsequent anticancer therapies.

ClinicalTrials.gov

NCT01006980.

Selumetinib in Combination With Dacarbazine in Patients With Metastatic Uveal Melanoma: A Phase III, Multicenter, Randomized Trial (SUMIT)

Purpose Uveal melanoma is the most common primary intraocular malignancy in adults with no effective systemic treatment option in the metastatic setting. Selumetinib (AZD6244, ARRY-142886) is an oral, potent, and selective MEK1/2 inhibitor with a short half-life, which demonstrated single-agent activity in patients with metastatic uveal melanoma in a randomized phase II trial. Methods The Selumetinib (AZD6244: ARRY-142886) (Hyd-Sulfate) in Metastatic Uveal Melanoma (SUMIT) study was a phase III, double-blind trial ( ClinicalTrial.gov identifier: NCT01974752) in which patients with metastatic uveal melanoma and no prior systemic therapy were randomly assigned (3:1) to selumetinib (75 mg twice daily) plus dacarbazine (1,000 mg/m2 intravenously on day 1 of every 21-day cycle) or placebo plus dacarbazine. The primary end point was progression-free survival (PFS) by blinded independent central radiologic review. Secondary end points included overall survival and objective response rate. Results A total of 129 patients were randomly assigned to receive selumetinib plus dacarbazine (n = 97) or placebo plus dacarbazine (n = 32). In the selumetinib plus dacarbazine group, 82 patients (85%) experienced a PFS event, compared with 24 (75%) in the placebo plus dacarbazine group (median, 2.8 v 1.8 months); the hazard ratio for PFS was 0.78 (95% CI, 0.48 to 1.27; two-sided P = .32). The objective response rate was 3% with selumetinib plus dacarbazine and 0% with placebo plus dacarbazine (two-sided P = .36). At 37% maturity (n = 48 deaths), analysis of overall survival gave a hazard ratio of 0.75 (95% CI, 0.39 to 1.46; two-sided P = .40). The most frequently reported adverse events (selumetinib plus dacarbazine v placebo plus dacarbazine) were nausea (62% v 19%), rash (57% v 6%), fatigue (44% v 47%), diarrhea (44% v 22%), and peripheral edema (43% v 6%). Conclusion In patients with metastatic uveal melanoma, the combination of selumetinib plus dacarbazine had a tolerable safety profile but did not significantly improve PFS compared with placebo plus dacarbazine.

Association of body-mass index and outcomes in patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy: a retrospective, multicohort analysis

BACKGROUND

Obesity has been linked to increased mortality in several cancer types; however, the relation between obesity and survival outcomes in metastatic melanoma is unknown. The aim of this study was to examine the association between body-mass index (BMI) and progression-free survival or overall survival in patients with metastatic melanoma who received targeted therapy, immunotherapy, or chemotherapy.

METHODS

This retrospective study analysed independent cohorts of patients with metastatic melanoma assigned to treatment with targeted therapy, immunotherapy, or chemotherapy in randomised clinical trials and one retrospective study of patients treated with immunotherapy. Patients were classified according to BMI, following the WHO definitions, as underweight, normal, overweight, or obese. Patients without BMI and underweight patients were excluded. The primary outcomes were the associations between BMI and progression-free survival or overall survival, stratified by treatment type and sex. We did multivariable analyses in the independent cohorts, and combined adjusted hazard ratios in a mixed-effects meta-analysis to provide a precise estimate of the association between BMI and survival outcomes; heterogeneity was assessed with meta-regression analyses. Analyses were done on the predefined intention-to-treat population in the randomised controlled trials and on all patients included in the retrospective study.

