Northwestern University sponsored a resent stem cell therapy trial involving multiple sclerosis (MS)– at onset an immune-mediated demyelinating disease. In most cases, it starts as a relapsing-remitting disease with distinct attacks and no symptoms between flares. Over years or decades, virtually all cases transition into a progressive disease in which insidious and slow neurologic deterioration occurs with or without acute flares. Relapsing-remitting disease is often responsive to immune suppressive or modulating therapies, while immune based therapies are generally ineffective in patients with a progressive clinical course. This clinical course and response to immune suppression, as well as neuropathology and neuroimaging studies, suggest that disease progression is associated with axonal atrophy. Disability correlates better with measures of axonal atrophy than immune mediated demyelination. Therefore, immune based therapies, to be effective, need to be started early in the disease course while MS is predominately an immune-mediated and inflammatory disease. While current immune based therapies delay disability, no intervention has been proven to prevent progressive disability. The sponsors proposed, as a randomized study, autologous unmanipulated PBSCT using a conditioning regimen of cyclophosphamide and rabbit antithymocyte globulin (rATG) versus FDA approved standard of care (i.e. interferon, glatiramer acetate, mitoxantrone, natalizumab, fingolimod, or tecfidera) in patients with inflammatory (relapsing) MS despite treatment with alternate approved therapy. The results were recently published in JAMA Network.
Question Is nonmyeloablative autologous hematopoietic stem cell transplantation (HSCT) more effective than disease-modifying therapy for patients with highly active relapsing-remitting multiple sclerosis (MS)?
Findings In this randomized clinical trial that included 110 patients with relapsing-remitting MS, treatment with nonmyeloablative HSCT compared with disease-modifying therapy resulted in a significantly prolonged time to disease progression (hazard ratio, 0.07).
Meaning In this preliminary study, nonmyeloablative HSCT was more effective than disease-modifying therapy for patients with relapsing-remitting MS.
Importance Hematopoietic stem cell transplantation (HSCT) represents a potentially useful approach to slow or prevent progressive disability in relapsing-remitting multiple sclerosis (MS).
Objective To compare the effect of nonmyeloablative HSCT vs disease-modifying therapy (DMT) on disease progression.
Design, Setting, and Participants Between September 20, 2005, and July 7, 2016, a total of 110 patients with relapsing-remitting MS, at least 2 relapses while receiving DMT in the prior year, and an Expanded Disability Status Scale (EDSS; score range, 0-10 [10 = worst neurologic disability]) score of 2.0 to 6.0 were randomized at 4 US, European, and South American centers. Final follow-up occurred in January 2018 and database lock in February 2018.
Interventions Patients were randomized to receive HSCT along with cyclophosphamide (200 mg/kg) and antithymocyte globulin (6 mg/kg) (n = 55) or DMT of higher efficacy or a different class than DMT taken during the previous year (n = 55).
Main Outcomes and Measures The primary end was disease progression, defined as an EDSS score increase after at least 1 year of 1.0 point or more (minimal clinically significant difference, 0.5) on 2 evaluations 6 months apart, with differences in time to progression estimated as hazard ratios.
Results Among 110 randomized patients (73 [66%] women; mean age, 36 [SD, 8.6] years), 103 remained in the trial, with 98 evaluated at 1 year and 23 evaluated yearly for 5 years (median follow-up, 2 years; mean, 2.8 years). Disease progression occurred in 3 patients in the HSCT group and 34 patients in the DMT group. Median time to progression could not be calculated in the HSCT group because of too few events; it was 24 months (interquartile range, 18-48 months) in the DMT group (hazard ratio, 0.07; 95% CI, 0.02-0.24; P < .001). During the first year, mean EDSS scores decreased (improved) from 3.38 to 2.36 in the HSCT group and increased (worsened) from 3.31 to 3.98 in the DMT group (between-group mean difference, −1.7; 95% CI, −2.03 to −1.29; P < .001). There were no deaths and no patients who received HSCT developed nonhematopoietic grade 4 toxicities (such as myocardial infarction, sepsis, or other disabling or potential life-threatening events).Conclusions and Relevance In this preliminary study of patients with relapsing-remitting MS, nonmyeloablative HSCT, compared with DMT, resulted in prolonged time to disease progression.