Pfizer announces positive results from the REFLECTIONS study for potential biosimilar to Herceptin (trastuzumab)

Pfizer Inc. announced that the pivotal REFLECTIONS B3271002 study, a comparative safety and efficacy study of PF-05280014 versus Herceptin (trastuzumab), met its primary endpoint. PF-05280014 is being developed by Pfizer as a potential biosimilar to Herceptin.

The trial demonstrated equivalence in the primary endpoint of objective response rate (ORR) of PF-05280014 versus Herceptin, taken in combination with paclitaxel, in first line patients with HER2-positive metastatic breast cancer. ORR is defined as the proportion of patients with tumor size reduction of a predefined amount and for a minimum period of time.

“As the leading global biosimilars company, we are committed to advancing our robust pipeline of biosimilar therapies in hopes of expanding access to high-quality treatment options for patients living with serious, life-threatening conditions such as cancer,” said Sumant Ramachandra, MD, PhD, MBA, Head of Research and Development, Pfizer Essential Health. “Favorable comparative clinical data between proposed biosimilars and their respective reference product contribute to physician and patient understanding of and confidence in the value and importance of biosimilars. We are encouraged by these data and look forward to sharing the complete results with health authorities and the oncology community once available.”

A separate comparative, randomized, double-blind clinical trial [REFLECTIONS B3271004] in early breast cancer patients [N=226] also met its primary endpoint of steady-state Ctrough concentrations (PK) in patients treated with PF-05280014 and Herceptin.

PF-05280014 is a monoclonal antibody (mAb) that is in development as a potential biosimilar for all currently approved indications of Herceptin. Herceptin is currently approved in the U.S., EU and other markets for HER2-positive breast cancer and gastric cancer.

PF-05280014 is an investigational compound and has not received regulatory approval in any country. Biosimilarity has not yet been established by regulatory authorities and is not yet claimed.