FINDINGS

The six cohorts consisted of a total of 2046 patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy between Aug 8, 2006, and Jan 15, 2016. 1918 patients were included in the analysis. Two cohorts containing patients from randomised controlled trials treated with targeted therapy (dabrafenib plus trametinib [n=599] and vemurafenib plus cobimetinib [n=240]), two cohorts containing patients treated with immunotherapy (one randomised controlled trial of ipilimumab plus dacarbazine [n=207] and a retrospective cohort treated with pembrolizumab, nivolumab, or atezolizumab [n=331]), and two cohorts containing patients treated with chemotherapy (two randomised controlled trials of dacarbazine [n=320 and n=221]) were classified according to BMI as normal (694 [36%] patients), overweight (711 [37%]), or obese (513 [27%]). In the pooled analysis, obesity, compared with normal BMI, was associated with improved survival in patients with metastatic melanoma (average adjusted hazard ratio [HR] 0·77 [95% CI 0·66-0·90] for progression-free survival and 0·74 [0·58-0·95] for overall survival). The survival benefit associated with obesity was restricted to patients treated with targeted therapy (HR 0·72 [0·57-0·91] for progression-free survival and 0·60 [0·45-0·79] for overall survival) and immunotherapy (HR 0·75 [0·56-1·00] and 0·64 [0·47-0·86]). No associations were observed with chemotherapy (HR 0·87 [0·65-1·17, p_interaction=0·61] for progression-free survival and 1·03 [0·80-1·34, p_interaction=0·01] for overall survival). The association of BMI with overall survival for patients treated with targeted and immune therapies differed by sex, with inverse associations in men (HR 0·53 [0·40-0·70]), but no associations observed in women (HR 0·85 [0·61-1·18, p_interaction=0·03]).

INTERPRETATION

Our results suggest that in patients with metastatic melanoma, obesity is associated with improved progression-free survival and overall survival compared with those outcomes in patients with normal BMI, and that this association is mainly seen in male patients treated with targeted or immune therapy. These results have implications for the design of future clinical trials for patients with metastatic melanoma and the magnitude of the benefit found supports further investigation of the underlying mechanism of these associations.

FUNDING

ASCO/CCF Young Investigator Award, ASCO/CCF Career Development Award, MD Anderson Cancer Center (MDACC) Melanoma Moonshot Program, MDACC Melanoma SPORE, and the Dr Miriam and Sheldon G Adelson Medical Research Foundation.

Peripheral blood clinical laboratory variables associated with outcomes following combination nivolumab and ipilimumab immunotherapy in melanoma

Both the combination of nivolumab + ipilimumab and single-agent anti-PD-1 immunotherapy have demonstrated survival benefit for patients with advanced melanoma. As the combination has a high rate of serious side effects, further analyses in randomized trials of combination versus anti-PD-1 immunotherapy are needed to understand who benefits most from the combination. Clinical laboratory values that were routinely collected in randomized studies may provide information on the relative benefit of combination immunotherapy. To prioritize which clinical laboratory factors to ultimately explore in these randomized studies, we performed a single-center, retrospective analysis of patients with advanced melanoma who received nivolumab + ipilimumab either as part of a clinical trial (n = 122) or commercial use (n = 87). Baseline routine laboratory values were correlated with overall survival (OS) and overall response rate (ORR). Kaplan-Meier estimation and Cox regression were performed. Median OS was 44.4 months, 95% CI (32.9, Not Reached). A total of 110 patients (53%) responded (CR/PR). Significant independent variables for favorable OS included the following: high relative eosinophils, high relative basophils, low absolute monocytes, low LDH, and a low neutrophil-to-lymphocyte ratio. These newly identified factors, along with those previously reported to be associated with anti-PD-1 monotherapy outcomes, should be studied in the randomized trials of nivolumab + ipilimumab versus anti-PD-1 monotherapies to determine whether they help define the patients who benefit most from the combination versus anti-PD-1 alone.

Quantification of tumor-derived cell free DNA(cfDNA) by digital PCR (DigPCR) in cerebrospinal fluid of patients with BRAFV600 mutated malignancies

Tumor-derived cell free DNA (cfDNA) can be detected in plasma. We hypothesized that mutated BRAF V600 cfDNA could be quantified in the cerebrospinal fluid (CSF) of patients with central nervous system (CNS) metastases. We collected CSF from patients with BRAF V600E or K-mutated melanoma (N=8) or BRAF V600E mutated Erdheim-Chester Disease (ECD) (N=3) with suspected central nervous system (CNS) involvement on the basis of neurological symptoms (10/11), MRI imaging (8/11), or both. Tumor-derived cfDNA was quantified by digital PCR in the CSF of 6/11 patients (range from 0.15-10.56 copies/μL). Conventional cytology was negative in all patients except in the two patients with markedly elevated levels of tumor-derived cfDNA. In 2 patients with serial measurements, CSF tumor-derived cfDNA levels reflected response to treatment or progressive disease. CSF tumor-derived cfDNA has the potential to serve as a diagnostic tool that complements MRI and may be more sensitive than conventional cytology.

