Pharmaceutical giant Pfizer suffered a setback this week in the high-stakes race to tap into the burgeoning multi-billion dollar weight loss drug market. The company announced it is halting development of the twice-daily formulation of its experimental obesity pill danuglipron after underwhelming mid-stage trial results.
While the drug induced significant weight loss in obese patients, it came at the cost of poor tolerability. Over half of participants dropped out of the phase 2 study due to adverse gastrointestinal side effects like nausea and diarrhea.
Nonetheless, Pfizer still intends to stay in the game with a once-daily version of danuglipron. The company aims to release fresh phase 2 data on the more competitive formulation in early 2024 before determining next steps.
For a drugmaker grappling with fading Covid-19 revenues, the news deals a tough blow to its strategy to offset declines through potential new blockbusters for obesity. Just last year, CEO Albert Bourla tagged the total addressable weight loss market at a whopping $90 billion.
But competition is cutthroat, with Novo Nordisk and Eli Lilly vying to convert millions from their injectable diabetes meds to an oral option. Their rival pills have already posted mid-teens percentage weight loss results that position them to potentially leapfrog Pfizer’s attempt.
Danuglipron Quick Facts
- Twice-daily formulation now discontinued after 6.9% to 11.7% weight loss at 32 weeks
- Well below 14-15% loss seen as competitive threshold
- High rates of nausea, vomiting, diarrhea
- Over 50% dropout rate
Key Takeaways for Investors
The disappointing data for danuglipron’s twice-daily pill underscores several investor concerns around Pfizer’s efforts to expand into weight loss medicines.
Uphill Battle Against Rivals
Novo Nordisk and Eli Lilly already dominate the obesity drug landscape with their injectable products Saxenda and Ozempic. Lilly’s oral candidate tirzepatide is showing roughly 15% weight loss over 72 weeks, clearing the competitive bar Pfizer failed to hit.
While the field is large enough for multiple winners, Pfizer faces substantial share challenges from these deeply entrenched rivals. Its best-case outcome may be carving off a small slice rather than market leadership.
Tolerability Issues Limiting
Danuglipron has now faltered twice in mid-stage studies due to side effects leading over half of volunteers to quit treatment. The once-daily route shows some promise, but gastrointestinal problems may hamper uptake if they persist. By comparison, tirzepatide posted a 21% dropout rate.
Uncertainty Remains High
With phase 3 trials still a distant prospect, the program faces a long road ahead fraught with risk. While danuglipron evinced significant weight-loss efficacy, real-world commercial success depends greatly on improving its poor tolerability profile.
Until then, uncertainty around Pfizer’s weight loss aspirations stays high. Expect sales projections to remain muted absent positive late-stage outcomes down the line. But rivals like Lilly and Novo aren’t standing still either, making danuglipron’s path ahead even trickier.