Pfizer (NYSE:PFE) shares sank on Friday, after the drug manufacturer said it would stop developing the twice-daily version of its experimental weight loss pill after obese patients taking the drug lost significant weight but had trouble tolerating the drug in a mid-stage clinical study.
The drugmaker observed high rates of adverse side effects, which were mostly mild and gastrointestinal, among patients. A significant share of patients also stopped taking the drug.
“At this time, twice-daily danuglipron formulation will not advance into Phase 3 studies,” the company said.
But Pfizer said it still plans to release phase two trial data on a once-a-day version of the drug in the first half of 2024, which will “inform a path forward.” The pharmaceutical giant will wait to see that data before deciding whether to start a phase three study on the once-daily pill, which Wall Street views as the more competitive form of the treatment.
Shares of Pfizer toppled $1.63, or 5.4%, in early Friday trading, to $28.84, after it announced the trial results.
Still, the data on the twice-daily drug is a blow to Pfizer’s hopes to win a $10-billion slice of the booming weight loss drug market, which CEO Albert Bourla has said could grow to $90 billion. The company is betting on a successful weight loss pill to help it rebound from plummeting demand for its COVID products and a roughly 40% share price drop this year.
