Matteo S. Carlino

Pembrolizumab versus Ipilimumab in Advanced Melanoma

BACKGROUND The immune checkpoint inhibitor ipilimumab is the standard-of-care treatment for patients with advanced melanoma. Pembrolizumab inhibits the programmed cell death 1 (PD-1) immune checkpoint and has antitumor activity in patients with advanced melanoma. METHODS In this randomized, controlled, phase 3 study, we assigned 834 patients with advanced melanoma in a 1:1:1 ratio to receive pembrolizumab (at a dose of 10 mg per kilogram of body weight) every 2 weeks or every 3 weeks or four doses of ipilimumab (at 3 mg per kilogram) every 3 weeks. Primary end points were progression-free and overall survival. RESULTS The estimated 6-month progression-free-survival rates were 47.3% for pembrolizumab every 2 weeks, 46.4% for pembrolizumab every 3 weeks, and 26.5% for ipilimumab (hazard ratio for disease progression, 0.58; P<0.001 for both pembrolizumab regimens versus ipilimumab; 95% confidence intervals [CIs], 0.46 to 0.72 and 0.47 to 0.72, respectively). Estimated 12-month survival rates were 74.1%, 68.4%, and 58.2%, respectively (hazard ratio for death for pembrolizumab every 2 weeks, 0.63; 95% CI, 0.47 to 0.83; P=0.0005; hazard ratio for pembrolizumab every 3 weeks, 0.69; 95% CI, 0.52 to 0.90; P=0.0036). The response rate was improved with pembrolizumab administered every 2 weeks (33.7%) and every 3 weeks (32.9%), as compared with ipilimumab (11.9%) (P<0.001 for both comparisons). Responses were ongoing in 89.4%, 96.7%, and 87.9% of patients, respectively, after a median follow-up of 7.9 months. Efficacy was similar in the two pembrolizumab groups. Rates of treatment-related adverse events of grade 3 to 5 severity were lower in the pembrolizumab groups (13.3% and 10.1%) than in the ipilimumab group (19.9%). CONCLUSIONS The anti-PD-1 antibody pembrolizumab prolonged progression-free survival and overall survival and had less high-grade toxicity than did ipilimumab in patients with advanced melanoma. (Funded by Merck Sharp & Dohme; KEYNOTE-006 ClinicalTrials.gov number, NCT01866319.).

Overall Survival with Combined Nivolumab and Ipilimumab in Advanced Melanoma

BACKGROUND Nivolumab combined with ipilimumab resulted in longer progression‐free survival and a higher objective response rate than ipilimumab alone in a phase 3 trial involving patients with advanced melanoma. We now report 3‐year overall survival outcomes in this trial. METHODS We randomly assigned, in a 1:1:1 ratio, patients with previously untreated advanced melanoma to receive nivolumab at a dose of 1 mg per kilogram of body weight plus ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses, followed by nivolumab at a dose of 3 mg per kilogram every 2 weeks; nivolumab at a dose of 3 mg per kilogram every 2 weeks plus placebo; or ipilimumab at a dose of 3 mg per kilogram every 3 weeks for four doses plus placebo, until progression, the occurrence of unacceptable toxic effects, or withdrawal of consent. Randomization was stratified according to programmed death ligand 1 (PD‐L1) status, BRAF mutation status, and metastasis stage. The two primary end points were progression‐free survival and overall survival in the nivolumab‐plus‐ipilimumab group and in the nivolumab group versus the ipilimumab group. RESULTS At a minimum follow‐up of 36 months, the median overall survival had not been reached in the nivolumab‐plus‐ipilimumab group and was 37.6 months in the nivolumab group, as compared with 19.9 months in the ipilimumab group (hazard ratio for death with nivolumab plus ipilimumab vs. ipilimumab, 0.55 [P<0.001]; hazard ratio for death with nivolumab vs. ipilimumab, 0.65 [P<0.001]). The overall survival rate at 3 years was 58% in the nivolumab‐plus‐ipilimumab group and 52% in the nivolumab group, as compared with 34% in the ipilimumab group. The safety profile was unchanged from the initial report. Treatment‐related adverse events of grade 3 or 4 occurred in 59% of the patients in the nivolumab‐plus‐ipilimumab group, in 21% of those in the nivolumab group, and in 28% of those in the ipilimumab group. CONCLUSIONS Among patients with advanced melanoma, significantly longer overall survival occurred with combination therapy with nivolumab plus ipilimumab or with nivolumab alone than with ipilimumab alone. (Funded by Bristol‐Myers Squibb and others; CheckMate 067 ClinicalTrials.gov number, NCT01844505.)

