Background and importance Multiple sclerosis (MS) secondline disease modifying treatments (DMT) cause lymphocyte or B cell depletion, such as therapy with natalizumab, ocrelizumab, alemtuzumab or rituximab. They can present a varying degree of immunodeficiency that can translate into an increased risk of infections. The decision making process should balance the risks of stopping an active treatment and the risk of COVID-19 infection.

Aim and objectives To evaluate the management of MS patients with secondline DMT via infusion with natalizumab, ocrelizumab, rituximab and alemtuzumab during the COVID-19 pandemic.

Material and methods An observational retrospective study was conducted between January 2020 and October 2020 of MS patients on active treatment with natalizumab, ocrelizumab, rituximab or alemtuzumab who were expected to receive new dosages in this period. For data collection, the electronic clinic history system (Selene) and the programme Farmatools were used. Variables collected were: sex, age, expanded disability status scale (EDSS), COVID-19 diagnosis and type of MS. Treatment changes/delays due to COVID-19 were reviewed. In case of delay, the number of days was quantified.

Results 40 patients (65% women) treated with different infusion therapies were evaluated with a median age of 47.3 (SD 13,3). The average EDSS was 3.8 (SD 2.1). 29 patients had relapsing–remitting MS (72,5%), 7 had primary progressive MS (17.5%) and 4 had secondary progressive MS (10%). Five (12.5%) COVID-19 cases were diagnosed. No delays were registered in 13 infusions of natalizumab; 2 patients, due to a suboptimal response, were changed to ocrelizumab, reducing hospital visits, and one was transferred to another hospital.

Three patients were expected to receive alemtuzumab. No one received alemtuzumab and two were changed to ocrelizumab due to the European Medicines Agency (EMA) alert that recommended restricting the use of alemtuzumab during the COVID-19 pandemic. Two patients received rituximab in time; one was changed to natalizumab due to infusion reactions and in one case the dosing interval was extended to 36 days. Eight patients began ocrelizumab treatment, eight received their dose without delay, one died and in five cases the dosing interval was extended to 39 days (SD 23.8).

Conclusion and relevance According to the recommendations, a case-by-case analysis should be performed, but it seems that the COVID-19 pandemic has conditioned MS treatments as changes/delays were registered. Five (12.5%) COVID-19 cases were diagnosed, similar to the outcomes obtained in the seroprevalence study in the same region.

Conflict of interest No conflict of interest