Pyxis Oncology Stock Plunges 16.25% to 2025 Low on Adverse Trial Data Concerns

The share price fell to its lowest level since October 2025 today, with an intraday decline of 16.25%.

Pyxis Oncology’s stock has tumbled 23.58% over four consecutive trading days after the release of preliminary Phase I trial data for its ADC candidate, micvotabart pelidotin (MICVO). The therapy showed a 46% confirmed objective response rate in monotherapy and 71% in combination with Keytruda, but 89% of monotherapy patients experienced treatment-related adverse events, with 56% reporting Grade 3 or higher side effects. Investors reacted harshly to the safety profile, sending shares down 49.9% in premarket trading and 45% during the session. CEO Lara Sullivan emphasized MICVO’s “therapeutic potential,” but analysts highlighted the need for clearer risk-benefit balance, particularly as patient discontinuations due to side effects reached 28% in monotherapy trials.

Analyst reactions were mixed, with RBC Capital lowering its price target to $5 from $8 while maintaining an Outperform rating, citing the “complex dataset” and need for further data. Meanwhile, Stephens and Guggenheim raised targets to $8 and $7, respectively, reflecting optimism about combination therapy potential. Pyxis has since announced plans to adjust dosing in future trials to address safety concerns, particularly for high-body-weight patients, and expects updated monotherapy data by mid-2026. The company also secured $11 million in royalty rights sales to extend its cash runway and appointed a new investor relations executive to improve communication. Despite the recent selloff, Pyxis’s shares have risen 19% in 2025, underscoring the sector’s volatility as investors weigh near-term risks against long-term pipeline potential.

The broader biotech sector saw mixed performance, with some firms benefiting from risk-on sentiment following the FDA’s recent guidance on novel cell therapies, while Pyxis faced renewed skepticism over its ability to manage the safety profile of MICVO. Institutional investors accounted for 72% of today’s volume, with short sellers aggressively building positions as open interest surged to a 6-month high. Retail traders, meanwhile, largely avoided the name, as social media sentiment turned overwhelmingly bearish after a prominent analyst flagged the trial’s high discontinuation rate as a “red flag” for commercial viability.