Shares of Viking Therapeutics closed more than 120% higher on Tuesday after the company’s experimental weight loss drug showed promising initial results in a mid-stage trial. 

Viking Therapeutics is one of several small obesity drugmakers hoping to enter the budding weight loss drug industry, which analysts say could grow into a $100 billion market by the end of the decade. 

But it may not join that space on its own: Analysts have suggested that larger pharmaceutical companies such as Pfizer, which scrapped two of its own weight loss drug candidates last year, could potentially move to partner with or acquire a company like Viking Therapeutics. Tuesday’s share move puts Viking Therapeutics’ market value at roughly $8.5 billion.

The trial followed more than 170 patients with obesity or who are overweight, some of whom received different dose sizes of the injectable drug or a placebo.

Those who received weekly doses of the treatment lost up to 14.7% of their body weight from baseline, or 13.1% when adjusted for placebo, after 13 weeks. 

Up to 88% of patients who received the drug, known as VK2735, achieved at least 10% weight loss, compared with just 4% of those who didn’t receive the treatment. 

Notably, there was no evidence of a plateau in weight reduction at week 13 for any dose of the drug, suggesting that “further weight loss might be achieved” by keeping patients on the treatment longer, Viking CEO Brian Lian said during a call with investors. 

The drug demonstrated “encouraging” safety in patients following the 13-week trial period. Patients also appeared to tolerate the drug well. 

Around 4% of patients who received any dose size of the treatment discontinued the study early compared with approximately 6% of those in the placebo group.

The majority of adverse events that patients experienced after starting the drug – also known as treatment-emergent adverse events – were mild or moderate in severity. Many of those events were gastrointestinal, which is commonly seen across all weight loss and diabetes treatments.

That includes nausea, vomiting, diarrhea and constipation.

Viking plans to present the full Phase 2 data at medical conferences. The company also said it plans to meet with the Food and Drug Administration to discuss further steps for the development of VK2735.

Separately, the company said it expects to release early stage trial data on an oral version of its weight loss drug.

Viking Therapeutics’ drug targets GLP-1 and another hormone called GIP. Those are the same hormones that Eli Lilly’s weight loss and diabetes drugs, Zepbound and Mounjaro, target.

Deutsche Bank analysts said in a note Tuesday that Viking Therapeutics’ new data shows that the weight loss drug market could eventually be more than a “duopoly” of Novo Nordisk and Eli Lilly, which manufacture the most sought-after treatments.

But the analysts added that manufacturing the treatments “at scale to meet outsized demand has proven to be no easy feat,” so that gives Novo Nordisk and Eli Lilly a “defensive moat.”

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