Pyxis Oncology (PYXS) investor relations material

Differentiated ADC platform and target

• MICVO is a first-in-concept antibody-drug conjugate (ADC) targeting EDB+FN, a splice variant of fibronectin abundant in tumor extracellular matrix (ECM) and minimally expressed in normal tissue.

• The ADC is engineered for optimized stability, potency, and permeability, using site-specific conjugation and a uniform drug-antibody ratio (DAR) of 4.

• MICVO’s mechanism involves payload-driven tumor cell killing, bystander effect, and induction of immunogenic cell death, potentially remodeling the tumor microenvironment.

• Preclinical and translational data support strong binding, minimal off-target effects, and synergy with immune checkpoint inhibitors.

Clinical efficacy and safety in R/M HNSCC

• Phase 1 monotherapy in 2L+ recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) showed a 46% confirmed objective response rate (ORR) and 92% disease control rate (DCR) at 5.4 mg/kg.

• Responses were rapid, deep, and observed in heavily pre-treated, both HPV+ and HPV-unrelated patients.

• Safety profile at 5.4 mg/kg showed no grade 4/5 ADC payload-related adverse events; grade 3 events were primarily in high body weight patients.

• Modified weight-based dosing (dose capping or adjusted ideal body weight) is being implemented to mitigate overexposure and improve tolerability in high body weight patients.

Combination with KEYTRUDA® (pembrolizumab)

• Preliminary data for MICVO + KEYTRUDA® in R/M HNSCC showed a 71% confirmed ORR and 100% DCR (n=7), with no grade 3/4/5 ADC payload-related adverse events.

• Combination demonstrated rapid responses and promising activity in both first-line and later-line settings, especially in HPV+ patients.

• No overlapping toxicities observed between MICVO and KEYTRUDA®; future combinations may further differentiate benefit/risk profile.