A phase 2 trial of everolimus and pasireotide long-acting release in patients with metastatic uveal melanoma

The aim of this study was to test the hypothesis that inhibiting mammalian target of rapamycin and insulin-like growth factor-1 receptor would be efficacious in metastatic uveal melanoma. This was a phase 2 trial of everolimus 10 mg daily plus pasireotide long-acting release 60 mg every 28 days enrolling patients with progressive, metastatic uveal melanoma to treatment until progression by Response Evaluation Criteria In Solid Tumors 1.1 (RECIST 1.1) or unacceptable toxicity. The primary endpoint was clinical benefit rate, defined as any objective response or RECIST 1.1 stable disease at 16 weeks. A subset of patients underwent baseline indium-111-octreotide scans. A total of 14 patients were enrolled, of which 13 were evaluable for the primary endpoint, before the study was terminated due to poor accrual. Three of 13 (26%) patients obtained clinical benefit. Seven of 13 (54%) had stable disease lasting for a median of 8 weeks (range: 8-16 weeks). Grade 3 adverse events deemed at least possibly related to study drugs were hyperglycemia (n=7), oral mucositis (n=2), diarrhea (n=1), hypophosphatemia (n=1), and anemia (n=1). Seven of 14 (50%) patients required at least one dose reduction due to toxicity. Seven of eight (88%) patients with baseline indium-111-octreotide scans had at least one avid lesion, with significant intrapatient heterogeneity. There was a trend toward an association between octreotide avidity and cytostatic response to therapy (P=0.078). The combination of everolimus and pasireotide has limited clinical benefit in this small metastatic uveal melanoma cohort. Dose reductions for side effects were common. Further investigation into the relationship between somatostatin receptor expression and cytostatic activity of somatostatin analogues is warranted.

Quantifying Treatment Benefit in Molecular Subgroups to Assess a Predictive Biomarker

An increased interest has been expressed in finding predictive biomarkers that can guide treatment options for both mutation carriers and noncarriers. The statistical assessment of variation in treatment benefit (TB) according to the biomarker carrier status plays an important role in evaluating predictive biomarkers. For time-to-event endpoints, the hazard ratio (HR) for interaction between treatment and a biomarker from a proportional hazards regression model is commonly used as a measure of variation in TB. Although this can be easily obtained using available statistical software packages, the interpretation of HR is not straightforward. In this article, we propose different summary measures of variation in TB on the scale of survival probabilities for evaluating a predictive biomarker. The proposed summary measures can be easily interpreted as quantifying differential in TB in terms of relative risk or excess absolute risk due to treatment in carriers versus noncarriers. We illustrate the use and interpretation of the proposed measures with data from completed clinical trials. We encourage clinical practitioners to interpret variation in TB in terms of measures based on survival probabilities, particularly in terms of excess absolute risk, as opposed to HR. Clin Cancer Res; 22(9); 2114-20. ©2016 AACR.

Measuring Toxic Effects and Time to Treatment Failure for Nivolumab Plus Ipilimumab in Melanoma

IMPORTANCE

Nivolumab plus ipilimumab (nivo + ipi) is a standard treatment of advanced melanoma. Two randomized trials describe high objective response rates by Response Evaluation Criteria in Solid Tumors. The trials assessed toxic effects using the Common Terminology Criteria for Adverse Events (CTCAE), which may underestimate incidence of clinically significant immune-related adverse events (AEs).

OBJECTIVE

To describe detailed toxic effects and time to treatment failure of patients with melanoma treated with nivo + ipi in a prospective cohort.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 64 adults with advanced or unresectable melanoma were examined at a single tertiary cancer and enrolled in an expanded access program of nivo + ipi conducted from December 2014 to January 2016.

