Pyxis Oncology’s MICVO study produced a 36% confirmed objective response rate, or 12 of 33 patients, and a 94% disease control rate. The results support advancing MICVO into a pivotal program for second-line and beyond recurrent or metastatic head and neck cancer, with a Phase 3 trial planned for mid-2027.

Key Highlights

  • Median progression-free survival was 6.2 months, while the 12-month overall survival probability was 79%.
  • The study recorded no new safety signals, with all treatment-related adverse events reported in 32 of 35 patients.
  • Pyxis Oncology plans to begin the Phase 3 Headliner trial in mid-2027.

Pyxis Oncology, Inc. (NASDAQ: PYXS) reported updated Phase 1 results for MICVO that support advancing the drug into a key program after a 36% confirmed objective response rate, or 12 of 33 efficacy-evaluable patients. The study evaluated patients with second-line and beyond recurrent or metastatic head and neck squamous cell carcinoma. Disease control reached 94%, representing 31 of 33 patients. The data cutoff was August 18, 2026.

MICVO Efficacy Data

Median progression-free survival was 6.2 months, with a 95% confidence interval of 4.8 to 8.8 months. The 12-month overall survival probability was 79%, with a confidence interval of 58.1 to 90.3. Responses emerged quickly in the study. Activity was reported across the evaluated patient subgroups. Patients with HPV-positive oropharyngeal disease had a 35% confirmed objective response rate and median progression-free survival of 6.2 months, compared with 38% and 5.9 months, respectively, among patients with HPV-unrelated disease. Patients with prior EGFR inhibitor treatment recorded a 28% response rate and median progression-free survival of 5.0 months. Those without prior EGFR inhibitor treatment recorded a 47% response rate and 8.8 months of median progression-free survival. The prior novel EGFR inhibitor subgroup had a 40% response rate and median progression-free survival of 5.8 months. Patients with prior taxane treatment recorded a 35% response rate and 6.2 months of median progression-free survival, while those without prior taxane treatment recorded a 40% response rate and 4.9 months.

Safety Results Remain Manageable

The safety-evaluable population included 35 patients. Non-hematologic treatment-related adverse events of CTCAE Grade 3 or higher occurred in 15 patients, representing 42.9%. The median treatment duration was 120 days, with a range of 21 to 470 days. The tolerability results were described as consistent with other antibody-drug conjugates carrying auristatin payloads and generally manageable.

Phase 3 Trial Planned

Pyxis Oncology said the updated results support moving MICVO into a key program for second-line and beyond recurrent or metastatic head and neck squamous cell carcinoma. The company plans to initiate the Phase 3 Headliner trial in mid-2027. The company described MICVO as potentially addressing a significant unmet need in this patient population. The company described MICVO as having a non-EGFR-targeting mechanism as the first-line treatment environment evolves.