Pyxis Oncology stock falls 7% despite positive trial data

Shares of Pyxis Oncology (NASDAQ:PYXS) declined 7% on Tuesday following the release of updated results from its Phase 1 monotherapy trial of Micvotabart Pelidotin (MICVO) in patients with recurrent or metastatic head and neck squamous cell carcinoma who had received at least two prior lines of therapy.

Among 33 efficacy-evaluable patients receiving 5.4 mg/kg intravenously once every three weeks, the confirmed objective response rate was 36% and the disease control rate was 94%. Median progression-free survival stood at 6.2 months, with a 12-month overall survival probability of 79%; median overall survival had not yet been reached.

MICVO exhibited clinical activity across key patient subgroups, including by HPV status and prior treatment history. The confirmed objective response rate was 28% in patients previously treated with an EGFR inhibitor and 47% in those who had not received such therapy.

The safety profile revealed no new signals, with treatment-related adverse events consistent with other antibody-drug conjugates carrying auristatin payloads. Among 35 safety-evaluable patients, 54.3% experienced Grade 3 or higher treatment-related adverse events, and 14.3% discontinued treatment due to adverse events. There were no treatment-related deaths.

The company intends to launch the pivotal Phase 3 trial, Headliner, in mid-2027, following an End of Phase 2 meeting with the FDA anticipated in the first quarter of 2027. This randomized study will enroll roughly 500 patients with second- or third-line recurrent/metastatic head and neck squamous cell carcinoma and will compare MICVO against investigator’s choice of cetuximab, docetaxel, or methotrexate.

MICVO is a first-in-concept antibody-drug conjugate directed at extradomain-B of fibronectin, a structural element of the tumor extracellular matrix.

This article was produced with the assistance of AI and reviewed by an editor. Please refer to our Terms & Conditions for further details.