Autologous hematopoietic stem cell transplant (aHSCT), a procedure that aims to "reset" the immune system, generally reduces disability and relapse rates in people with multiple sclerosis (MS), according to a new meta-analysis. "Current data encourage a broader application of AHSCT for treating patients with MS while still considering proper patient selection and transplant methods," researchers wrote. The study, "Autologous Hematopoietic Stem-Cell Transplantation in Multiple Sclerosis: A Systematic Review and Meta-Analysis," was published in Neurology and Therapy. What is autologous hematopoietic stem cell transplant? aHSCT is a form of bone marrow transplant that basically involves first collecting blood stem cells from an individual, then wiping out that person's immune system using chemotherapy, and finally transplanting the stem cells back so they can repopulate the immune system with healthy cells. While the procedure has been used for decades to treat certain cancers, its use in MS has historically been restricted because MS is not considered life-threatening and aHSCT is a risky procedure. In recent years, however, technical advances and improvements in patient selection have markedly improved the safety profile of aHSCT, and the National Multiple Sclerosis Society has said that it is a feasible treatment option for MS patients with high disease activity. Here, a group led by scientists in Iran conducted a meta-analysis to assess the efficacy and safety of aHSCT in MS. A meta-analysis is a type of study where researchers pool data from many previously published studies. "Despite recent improvements in the application of AHSCT in MS, utilization of this treatment option is still limited," the researchers wrote. "In this systematic review, we aimed to address the lack of evidence supporting the confident application of AHSCT for patients with MS and to present a better view of the prospective benefits and potential risks," they added. The meta-analysis included 50 studies covering a total of 4,831 people with MS, ages 26 to 60. Because each of the studies performed assessments over different time periods, the researchers performed all efficacy analyses looking at outcomes five years after aHSCT (or the latest available timepoint for studies shorter than five years). What the results showed on safety, efficacy of aHSCT. Results showed that, on average, scores on the Expanded Disability Status Scale decreased by 0.48 points after aHSCT, suggesting slightly less severe disability. The procedure also led to a reduction in average annual relapse rate, by 1.58 relapses per year on average. Over the five years after aHSCT, 73% patients remained alive and without any disability progression, and 81% were relapse-free. Over two-thirds of patients (68%) had no evidence of disease activity — defined as no relapses, no new or enlarging lesions, and no disability worsening — in the five years following aHSCT. The overall survival rate following aHSCT was 94%, with 4% of patients dying due to transplant-related complications. The researchers said this rate of treatment-related mortality is "relatively high" compared with other studies of aHSCT, though they noted that other studies usually use much shorter follow-up times for this endpoint, which could explain the results at least in part. "Further studies with long follow-up duration are needed to determine the risk of potential adverse events after AHSCT in patients with MS," the researchers wrote. These results compare favorably with outcomes seen with many disease-modifying treatments (DMTs) for MS, according to the scientists. "Considering the superior efficacy of AHSCT in establishing long-term suppression of disease activity, it may be crucial to consider it before many of the second-generation DMTs to save time and prevent irreversible disease progression," they wrote. "However, this needs to be further investigated in large randomized controlled trials comparing the safety and efficacy of different DMTs with AHSCT in patients with distinct MS subtypes." The team noted that a Phase 3 clinical trial called BEAT-MS (NCT04047628), sponsored by the National Institute of Allergy and Infectious Diseases, is comparing aHSCT against the best available DMT in MS patients. BEAT-MS is enrolling adults, ages 18 to 55, with relapsing MS that is highly active despite treatment. Recruitment is ongoing at nearly 20 locations in the U.S.