PURPOSE: Combination programmed cell death protein 1/cytotoxic T-cell lymphocyte-4–blockade and dual BRAF/MEK inhibition have each shown significant clinical benefit in patients with BRAFV600-mutant metastatic melanoma, leading to broad regulatory approval. Little prospective data exist to guide the choice of either initial therapy or treatment sequence in this population. This study was conducted to determine which initial treatment or treatment sequence produced the best efficacy. PATIENTS AND METHODS: In a phase III trial, patients with treatment-naive BRAFV600-mutant metastatic melanoma were randomly assigned to receive either combination nivolumab/ipilimumab (arm A) or dabrafenib/trametinib (arm B) in step 1, and at disease progression were enrolled in step 2 to receive the alternate therapy, dabrafenib/trametinib (arm C) or nivolumab/ipilimumab (arm D). The primary end point was 2-year overall survival (OS). Secondary end points were 3-year OS, objective response rate, response duration, progression-free survival, crossover feasibility, and safety. RESULTS: A total of 265 patients were enrolled, with 73 going onto step 2 (27 in arm C and 46 in arm D). The study was stopped early by the independent Data Safety Monitoring Committee because of a clinically significant end point being achieved. The 2-year OS for those starting on arm A was 71.8% (95% CI, 62.5 to 79.1) and arm B 51.5% (95% CI, 41.7 to 60.4; log-rank P = .010). Step 1 progression-free survival favored arm A ( P = .054). Objective response rates were arm A: 46.0%; arm B: 43.0%; arm C: 47.8%; and arm D: 29.6%. Median duration of response was not reached for arm A and 12.7 months for arm B ( P < .001). Crossover occurred in 52% of patients with documented disease progression. Grade ≥ 3 toxicities occurred with similar frequency between arms, and regimen toxicity profiles were as anticipated. CONCLUSION: Combination nivolumab/ipilimumab followed by BRAF and MEK inhibitor therapy, if necessary, should be the preferred treatment sequence for a large majority of patients.

We conducted a randomized phase III trial to evaluate whether adjuvant pembrolizumab for one year (647 patients) improved recurrence-free survival (RFS) or overall survival (OS) in comparison with high-dose IFNα-2b for one year or ipilimumab for up to three years (654 patients), the approved standard-of-care adjuvant immunotherapies at the time of enrollment for patients with high-risk resected melanoma. At a median follow-up of 47.5 months, pembrolizumab was associated with significantly longer RFS than prior standard-of-care adjuvant immunotherapies [HR, 0.77; 99.62% confidence interval (CI), 0.59–0.99; P = 0.002]. There was no statistically significant association with OS among all patients (HR, 0.82; 96.3% CI, 0.61–1.09; P = 0.15). Proportions of treatment-related adverse events of grades 3 to 5 were 19.5% with pembrolizumab, 71.2% with IFNα-2b, and 49.2% with ipilimumab. Therefore, adjuvant pembrolizumab significantly improved RFS but not OS compared with the prior standard-of-care immunotherapies for patients with high-risk resected melanoma. Significance: Adjuvant PD-1 blockade therapy decreases the rates of recurrence, but not survival, in patients with surgically resectable melanoma, substituting the prior standard-of-care immunotherapies for this cancer. See related commentary by Smithy and Shoushtari, p. 599. This article is highlighted in the In This Issue feature, p. 587

Glembatumumab vedotin (CDX-011, GV) is a fully human Immunoglobulin G2 monoclonal antibody directed against glycoprotein NMB coupled via a peptide linker to monomethyl auristatin E (MMAE), a potent cytotoxic microtubule inhibitor. This phase II study evaluated the overall response rate and safety of GV, glycoprotein NMB (GPNMB) expression, and survival in patients with metastatic uveal melanoma. Eligible patients with metastatic uveal melanoma who had not previously been treated with chemotherapy received GV 1.9 mg/kg every three weeks. The primary endpoint was the objective response rate (ORR). Secondary endpoints included GPNMB expression, progression-free survival (PFS), overall survival (OS), and toxicity analysis. GPNMB expression was assessed pre- and post-treatment via immunohistochemistry for patients with available tumor tissue. Out of 35 patients who received treatment, two patients had confirmed partial responses (PRs; 6%), and 18 patients had a stable disease (SD; 51%) as the best objective response. 38% of the patients had stable disease >100 days. The grade 3 or 4 toxicities that occurred in two or more patients were neutropenia, rash, hyponatremia, and vomiting. The median progression-free survival was 3.1 months (95% CI: 1.5–5.6), and the median overall survival was 11.9 months (95% CI 9.0–16.9) in the evaluable study population. GV is well-tolerated in metastatic uveal melanoma. The disease control rate was 57% despite a low objective response rate. Exploratory immune correlation studies are underway to provide insight into target saturation, combination strategies, and antigen release.

