Outcomes in patients with multiple sclerosis and solid organ cancers treated with immune checkpoint inhibitors

Multiple sclerosis (MS) patients are excluded from studies of immune checkpoint inhibitors (ICIs) due to concern for MS flare. This study aims to report the incidence of MS relapse, immune-related adverse events (irAEs), and cancer outcomes in MS patients with solid-organ malignancy treated with ICIs.

In this retrospective study, MS patients who received ICIs at University Hospitals Seidman Cancer Center were identified electronically. Information on MS relapses, irAEs, and cancer outcomes after ICI initiation was collected and analyzed.

Twelve patients were included in the study, all of whom had inactive MS. No patient experienced MS relapse or new lesions on brain MRI after ICI initiation. Two patients (16.7%) had severe irAEs (grade ≥ 3), which was acute pneumonitis. No deaths were associated. The objective response rate was 50%. An additional year of age was associated with a 14.2% decrease in the risk of developing severe irAEs (hazard ratio (HR) = 0.858; 95% confidence interval (CI): 0.798-0.922; P < .0001) and a 10.3% decrease in the risk of disease progression (HR = 0.897; 95% CI: 0.823-0.976; P = .0120). No significant difference in risk of having severe irAEs, overall survival, or progression-free survival was found between MS patients with and without DMTs.

Our study suggests that ICIs could be safely used in patients with inactive MS with a low risk of MS relapse and comparable irAE risk with the general population. Although larger studies are needed for confirmation, the benefit of using ICIs to treat solid-organ malignancies might outweigh the risk of withholding treatment for this population.