Clinical outcomes after use of checkpoint inhibitor immunotherapies in people with multiple sclerosis.

Background: Immune checkpoint inhibitors (ICIs) represent a novel class of agents approved for the treatment of several cancers and progressive multifocal leukoencephalopathy (PML). However, due to the risk of autoimmune side effects, their use in people with autoimmune diseases such as multiple sclerosis (MS) has been limited.

Objective: To characterize outcomes in a cohort of adults with MS who received ICIs.

Methods: A single-center retrospective review of medical record data was performed for people with MS treated with ICIs.

Results: Seven people with MS were identified, with a mean (SD) age at ICI use of 55.4 (13.7) years and a mean MS duration of 18.2 (12.2) years. Six were treated for cancer; 1 was treated for PML. After mean (SD) follow-up of 1.76 (2.15) years after ICI, outcomes are: no evidence of disease (2), residual metastatic disease (1), death due to cancer (1), death due to PML (1), and lost to follow-up (2). Notably, 0 out of 7 patients experienced an MS relapse; two out of six had new asymptomatic demyelinating magnetic resonance imaging lesions. In the three patients with expanded disability status scale (EDSS) scores at baseline and follow-up, EDSS remained stable (mean delta 0.13).

Conclusion: In this cohort, no people with MS experienced clinical relapses and one-third experienced asymptomatic radiological activity following ICI treatment.