Pyxis Oncology (PYXS) investor relations material

MICVO design and rationale

• First-in-concept ADC targets EDB+FN in the extracellular matrix, found across many solid tumors but not normal tissue; its payload was optimized for this target.

• A basket study showed activity across multiple tumor types, strongest in head and neck; second-line head and neck was selected for its unmet need and sizable patient population.

• Management estimates ~20,000 patients seek second-line head and neck treatment; its market analysis estimates 30,000 patients in frontline and 70% progressing to second line, or 21,000 patients.

Second-line data and safety

• September data showed a 36% response rate regardless of HPV status, 94% disease control rate, 6.2-month median PFS and 79% OS probability; responses were often rapid and deep.

• More than two-thirds of patients responded by the first scan at six weeks; more than half had tumor reductions greater than 50%.

• After a dose cap was introduced in late December, discontinuations and any-grade 3 peripheral neuropathy were nearly halved; management said the modified weight-based approach supported enrollment.

• Response rates were nearly 50% without prior EGFR treatment, nearly 30% after prior EGFR treatment and 40% after a novel EGFR agent; second-line response rate was 45% versus 35% in third line.

• OS data were early, with six events at the September data cut; management guided to an update in H1 2027 and views the update as important to de-risking the pivotal trial.

Headliner pivotal trial

• Plan is a 500-patient, 1:1 randomized trial of MICVO versus investigator choice of docetaxel, methotrexate or cetuximab; stated primary endpoints are response rate and OS.

• An End-of-Phase 2 meeting is planned to finalize dose and address Project Optimus; management reported more than 30 patients dosed at 5.4 mg/kg with a dose cap and more than 20 at 3.6 mg/kg.

• Management expects 5.4 mg/kg with the dose cap to advance, citing September efficacy and a manageable safety profile; it plans to share the 3.6 mg/kg data with the agency.

• Target is to start the pivotal trial in mid-2027; management expects to share the full statistical plan in early 2027.

• Trial design aims to include patients treated with platinum plus PD-1 and accommodate patients who received an EGFR inhibitor in an earlier line, reflecting global frontline treatment differences.