Outcomes of COVID-19 in people with multiple sclerosis treated with cladribine tablets: an update

BACKGROUND: The COVID-19 pandemic is a concern for people with multiple sclerosis (pwMS), especially those receiving disease-modifying therapies. METHODS: We previously summarized outcomes for 46 pwMS treated with cladribine tablets (CladT) and confirmed or suspected COVID-19, as reported to the Merck KGaA Global Patient Safety Database (Jack et al., 2020). Here, we report an update to January 15, 2021 for 272 reported cases of COVID-19 among CladT-treated pwMS. Case definitions: confirmed = COVID-19 diagnostic test reported as positive; suspected = no confirmatory test performed/reported. Cases fulfilling the criteria of hospitalized, medically significant or fatal were designated as serious, while outcomes were classified per usual pharmacovigilance practice. RESULTS: Evaluable cohort: 261 pwMS, median age 41 (range: 18–73) years, 70% female. Confirmed COVID-19, n=160; suspected, n=101 (an additional 11 pwMS with compatible COVID-19 symptoms were not evaluated further given negative PCR tests). Median time to COVID-19 since last CladT treatment course was 162 (range: 0–643) days (n=139). Outcomes: recovered/recovering, n=133 (51%); not recovered/not resolved, n=19 (7%); died, n=1 (0.5%); not reported/missing/pending, n=108 (41%). Of the evaluable cohort, 40 (15%) experienced serious COVID-19; demographics and outcomes were comparable among all patients. A single fatal case was reported of a woman aged 60 years with suspected COVID-19 who initiated CladT treatment in July 2019. No COVID-19 test result was reported. The patient died in December 2020. CONCLUSION: CladT-treated pwMS do not appear to be at greater risk of serious disease and/or a severe outcome with COVID-19 versus the general and MS populations.