Regeneron Explores New Intralesional Use for Libtayo in Skin Cancer: What Investors Should Know

Regeneron Pharmaceuticals (REGN) announced an update on their ongoing clinical study.

Regeneron’s latest clinical update centers on a Phase 1 trial titled “A Phase 1 Study of Pre-Operative Cemiplimab (REGN2810), Administered Intralesionally, for Patients With Cutaneous Squamous Cell Carcinoma (CSCC) or Basal Cell Carcinoma (BCC).” The study aims to see how safe and tolerable intralesional cemiplimab is before surgery in skin cancer patients, and to get an early read on how well it shrinks tumors. For investors, this research matters because it explores a new way to use an already approved cancer drug, which could support broader use and longer product life if results are positive.

The trial tests cemiplimab, a cancer drug from Regeneron also known as REGN2810 and marketed as Libtayo. It is given as injections directly into the tumor rather than through the vein. The goal is to boost local anti-tumor activity before surgery while tracking safety, side effects, and how the drug behaves in the body.

This is an interventional Phase 1 study with a single treatment group. All patients receive intralesional cemiplimab; there is no placebo or comparison arm. Dose levels are increased step by step in small groups of patients to find a safe range, and there is no blinding, meaning doctors and patients know cemiplimab is being used. The main purpose is treatment-focused safety and early effectiveness, not head-to-head comparison against other options.

The study was first submitted in March 2019, marking the formal start of regulatory tracking and signaling an early-stage effort to expand cemiplimab’s use. The primary completion and overall completion dates are not spelled out here, but the status is now listed as completed, so key data collection is finished. The latest update was submitted on January 19, 2026, indicating that Regeneron has recently refreshed the record, likely reflecting final study status, data cleaning, or preparation for public disclosure.

For the market, this update adds another piece of optionality around Libtayo. Intralesional use in CSCC and BCC could open a niche pre-surgery setting where local control is important, supporting incremental revenue and reinforcing Regeneron’s oncology franchise. While a Phase 1 trial alone will not move the stock sharply, a completed and recently updated early study reduces development risk and may slightly improve sentiment around future skin cancer strategies. Competitors in immuno-oncology, such as Merck and Bristol Myers, are also working on new dosing strategies, but Regeneron’s focus on intralesional injections in non-melanoma skin cancers gives it a differentiated angle. Overall, investors can view this as a modest but positive sign of pipeline depth rather than a near-term earnings driver.

The study is now completed and recently updated, and further details are available on the ClinicalTrials portal.

To learn more about REGN’s potential, visit the Regeneron Pharmaceuticals drug pipeline page.