(Associated Press)- Pfizer shares sank Friday when the drugmaker announced that it was abandoning a twice-daily obesity treatment after more than half the patients in a clinical trial stopped taking it.

The New York company will focus instead on a once-daily version of the pill, danuglipron, instead of starting a late-stage study of the other version.

Late-stage studies are usually the last and most expensive trials a drugmaker undertakes before seeking regulatory approval.

Obesity treatments are one of the hottest and more lucrative areas of medicine.

Pfizer rivals Novo Nordisk and Eli Lilly already have injectable drugs on the market.