Distinguishing Clinicopathologic Features of Patients with V600E and V600K BRAF-Mutant Metastatic Melanoma

Purpose: Certain clinicopathologic features correlate with BRAF mutation status in melanoma including younger age and primary subtype. This study sought to determine the BRAF mutation status by age-decade and whether BRAF-mutant genotypes correlated with clinicopathologic features and outcome in patients with metastatic melanoma. Methods: A prospectively assembled cohort of Australian patients were followed from diagnosis of metastatic melanoma (N = 308). Clinicopathologic variables were correlated with BRAF mutational status, genotype, and survival. Results: Forty-six percent of patients had a BRAF mutation; 73% V600E, 19% V600K, and 8% other genotypes. An inverse relationship existed between BRAF mutation prevalence and age-decade (P < 0.001). All patients <30 years and only 25% ≥70 years had BRAF-mutant melanoma. Amongst BRAF-mutant melanoma, the frequency of non-V600E genotypes (including V600K) increased with increasing age. Non-V600E genotypes comprised <20% in patients <50 years and >40% in those ≥70 years. A higher degree of cumulative sun-induced damage correlated with V600K but not V600E melanoma (P = 0.002). The disease-free interval from diagnosis of primary melanoma to first distant metastasis was shorter for patients with V600K compared with V600E melanoma (17.4 vs. 39.2 months, P = 0.048), with no difference in survival thereafter. In patients BRAF tested at diagnosis of metastatic melanoma, one year survival from diagnosis of metastasis was significantly longer for patients with BRAF-mutant melanoma treated with an inhibitor (83%), than those not treated with an inhibitor (29%, P < 0.001), or patients with BRAF wild-type melanoma (37%, P < 0.001). Conclusion: Different genotypes exist within BRAF-mutant metastatic melanoma, representing biologically and clinically discrete subtypes, suggesting distinct etiology and behavior. Clin Cancer Res; 18(12); 3242–9. ©2012 AACR.

BRAF Inhibitor Resistance Mechanisms in Metastatic Melanoma: Spectrum and Clinical Impact

Purpose: Multiple BRAF inhibitor resistance mechanisms have been described, however, their relative frequency, clinical correlates, and effect on subsequent therapy have not been assessed in patients with metastatic melanoma. Experimental Design: Fifty-nine BRAFV600-mutant melanoma metastases from patients treated with dabrafenib or vemurafenib were analyzed. The genetic profile of resistance mechanisms and tumor signaling pathway activity was correlated with clinicopathologic features and therapeutic outcomes. Results: Resistance mechanisms were identified in 58% progressing tumors and BRAF alterations were common. Gene expression analysis revealed that mitogen-activated protein kinase (MAPK) activity remained inhibited in 21% of resistant tumors, and the outcomes of patients with these tumors were poor. Resistance mechanisms also occurred in pretreatment biopsies and heterogeneity of resistance mechanisms occurred within patients and within tumors. There were no responses to subsequent targeted therapy, even when a progressing tumor had a resistance mechanism predicted to be responsive. Conclusions: Selecting sequential drugs based on the molecular characteristics of a single progressing biopsy is unlikely to provide improved responses, and first-line therapies targeting multiple pathways will be required. Clin Cancer Res; 20(7); 1965–77. ©2014 AACR.

