The U.S. Food and Drug Administration approved Pfizer Inc.'s Talzenna for treating a subtype of breast cancer that has advanced locally or spread to other organs.

Talzenna, or talazoparib, will treat breast cancer with inherited BRCA-mutation, which does not express a large amount of a protein called HER2. Cancer cells without HER2, which helps to control cell growth, may grow more slowly and are less likely to recur compared to HER2-positive cancer.

The BRCA genes produce proteins responsible for repairing damaged DNA and their mutation may result in cells become unstable, ultimately leading to cancer.

According to an Oct. 16 news release, the approval is based on a phase 3 study named Embraca, which showed that Talzenna extended patients' lives while keeping the disease at bay for a median of 8.6 months, compared to 5.6 months for those receiving chemotherapy.

The drug's label includes potential side effects such as myelodysplastic syndrome, a group of blood disorders, or acute myeloid leukemia and myelosuppression, characterized by a lower count of blood cells as well as adverse effects on the fetus.

Talzenna, to be given as a single daily tablet, blocks the PARP enzyme that helps repair damaged DNA. The drug helps kill cancer cells by preventing them from repairing their damaged DNA.

Talzenna has become the second PARP inhibitor to get U.S. approval for treating breast cancer after AstraZeneca PLC's Lynparza got the FDA nod in January.

In addition, the FDA approved Myriad Genetics Inc.'s genetic test, BRACAnalysis CDx, to identify breast cancer patients eligible to use Talzenna. The test is already approved for use with Lynparza.