The positive trial results could help Regeneron cushion the blow of its disappointing fourth-quarter sales for Eylea, which exceeded the consensus by a modest 1% and are bogged down by the slow conversion of patients to the high-dose formulation.
Regeneron Pharmaceuticals on Monday presented positive Phase III data for its PD-1 inhibitor Libtayo, which yielded significant survival benefits when used as an adjuvant treatment for patients with high-risk cutaneous squamous cell carcinoma.
With these findings, Libtayo has become “the first and only immunotherapy” to demonstrate “statistically significant and clinically meaningful benefit” in high-risk patients with cutaneous squamous cell carcinoma (CSCC) in the adjuvant setting, the pharma noted in its news release on Monday. Merck’s blockbuster Keytruda—widely regarded as a cornerstone cancer therapy—failed in this indication in August 2024.
According to the interim readout on Monday, patients who were treated with adjuvant Libtayo saw a 68% drop in the risk of disease recurrence or death versus placebo at a median follow-up of 24 months. This effect was highly statistically significant, with a p-value less than 0.0001.
As for safety, side effects of any grade arose in 91% of the Libtayo-treated patients and 89% of placebo comparators. Dropouts were common in the Libtayo group, with 10% of patients discontinuing the study due to adverse reactions, as opposed to 1.5% in the placebo arm. Two patients in each study group developed complications leading to death.
These findings underline Libtayo’s “potential to also transform the treatment of high-risk resectable cutaneous squamous cell carcinoma with adjuvant treatment,” Israel Low, clinical development unit head of Oncology at Regeneron, said in a statement. The pharma plans to continue the study’s follow-up—including an analysis of overall survival—building up to a regulatory submission planned for the first half of 2025.
Libtayo is a fully human monoclonal antibody designed to target PD-1, in turn blocking the cancer cells’ immune evasion mechanism. The treatment has been so far approved for certain types of CSCC, basal cell carcinoma and non-small cell lung cancer.
Also on Monday, at the ongoing 2025 J.P. Morgan Healthcare Conference, Regeneron provided a preview of its product sales in 2024, with Libtayo bringing in more than $1 billion last year and emerging as a “bright spot” for the pharma’s earnings, BMO Capital Markets analysts wrote in an investor note.
“While it is unclear what the exact revenue total is for the drug, we view steady increases in revenue as broadly supportive of Regeneron’s decision to fully invest in the franchise,” the analysts wrote.
Meanwhile, Regeneron’s Eylea products—widely considered to be headline franchise—returned disappointing sales. Total Eylea sales were $1.495 billion in the final quarter of 2024, coming in 1% ahead of the $1.478 billion expectation, according to the BMO note. Meanwhile, sales of the drug’s more recently approved high-dose version fell 26% short of the $411 million consensus expectation with $305 million in earnings.
The fourth-quarter miss for high-dose Eylea “may raise concerns about conversion speed,” according to the BMO analysts, noting that the year ahead could pose even more challenges for Regeneron and Eylea amid incoming pressure from Genentech’s Vabysmo and Amgen’s biosimilar Pavblu.
