Pfizer’s Talzenna approved for breast cancer treatment

By Rajaneesh K Gopinath

The PARP inhibitor receives an earlier than expected nod from the FDA which aptly falls on the Breast Cancer Awareness Month (BCAM) of October by coincidence.

On October 16^th, the US Food and Drug Administration approved the use of Pfizer’s Talzenna (talazoparib) following a successful Phase III EMBRACA (NCT01945775) clinical trial. It is a randomized, open-label, multi-center study which evaluated Talzenna in comparison to existing chemotherapy treatments in 431 HER2-negative, locally advanced or metastatic breast cancer patients with inherited, deleterious or suspected deleterious germline BRCA mutations (1). The patients either received 1 mg of Talzenna or healthcare provider’s choice of chemotherapy such as capecitabine, eribulin, gemcitabine, or vinorelbine.

Progression free survival (PFS) was the study’s major outcome and Talzenna registered a statistically significant improvement of 8.6 months versus the 5.6 months in the chemotherapy arm. Jennifer Litton, MD, of the University of Texas MD Anderson Cancer Center presented the findings at the San Antonio Breast Cancer Symposium held in December 2017 and the same was published recently in the New England Journal of Medicine (2). The prescribed use includes warnings and precautions for Myelodysplastic Syndrome/Acute Myeloid Leukemia, myelosuppression, and embryo-fetal toxicity. Other common adverse effects include fatigue, anemia, nausea and diarrhea among others.

Talzenna was originally a pipeline drug of Medivation, a biopharmaceutical acquired by Pfizer in 2016 with a highest bid of $14 billion edging out competitors like Sanofi. Although, the major motivation for acquisition was the prostate cancer drug Xtandi (enzalutamide), Talzenna was also a crucial asset, the approval of which would now prove valuable for Pfizer. However, Talzenna has to withstand competition from AstraZeneca’s Lynparza (olaparib), the first PARP inhibitor to be approved for breast cancer (3). Meanwhile, Myriad Genetic’s BRACAnalysis CDx, was approved as a companion diagnostic of Talzenna to identify the germline mutation. The FDA approved laboratory test was previously used in combination with other PARP inhibitors like Lynparza and Zejula (niraparib).

References

1. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/211651s000lbl.pdf
2. https://www.nejm.org/doi/full/10.1056/NEJMoa1802905
3. https://www.biopharmadive.com/news/an-early-approval-puts-pfizers-talzenna-in-a-crowded-field/539893/

Author

Rajaneesh K. Gopinath