INTERVENTIONS

Intravenous nivolumab (1 mg/kg) and ipilimumab (3 mg/kg) administered every 3 weeks for up to 4 doses, followed by nivolumab (3 mg/kg) every 2 weeks or pembrolizumab (2 mg/kg) every 3 weeks until unacceptable toxic effects, disease progression, or complete response.

MAIN OUTCOMES AND MEASURES

Clinically significant immune-related AEs were defined as CTCAE grade 2 or higher or any immune-related AEs requiring systemic steroids. Time to treatment failure was defined as the interval between initiating therapy and the earliest of clinical progression, new locally directed or systemic treatment other than anti-programmed cell death 1 protein (anti-PD-1) monotherapy, or death.

RESULTS

Overall 64 adults with advanced or unresectable melanoma were enrolled (male to female ratio, 1:1; median [range] age, 56 [22-82] years); 25 patients (39%) received all 4 doses of nivo + ipi, and 31 patients (48%) received no maintenance anti-PD-1 therapy. Most who discontinued treatment (n = 31 [80%]) stopped because of toxic effects. Among those patients who were progression free at 12 weeks, time to treatment failure was similar between those who did or did not modify therapy for toxic effects. Fifty-eight patients (91%) had a clinically significant immune-related AE (median, 2/patient), and 46 patients (72%) required systemic steroids. Infliximab or mycophenolate was required in 16 patients (25%) for steroid-refractory immune-related AEs. Seven patients (11%) developed hyperglycemia, 32 patients (50%) had an emergency department visit, and 23 patients (36%) required a hospital admission related to an immune-related AE. Four of 31 patients (13%) who stopped combination therapy early for toxic effects developed a new, clinically significant immune-related AE more than 16 weeks after the last treatment.

CONCLUSIONS AND RELEVANCE

We observed a 91% incidence of clinically significant immune-related AEs leading to frequent emergency department visits, hospitalizations, and systemic immunosuppression. Immuno-oncology trials should routinely report these metrics. Most patients do not tolerate 4 doses of nivo + ipi; however, 4 doses may not be required for clinical benefit.

Four-month course of adjuvant dabrafenib in patients with surgically resected stage IIIC melanoma characterized by a BRAFV600E/K mutation

BACKGROUND

We tested the hypothesis that a 4-month course of adjuvant dabrafenib in stage IIIC BRAF-mutated melanoma would improve 2 year RFS from 24% to 51%, and that tumor-derived cell free DNA (cfDNA) in plasma would correlate with and predict recurrence.

METHODS

Patients with stage IIIC BRAF V600E/K mutated melanoma who were free of disease after surgical resection received 4 months of adjuvant dabrafenib. Patients were evaluated with imaging at baseline, at the end of cycles 2, 4, 6, then every 3 months until disease relapse or 2 years, whichever came first. Serial blood samples were collected for evaluation of cfDNA at the same time.

RESULTS

21/23 patients enrolled were evaluable; 2 patients withdrew consent during the first week of treatment. The 2 year RFS was 28.6% (95% CI 12-48%). The estimated overall survival at 2 years was 78% (95% CI 51-91%). cfDNA detection had a 53% sensitivity in relapsing patients but cfDNA detection did not provide lead-time advantage over CT scanning.

CONCLUSION

A 4-month course of adjuvant dabrafenib did not result in a detectable improvement in 2-year RFS. cfDNA was less sensitive than standard CT imaging and did not provide a lead-time advantage in detecting relapse.

Dual MEK/AKT inhibition with trametinib and GSK2141795 does not yield clinical benefit in metastatic NRAS-mutant and wild-type melanoma

Aberrant MAPK and PI3K pathway signaling may drive the malignant phenotype in NRAS-mutant and BRAF^WT NRAS^WT metastatic melanoma. To target these pathways, NRAS-mutant and BRAF^WT NRAS^WT patients received oral trametinib at 1.5 mg daily and GSK2141795 at 50 mg daily in a two-cohort Simon two-stage design. Participants had adequate end-organ function and no more than two prior treatment regimens. Imaging assessments were performed at 8-week intervals. A total of 10 NRAS-mutant and 10 BRAF^WT NRAS^WT patients were enrolled. No objective responses were noted in either cohort. The median PFS and OS were 2.3 and 4.0 months in the NRAS-mutant cohort and 2.8 and 3.5 months in the wild-type cohort. Grade 3 and grade 4 adverse events, primarily rash, were observed in 25% of patients. We conclude that the combination of trametinib and GSK2141795 does not have significant clinical activity in NRAS-mutant or BRAF^WT NRAS^WT melanoma.