Ipilimumab Therapy in Patients With Advanced Melanoma and Preexisting Autoimmune Disorders

IMPORTANCE Ipilimumab and other immune therapies are effective treatment options for patients with advanced melanoma but cause frequent immune-related toxic effects. Autoimmune diseases are common, and the safety and efficacy of ipilimumab therapy in patients with preexisting autoimmune disorders is not known. OBJECTIVE To determine the safety and efficacy of ipilimumab therapy in patients with advanced melanoma with preexisting autoimmune disorders. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of patients with advanced melanoma and preexisting autoimmune disorders who received ipilimumab at 9 academic tertiary referral centers from January 1, 2012, through August 1, 2015. The data analysis was performed on August 24, 2015. EXPOSURE Ipilimumab therapy. MAIN OUTCOMES AND MEASURES Safety, in terms of frequency of autoimmune flares and conventional immune-related adverse events (irAEs), and efficacy, in terms of response rates and overall survival, were evaluated descriptively. RESULTS Of the 30 patients who received ipilimumab (17 [57%] male; median [range] age, 59.5 [30-80] y), 6 had rheumatoid arthritis, 5 had psoriasis, 6 had inflammatory bowel disease, 2 had systemic lupus erythematosus, 2 had multiple sclerosis, 2 had autoimmune thyroiditis, and 7 had other conditions. Thirteen patients (43%) were receiving immunosuppressive therapy at the time of initiation of ipilimumab therapy, most commonly low-dose prednisone or hydroxychloroquine. With ipilimumab treatment, 8 patients (27%) experienced exacerbations of their autoimmune condition necessitating systemic treatment; all were managed with corticosteroids. Conventional grade 3 to 5 irAEs occurred in 10 patients (33%) and were reversible with corticosteroids or with infliximab therapy in 2 cases. One patient with baseline psoriasis died of presumed immune-related colitis after a 1-week delay prior to reporting symptoms. Fifteen patients (50%) had neither autoimmune disease flares nor irAEs. Six patients experienced an objective response (20%), including 1 with a durable complete response. CONCLUSIONS AND RELEVANCE To our knowledge, this is the largest series of patients with preexisting autoimmune disease treated with immune checkpoint inhibitors. Ipilimumab was clinically active and was associated with exacerbations of autoimmune disease and conventional ipilimumab-induced irAEs that were readily manageable with standard therapies when started in a timely fashion. Ipilimumab therapy may be considered in this setting with vigilant clinical monitoring.

Pneumonitis in Patients Treated With Anti-Programmed Death-1/Programmed Death Ligand 1 Therapy.

Purpose Pneumonitis is an uncommon but potentially fatal toxicity of anti-programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) monoclonal antibodies (mAbs). Clinical, radiologic, and pathologic features are poorly described. Methods Patients who received anti-PD-1/PD-L1 monotherapy or in combination with anti-cytotoxic T-cell lymphocyte-4 mAb were identified at two institutions (Memorial Sloan Kettering Cancer Center: advanced solid cancers, 2009 to 2014, and Melanoma Institute of Australia: melanomas only, 2013 to 2015). Pneumonitis was diagnosed by the treating investigator; cases with confirmed malignant lung infiltration or infection were excluded. Clinical, radiologic, and pathologic features of pneumonitis were collected. Associations among pneumonitis incidence, therapy received, and underlying malignancy were examined with Fishers exact test as were associations between pneumonitis features and outcomes. Results Of 915 patients who received anti-PD-1/PD-L1 mAbs, pneumonitis developed in 43 (5%; 95% CI, 3% to 6%; Memorial Sloan Kettering Cancer Center, 27 of 578 [5%]; Melanoma Institute of Australia, 16 of 337 [5%]). Time to onset of pneumonitis ranged from 9 days to 19.2 months. The incidence of pneumonitis was higher with combination immunotherapy versus monotherapy (19 of 199 [10%] v 24 of 716 [3%]; P < .01). Incidence was similar in patients with melanoma and non-small-cell lung cancer (overall, 26 of 532 [5%] v nine of 209 [4%]; monotherapy, 15 of 417 v five of 152 [ P = 1.0]; combination, 11 of 115 v four of 57 [ P = .78]). Seventy-two percent (31 of 43) of cases were grade 1 to 2, and 86% (37 of 43) improved/resolved with drug holding/immunosuppression. Five patients worsened clinically and died during the course of pneumonitis treatment; proximal cause of death was pneumonitis (n = 1), infection related to immunosuppression (n = 3), or progressive cancer (n = 1). Radiologic and pathologic features of pneumonitis were diverse. Conclusion Pneumonitis associated with anti-PD-1/PD-L1 mAbs is a toxicity of variable onset and clinical, radiologic, and pathologic appearances. It is more common when anti-PD-1/PD-L1 mAbs are combined with anti-cytotoxic T-cell lymphocyte-4 mAb. Most events are low grade and improve/resolve with drug holding/immunosuppression. Rarely, pneumonitis worsens despite immunosuppression, and may result in infection and/or death.

