- Neoadjuvant nivolumab is well tolerated, shows response, and improves recurrence-free survival in high-risk patients with resectable Merkel cell carcinoma (MCC).
Why this matters
- Patients with high-risk MCC relapse within a year after neoadjuvant chemotherapy.
- Further research of nivolumab in MCC is warranted.
- Phase 1/2 CheckMate 358 study.
- 39 patients with stage IIA-IV MCC received neoadjuvant nivolumab.
- Funding: Bristol Myers Squibb; ONO Pharmaceutical Company Limited.
- 3 patients did not undergo surgery.
- Median follow-up was 20.3 months.
- 46.2% of patients had any grade and 7.7% had grade 3/4 toxicities.
- No treatment-related deaths were reported.
- 47.2% of patients achieved pathologic complete response, and 15.4% achieved major partial response.
- No relapses were observed among responders during follow-up.
- 54.5% of patients had tumor reduction ≥30%.
- Median relapse-free survival (RFS) was not reached.
- 24-month RFS rate was 68.5%.
- 24-month RFS rate was significantly higher in patients with pathologic complete response vs those without:
- 88.9% vs 52.2%;
- HR, 0.12 (95% CI, 0.01-0.93).
- RFS and OS were similar regardless of tumor Merkel cell polyomavirus (P=.394 and .666, respectively) and programmed death-ligand 1 status (P=.998 and .761, respectively).
- Tumor mutation burden did not differ between patients with or without responses.
- Small study.