Viking Therapeutics reported that participants maintained most of their prior weight loss after moving from weekly VK2735 injections to every-other-week or monthly dosing in a Phase 2 obesity study. After 21 weeks of weekly subcutaneous induction treatment and a subsequent 12-week maintenance phase, participants assigned to monthly injections retained an average 85% of their Week 21 weight loss, while those receiving every-other-week treatment retained 90%; placebo-switch participants retained 61%. The company said monthly regimens preserved up to 90% of weight loss and every-other-week dosing preserved up to 97%. Participants continuing weekly 17.5-milligram injections in an exploratory arm had mean weight loss of 21.7% from baseline at Week 33, with no plateau observed. Viking said gastrointestinal side effects during maintenance were comparable with placebo and adverse-event discontinuations were low. Shares rose roughly 24% Tuesday morning following the announcement. VK2735 is a dual GLP-1/GIP receptor agonist, and Viking is running Phase 3 trials of the injectable medicine while developing an oral version and planning a follow-on study of oral maintenance regimens.