An analysis of two phase III clinical trials, CheckMate 238 and EORTC 18071, published in the Journal of Clinical Oncology, has identified notable cure rates with adjuvant nivolumab and ipilimumab in patients with resected stage III/IV melanoma. The study, led by Peter Mohr, MD, provides insights into the long-term benefits of immune checkpoint inhibitors (ICIs) in the adjuvant setting.
The analysis employed mixture cure models (MCMs) on patient-level recurrence-free survival data from the CheckMate 238 trial (nivolumab vs ipilimumab) and the EORTC 18071 trial (ipilimumab vs placebo). MCMs were used to estimate cure rates, assuming cured patients experience no disease recurrence and have mortality risks similar to the general population, while uncured patients remain at risk of recurrence and death.
Cure Rate Estimates
After a minimum follow-up of 5 years in CheckMate 238, the estimated cure rate with nivolumab was 48.3% (95% CI = 41.8%–54.9%), compared to 38.2% (95% CI = 32.7%–44.1%) with ipilimumab. In the EORTC 18071 trial, with a median follow-up of 6.9 years, the estimated cure rate was 38.0% (95% CI = 32.1%–44.2%) with ipilimumab and 29.2% (95% CI = 24.4%–34.6%) with placebo.
Indirect Comparison
An indirect comparison of the two trials revealed that the likelihood of cure was significantly higher with nivolumab compared to placebo (odds ratio [OR] = 2.33, 95% CI = 1.49–3.65). Similarly, the likelihood of cure was significantly higher with ipilimumab compared to placebo (OR = 1.55, 95% CI = 1.13–2.12).
The study authors concluded that their analyses demonstrate higher cure rates for both nivolumab and ipilimumab compared to placebo in the adjuvant treatment of resected melanoma, with nivolumab showing the highest cure rate. They also noted that similar cure rates were estimated for patients treated with ipilimumab in both trials, despite differences in staging and dosing.
