Highlights
- The EBIN phase 2 trial evaluated whether targeted therapy induction followed by immunotherapy is superior to immunotherapy alone in advanced BRAFV600-mutant melanoma.
- No significant difference in progression-free survival (PFS) was observed between the two strategies.
- The induction group experienced higher rates of severe (grade 3-5) treatment-related adverse events.
- Current data do not support routine use of targeted therapy induction in unselected patients with BRAFV600-mutant metastatic melanoma.
Study Background and Disease Burden
Metastatic melanoma with BRAFV600E or BRAFV600K mutations represents a significant clinical challenge, accounting for approximately 40-50% of all advanced melanoma cases. The introduction of immune checkpoint inhibitors (ICIs) such as nivolumab and ipilimumab, and targeted therapies like BRAF and MEK inhibitors (e.g., encorafenib, binimetinib), has transformed the treatment landscape. While both approaches are effective, the optimal sequencing to maximize durable disease control remains unresolved. Preclinical rationale suggests that targeted therapy may prime the tumor microenvironment for subsequent immunotherapy, but prospective evidence is limited.
Study Design
The EBIN trial (NCT03235245) was a multicenter, open-label, randomized, controlled phase 2 study conducted across 37 centers in eight European countries. Eligible participants were adults with previously untreated, unresectable stage III or IV melanoma harboring BRAFV600E or BRAFV600K mutations, and with good performance status (ECOG 0–1). Patients were randomly assigned (1:1) to two arms:
- Induction Arm: 12 weeks of targeted therapy (oral encorafenib 450 mg once daily plus oral binimetinib 45 mg twice daily), followed by immune checkpoint inhibitors (nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 weeks for four doses, then maintenance nivolumab 480 mg every 4 weeks).
- Control Arm: Immediate initiation of immune checkpoint inhibitors as per the above regimen, without prior targeted therapy.
Randomization was stratified by center and a composite variable (disease stage and LDH level). The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. Secondary endpoints included overall survival, response rates, and safety.
Key Findings
Between November 12, 2018, and July 11, 2022, 271 patients were randomized (136 induction, 135 control). Baseline demographics were well-balanced, with a median age of 55 years and 38% female. The median follow-up was 21 months.
- Progression-Free Survival: Median PFS was 9 months in both arms (induction: 9 months [95% CI 7–13]; control: 9 months [5–14]). The hazard ratio for PFS was 0.87 (90% CI 0.67–1.12; p=0.36), indicating no statistically significant improvement with targeted therapy induction.
- Safety: Grade 3-5 treatment-related adverse events occurred in 42% of patients in the induction group versus 32% in the control group. Hepatitis was the most common severe adverse event (13% vs 7%). Serious treatment-related events were also more frequent in the induction arm (33% vs 25%). There were three treatment-related deaths (two cardiac events in induction, one meningitis in control).
- Other Outcomes: Secondary efficacy endpoints and detailed response rates were not superior in the induction group, and the higher toxicity burden raises concern for this sequencing approach.
Expert Commentary
The EBIN trial delivers a clear message: targeted therapy induction does not confer a PFS advantage over immediate immune checkpoint blockade in unselected patients with BRAFV600-mutant advanced melanoma. This finding aligns with emerging data from other sequencing studies (e.g., SECOMBIT) and underscores the complexity of integrating targeted and immune-based strategies. Higher toxicity in the induction arm further tips the risk-benefit balance.
Notably, subgroup analyses (not detailed in the primary publication) may still reveal clinical niches—such as patients with bulky or highly symptomatic disease—where rapid cytoreduction by targeted agents may be desirable. Additionally, future biomarker-driven studies may identify patient subsets who benefit from induction or alternating approaches.
Current international guidelines continue to support either modality as first-line for BRAFV600-mutant melanoma, with treatment choice individualized based on patient and disease characteristics, comorbidities, and patient preferences.
Conclusion
The EBIN phase 2 study demonstrates that, for most patients with advanced BRAFV600E/K-mutant melanoma, induction with encorafenib and binimetinib before nivolumab and ipilimumab does not improve progression-free survival compared to immune checkpoint inhibitors alone, while increasing the risk of severe adverse events. These results support continued use of ICIs as frontline therapy and highlight the need for further research to optimize sequencing, identify predictive biomarkers, and develop safer combination strategies.
References
- Robert C, Kicinski M, Dutriaux C, et al. 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. Lancet Oncol. 2025 Jun;26(6):781-794. doi: 10.1016/S1470-2045(25)00133-0. PMID: 40449497.
- National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Melanoma: Cutaneous. Version 1.2024.