A phase 2 trial published in Nature Medicine on November 4, 2026, reports that perioperative ivonescimab significantly reduces viable tumor cells in patients with resectable non-small cell lung cancer (NSCLC). Researchers tested the treatment in two cohorts: one receiving ivonescimab as a monotherapy and another receiving the drug in combination with chemotherapy. Both cohorts received neoadjuvant treatment prior to surgery, followed by adjuvant ivonescimab. The primary takeaway is the presence of a strong biological signal regarding the reduction of viable tumor cells.1

For this patient population, the surgical procedure is only part of the challenge. The risk of recurrence remains elevated even after the primary tumor has been excised. Consequently, perioperative strategies—those integrating treatments before and after surgery—have become a major focus of recent oncological research.

Key findings in this report:
  • What levels of major pathological response were achieved in the phase 2 study?
  • Where might serious adverse event rates impact treatment progression?
  • Why do experts maintain a cautious stance pending randomized phase 3 results?
  • Why are these therapeutic approaches critical in addressing the global lung cancer burden?

What levels of major pathological response were achieved in the phase 2 study?

In the primary cohort treated with a combination of chemotherapy and ivonescimab, the major pathological response (MPR) rate was 70.1 percent, with 47 out of 67 patients showing significant tumor regression in the surgical specimens. The study notes that this rate exceeds the historical 41 percent threshold, effectively meeting the trial's primary endpoint.2 The monotherapy cohort, though smaller, showed a similar trend: 6 out of 10 patients achieved an MPR. Furthermore, in the majority of patients who reached an MPR, the remaining viable tumor burden was 5 percent or less, an indicator of the depth of the pathological response.

Notes and Sources

  1. Wang, Z., Peng, L., Wang, Y. et al. (November 4, 2026). "Perioperative ivonescimab with or without chemotherapy in resectable non-small cell lung cancer: a phase 2 trial." Nature Medicine. DOI: 10.1038/s41591-026-04745-4. Data regarding MPR, adverse events, and surgical delays are derived from this article. Clinical trial identifier: NCT05247684. ↩
  2. IARC Global Cancer Observatory (GLOBOCAN 2022). Current statistics on the global lung cancer burden. Fact sheet (PDF). ↩

This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment recommendations. Decisions regarding lung cancer treatment should be made exclusively in consultation with oncology and thoracic surgery teams.