Evaluating efficacy and safety of ocrelizumab biosimilar (Xacrel) compared to the originator (Ocrevus) in relapsing multiple sclerosis: a phase III, randomized, equivalency, clinical trial.

Multiple sclerosis is an inflammatory demyelinating disease and represents a global health concern. Ocrelizumab, a humanized IgG monoclonal antibody, selectively targets CD20 on B cells and CD20-expressing T cells. This study aimed to compare the efficacy and safety of the biosimilar ocrelizumab candidate (Xacrel) to the originator product (Ocrevus) in Relapsing Multiple Sclerosis (RMS) patients. In this randomized trial, patients received either Xacrel or Ocrevus for 96 weeks. The primary endpoint was the equivalency of the medications in reducing the annualized relapse rate (ARR) at week 48. The secondary endpoints included time to the onset of disability progression confirmed at 12 and 24 weeks, the proportion of relapse-free patients, magnetic resonance imaging (MRI) evaluations, safety assessments, and immunogenicity over 96 weeks. A total of 170 patients were randomized (1:1 ratio). In the per protocol analysis, the upper and lower limits of 95% two-sided confidence intervals of difference between treatments in the 48-week ARR rate were in the predefined margin of - 0.2 to 0.2 (- 0.002; 95% CI - 0.080 to 0.075). The two products were also comparable in terms of other efficacy parameters, safety, and immunogenicity. The results confirmed that Xacrel is equivalent to Ocrevus in terms of 48-week ARR in RMS patients, with no considerable difference in other efficacy parameters and the safety profile during the 96 weeks. The trial was registered in Iranian registry of clinical trials (IRCT) on 10/06/2019 with the registration number of IRCT20150303021315N13 and in Clinicaltrials.gov on 19/07/2021 with the registration code of NCT04966338.