micvotabart pelidotin (PYX-201-101) - (MICVO)

September 9, 2026: Pyxis Oncology (NASDAQ: PYXS) reported updated Phase 1 monotherapy data for micvotabart pelidotin (MICVO) in second-line and beyond recurrent/metastatic head and neck squamous cell carcinoma. In the 5.4 mg/kg every-3-weeks dose-cap cohort, efficacy-evaluable N=33 and safety N=35, MICVO showed a 36% confirmed ORR (12/33), 94% disease control rate (31/33), median PFS of 6.2 months (95% CI 4.8-8.8), 12-month OS probability of 79% (95% CI 58.1-90.3), and median OS not reached. Among responders, 75% responded by the first scan at 6 weeks and 83% had >50% tumor reduction. Activity was seen across HPV and prior-treatment subgroups.

Safety showed no new signals; grade 3+ treatment-related AEs occurred in 54.3%, serious TRAEs in 14.3%, discontinuations in 14.3%, and there were no treatment-related deaths. Dose capping reduced frequency and severity of AEs in high-body-weight patients.

Next catalysts: End-of-Phase 2 FDA meeting on dose selection is expected in Q1 2027; updated overall survival data from the monotherapy study are expected in 1H 2027. The planned pivotal Phase 3 Headliner trial in 2L/3L R/M HNSCC is expected to start in mid-2027, enrolling about 500 patients versus investigator’s choice of cetuximab, docetaxel, or methotrexate, with co-primary endpoints of ORR and OS. Updated Phase 1/2 MICVO + KEYTRUDA data in 1L R/M HNSCC are expected in Q4 2026.