WASHINGTON -- The FDA approved the biologic drug ipilimumab (Yervoy) to treat metastatic melanoma, following clinical studies indicating that the agent prolongs overall survival -- the first such drug ever to do so, the agency said.
Ipilimumab is a monoclonal antibody against the cytotoxic T-lymphocyte antigen-4, which is believed to downregulate immune function.
By inhibiting this molecule, the drug may allow the immune system to recognize and attack tumor cells more effectively, according to the FDA.
In a multicenter trial involving 676 patients with melanoma, ipilimumab treatment extended mean overall survival by about 3.5 months -- reaching 10 months, compared with 6.5 months in a control group treated with an investigational immunotherapy called GP100.
But the FDA cautioned that ipilimumab comes with "unusual and severe side effects," including "severe to fatal autoimmune reactions" in 13% of patients receiving the drug.
Such effects were not unexpected given that the drug essentially removes a braking mechanism from the immune system, making it more vigilant and reactive than normal.
Stopping the drug and adding corticosteroids were helpful in some cases but not all. "Patients who did respond in some cases did not see any improvement for several weeks," the FDA noted.
As has become customary for new drug approvals, ipilimumab's manufacturer, Bristol-Myers Squibb, must implement a risk evaluation and mitigation strategy to educate healthcare providers about the risks. It will also include a patient medication guide explaining the potential side effects.
In addition to the autoimmune effects, ipilimumab was also associated with diarrhea, skin rashes, endocrine deficiencies (glandular or hormonal), and colitis.