The study, called Redefine 4, compared Cagrisema, being developed by Novo Nordisk, with tirzepatide, the active ingredient in competitor Eli Lilly's treatments Mounjaro and Zepbound.
The Danish drug Cagrisema showed a weight loss of 23 percent after 84 weeks, compared with 25.5 percent for Eli Lilly's treatment.
Today's price plunge means Novo Nordisk's stock is trading at its lowest level since 2021. The stock is down nearly 24 percent since the start of the year.
Competitor Eli Lilly's stock was also rising on the New York Stock Exchange. After 1.5 hours of trading, it was up just over 4 percent.
