New York, February 4, 2026, 19:44 EST — After-hours
- Pfizer shares ended the day 3.9% higher at $26.78, with after-hours trading showing little movement.
- Investors continue to digest early results and side effect reports for Pfizer’s monthly obesity treatment, PF-3944.
- Management stuck to its 2026 outlook but warned of challenges ahead from drug pricing pressures and looming patent expirations.
Pfizer Inc shares gained 3.9%, closing at $26.78 on Wednesday, then held steady in after-hours trading. The move capped a volatile two days driven by fresh obesity drug data and quarterly earnings.
Pfizer’s move is crucial as the company tries to reset expectations following a post-pandemic slump and faces a wave of products nearing exclusivity loss—when patents or regulatory barriers drop, allowing cheaper generics or biosimilars to cut into sales. The company stuck to its 2026 revenue forecast of $59.5 billion to $62.5 billion and earnings per share guidance of $2.80 to $3.00. Pfizer also confirmed it does not plan any share buybacks in 2026 under the current outlook.
Investors are also recalibrating their bets on the weight-loss sector. Novo Nordisk’s disappointing 2026 forecast rattled obesity-related stocks on Tuesday. Citizens analyst Jonathan Wolleben noted the market is focused on whether longer-acting injections will deliver on both “efficacy and tolerability.” Reuters
Pfizer’s obesity drug PF-3944 delivered up to 12.3% weight loss by week 28 in a mid-stage trial involving non-diabetic participants. The company noted no signs of a weight loss plateau at that point, with the study continuing through week 64. Reuters reported that five patients dropped out during the weekly dosing phase due to side effects, and another five halted treatment in the monthly phase.
During a separate interview on earnings day, CEO Albert Bourla dismissed concerns over price competition in obesity drugs. Chief Scientific Officer Chris Boshoff added that the company believes their drug “has the potential to deliver efficacy that is competitive with the standard of care.” Daniel Barasa, portfolio manager at Gabelli Funds, described the weight loss results as “good, but not category-defining,” cautioning that dropout rates may rise as the 64-week data unfold. Reuters
Trading surged on Wednesday as Pfizer’s shares changed hands over 80 million times, far exceeding its usual volume. The stock closed only a few points shy of its 52‑week peak, despite a mixed day for the broader market, MarketWatch reported.
The company’s results and outlook were detailed in a Feb. 3 filing with the U.S. Securities and Exchange Commission, which included Pfizer’s earnings release as an exhibit.
The situation remains complicated. MarketWatch reports that Wall Street’s initial reaction to PF-3944 is divided. Some see monthly dosing as a clear advantage, while others raise concerns about its effectiveness and side effects compared to Eli Lilly’s Zepbound and Novo’s Wegovy.
The next major event is set: Pfizer will unveil detailed VESPER‑3 results on June 6, 2026, at the American Diabetes Association’s scientific sessions. Traders are watching closely, expecting this data to intensify discussions around durability and tolerability.
