Since the early 1990s the FDA has granted accelerated approval to dozens of drugs based on promising early results, on the condition that their effectiveness is confirmed in later studies. That policy has been praised by patients with HIV, cancer and other deadly diseases where access to experimental treatments can mean life or death.
But the flipside of the program means removing drugs from the market if their initial promise isn’t confirmed by later studies. In 2011 the FDA was criticized by some cancer patients when it revoked breast cancer approval for another Genentech drug, Avastin.
The FDA concluded that the drug did not help breast cancer patients live longer or bring enough other benefit to outweigh its dangerous side effects. The drug is still approved to treat colon cancer and other forms of the disease.
The FDA is scheduled to make a decision on whether to approve Perjeta for early-stage breast cancer by Oct. 31.