Time to publication of oncology trials and why some trials are never published

Background

Very little is known about the proportion of oncology trials that get published, the time it takes to publish them, or the reasons why oncology trials do not get published.

Methods

We analyzed all clinical trials that closed to accrual at our cancer center between 2009–2013. Trials were categorized by study purpose (therapeutic vs. diagnostic), phase (pilot, phase I, II, or III), and sponsor (industrial, cooperative group, institutional, or peer-reviewed). Final publications were identified in MEDLINE and EMBASE by NCT numbers, or by querying the principal investigator. For trials not published, we surveyed the principal investigators to identify the reason for non-publication.

Findings

469 of 809 protocols (58%) had been published by November 2016. The calculated probability of publication 7 years after completing accrual was 70.4%; the calculated median time to publication was 47 months. Only 18.8% of protocols overall were estimated to be published within 2 years from completing accrual. The calculated probability of publication was higher for therapeutic trials than non-therapeutic trials, but there was no difference based on phase or sponsor. Among protocols not published, 45.3% had completed accrual, and among these, a majority had a manuscript in preparation or review, or the trial was still collecting data. Failure to publish due to a pharmaceutical sponsor was rare. 30.6% of unpublished trials had closed for various reasons before completing accrual, usually due to poor accrual or pharmaceutical sponsor issues.

Interpretation

Almost 30% of trials were calculated to be unpublished by 7 years after closing to accrual at our institution. Failure to reach accrual goals was an important factor in non-publication. We have devised new institutional policies that identify trials likely not to meet accrual goals and require early closure. We should be able to shorten the time from accrual completion to publication, especially for pilot and phase I trials for which long follow up is not needed.

Clinical and Morphologic Characteristics of MEK Inhibitor-Associated Retinopathy: Differences from Central Serous Chorioretinopathy

PURPOSE

To investigate the clinical and morphologic characteristics of serous retinal disturbances in patients taking mitogen-activated protein kinase kinase (MEK) inhibitors.

PARTICIPANTS

A total of 313 fluid foci in 50 eyes of 25 patients receiving MEK inhibitors for treatment of their metastatic cancer, who had evidence of serous retinal detachments confirmed by optical coherence tomography (OCT).

DESIGN

Single-center, retrospective cohort study.

METHODS

Clinical examination and OCT were used to evaluate MEK inhibitor-associated subretinal fluid. The morphology, distribution, and location of fluid foci were serially evaluated for each eye. Choroidal thickness was measured at each time point (baseline, fluid accumulation, and fluid resolution). Two independent observers performed all measurements. Statistical analysis was used to correlate interobserver findings and compare choroidal thickness and visual acuity at each time point.

MAIN OUTCOME MEASURES

Comparison of OCT characteristics of retinal abnormalities at baseline to fluid accumulation.

RESULTS

The majority of patients had fluid foci that were bilateral (92%) and multifocal (77%) and at least 1 focus involving the fovea (83.3%). All fluid foci occurred between the interdigitation zone and an intact retinal pigment epithelium. The 313 fluid foci were classified into 4 morphologies, as follows: 231 (73.8%) dome, 36 (11.5%) caterpillar, 31 (9.9%) wavy, and 15 (4.8%) splitting. Best-corrected visual acuity at fluid resolution was not statistically different from baseline; and no eye lost more than 2 Snellen lines from baseline at the time of fluid accumulation. There was no statistical difference in the choroidal thickness between the different time points (baseline, fluid accumulation, and fluid resolution). A strong positive interobserver correlation was obtained for choroidal thickness measurements (r = 0.97, P < 0.0001) and grading of foci morphology (r = 0.97, P < 0.0001).

CONCLUSION

The subretinal fluid foci associated with MEK inhibitors have unique clinical and morphologic characteristics, which can be distinguished from the findings of central serous chorioretinopathy. In this series, MEK inhibitors did not cause irreversible loss of vision or serious eye damage.

