Shares in Viking Therapeutics (NASDAQ:VKTX) ended a bloody session 42% lower after the US biotech released trial data on its experimental obesity pill that underwhelmed investors.
The phase two results showed patients lost up to 12.2 % of body weight after three months on the treatment, VK2735.
However, analysts said the data compared poorly with treatments in late-stage trials from Eli Lilly and Novo Nordisk, which showed stronger weight loss over longer periods.
High rates of side effects such as nausea and vomiting also raised concerns.
Viking said most symptoms were mild, but nearly 30% of patients discontinued treatment.