Stumped by a red flag over possible liver injury as well as an elevated risk of cancer, a panel of FDA experts shot down the first in a new class of diabetes drugs advanced by AstraZeneca ($AZN) and its partner Bristol-Myers Squibb ($BMY). Agency advisers voted 9 to 6 against dapagliflozin, a diabetes drug that had been considered a top prospect with potential earnings of around $631 million a year.
Dapagliflozin is designed to lower blood sugar in diabetics by causing it to be excreted in urine. However, over a two-year study, there were 9 cases of bladder cancer and 9 breast cancer cases in the treatment group. The experts were also clearly worried about liver and kidney risks, particularly as it was intended for long-term use among a big disease group.
The rejection is a significant setback for the developers, who had hoped to study safety aspects following an approval. Now they will have to consider the very real possibility that the FDA--not known for taking safety issues lightly--will send them back to design and execute another costly trial.
"There are a whole host of questions that we need to know more about," noted panel member Dr. Peter Savage in a story by Reuters. "The problem is that if you make a mistake, making a drug widely available that causes cancer would cause much more harm than designing another study that could give a quick answer."
The news also triggered second thoughts among other developers of SGLT2 inhibitors. A number of drug developers, including Johnson & Johnson, a partnership involving Lilly and Boehringer, Lexicon, Isis and others have similar diabetes therapies in development. Goldman Sachs analyst Jami Rubin noted that the vote casts a pall over the entire field.
"In a surprisingly broad and lengthy discussion of where the data fell short, the FDA panelists cited concerns on not only the drug's safety but also efficacy," wrote Rubin, according to a post by Forbes' Matthew Herper.