An article on Health.com recently quoted me about an exciting new FDA-approved drug shown to extend metastatic breast cancer patients’ lives significantly. Enhertu is a combination of two known therapies, trastuzumab and deruxtecan work in tandem to target the lower levels of HER2 proteins present.
As I described in the article, these two therapies work in tandem as a sort of “smart bomb.” Here’s more information about this innovative drug.
How is Enhertu different from other oncology drugs?
Enhertu is in a class of drugs called antibody-drug conjugates where a biologic drug is attached to a very potent and toxic chemotherapy drug using advanced linking technology. There’s only a handful of these type of drugs.
HER2 positive breast cancer is a type of breast cancer that expresses higher than normal levels of the HER2 (human epidermal growth factor 2) protein on the tumor. It occurs in 15-20% of breast cancer patients. HER2 causes the cancer to grow more quickly.
Trastuzumab is a monoclonal antibody (a type of biologic drug) targeting HER2 that doesn’t work well as a single agent. It’s usually combined with other chemotherapy drugs in separate infusions to treat metastatic breast cancer.
Deruxtecan is a potent chemotherapy drug and Enhertu is a kind of like a “smart bomb” that combines these 2 drugs together with a special linking technology. The trastuzumab portion of the combination attaches to cancer cells expressing HER2 and drops its “payload” (deruxtecan) directly into the cancer cell.
Why the drug is particularly effective against HER-2 breast cancer?
Kadcyla had been the standard of care in 2nd line treatment of HER2 positive, metastatic breast cancer for many years. It’s another antibody drug conjugate. It’s a combination of trastuzumab with another chemotherapy drug.
In a head-to-head trial, Enhertu more than doubled the 12-month progression-free survival rate compared to Kadcyla in people diagnosed with metastatic HER2-positive breast cancer that had been previously treated. Enhertu may soon take over as the standard of care in the 2nd line setting in most cases. Kadcyla would still be a viable alternative in certain situations.
Enhertu is not only indicated for HER2 positive patients but in HER2 low patients, where patients have some HER2 cells on the tumor surface, but not enough to be considered HER2 positive.
How is the drug likely to be priced/covered by insurance?
Enhertu is a physician administered drug which will usually be covered under the medical benefit. Its annual list price is a little over $168,000.