Pyxis Oncology Stock Plummets on Disappointing Cancer Trial Data

Pyxis Oncology's (PYXS) stock price plummeted by over 13% in premarket trading on Wednesday due to disappointing new trial data for its lead asset, micvotabart pelidotin (MICVO). The antibody-drug conjugate is being tested as a late-line option for certain head and neck carcinoma patients.

The Phase 1 study enrolled patients with recurrent/metastatic head and neck squamous cell carcinoma who had received at least two prior lines of therapy. The latest data cut, based on 33 efficacy-evaluable patients, showed that MICVO at a dose of 5.4 mg/kg was associated with a 36% confirmed objective response rate and a 94% disease control rate.

This is a decline from the previously reported data cut from November 3, which indicated that MICVO led to a 46% cORR (confirmed objective response rate) and 92% DCR (disease control rate) when administered intravenously once every three weeks. The company stated that there were no new safety signals and the tolerability profile of the experimental therapy met its expectations.

The study is set to generate updated overall survival data in H1 2027, and Pyxis Oncology aims to report updated results from its Phase 1/2 combination study testing MICVO with Merck's Keytruda (MRK) in first-line R/M HNSCC patients by Q4 2026.