Pyxis Oncology (PYXS) Stifel 2026 Targeted Oncology Virtual Forum summary

Program overview and scientific rationale

• Lead program MICVO targets EDB-FN in the extracellular matrix, a feature common in many cancers but absent in normal cells, making it an ideal ADC target.

• MICVO originated from Pfizer's FACT platform, representing a decade of research into novel ADC constructs.

• Preclinical and early clinical studies showed efficacy across multiple tumor types, with a focus on following the strongest clinical signals.

Clinical trial design and progress

• Dose escalation reached 5.4 mg/kg, higher than typical for similar ADCs, without classical dose-limiting toxicities.

• Dose expansion prioritized head and neck cancer due to strong efficacy signals, with a 46–50% response rate at 5.4 mg/kg.

• Two monotherapy cohorts (post-platinum+PD-1 and post-EGFR+PD-1) and a combination cohort with KEYTRUDA are being studied.

• Enrollment in monotherapy cohorts is complete, with about 40 patients in dose expansion and data expected mid-year.

Dosing strategy and safety considerations

• Dose cap was implemented to mitigate adverse events in high body weight patients, improving safety and enrollment.

• Adjusted ideal body weight (AIBW) dosing is being explored, but mid-year data will focus on dose cap and total body weight dosing.

• Dose capping and AIBW are considered equivalent for MICVO exposure and safety.