FDA Rejects Pfizer's Proposed Trastuzumab Biosimilar

Pfizer announced this morning that the FDA has issued a Complete Response Letter (CRL) for PF-05280014, a proposed trastuzumab biosimilar referencing Herceptin.

The company says that the FDA highlighted the need for “additional technical information,” and that the agency did not request information related to safety or clinical data submitted in the Biologics License Application. Pfizer says that it is working closely with the FDA to address the letter’s contents and remains committed to developing the proposed product.

Pfizer presented positive results for PF-05280014 at the September 2017 meeting of the European Society for Medical Oncology; in the REFLECTIONS B327-02 study, the proposed biosimilar showed an equivalent objective response rate versus reference trastuzumab in patients receiving first-line treatment, in combination with paclitaxel, for HER2-positive metastatic breast cancer. The REFLECTIONS B327-04 study showed no clinically meaningful differences between the proposed biosimilar and the reference trastuzumab in terms of safety or immunogenicity, and noninferiority in pharmacokinetics.

Rejection of Pfizer’s trastuzumab candidate follows closely on the heels of another biosimilar trastuzumab’s rejection by the FDA; on April 5, Celltrion and Teva announced that the FDA had issued a CRL for their CT-P6, a decision that followed receipt a warning letter from the agency concerning manufacturing practices.

These 2 regulatory setbacks for biosimilar trastuzumab leave Mylan and Biocon’s Ogivri, which received the FDA’s approval 2017, as the only approved trastuzumab biosimilar in the United States. No launch date for Ogivri has yet been announced, however.