Safety of Checkpoint Inhibitors for Cancer Treatment in Patients with Multiple Sclerosis: A Case Report

Objective: To describe autoimmune outcomes in a patient with multiple sclerosis (MS) treated for lung cancer treated with programmed cell death ligand 1 (PD-L1) checkpoint inhibitor. Background: PD-L1 inhibitors have become an important treatment for non-small-cell lung cancer (NSCLC). Safety in patients with underlying autoimmune diseases has yet to be established. Design/Methods: This is a novel case report that describes the autoimmune outcomes for a patient with MS who was treated with atezolizumab. Results: A 46-year-old man with history of MS and stage IV metastatic NSCLC received a single dose of atezolizumab (PD-L1 checkpoint inhibitor). His MS had been diagnosed in 2001 after an optic neuritis, initially treated with interferon beta-1b then fingolimod for breakthrough disease. Fingolimod was stopped when he was diagnosed with cancer two years prior to presentation, at which point he had no evidence of active demyelination on brain MRI. Staging included positron emission tomography-computed tomography showing new left cerebellar lesion and concern for other brain metastasis. Cerebrospinal fluid (CSF) analysis showed 6 cells/uL with 71% lymphocytes, protein of 51, normal IgG index, positive oligoclonal bands isolated to CSF. He had whole brain radiotherapy (RT) with 3000 cGy over 10 fractions, followed by cisplatin/etoposide for 3 cycles. Five months after RT, he received one dose of atezolizumab. His tumoral load had dramatically stabilized after this treatment, but subsequent MRI monitoring revealed new enhancing brain lesions concerning for demyelination in conjunction with months of neurological deterioration. Brain biopsy was consistent with demyelination. Worsening MS was treated with rituximab, but failed to achieve remission. Subsequent MRIs revealed refractory new demyelinating lesions and rapid brain atrophy. Conclusions: PD-1 and PD-L1 checkpoint inhibitors have become an important treatment for NSCLC. To our knowledge this is the first case report of atezolizumab associated central nervous system autoimmune complications, specifically treatment-refractory demyelinating disease. Disclosure: Dr. Isitan has nothing to disclose. Dr. Wesley has received personal compensation in an editorial capacity for Elsevier and Clinical Therapeutics.