Early on-treatment assessment of T-cells, cytokines and tumor DNA with adaptively-dosed nivolumab + ipilimumab: final results from the phase 2 ADAPT-IT study.

PURPOSE: ADAPT-IT (NCT03122522) investigated adaptive ipilimumab discontinuation in melanoma based on early radiographic assessment. Initial findings indicated similar effectiveness compared to conventional nivolumab-ipilimumab (nivo-ipi). Exploratory biomarker analyses and final clinical results are now reported. PATIENTS AND METHODS: Patients with unresectable melanoma received two doses of nivo-ipi. Radiographic assessment at Week 6 informed continuation of ipilimumab before nivolumab maintenance. The primary endpoint was overall response rate (ORR) at Week 12. Plasma was assayed for circulating tumor DNA (ctDNA) and ten cytokines using a multiplex immunoassay. Flow cytometry of peripheral blood mononuclear cells was performed with an 11-color panel. RESULTS: Among treated patients, expansion of proliferating T-cell populations was observed in both responders and non-responders. Baseline IL-6 levels were lower in patients achieving an objective radiographic response (median 1.30 vs 2.86 pg/mL; p=0.025). Higher baseline IL-6 levels were associated with shorter progression-freesurvival (PFS; hazard ratio (HR)=1.24, 95% CI:1.01-1.52; p=0.041). At Week 6, patients with response had lower average tumor variant allele fractions (VAF) compared to non-responders (median 0.000 v 0.019; p=0.014). Greater increases in average VAF from baseline to Week 6 correlated with shorter PFS (HR=1.11, 95% CI:1.01-1.21; p=0.023). Week 12 ORR was 47% (95% CI:35-59%) with a median follow-up of 34 months among survivors. Median PFS was 21 months (95% CI:10-not reached); 76% of responses (95% CI:64%-91%) persisted at 36 months. CONCLUSIONS: Adaptively dosed nivo-ipi responses are durable and resemble historical data for conventional nivo-ipi. Baseline IL-6 and ctDNA changes during treatment warrant further study as biomarkers of nivo-ipi response.

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.

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.

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.

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.

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.

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.

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).

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.