Pfizer's Monthly Obesity Injection Shows Strong Early Results, Aims for 2026 Market Entry

In a significant development for its metabolic health pipeline, Pfizer announced promising mid-stage trial results for a new monthly obesity injection. The data, released Tuesday alongside quarterly earnings, indicate the treatment could offer a less frequent dosing option in a competitive field.

The ongoing Phase 2 study found that patients receiving the drug, known as PF'3944, lost up to 12.3% of their body weight after 28 weeks compared to those on a placebo. Notably, weight loss continued without plateauing after patients switched from weekly to monthly injections, suggesting further reductions are possible as the trial continues.

For Pfizer, these results mark a needed advance after previous obesity drug setbacks. The company is aiming to challenge the established weekly injections from Eli Lilly and Novo Nordisk, as well as Novo's daily pill. A monthly option could appeal to patients seeking greater convenience.

"These topline results reinforce the potential of PF'3944 as a monthly treatment with competitive efficacy," said Dr. Jim List, Pfizer's chief internal medicine officer.

The company plans to initiate ten Phase 3 trials this year. Internal modeling predicts that a higher monthly dose planned for late-stage testing could achieve up to 16% weight loss at 28 weeks.

Pfizer acquired the drug through Metsera. It is an ultra-long-acting GLP-1 agonist, engineered to remain active longer than current treatments. The trial was designed to test tolerability and efficacy of monthly dosing after an initial weekly phase. Most side effects were reported as mild to moderate, with no new safety issues identified.

Despite the positive clinical news, Pfizer's stock dipped nearly 3% in premarket trading Tuesday.

Source: CNBC