MICVO (maMICVO)

April 17, 2026: Pyxis Oncology, Inc. (NASDAQ: PYXS) announced it will present new preclinical data at the AACR Annual Meeting 2026 (San Diego; April 17–22, 2026) on a mouse analog of micvotabart pelidotin (MICVO; maMICVO), an antibody-drug conjugate targeting extradomain-B of fibronectin (EDB+FN), in head and neck squamous cell carcinoma (HNSCC) models. In the syngeneic MOC2 HNSCC model, maMICVO monotherapy produced dose-dependent tumor growth inhibition, with 6 mg/kg showing the strongest inhibition, and modulated the tumor immune environment by reducing regulatory T cells, increasing the CD8 T cell-to-Treg ratio, and increasing a progenitor exhausted T-cell subset described as responsive to anti-PD-1 therapy. In an immunotherapy-refractory syngeneic HNSCC model, maMICVO plus anti-mouse PD-1 showed greater tumor control than either agent alone; Bliss independence analysis supported synergy.

The company said the findings support ongoing clinical development of MICVO as monotherapy and with pembrolizumab (KEYTRUDA) in recurrent/metastatic HNSCC. Upcoming catalysts cited: a mid-year 2026 Phase 1 monotherapy update in 2L+ R/M HNSCC and updated data in 2H 2026 from an ongoing Phase 1/2 combination dose-escalation study of MICVO plus pembrolizumab in 1L/2L+ R/M HNSCC (and other solid tumors). Poster presentation: April 21, 2026 (9:00 AM–12:00 PM PT).