Viking (VKTX) Plunges 37% After VK2735 Delivers 12.2% Weight Loss - 28% Discontinuation Sparks Concern

Shares of Viking Therapeutics (NASDAQ: VKTX) slid as much as 37% Tuesday after the company released Phase 2 VENTURE-Oral Dosing data for VK2735, its oral dual GLP‑1/GIP receptor agonist aimed at treating obesity. Meanwhile, Eli Lilly (NYSE: LLY) ticked up about 1.5% as market watchers pointed to its stronger footing in the space.

The headline: the trial hit its primary endpoint. Patients on the highest doses lost up to 12.2% of body weight at 13 weeks versus 1.3% for placebo. That's solid efficacy on face value. But the market's reaction focused on a different stat - a 28% discontinuation rate in treated patients versus 18% with placebo over the 13‑week window.

That dropout figure was the alarm bell. Analysts at Mizuho, led by Jared Holz, essentially argued that when you stack the Viking data against Lilly's programs, the short, sharp 28% quit rate over 13 weeks doesn't look great next to Lilly's mid‑20% discontinuation numbers - albeit measured over a much longer 72‑week period. In their view, that gap undermines Viking's near‑ to medium‑term commercial prospects.

JPMorgan's Hardik Parikh struck a different tone. He flagged that the three top dose arms (60/90/120 mg) produced placebo‑adjusted weight loss of roughly 7.5%, 10% and 11% - numbers he called competitive against other oral candidates - and described overall tolerability as manageable even if worse than Phase 1 had suggested.

The safety profile is mixed. Viking said 99% of gastrointestinal adverse events were classed as mild or moderate. Still, vomiting occurred in roughly 20-35% of patients in the three highest dose arms versus about 10% on placebo; nausea was around 58% on treatment compared with 48% for placebo. The company also mentioned an exploratory maintenance arm where lower doses appeared to sustain weight loss.

For traders, the story the market chewed through is clear: efficacy is there, but side effects and dropouts are big enough to prompt questions about real‑world adoption and competitive positioning against entrenched names like Eli Lilly (NYSE: LLY). Shorter trial duration, higher early discontinuations and a bumpier tolerability signal are what pushed VKTX into a sharp selloff rather than a relief rally.

There are two threads to watch now - will Viking be able to tighten the tolerability profile in future studies, and can lower maintenance doses protect efficacy while cutting adverse events? The numbers say the next set of data will determine whether VK2735 is a niche oral contender or a product that struggles to gain traction against bigger rivals.