Increased MAPK reactivation in early resistance to dabrafenib/trametinib combination therapy of BRAF-mutant metastatic melanoma

One-third of BRAF-mutant metastatic melanoma patients treated with combined BRAF and MEK inhibition progress within 6 months. Treatment options for these patients remain limited. Here we analyse 20 BRAF(V600)-mutant melanoma metastases derived from 10 patients treated with the combination of dabrafenib and trametinib for resistance mechanisms and genetic correlates of response. Resistance mechanisms are identified in 9/11 progressing tumours and MAPK reactivation occurred in 9/10 tumours, commonly via BRAF amplification and mutations activating NRAS and MEK2. Our data confirming that MEK2(C125S), but not the synonymous MEK1(C121S) protein, confers resistance to combination therapy highlight the functional differences between these kinases and the preponderance of MEK2 mutations in combination therapy-resistant melanomas. Exome sequencing did not identify additional progression-specific resistance candidates. Nevertheless, most melanomas carried additional oncogenic mutations at baseline (for example, RAC1 and AKT3) that activate the MAPK and PI3K pathways and are thus predicted to diminish response to MAPK inhibitors.

Anti-PD-1 therapy in patients with advanced melanoma and preexisting autoimmune disorders or major toxicity with ipilimumab

Background Anti-PD-1 antibodies (anti-PD-1) have clinical activity in a number of malignancies. All clinical trials have excluded patients with significant preexisting autoimmune disorders (ADs) and only one has included patients with immune-related adverse events (irAEs) with ipilimumab. We sought to explore the safety and efficacy of anti-PD-1 in such patients. Patients and methods Patients with advanced melanoma and preexisting ADs and/or major immune-related adverse events (irAEs) with ipilimumab (requiring systemic immunosuppression) that were treated with anti-PD-1 between 1 July 2012 and 30 September 2015 were retrospectively identified. Results One hundred and nineteen patients from 13 academic tertiary referral centers were treated with anti-PD-1. In patients with preexisting AD (N = 52), the response rate was 33%. 20 (38%) patients had a flare of AD requiring immunosuppression, including 7/13 with rheumatoid arthritis, 3/3 with polymyalgia rheumatica, 2/2 with Sjogrens syndrome, 2/2 with immune thrombocytopaenic purpura and 3/8 with psoriasis. No patients with gastrointestinal (N = 6) or neurological disorders (N = 5) flared. Only 2 (4%) patients discontinued treatment due to flare, but 15 (29%) developed other irAEs and 4 (8%) discontinued treatment. In patients with prior ipilimumab irAEs requiring immunosuppression (N = 67) the response rate was 40%. Two (3%) patients had a recurrence of the same ipilimumab irAEs, but 23 (34%) developed new irAEs (14, 21% grade 3-4) and 8 (12%) discontinued treatment. There were no treatment-related deaths. Conclusions In melanoma patients with preexisting ADs or major irAEs with ipilimumab, anti-PD-1 induced relatively frequent immune toxicities, but these were often mild, easily managed and did not necessitate discontinuation of therapy, and a significant proportion of patients achieved clinical responses. The results support that anti-PD-1 can be administered safely and can achieve clinical benefit in patients with preexisting ADs or prior major irAEs with ipilimumab.

Circulating tumor DNA to monitor treatment response and detect acquired resistance in patients with metastatic melanoma

