Sequencing of Checkpoint or BRAF/MEK Inhibitors on Brain Metastases in Melanoma

Combination of encorafenib and binimetinib followed by ipilimumab and nivolumab versus ipilimumab and nivolumab in patients with advanced melanoma with BRAFV600E or BRAFV600K mutations (EBIN): an international, open-label, randomised, controlled, phase 2 study

BACKGROUND

Current first-line treatment for patients with metastatic melanoma with BRAFV600E or BRAFV600K mutations includes immunotherapy with immune checkpoint inhibitors and targeted therapy; however, the optimal sequencing of these treatments is unclear. We aimed to investigate the use of a targeted-therapy induction regimen before treatment with immune checkpoint inhibitors.

METHODS

This open-label, randomised, controlled, phase 2 trial (EBIN) was conducted at 37 centres in eight European countries. Eligible patients were 18 years or older and had previously untreated, unresectable, stage III or IV melanoma with BRAFV600E or BRAFV600K mutations and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1) to one of two groups. Those in the induction group received targeted therapy (oral encorafenib 450 mg once a day plus oral binimetinib 45 mg twice a day for 12 weeks) followed by immune checkpoint inhibitors (intravenous nivolumab 3 mg/kg plus intravenous ipilimumab 1 mg/kg once every 3 weeks for four doses, followed by intravenous nivolumab 480 mg once every 4 weeks until unacceptable toxicity, disease progression, or 2 years of treatment). Patients in the control group received immune checkpoint inhibitors as above without any induction targeted therapy. Randomisation was conducted using a minimisation technique and was stratified by centre and a variable defined using stage and lactate dehydrogenase activity. The primary outcome was progression-free survival in the intention-to-treat population. Safety was assessed in all patients who initiated the protocol treatment. In this Article we report the primary analysis. The study is registered with ClinicalTrials.gov, NCT03235245, and is ongoing.

FINDINGS

Between Nov 12, 2018, and July 11, 2022, 271 patients were randomly assigned: 136 to the induction group and 135 to the control group. 103 (38%) patients were female, 168 (62%) were male, and the median age was 55 years (IQR 43-66). The median follow-up time was 21 months (IQR 13-33). There was no evidence of a longer progression-free survival in the induction group than in the control group (hazard ratio 0·87, 90% CI 0·67-1·12; p=0·36). The median progression-free survival was 9 months (95% CI 7-13) in the induction group and 9 months (5-14) in the control group. Grade 3-5 treatment-related adverse events occurred in 57 (42%) of 136 patients who started treatment in the induction group and in 42 (32%) of 131 patients who started treatment in the control group. The most common grade 3-4 treatment-related adverse event was hepatitis (17 [13%] of 136 patients in the induction group and nine [7%] of 131 patients in the control group). Serious treatment-related adverse events occurred in 45 (33%) of 136 patients in the induction group and 33 (25%) of 131 patients in the control group. There were three treatment-related deaths: two from cardiac events (heart failure and arrhythmia) in the induction group and one from meningitis in the control group.

INTERPRETATION

The targeted-therapy induction regimen did not improve progression-free survival compared with first-line treatment with immune checkpoint inhibitors in unselected patients with advanced melanoma with BRAFV600E or BRAFV600K mutations.

FUNDING

Bristol Myers Squibb and Pierre Fabre.

Early switch from run-in with targeted to immunotherapy in advanced BRAFV600-positive melanoma: final results of the randomised phase II ImmunoCobiVem trial

BACKGROUND

Optimal sequencing of immune checkpoint inhibitors (ICIs) and targeted therapies (TTs) in BRAFV600-positive advanced melanoma should achieve rapid tumour control and durable progression-free survival (PFS), translating into prolonged overall survival (OS).

PATIENTS AND METHODS

The 1 : 1 randomised phase II ImmunoCobiVem trial compared-after a 3-month run-in phase with vemurafenib (VEM, 960 mg twice daily) and cobimetinib (COB, 60 mg daily days 21-28, q4w)-continuous VEM + COB until disease progression (PD1) and second-line atezolizumab (ATEZO, 1200 mg, q3w) in arm A versus early switch to ATEZO after run-in, followed by crossover to VEM + COB at PD1, in arm B. PFS from the start of run-in until PD1 was the primary endpoint (PFS1); secondary efficacy endpoints were OS, overall PFS (PFS2) and PFS3 (time from PD1 to PD after crossover, i.e. PD2) and best overall response rates (BORRs).

RESULTS

The final analysis (median follow-up 57.0 months, interquartile range 22.7-63.0 months) confirmed longer PFS1 for continuous TT [arm A (69 patients) versus arm B (early switch, 66 patients); hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.41-0.91, P = 0.006], but early switch to ICIs resulted in better long-term OS [4- and 5-year landmark OS 42% (95% CI 29% to 55%) and 40% (95% CI 27% to 53%) for arm A, and 53% (95% CI 38% to 65%) and 45% (95% CI 31% to 58%) for arm B; descriptive HR 1.17, 95% CI 0.71-1.91]. Absolute BORRs were 81% and 89%, respectively, with 15 (22%) and 19 (29%) patients achieving a complete response at least once along each sequence. At crossover, TT retreatment (arm B) resulted in higher PFS3 than second-line ICI (arm A).

CONCLUSIONS

Early switch to ICIs after TT run-in (arm B) led to an improved, although not statistically significant, 4- and 5-year landmark OS compared with arm A. No subgroups were identified for which a TT run-in provided clinical benefit. The number of patients developing brain metastasis and the time to brain metastasis were not improved by an early TT to ICI switch.

Current Treatment Paradigms for Advanced Melanoma with Brain Metastases

The therapeutic management of melanoma brain metastases has undergone a profound revolution during recent decades. Optimal integration of systemic therapies with local treatments seems to represent the strategy to pursue in order to maximize clinical outcomes, stressing the need for real multidisciplinary care in this setting of patients. However, the current approach in the clinics does not necessarily reflect what the current guidelines state, and several pending issues are present, from the ideal therapeutic sequence between stereotactic radiosurgery (SRS) and drug administration to the current role of surgery and whole brain radiotherapy (WBRT), all of which need to be addressed. This narrative review aims to provide practical help for navigating the current controversies, with an eye towards possible future advancements in the field, which could help to obtain a comprehensive molecular characterization of the tumor and a more personalized patient-centered therapeutic approach.

Overcoming Resistance Mechanisms to Melanoma Immunotherapy

The advent of immune checkpoint inhibition has revolutionized treatment of advanced melanoma. While most patients derive survival benefit from established immunotherapies, notably monoclonal antibodies blocking cytotoxic T-lymphocyte antigen 4 and programmed cell death protein 1, a subset does not optimally respond due to the manifestation of innate or acquired resistance to these therapies. Combination regimens have proven efficacious relative to single-agent blockade, but also yield high-grade treatment toxicities that are often dose-limiting for patients. In this review, we discuss the significant strides made in the past half-decade toward expanding the melanoma immunotherapy treatment paradigm. These include newly approved therapies, adoption of neoadjuvant immunotherapy, and studies in the clinical trials pipeline targeting alternative immune checkpoints and key immunoregulatory molecules. We then review how developments in molecular and functional diagnostics have furthered our understanding of the tumor-intrinsic and -extrinsic mechanisms driving immunotherapy resistance, as well as highlight novel biomarkers for predicting treatment response. Throughout, we discuss potential approaches for targeting these resistance mechanisms in rational combination with established immunotherapies to improve outcomes for patients with melanoma.