Initial Evidence for the Efficacy of Naporafenib in Combination With Trametinib in NRAS-Mutant Melanoma: Results From the Expansion Arm of a Phase Ib, Open-Label Study.

PURPOSE: No approved targeted therapy for the treatment of patients with neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS)-mutant melanoma is currently available. PATIENTS AND METHODS: In this phase Ib escalation/expansion study (ClinicalTrials.gov identifier: NCT02974725), the safety, tolerability, and preliminary antitumor activity of naporafenib (LXH254), a BRAF/CRAF protein kinases inhibitor, were explored in combination with trametinib in patients with advanced/metastatic KRAS- or BRAF-mutant non-small-cell lung cancer (escalation arm) or NRAS-mutant melanoma (escalation and expansion arms). RESULTS: Thirty-six and 30 patients were enrolled in escalation and expansion, respectively. During escalation, six patients reported grade ≥3 dose-limiting toxicities, including dermatitis acneiform (n = 2), maculopapular rash (n = 2), increased lipase (n = 1), and Stevens-Johnson syndrome (n = 1). The recommended doses for expansion were naporafenib 200 mg twice a day plus trametinib 1 mg once daily and naporafenib 400 mg twice a day plus trametinib 0.5 mg once daily. During expansion, all 30 patients experienced a treatment-related adverse event, the most common being rash (80%, n = 24), blood creatine phosphokinase increased, diarrhea, and nausea (30%, n = 9 each). In expansion, the objective response rate, median duration of response, and median progression-free survival were 46.7% (95% CI, 21.3 to 73.4; 7 of 15 patients), 3.75 (95% CI, 1.97 to not estimable [NE]) months, and 5.52 months, respectively, in patients treated with naporafenib 200 mg twice a day plus trametinib 1 mg once daily, and 13.3% (95% CI, 1.7 to 40.5; 2 of 15 patients), 3.75 (95% CI, 2.04 to NE) months, and 4.21 months, respectively, in patients treated with naporafenib 400 mg twice a day plus trametinib 0.5 mg once daily. CONCLUSION: Naporafenib plus trametinib showed promising preliminary antitumor activity in patients with NRAS-mutant melanoma. Prophylactic strategies aimed to lower the incidence of skin-related events are under investigation.

A Randomized Phase II Study of Anti-CSF1 Monoclonal Antibody Lacnotuzumab (MCS110) Combined with Gemcitabine and Carboplatin in Advanced Triple-Negative Breast Cancer.

PURPOSE: This phase II study determined the efficacy of lacnotuzumab added to gemcitabine plus carboplatin (gem-carbo) in patients with advanced triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Female patients with advanced TNBC, with high levels of tumor-associated macrophages not amenable to curative treatment by surgery or radiotherapy were enrolled. Lacnotuzumab was dosed at 10 mg/kg every 3 weeks, ± a dose on cycle 1, day 8. Gemcitabine (1,000 mg/m2) and carboplatin (dose in mg calculated by area under the curve [mg/mL/min] × (glomerular filtration rate [mL/min] + 25 [mL/min]) were dosed every 3 weeks. Treatment continued until unacceptable toxicity, disease progression, or discontinuation by physician/patient. RESULTS: Patients received lacnotuzumab + gem-carbo (n = 34) or gem-carbo (n = 15). Enrollment was halted due to recruitment challenges owing to rapid evolution of the therapeutic landscape; formal hypothesis testing of the primary endpoint was therefore not performed. Median progression-free survival was 5.6 months [90% confidence interval (CI), 4.47-8.64] in the lacnotuzumab + gem-carbo arm and 5.5 months (90% CI, 3.45-7.46) in the gem-carbo arm. Hematologic adverse events were common in both treatment arms; however, patients treated with lacnotuzumab experienced more frequent aspartate aminotransferase, alanine aminotransferase, and creatine kinase elevations. Pharmacokinetic results showed that free lacnotuzumab at 10 mg/kg exhibited a typical IgG pharmacokinetic profile and target engagement of circulating colony-stimulating factor 1 ligand. CONCLUSIONS: Despite successful target engagement and anticipated pharmacokinetic profile, lacnotuzumab + gem-carbo showed comparable antitumor activity to gem-carbo alone, with slightly poorer tolerability. However, the data presented in this article would be informative for future studies testing agents targeting the CSF1-CSF1 receptor pathway in TNBC.