Pyxis Oncology revealed promising preclinical data for its lead antibody-drug conjugate, micvotabart pelidotin (MICVO), at the 2025 American Association for Cancer Research (AACR) annual meeting. The data demonstrated MICVO’s unique mechanism of action involving direct tumor cell death, a bystander effect impacting surrounding cells, and immunogenic cell death stimulating an immune response. The studies further validated MICVO’s potential as a monotherapy and in combination with anti-PD-1 therapy.
This news holds considerable importance for the oncology field, particularly for patients with difficult-to-treat solid tumors like recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC). The data suggests that MICVO’s three-pronged attack could offer a more comprehensive and effective treatment approach compared to existing therapies, potentially leading to improved outcomes and enhanced survival rates. Specifically, the potential to convert “cold” tumors, which are typically resistant to immunotherapy, into “hot” tumors susceptible to immune attack, represents a significant advancement in the fight against cancer.
Preclinical studies revealed that MICVO exhibited broad anti-tumor activity in patient-derived xenograft (PDX) models across ten solid tumor types, with 45% of the models showing strong to very strong tumor growth inhibition. Gene expression analysis identified specific enzyme and tumor stroma signatures associated with increased efficacy due to greater linker cleavage and payload release. Furthermore, a mouse analog of MICVO combined with anti-PD-1 therapy demonstrated enhanced tumor clearance and longer-lasting immunological memory compared to either treatment alone, suggesting a synergistic effect.
This preclinical data reinforces the rationale for MICVO’s ongoing clinical development. The findings support further investigation into MICVO’s potential to improve treatment outcomes for patients with advanced solid tumors, especially in combination with immunotherapy. The results also highlight the value of targeting the tumor extracellular matrix with ADCs as a novel and promising therapeutic strategy.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
