The Phase III LEAP-10 trial represents a major collaborative effort between Merck & Co. and Eisai, addressing a persistent unmet need in recurrent /metastatic head and neck squamous cell carcinoma (R/M HNSCC).
In patients with PD-L1 CPS ≥1 disease, the combination of lenvatinib + pembrolizumab demonstrated:
- Improved objective response rate (ORR)
- Prolonged progression-free survival (PFS)
However, these gains did not translate into an overall survival (OS) benefit compared with pembrolizumab monotherapy, which remains the backbone of first-line treatment.
Clinical Context: Why OS Remains Elusive
Despite encouraging activity, the absence of OS improvement reinforces the durability of the current standard established by KEYNOTE-048 trial, where:
- Pembrolizumab ± chemotherapy continues as standard of care
- Survival benefit is tightly linked to PD-L1 expression and patient selection
The LEAP-10 findings highlight a recurring challenge in HNSCC:
Early efficacy signals (ORR, PFS) do not reliably predict survival benefit, particularly in an immunotherapy-sensitive disease where post-progression treatments and tumor biology heavily influence OS.
Biologic Interpretation
The addition of lenvatinib, a multi-kinase inhibitor targeting VEGFR, FGFR, and others, likely:
- Enhances tumor microenvironment modulation
- Improves initial tumor shrinkage and disease control
However, potential limitations include:
- Lack of deep, durable immune reprogramming
- Emergence of resistance mechanisms
- Possible toxicity-related treatment discontinuation
These factors may blunt long-term survival impact despite improved early endpoints.
Where the Field Is Heading: EGFR and Beyond
Attention is now shifting toward next-generation EGFR-targeted strategies, with the hypothesis that:
- More precise targeting of EGFR-driven signaling
- Coupled with immune engagement mechanisms
may yield more durable survival benefits.
Key players advancing this space include:
- Dana-Farber Cancer Institute
- Genmab
- Bicara Therapeutics
- Johnson & Johnson
- Merus N.V.
- Harvard Medical School
Emerging modalities include:
- Bispecific antibodies (EGFR × immune targets)
- Antibody-drug conjugates (ADCs)
- Combination immunotherapy strategies
These approaches aim to:
- Overcome primary and acquired resistance
- Deliver more sustained immune activation
- Ultimately shift the OS curve, not just early endpoints
Key Takeaway for Clinical Practice
While lenvatinib + pembrolizumab shows meaningful biologic and clinical activity, it does not currently challenge pembrolizumab-based regimens as standard of care in PD-L1–positive R/M HNSCC.
The central question remains:
What therapeutic strategy will meaningfully and reproducibly improve overall survival in first-line HNSCC?
The next wave of EGFR-targeted and immune-engaging therapies may be the most promising path forward.
Rodrigo Arrangoiz MS, MD, FACS, FSSO 