COVID-19 in patients with multiple sclerosis treated with cladribine tablets: An update.

Background: We previously summarized outcomes for 46 cladribine tablets (CladT)-treated patients with multiple sclerosis (MS) and confirmed or suspected COVID-19, as reported to the Merck KGaA Global Patient Safety Database. This report updates on these findings, to 15 January 2021, for a total of 272 reported cases of COVID-19 among CladT recipients.

Methods: Case definitions: confirmed (COVID-19 diagnostic test was positive); suspected (no confirmatory test performed/reported). Cases fulfilling the criteria of hospitalized, medically significant, or fatal were designated as serious and outcomes were classified per usual pharmacovigilance practice.

Results: The evaluable cohort comprised 261 patients (confirmed COVID-19, n=160; suspected, n=101); an additional 11 patients had symptoms compatible with COVID-19 but were not evaluated further given their negative diagnostic tests. Median time to onset of COVID-19 from the most recent preceding CladT treatment course was 162 days (n=139). Outcomes were: recovered/recovering, n=133 (51%); not recovered/not resolved, n=19 (7%); died, n=1 (0.4%); and not reported/missing/pending, n=108 (41%). Of the total cohort, 40 (15%) experienced serious COVID-19.

Conclusion: Our results suggest that CladT-treated patients with MS are generally not at greater risk of serious disease and/or a severe outcome with COVID-19 compared with the general population and other patients with MS who acquired COVID-19.