Phase III REFLECTIONS B327-02 study of PF-05280014 (trastuzumab biosimilar) met primary objective in HER2-positive metastatic breast cancer.- Pfizer.

Pfizer announced positive findings from REFLECTIONS B327-02 (n=707), a pivotal Phase III randomized, double-blind comparative safety and efficacy study of PF-05280014 (trastuzumab biosimilar) versus Herceptin (trastuzumab), in patients with HER2-positive metastatic breast cancer. Positive data from a supplemental study, REFLECTIONS B327-04 (n=226), were also presented.

The REFLECTIONS B327-02 study achieved the primary objective for equivalence in the objective response rate (ORR) of PF-05280014 versus Herceptin in patients receiving first-line treatment, in combination with paclitaxel, for HER2-positive metastatic breast cancer [risk ratio of 0.940; within the pre-specified equivalence margin of 0.8–1.25]. Additionally, rates of one year progression-free survival and one year survival were similar across groups (56% and 88.84% vs. 52% and 87.96% for PF-05280017 and Herceptin, respectively).

The REFLECTIONS B327-04 study found there were no clinically meaningful differences between PF-05280014 and Herceptin in terms of efficacy, safety, immunogenicity, and noninferiority in pharmacokinetics, as neoadjuvant treatment taken in combination with docetaxel and carboplatin for patients with operable HER2-positive breast cancer. Data were presented at the European Society for Medical Oncology (ESMO) 2017 Congress in Madrid.