HSCT delayed disease progression
In a previous case series, Richard K. Burt, MD, of Northwestern University in Chicago, and his colleagues found that patients with relapsing-remitting MS who underwent nonmyeloablative HSCT had neurologic improvement and a 70% likelihood of having a 4-year period of disease remission. Dr. Burt and his colleagues undertook the MS international stem cell transplant trial to compare the effects of nonmyeloablative HSCT with those of continued DMT treatment on disease progression in participants with highly active relapsing-remitting MS.
The researchers enrolled 110 participants at four international centers into their open-label trial. Eligible participants had two or more clinical relapses or one relapse and at least one gadolinium-enhancing lesion at a separate time within the previous 12 months, despite DMT treatment. The investigators also required participants to have an EDSS score between 2.0 and 6.0. Patients with primary or secondary progressive MS were excluded.
Dr. Burt and his colleagues randomized participants to receive HSCT or an approved DMT that was more effective or in a different class than the one they were receiving at baseline. Ocrelizumab (Ocrevus) was not administered during the study because it had not yet been approved. The investigators excluded alemtuzumab because of its association with persistent lymphopenia and autoimmune disorders. After 1 year of treatment, patients receiving a DMT who had disability progression could cross over to the HSCT arm. Patients randomized to HSCT stopped taking their usual DMT.
Time to disease progression was the study’s primary endpoint. The investigators defined disease progression as an increase in EDSS score of at least 1 point on two evaluations 6 months apart after at least 1 year of treatment. The increase was required to result from MS. The neurologist who recorded participants’ EDSS evaluations was blinded to treatment group assignment.
The researchers randomized 55 patients to each study arm. Approximately 66% of participants were women, and the sample’s mean age was 36 years. There were no significant baseline differences between groups on demographic, clinical, or imaging characteristics. Three patients in the HSCT group were withdrawn from the study, and four in the DMT group were lost to follow-up after seeking HSCT at outside facilities.
Three patients in the HSCT group and 34 patients in the DMT group had disease progression. Mean follow-up duration was 2.8 years. The investigators could not calculate the median time to progression in the HSCT group because too few events occurred. Median time to progression was 24 months in the DMT group (HR, 0.07). During the first year, mean EDSS scores decreased (indicating improvement) from 3.38 to 2.36 in the HSCT group. Mean EDSS scores increased from 3.31 to 3.98 in the DMT group. No participants died, and no patients who received HSCT-developed nonhematopoietic grade 4 toxicities.
“To our knowledge, this is the first randomized trial of HSCT in patients with relapsing-remitting MS,” Dr. Burt and his colleagues said. Although observational studies have found similar EDSS improvements following HSCT, “this degree of improvement has not been demonstrated in pharmaceutical trials even with more intensive DMT such as alemtuzumab,” they concluded.
The Danhakl Family Foundation, the Cumming Foundation, the McNamara Purcell Foundation, Morgan Stanley, and the National Institute for Health Research Sheffield Clinical Research Facility provided financial support for this study. No pharmaceutical companies supported the study.
SOURCEs: Brown JWL et al. JAMA. 2019;321(2):175-87. doi: 10.1001/jama.2018.20588.; and Burt RK et al. JAMA. 2019;321(2):165-74. doi: 10.1001/jama.2018.18743.