Evaluating the Efficacy and Safety of ZytuxTM (Rituximab, AryoGen Pharmed) in Iranian Multiple Sclerosis Patients: An observational Study

Abstract Background Anti-CD20 monoclonal antibodies such as ocrelizumab, rituximab, and ofatumumab target B-cell lineage. Clinical trials have demonstrated their effect on reducing both magnetic resonance imaging (MRI) active lesion burden as well as clinical activity. Zytux™ (Rituximab, AryoGen Pharmed) used in the present study for multiple sclerosis (MS) patients is basically a biosimilar rituximab. In this observational study, a total of 100 patients receiving Zytux™ were collected to see its effect on the clinical course of the disease. Materials and Methods The files of 100 MS patients, who received Zytux™ in a referral center (Sina MS Clinic in Tehran, Iran), were analyzed as a hospital-based observational study. Patients’ age and disease duration until the start of Zytux™, expanded disability status scale (EDSS) at the baseline and in the last visit after administration of the drug, and annual relapse rate (ARR) before and after initiating Zytux™ were studied. Disease activity was evaluated both clinically and via MRI. Result A total of 100 MS patients including 36 males and 64 females participated in the present study. The patients included 20 relapsing remitting MS (RRMS), 20 primary progressive MS (PPMS), and 60 secondary progressive MS (SPMS) patients. Totally, the mean of EDSS score before and after the administration of drug was 5.50 ± 1.04 (ranging from 1 to 7) and 5.11 ± 1.59 (ranging from 0 to 7), respectively, with the difference between them being very significant (p-value: 0.000). Also, the mean of ARR before and after the initiation of the medication was 0.47 and 0.10, respectively, whose difference was also significant (p-value: 0.000). In our study, the greatest effect of Zytux™ was observed in RRMS patients. At the time of injection, 70 patients indicated some reactions including limb pain, skin sensitivity, and throat irritation. One month after the injection, one of the patients suffered from pneumonia and two patients had a urinary tract infection. Conclusion The observed results revealed that the Zytux™ could have a positive and significant effect on all types of MS.