For a pharmaceutical company, the only thing better than having a drug with more than $1 billion in annual sales is getting it approved to treat more patients.
EVISTA is a selective estrogen receptor modulator (SERM), which acts differently on estrogen receptors in different parts of the body. EVISTA appears to prevent breast cancer by blocking estrogen from stimulating the growth of tumor cells.
The new indication is coming at the perfect time. Merck's
Being able to market the drug for the prevention of breast cancer should also help EVISTA compete against Roche's and GlaxoSmithKline's
While the approval will certainly help EVISTA compete against other osteoporosis drugs, it's not clear how many patients will take the drug just for the prevention aspect. The new approval doesn't increase the patient population by that much -- there are many more women with osteoporosis than those at risk for invasive breast cancer. Given that the drug will still contain a "black box" warning regarding patients with a past history of venous thromboembolism or a risk of stroke, doctors may be a little leery of prescribing it strictly for its preventative aspects.