Disease-Modifying Therapies in Multiple Sclerosis

Abstract

Background: Multiple sclerosis (MS) is a demyelinating condition resulting from the damage of the insulating covers of the brain nerve cells and the spinal cord. The damage affects the ability of the nervous system to transmit signals, and affected individuals end up experiencing physical, mental, and psychiatric problems. Specific symptoms of multiple sclerosis include one-sided blindness, double vision, trouble with sensation and coordination, and muscle weakness. Disease-modifying therapies (DMTs) are preferred for managing relapsing MS and preventing associated disabilities. Their mechanism of action determines how they initiate the therapeutic effect. Besides, each class of DMTs may cause adverse effects to the patients, so they need to be monitored frequently. They exist in injectable, oral, and infusion forms. The purpose of the study was to research the efficacy, efficiency, and tolerability of the mentioned forms of DMTs in managing MS and its complications. Methods: Systematic review and meta-analysis of peer-reviewed articles using databases such as PubMed, MEDLINE, and Cochrane library. Randomized controlled trials were considered. Articles published in the past 20 years were selected as long as they related to the study objectives. Literature search entailed the use of key terms such as "management of multiple sclerosis,” "injectable disease-modifying therapies,” "oral disease-modifying therapies,” "infusion disease-modifying therapies," and "randomized controlled trials." Data extraction was based on study characteristics such as the title, publication year, number of participants, and the study duration. Data presentation was done using tables. Results: 24 out of 99 sources met the study requirements. Among them, those that investigated injectable DMTs were 8, oral DMTs, were 11, and infusion DMTs were 5. In the injectable DMT group, interferon beta-1a was the most tested injectable DMT such that it appeared in all 8 studies. Secondly, the 6 studies in the oral DMTs group used oral fingolimod as a major drug, 4 studies used Oral teriflunomide, and the remaining 2 studies used ozanimod and cladribine. 2 studies in the infusion DMTs group tested Ocrelizumab, and the remaining study measured natalizumab and Alemtuzumab. In injectable DMTs, Avonex® (interferon beta-1a) showed the highest efficacy than Betaseron® (interferon beta-1b). Aubagio® (teriflunomide), Gilenya® (fingolimod), Mavenclad® (cladribine and Zeposia® (ozanimod) were the most common oral DMTs in the identified studies. Lastly, Lemtrada® (alemtuzumab), Ocrevus® (ocrelizumab), and Tysabri® (natalizumab) were the most investigated infusion DMTs. Conclusion: Findings of the identified studies show that several disease-modifying therapies can prevent the relapse of multiple sclerosis. Although some of the DMTs have adverse effects, selecting therapies with maximal efficacy and minimal adverse effects can help patients to tolerate DMTs well and achieve quality outcomes. Therefore, injectable, oral, and infusion disease-modifying therapies can be administered to patients with multiple sclerosis to prevent relapse and associated complications and disabilities.