Regeneron Pharmaceuticals recently unveiled promising Phase III data for Libtayo, its PD-1 inhibitor, demonstrating substantial survival advantages for patients with high-risk cutaneous squamous cell carcinoma (CSCC) when used as an adjuvant treatment. This development positions Libtayo as the first immunotherapy to show statistically significant and clinically meaningful benefits in this patient group, a milestone not achieved by Merck's Keytruda, which did not meet expectations in this indication in August 2024.
Interim results revealed a 68% reduction in the risk of disease recurrence or death among patients treated with adjuvant Libtayo compared to placebo, with a median follow-up of 24 months. The statistical significance of these findings was underscored by a p-value of less than 0.0001.
Regarding safety, adverse effects of any grade were observed in 91% of Libtayo-treated patients and 89% of those on placebo. The study noted a higher discontinuation rate due to adverse reactions in the Libtayo group (10%) compared to the placebo group (1.5%), with two fatalities reported in each group.
Israel Low, head of the Oncology Clinical Development Unit at Regeneron, emphasized Libtayo's potential to revolutionize the treatment of high-risk resectable CSCC through adjuvant therapy. Regeneron plans to continue the study's follow-up, including an overall survival analysis, aiming for a regulatory submission in the first half of 2025.
Libtayo, a fully human monoclonal antibody targeting PD-1, has been approved for certain types of CSCC, basal cell carcinoma, and non-small cell lung cancer. Its success was highlighted at the 2025 J.P. Morgan Healthcare Conference, where it was noted that Libtayo generated over $1 billion in sales in 2024, becoming a significant contributor to Regeneron's earnings.
In contrast, Regeneron's Eylea products, a key franchise, underperformed in sales, with the high-dose version falling 26% short of expectations in the final quarter of 2024. This performance raises concerns about the conversion speed and the competitive challenges ahead, especially with new entrants like Genentech’s Vabysmo and Amgen’s biosimilar Pavblu.
