Business Description

Overview Pyxis Oncology is a clinical-stage oncology company advancing a development strategy focused on addressing unmet medical needs in patients with solid tumors with an immediate focus on head and neck squamous cell carcinoma (HNSCC). Our lead product candidate, micvotabart pelidotin (MICVO, formerly PYX-201), is an investigational novel antibody-drug conjugate (ADC) that uniquely targets the splice variant of fibronectin, extradomain-B of fibronectin (EDB+FN), a non-cellular structural component of the extracellular matrix (ECM) in the tumor microenvironment (TME). EDB+FN is an isoform of fibronectin present in tumors that is negligibly expressed in normal adult tissues and facilitates cancer progression by playing multiple roles including promoting cell proliferation, adhesion, and migration, activating the integrin signaling pathway, stimulating angiogenesis and vascular remodeling, driving epithelial-mesenchymal transition (EMT), and establishing the pre-metastatic niche. We believe EDB+FN is a compelling target for cancer therapeutics as the physiological expression of EDB+FN is very low in healthy adult tissues, yet it is found to be highly expressed in a variety of solid tumors. Our ADC, MICVO, consists of a fully human IgG1 monoclonal antibody that is site-specifically conjugated to a cleavable linker with an optimized auristatin (Aur0101) microtubule inhibitor payload. Unlike conventional ADCs which bind to an antigen on the surface of a cancer cell, MICVO is designed to bind to EDB+FN in the tumor ECM, where extracellular proteases under acidic conditions cleave the linker to release the Aur0101 payload. The payload diffuses through the membrane of cancer cells to kill them directly, which is the first component of MICVO’s three-pronged mechanism of action (MOA). The dying cancer cells release the payload which diffuses into nearby cancer cells and kills them via the bystander effect, representing the second component of MICVO’s MOA. The dying cancer cells also release neoantigens which trigger immunogenic cell death (ICD), the final component of its MOA. Together with its purpose-built design and postulated three-pronged MOA, MICVO has the potential for improved stability and anti-tumor activity compared to conventional ADCs. MICVO is currently being studied as monotherapy in recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC) and in combination with KEYTRUDA® (pembrolizumab) in 1L/2L+ R/M HNSCC and other solid tumors. MICVO Monotherapy PYX-201-101 Phase 1 (Part 1) Monotherapy Dose Escalation Study As part of our Phase 1 monotherapy study, referred to as PYX-201-101, we conducted a dose escalation study to evaluate MICVO monotherapy in patients with advanced solid tumors known to express EDB+FN. In November 2024, we reported positive preliminary results from the dose escalation study, which included a total of 80 patients dosed across nine solid tumor types at doses ranging from 0.3 mg/kg to 8 mg/kg, with a data cut-off of October 4, 2024. Of the nine solid tumor types included in the study, the strongest tumor regression response was observed in R/M HNSCC. Among the six efficacy evaluable heavily pre-treated patients with R/M HNSCC, the confirmed objective response rate (ORR) was 50% per RECIST v1.1 at the therapeutically active dose response range of 3.6 mg/kg – 5.4 mg/kg administered intravenously every three weeks (IV Q3W), including one confirmed complete response (CR) and two confirmed partial responses (PRs), with a disease control rate (DCR) of 100%. Based on observations from the dose-escalation study, 5.4 mg/kg IV Q3W presented an optimal benefit-risk profile within the efficacious dose range and was selected for dose expansion. Subsequent translational data indicated reduction in ctDNA TF after treatment with MICVO, particularly at the 5.4 mg/kg dose, supported a positive molecular response to MICVO, providing further validation of the dose selection strategy for dose expansion. PYX-201-101 Phase 1 (Part 2) Monotherapy Dose Expansion in R/M HNSCC In January 2025, we initiated the dose expansion portion (Part 2) of the Phase 1 PYX-201-101 monotherapy study to further evaluate MICVO as a monotherapy at a dose of 5.4 mg/kg IV Q3W and to assess preliminary efficacy in R/M HNSCC.…