Report on clinical outcomes in patients with multiple sclerosis (MS) who developed COVID-19 during two ongoing Phase IV studies of cladribine tablets (CladT): CLARIFY-MS (NCT03369665) and MAGNIFY-MS (NCT03364036).

The COVID-19 pandemic has prompted various guidelines on the appropriate use of disease-modifying therapy for MS, including CladT.

CLARIFY-MS is investigating the effect of CladT on health-related quality of life in patients with highly active relapsing MS, while MAGNIFY-MS is evaluating the onset of action of CladT in this population. Both studies have an open-label, single-arm, multicenter design in which patients receive CladT 3.5 mg/kg cumulative dose over 2 years. A total of 485 and 270 patients, respectively, have been enrolled to CLARIFY-MS and MAGNIFY-MS. Cases of suspected or confirmed COVID-19 in these studies were identified from adverse event (AE) reports and reviewed in terms of patient characteristics, COVID-19 severity and outcomes.

From the combined population (n=755), 30 patients aged 19–55 years were identified with either suspected (n=2) or confirmed (n=28) COVID-19 (CLARIFY-MS, n=16; MAGNIFY-MS, n=14). Time to infection since last CladT dose was 0–11 months. The majority of patients were female (25 out of 30 patients) and experienced mild (20 patients) or moderate (8 patients) COVID-19. Three cases were reported as serious AEs, including two patients who were hospitalized. No patient required mechanical ventilation and there were no deaths. At time of reporting, 27 out of 30 patients had recovered and 3 patients recovered with sequelae.

Findings show that the small number of CladT-treated MS patients who acquired COVID-19 in these Phase IV studies typically experienced mild disease with no increased risk of serious outcomes.