Pyxis Oncology Announces Updated Phase 1 MICVO Data in HNSCC

What Happened
Pyxis Oncology (PYXS) announced updated clinical data on September 9, 2026 (data cutoff August 18, 2026) from its ongoing global Phase 1 monotherapy study of micvotabart pelidotin (MICVO) in second-line and beyond (2L+) recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). The company filed a Regulation FD 8-K attaching a press release and corporate presentation (Exhibits 99.1 and 99.2).

Key Details

• Population/cutoff: 5.4 mg/kg dose-cap population N=35; efficacy-evaluable N=33; data cutoff August 18, 2026.
• Efficacy: Confirmed objective response rate (cORR) 36% (12/33); disease control rate (DCR) 94% (31/33); median progression-free survival (mPFS) 6.2 months (95% CI 4.8–8.8); 12‑month overall survival probability 79% (95% CI 58.1–90.3); median OS not reached.
• Subgroups: HPV+ oropharyngeal ORR 35% (n=17); HPV-unrelated ORR 38% (n=16). Prior EGFR inhibitor: ORR 28% (yes, n=18) vs 47% (no, n=15).
• Safety/tolerability: No new safety signals reported. Any treatment‑related adverse event (TRAE) in 91.4% (32/35); Grade ≥3 TRAEs in 54.3% (19/35); serious TRAEs 14.3% (5/35); TRAEs leading to discontinuation 14.3% (5/35); no treatment‑related deaths. ADC‑payload events: peripheral neuropathy overall 40% (14/35), Grade 3 in 17.1% (6/35); cutaneous and ocular events reported, pneumonitis infrequent.

Why It Matters
These Phase 1 results provide updated signals on both activity (ORR, DCR, mPFS) and tolerability for MICVO in a heavily pretreated HNSCC population. For investors, the data help assess clinical progress and risk: the response rates and 12‑month survival probability suggest potential clinical benefit, while the safety profile (notably peripheral neuropathy and dose modifications/discontinuations) highlights tolerability and development considerations. The filing is informational (Regulation FD) and includes the company’s press release and investor presentation for further details.