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Oct 14, 2025 4:00 PM

Pfizer Seeks Expanded Use Approval For Breast Cancer Drug

Pfizer Inc. (NYSE:PFE) on Tuesday announced the initial results from a clinical trial called HER2CLIMB-05.  

This trial tested a new treatment for patients with a type of breast cancer (metastatic breast cancer (MBC)) that is positive for HER2, which means the cancer cells have a specific protein that helps them grow.

The treatment combines a drug called Tukysa (tucatinib), which is a type of medicine that targets cancer cells, with other therapies. The trial is in its third phase, which means it’s a large study to see how well this combination works for patients with advanced breast cancer.

HER2CLIMB-05 is evaluating Tukysa ...