Repeat tumor biopsies to study genomic changes during therapy are difficult, invasive and data are confounded by tumoral heterogeneity. The analysis of circulating tumor DNA (ctDNA) can provide a non-invasive approach to assess prognosis and the genetic evolution of tumors in response to therapy. Mutation-specific droplet digital PCR was used to measure plasma concentrations of oncogenic BRAF and NRAS variants in 48 patients with advanced metastatic melanoma prior to treatment with targeted therapies (vemurafenib, dabrafenib or dabrafenib/trametinib combination) or immunotherapies (ipilimumab, nivolumab or pembrolizumab). Baseline ctDNA levels were evaluated relative to treatment response and progression-free survival (PFS). Tumor-associated ctDNA was detected in the plasma of 35/48 (73%) patients prior to treatment and lower ctDNA levels at this time point were significantly associated with response to treatment and prolonged PFS, irrespective of therapy type. Levels of ctDNA decreased significantly in patients treated with MAPK inhibitors (p < 0.001) in accordance with response to therapy, but this was not apparent in patients receiving immunotherapies. We show that circulating NRAS mutations, known to confer resistance to BRAF inhibitors, were detected in 3 of 7 (43%) patients progressing on kinase inhibitor therapy. Significantly, ctDNA rebound and circulating mutant NRAS preceded radiological detection of progressive disease. Our data demonstrate that ctDNA is a useful biomarker of response to kinase inhibitor therapy and can be used to monitor tumor evolution and detect the early appearance of resistance effectors.

Pembrolizumab versus ipilimumab for advanced melanoma: Final overall survival results of a multicentre, randomised, open-label phase 3 study (KEYNOTE-006)

BACKGROUND Interim analyses of the phase 3 KEYNOTE-006 study showed superior overall and progression-free survival of pembrolizumab versus ipilimumab in patients with advanced melanoma. We present the final protocol-specified survival analysis. METHODS In this multicentre, open-label, randomised, phase 3 trial, we recruited patients from 87 academic institutions, hospitals, and cancer centres in 16 countries (Australia, Austria, Belgium, Canada, Chile, Colombia, France, Germany, Israel, Netherlands, New Zealand, Norway, Spain, Sweden, UK, and USA). We randomly assigned participants (1:1:1) to one of two dose regimens of pembrolizumab, or one regimen of ipilimumab, using a centralised, computer-generated allocation schedule. Treatment assignments used blocked randomisation within strata. Eligible patients were at least 18 years old, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, at least one measurable lesion per Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), unresectable stage III or IV melanoma (excluding ocular melanoma), and up to one previous systemic therapy (excluding anti-CTLA-4, PD-1, or PD-L1 agents). Secondary eligibility criteria are described later. Patients were excluded if they had active brain metastases or active autoimmune disease requiring systemic steroids. The primary outcome was overall survival (defined as the time from randomisation to death from any cause). Response was assessed per RECIST v1.1 by independent central review at week 12, then every 6 weeks up to week 48, and then every 12 weeks thereafter. Survival was assessed every 12 weeks, and final analysis occurred after all patients were followed up for at least 21 months. Primary analysis was done on the intention-to-treat population (all randomly assigned patients) and safety analyses were done in the treated population (all randomly assigned patients who received at least one dose of study treatment). Data cutoff date for this analysis was Dec 3, 2015. This study was registered with ClinicalTrials.gov, number NCT01866319. FINDINGS Between Sept 18, 2013, and March 3, 2014, 834 patients with advanced melanoma were enrolled and randomly assigned to receive intravenous pembrolizumab every 2 weeks (n=279), intravenous pembrolizumab every 3 weeks (n=277), or intravenous ipilimumab every 3 weeks (ipilimumab for four doses; n=278). One patient in the pembrolizumab 2 week group and 22 patients in the ipilimumab group withdrew consent and did not receive treatment. A total of 811 patients received at least one dose of study treatment. Median follow-up was 22·9 months; 383 patients died. Median overall survival was not reached in either pembrolizumab group and was 16·0 months with ipilimumab (hazard ratio [HR] 0·68, 95% CI 0·53-0·87 for pembrolizumab every 2 weeks vs ipilimumab; p=0·0009 and 0·68, 0·53-0·86 for pembrolizumab every 3 weeks vs ipilimumab; p=0·0008). 24-month overall survival rate was 55% in the 2-week group, 55% in the 3-week group, and 43% in the ipilimumab group. INTERPRETATION Substantiating the results of the interim analyses of KEYNOTE-006, pembrolizumab continued to provide superior overall survival versus ipilimumab, with no difference between pembrolizumab dosing schedules. These conclusions further support the use of pembrolizumab as a standard of care for advanced melanoma. FUNDING Merck & Co.