Background and importance Ocrelizumab is the first drug approved in Europe for the treatment of primary progressive multiple sclerosis (PPMS). It is an anti-CD20 monoclonal antibody whose use has also been authorised in early forms of PPMS and recurrent forms of MS.

Aim and objectives To evaluate the prescription of ocrelizumab and to describe its safe drug administration.

Material and methods This was a retrospective observational study of patients treated with ocrelizumab from May 2018 to March 2019. All patients who received the two initial 300 mg infusions of ocrelizumab were included. Age, sex and the variant of the disease were collected. The number of administrations of ocrelizumab and the previous use of other anti-CD20 drugs or disease modifying drugs (DMDs) were analysed. Safe drug administration was evaluated as the presence of adverse reactions during infusion or treatment according to the common terminology criteria for adverse events V.5.0.

Results Twenty-seven patients were treated, 15 men (55.6%), with an average age of 49±9.2 years. Nineteen patients were diagnosed with PPMS (70.4%), three with relapsing–remitting MS (22.2%) and two with secondary progressive MS (7.4%). Twenty patients were previously treated (74.1%): 14 were treated with one drug (51.9%), 5 with two drugs (18.5%) and 1 had received three different drugs previously (3.7%). One patient had previously been treated with an anti-CD20 drug (6.7%). Ocrelizumab was administered 67 times. Fourteen patients completed three administrations (51.9%). In terms of safety, nine reactions developed after infusion (13.3%): four were pruritus grade 1 (6.0%), two were palate irritation grade 1 (2.9%), two hypertensive episodes (2.9%) and one chest rash. In the first week after administration, three patients needed medical assistance due to gastrointestinal disorders, one episode of joint swelling and fever, and an influenza infection. One patient needed to be hospitalised 3 weeks after the second administration due to pericarditis.

Conclusion and relevance Ocrelizumab was used most commonly in PPMS, with the majority of patients been treated with DMDs. Although infusional reactions appeared frequently, the incidence was less than that described in the pivotal trials. However, more experience is needed to determine the possible complications of its administration.

References and/or acknowledgements No conflict of interest.