Viking's GLP-1 spurs steep weight loss, sending shares up 80%

Pass the mead, because Viking Therapeutics has plenty to celebrate after its dual agonist of GLP-1 and GIP was linked to weight loss of up to 14.7% after 13 weeks of treatment, sending the biotech's stock soaring.  

Dose-dependent reductions in the weight of recipients of VK2735, which ranged from 9.1% to 14.7%, were all significantly larger than the 1.7% dip tracked in participants on placebo. While that was enough for the phase 2 study to meet its primary endpoint and clear the 8% bar Viking set as an internal hurdle, the comparison to other molecules is equally important in the increasingly competitive obesity space.

VK2735 looks good compared to the incumbents, with usual caveats about cross-trial comparisons. After 13 weeks, people in Novo Nordisk’s semaglutide phase 3 trial were yet to lose 10% of their body weight. Eli Lilly’s tirzepatide triggered faster, deeper weight loss than semaglutide, but VK2735 looks competitive against that molecule, too. That could catch the eye of pharma dealmakers—and Viking is open to talks.

“Our plan is to proceed aggressively with further clinical development. We're always open … to [business development] discussions,” Viking CEO Brian Lian, Ph.D., said on a call with investors to discuss the data. “Right now we’re really focused on next steps with the program for us and remain with the ‘open door’ policy for discussing opportunities.”

Would-be buyers may need to dig deep to prise VK2735 away from Viking or buy the biotech outright. The company ended yesterday with a market cap of $3.9 billion but saw its stock climb 80% to above $69 in premarket trading.

Investors sent the stock skyward as they digested data from a 176-subject phase 2 trial that paints Viking as a serious force in the red-hot obesity space. Up to 88% of patients on VK2735 experienced weight loss of 10% or more, compared to 4% of people on placebo, and Viking believes further weight loss is possible beyond Week 13. 

“There wasn't really an indication yet of a plateau signal. The two higher doses, the 10 and the 15, one of them appeared to maybe be accelerating a little bit, but it's hard to know. These are weekly reads, so you get a little bumpiness as the curve evolves,” Lian said.

Asked by an analyst why VK2735 may outperform the competition, Lian pointed to a pharmacokinetic profile that “provides very good exposures” and a half-life that is “quite long.” Lian said those connected factors may help “drive this level of efficacy.” 

The next step is to hold a meeting with the FDA, something Lian expects to happen around the middle of the year. “It seems more than likely that a phase 2b will be the next step here but we'll have a better idea after we speak with the FDA and get some guidance,” the CEO said.

On the safety and tolerability front, the discontinuation rate across all VK2735 doses was slightly lower than in the placebo group, with 13% playing off against 14%, although the rate at the highest dose was 20%. 

As with other GLP-1 drugs, many patients experienced nausea, with the rate peaking at 63% at the top dose, but most of the cases were mild and none were severe. One patient went to hospital with symptoms of dizziness. The patient was diagnosed with dehydration and admitted to the hospital, triggering a serious adverse event, but then recovered. 

Viking is yet to share data on markers such as liver fat and plasma lipids, but earlier studies suggest the candidate may benefit patients with comorbidities linked to obesity. Lian said the mechanism “seems to be applicable” to metabolic dysfunction-associated steatohepatitis, an indication Viking knows well from its work on VK2809, but, for now, the biotech is going to direct its resources to obesity.