PTEN Loss-of-Function Alterations Are Associated With Intrinsic Resistance to BRAF Inhibitors in Metastatic Melanoma

Purpose

The clinical use of BRAF inhibitors in patients with melanoma is limited by intrinsic and acquired resistance. We asked whether next-generation sequencing of pretreatment tumors could identify coaltered genes that predict for intrinsic resistance to BRAF inhibitor therapy in patients with melanoma as a prelude to rational combination strategies.

Patients and Methods

We analyzed 66 tumors from patients with metastatic BRAF-mutant melanoma collected before treatment with BRAF inhibitors. Tumors were analyzed for > 250 cancer-associated genes using a capture-based next-generation sequencing platform. Antitumor responses were correlated with clinical features and genomic profiles with the goal of identifying a molecular signature predictive of intrinsic resistance to RAF pathway inhibition.

Results

Among the 66 patients analyzed, 11 received a combination of BRAF and MEK inhibitors for the treatment of melanoma. Among the 55 patients treated with BRAF inhibitor monotherapy, objective responses, as assessed by Response Evaluation Criteria in Solid Tumors (RECIST), were observed in 30 patients (55%), with five (9%) achieving a complete response. We identified a significant association between alterations in PTEN that would be predicted to result in loss of function and reduced progression-free survival, overall survival, and response grade, a metric that combines tumor regression and duration of treatment response. Patients with melanoma who achieved an excellent response grade were more likely to have an elevated BRAF-mutant allele fraction.

Conclusion

These results provide a rationale for cotargeting BRAF and the PI3K/AKT pathway in patients with BRAF-mutant melanoma when tumors have concurrent loss-of-function mutations in PTEN. Future studies should explore whether gain of the mutant BRAF allele and/or loss of the wild-type allele is a predictive marker of BRAFi sensitivity.

Updated 5-y landmark analyses of phase 2 (BREAK-2) and phase 3 (BREAK-3) studies evaluating dabrafenib monotherapy in patients with BRAF V600–mutant melanoma

9526

Background: Prior analyses of phase 2 (BREAK-2; NCT01153763) and phase 3 (BREAK-3; NCT01227889) trials showed that durable clinical benefit and tolerability lasting ≥ 3 y are achievable with the BRAF inhibitor dabrafenib in some patients (pts) with BRAFV600–mutant metastatic melanoma. Here, we report 5-y landmark analyses for BREAK-2 and BREAK-3. Methods: BREAK-2, a single-arm, phase 2 study, evaluated dabrafenib 150 mg twice daily in pts with stage IV BRAF V600E/K–mutant MM. BREAK-3, an open-label, randomized (3:1), phase 3 study, assessed dabrafenib 150 mg twice daily vs dacarbazine 1000 mg/m2 every 3 weeks in pts with previously untreated BRAFV600E–mutant unresectable stage III or stage IV MM. Updated analyses were performed to describe ≥ 5-y outcomes in each study. Results: BREAK-2 enrolled 92 pts (V600E, n = 76; V600K, n = 16), of whom most (90%) had prior systemic anticancer therapy. At data cutoff (17 Jun 2016), all pts had discontinued, mostly due to progression (84%). In V600E pts, 5-y progression-free survival (PFS) was 11%, and 5-y overall survival (OS) was 20%. Postprogression immunotherapy was received by 22% of enrolled pts. In BREAK-3 (data cutoff, 16 Sep 2016), median follow-up was 18.6 mo for the dabrafenib arm (n = 187) and 12.8 mo for the dacarbazine arm (n = 63). Follow-up for the 37 dacarbazine-arm pts (59%) who crossed over to receive dabrafenib was based on the initial assignment of dacarbazine. The 5-y PFS was 12% vs 3% and 5-y OS was 24% vs 22% for the dabrafenib and dacarbazine arms, respectively. A subset of pts in each respective arm received postprogression anti–CTLA-4 (24% vs 24%) and/or anti–PD-1 (8% vs 2%) therapy, whereas 31% vs 17% did not receive any further therapy following study treatment. No new safety signals were observed in either study with long-term follow-up. Additional characterization of pts using cfDNA analysis will be presented. Conclusions: These data provide the longest reported PFS and OS follow-up for BRAF inhibitor monotherapy in BRAF V600–mutant MM. Both BREAK-2 and BREAK-3 showed that 11%-12% of pts initially treated with single-agent dabrafenib remained progression free at 5 y. Clinical trial information: NCT01153763; NCT01227889.

