Dive Insight:

Margenza, also known as margetuximab, offers a new option to patients with HER2-positive metastatic breast cancer who have already tried other regimens. The drug’s approval covers patients who have received two or more other anti-HER2 therapies, including at least one treatment for metastatic disease.

Like Herceptin, Margenza targets a protein on the HER2 gene responsible for tumor growth. HER2-positive cases make up as much as 20% of all breast cancer diagnoses, and anti-HER2 therapies have burgeoned since Herceptin’s ground-breaking approval in 1998.

The FDA approved Margenza based on a Phase 3 study called Sophia, which found that patients on a combination of chemotherapy and the drug had a 24% reduction in their risk of disease progression or death compared with patients on chemotherapy and Herceptin. MacroGenics is continuing to look at overall survival rates and expects to have data in the second half of next year.

The Rockville, Maryland-based company is also studying the use of Margenza for other types of cancer, including gastric.

The most common side effects of Margenza are fatigue, nausea, diarrhea and vomiting, MacroGenics said. But a boxed warning will alert patients of the risk of left ventricular dysfunction. Doctors will also have to advise patients of possible embryo-fetal harm and the need for effective contraception both during treatment and for four months following therapy.

Margenza is at least the 15th cancer therapy approved in the U.S. this year, reflecting the industry-wide push into oncology that’s taken place over the last decade.