This study was designed to evaluate the safety, pharmacokinetics, and clinical activity of pazopanib combined with paclitaxel to determine the recommended phase II dose in the first-line setting in patients with advanced solid tumors. Patients were enrolled in a 3+3 dose-escalation design to determine the maximum tolerated regimen (MTR) of once daily pazopanib plus paclitaxel administered every 3 weeks at four dose levels (DL1-4). Safety, pharmacokinetics, pharmacogenetics, and disease assessments were performed. Twenty-eight patients received treatment. One patient at DL1 had dose-limiting toxicity (DLT) of elevated hepatic enzymes. After pazopanib discontinuation, liver enzyme concentrations remained high until a concurrent medication, simvastatin, was discontinued. This patient had the defective CYP2C8*3*3 genotype. At DL2, 1 patient had DLT of elevated hepatic enzymes with rash and 1 patient had DLT of rash. The MTR was paclitaxel 150 mg/m2 plus pazopanib 800 mg. The most common toxicities were alopecia, fatigue, hypertension, nausea, diarrhea, dysgeusia, neutropenia, myalgia, hair color changes, and peripheral neuropathy. Coadministration of pazopanib and paclitaxel resulted in a 38% increase in systemic exposure to paclitaxel, relative to administration of paclitaxel alone, at the MTR. Of the 28 patients treated with the combination, 10 achieved a partial response and 10 achieved stable disease of ≥12 weeks. Pazopanib 800 mg daily plus paclitaxel 150 mg/m2 every 3 weeks was the recommended phase II dose, with a manageable safety profile, and with clinical activity in both melanoma and non–small cell lung cancer that suggest further evaluation of this combination is warranted. Mol Cancer Ther; 14(2); 461–9. ©2014 AACR.

BRD4 is an epigenetic reader protein that regulates oncogenes such as myc in cancer. However, its additional role in shaping immune responses via regulation of inflammatory and myeloid cell responses is not yet fully understood. This work further characterized the multifaceted role of BRD4 in antitumor immunity. Nanostring gene expression analysis of EMT6 tumors treated with a BRD4 inhibitor identified a reduction in myeloid gene expression signatures. Additionally, BRD4 inhibition significantly reduced myeloid-derived suppressor cells (MDSCs) in the spleens and tumors of mice in multiple tumor models and also decreased the release of tumor-derived MDSC growth and chemotactic factors. Pharmacologic inhibition of BRD4 in MDSCs induced apoptosis and modulated expression of apoptosis regulatory proteins. A BRD4 myeloid–specific knockout model suggested that the dominant mechanism of MDSC reduction after BRD4 inhibition was primarily through a direct effect on MDSCs. BRD4 inhibition enhanced anti–PD-L1 therapy in the EMT6, 4T1, and Lewis lung carcinoma tumor models, and the efficacy of the combination treatment was dependent on CD8 ⁺ T cells and on BRD4 expression in the myeloid compartment. These results identify BRD4 as a regulator of MDSC survival and provide evidence to further investigate BRD4 inhibitors in combination with immune-based therapies.

Brain metastases are a devastating sequela of common primary cancers (e.g., lung, breast, and skin) and have limited effective therapeutic options. Previously, systemic chemotherapy failed to demonstrate significant benefit in patients with brain metastases, but in recent decades, targeted therapies and more recently immune checkpoint inhibitors (ICIs) have yielded promising results in preclinical and clinical studies. Furthermore, there is significant interest in harnessing the immunomodulatory effects of radiotherapy (RT) to synergize with ICIs. Herein, we discuss studies evaluating the impact of RT dose and fractionation on the immune response, early studies supporting the synergistic interaction between RT and ICIs, and ongoing clinical trials assessing the benefit of combination therapy in patients with brain metastases.