Merus’ Petosemtamab Delivers Promising Results in Head and Neck Cancer, May Set New Standard Ahead of ASCO.

Merus has released new Phase II clinical data for its investigational bispecific antibody petosemtamab, suggesting a potentially transformative impact on the treatment landscape for head and neck squamous cell carcinoma (HNSCC). Combined with Merck’s Keytruda, the therapy demonstrated a 12-month overall survival (OS) rate of 79% in the first-line setting, significantly outperforming the historical OS rate of 50–59% for Keytruda alone.

The findings, announced Thursday and based on data from 43 patients who had received at least one dose of the petosemtamab-Keytruda combination and undergone a post-baseline tumor assessment, showed a confirmed overall response rate (ORR) of 63%. Among the responders, six patients achieved complete responses and 21 had partial responses. Median progression-free survival was reported at nine months, while median overall survival had not been reached at the time of analysis.

Analysts have reacted positively. William Blair emphasized petosemtamab’s "best-in-disease" potential and highlighted its significant commercial opportunity in HNSCC, stating it could lead to substantial upside in Merus’ valuation. Similarly, Leerink Partners described the survival benefit as both “landmark” and “unprecedented” in the frontline treatment of HNSCC, including in both HPV-positive and HPV-negative patient populations.

The bispecific nature of petosemtamab allows it to target both EGFR and LGR5, enhancing the immune system’s ability to attack tumors. Merus is currently conducting two Phase III trials evaluating the antibody in different treatment lines for recurrent or metastatic HNSCC. Interim topline data from one or both of these trials could emerge as early as 2026, according to CEO Bill Lundberg.

In addition, analysts at BMO Capital Markets suggested the latest results may support a pathway to accelerated approval, given the strength of the OS data and unmet need in the first-line treatment space.

Merus is scheduled to present the full dataset on June 2 at the 2025 American Society for Clinical Oncology (ASCO) Annual Meeting in Chicago and online.

Source:https://www.biospace.com/drug-development/merus-bispecific-shows-best-in-disease-profile-in-head-and-neck-cancer-ahead-of-asco

This is non-financial/medical advice and made using AI so could be wrong.