Viking Therapeutics' Obesity Pill Shows Promise, But Safety Concerns Linger

Viking Therapeutics has unveiled promising Phase II data for its investigational obesity pill VK2735, demonstrating significant weight loss results. However, the drug's efficacy is overshadowed by safety concerns, leading to a sharp decline in the company's stock value.

Impressive Weight Loss Results

The VENTURE-Oral trial, which enrolled 280 adults with obesity, showed that patients treated with the highest dose of VK2735 (120 mg) lost 12.2% of their body weight over 13 weeks. This result was highly statistically significant compared to the placebo group. On a placebo-adjusted basis, VK2735 lowered body weight by up to 10.9% at the 13-week mark.

The drug's efficacy demonstrated a clear dose-response relationship, with increasing weight loss observed at doses starting from 15mg and progressing to 120mg. Notably, 80% of patients in the highest dose group achieved at least 10% weight loss, compared to only 5% in the placebo group.

Safety Profile Raises Concerns

Despite the impressive weight loss results, VK2735's safety profile has raised concerns among investors and analysts. The study reported that 20% of patients treated with the obesity pill dropped out due to side effects, compared to 13% in the placebo group. The majority of adverse events were gastrointestinal in nature, with 58% of VK2735-treated patients experiencing nausea and 26% reporting vomiting.

BMO Capital Markets analysts noted that while the drug's efficacy was clear, its tolerability issues were "similar to worse than what we have previously seen with oral agents and are clearly a step-down compared to [Eli Lilly's] injectable tirzepatide."

Market Impact and Competition

The release of these results has had a significant impact on Viking Therapeutics' stock, which plummeted by approximately 40% after the markets opened on Tuesday. This reaction highlights the importance of both efficacy and safety in the highly competitive obesity drug market.

VK2735's performance can be compared to other recent entrants in the obesity treatment landscape. Eli Lilly's oral obesity medication, orforglipron, recently reported Phase III data showing a 12.4% reduction in body weight at 72 weeks. While this appears slightly ahead of VK2735's results, direct comparisons are limited due to differences in trial design and duration.

The obesity drug market is becoming increasingly crowded, with injectable treatments like Novo Nordisk's semaglutide setting high standards for efficacy. As oral medications aim to capture market share, factors such as safety profiles, manufacturing capabilities, and long-term efficacy will play crucial roles in determining their success.