Core Insights - Pyxis Oncology, Inc. announced robust preclinical data supporting the unique mechanism of action of micvotabart pelidotin (MICVO), an antibody-drug conjugate (ADC) targeting extradomain-B fibronectin (EDB+FN), which is highly expressed in various solid tumors [1][5] - MICVO demonstrated significant anti-tumor activity across multiple solid tumor indications, with 45% of models showing strong to very strong tumor growth inhibition (TGI) and complete responses observed in several tumor types [2][3] - The combination of MICVO with anti-PD-1 therapy showed enhanced tumor clearance and longer immunological memory compared to either treatment alone, reinforcing the potential for MICVO as both a monotherapy and in combination therapies [1][3] Preclinical Findings - Evaluation of MICVO in patient-derived xenograft (PDX) models identified gene signatures associated with anti-tumor activity, with 45% of models showing TGI between 70% and 90% or greater than 90% [2][3] - The preclinical studies indicated that MICVO is well-tolerated at a dosage of 3 mg/kg, with significant tumor regression responses confirmed in Phase 1 studies [2][4] - Upregulation of certain proteases may enhance linker cleavage, contributing to increased MICVO activity, supporting the hypothesis for its extracellular mechanism [3] Clinical Development - MICVO is currently being evaluated in Phase 1 studies as a monotherapy and in combination with KEYTRUDA® (pembrolizumab) for advanced solid tumors, particularly recurrent and metastatic head and neck squamous cell carcinoma [4][5][8] - The company has received Fast Track Designation from the U.S. FDA for MICVO in treating adult patients with recurrent and metastatic head and neck squamous cell carcinoma whose disease has progressed after prior treatments [8]