Overall survival (OS) analysis from an expanded access program (EAP) of nivolumab (NIVO) in combination with ipilimumab (IPI) in patients with advanced melanoma (MEL)

9522

Background: NIVO (anti-PD-1) and IPI (anti-CTLA-4), alone and in combination, are approved for the treatment of MEL. Phase II and III trials showed improved efficacy for NIVO+IPI versus IPI alone, but with a higher frequency of adverse events (AEs). In the phase II CheckMate 069 trial, the 2-year OS rate was 63.8% for all patients (pts) in the NIVO+IPI group. We report the first OS analysis, as well as updated safety data, from a North American EAP of NIVO+IPI in pts with MEL (CheckMate 218; NCT02186249). Methods: CheckMate 218 included pts with MEL who could have progressed on other therapies, but were anti-CTLA-4 and anti-PD-1 treatment-naive. Pts received NIVO 1 mg/kg + IPI 3 mg/kg Q3W x 4, followed by NIVO 3 mg/kg Q2W until disease progression or a maximum of 48 weeks from the first monotherapy dose. We assessed OS in the US cohort (n = 580) and safety in all pts (n = 732). Pts were followed for a minimum of 1 year in the USA and 6 months in Canada. Results: Of 732 pts, 43% had a BRAFmutation, 84% stage IV MEL, 51% M1c disease, 31% LDH > ULN (9% LDH > 2x ULN), and 13% received ≥1 prior systemic therapy in the metastatic setting. All pts received a median of 3 doses each for NIVO (range: 1–4) and IPI (range: 0–4) in the induction phase; 34% of pts received at least 1 dose of NIVO maintenance. The 1- and 2-year OS rates were 78.6% (95% CI: 74.2–82.4) and 65.3% (95% CI: 56.1–73.0), respectively. AEs of any grade occurred in 717 pts (98%), with grade 3/4 AEs in 470 pts (64%). Immune-modulating medications were used to manage any grade AEs, including grade 1/2 skin and gastrointestinal AEs, in 538 of 717 pts (75%), and to manage grade 3/4 AEs in 279 of 470 pts (59%). The most common treatment-related AEs of any grade were diarrhea (39%), pruritus (26%), and an increase in aspartate aminotransferase level (23%). Treatment-related deaths in 2 pts were reported as drug-induced liver injury and myocardial infarction. Conclusions: In this EAP, which included pts who had received prior systemic therapies for MEL and pts with poor prognostic factors generally not included in clinical trials, NIVO+IPI treatment demonstrated survival outcomes and a safety profile consistent with clinical trial data. Clinical trial information: NCT02186249.

MicroRNA-125a promotes resistance to BRAF inhibitors through suppression of the intrinsic apoptotic pathway

Melanoma patients with BRAF^V600E -mutant tumors display striking responses to BRAF inhibitors (BRAFi); however, almost all invariably relapse with drug-resistant disease. Here, we report that microRNA-125a (miR-125a) expression is upregulated in human melanoma cells and patient tissues upon acquisition of BRAFi resistance. We show that miR-125a induction confers resistance to BRAF^V600E melanoma cells to BRAFi by directly suppressing pro-apoptotic components of the intrinsic apoptosis pathway, including BAK1 and MLK3. Apoptotic suppression and prolonged survival favor reactivation of the MAPK and AKT pathways by drug-resistant melanoma cells. We demonstrate that miR-125a inhibition suppresses the emergence of resistance to BRAFi and, in a subset of resistant melanoma cell lines, leads to partial drug resensitization. Finally, we show that miR-125a upregulation is mediated by TGFβ signaling. In conclusion, the identification of this novel role for miR-125a in BRAFi resistance exposes clinically relevant mechanisms of melanoma cell survival that can be exploited therapeutically.