WEST PALM BEACH, FLORIDA — , according to data presented as a late-breaker at the annual meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS).
After at least 1 year of follow-up in 23 patients participating in the extension analysis, “there has been favorable effects on cognitive function, neurological functional tests, quality of life, and both of two major biomarkers linked to neurodegeneration,” reported Dimitrios Karussis, MD, PhD, Chairman of the Multiple Sclerosis Center, Hadassah Hospital, Jerusalem.
Based on promising preclinical studies, the initial clinical study with MSCs was published in Brain in 2020. In that study, 48 participants were randomized to receive an intrathecal injection of MSCs, an intravenous injection of MSCs, or a sham injection. The MSCs were collected from the bone marrow of each participant and cultured.
A second injection in the active treatment groups was administered at 6 months. At this time, those initially randomized to a sham injection received either an intrathecal or an IV injection of MSCs harvested from their bone marrow.
No Disease Activity Seen in 60% at 1 Year
When evaluated at the end of 1 year, there was no evidence of disease activity in 58.6% of those receiving the two intrathecal injections of MSCs, 40.6% of those receiving two IV injections of MSCs, and 9.7% of those initially randomized to the sham group. The intrathecal injection of MSCs, which was well tolerated, appeared to offer greater efficacy and was associated with relative benefits on multiple additional measures, including reduced T2 lesion load, lower relapse rates, and sustained cognitive function.
Ted Bosworth/MDedge News
Dr. Dimitrios Karussis
Forty of the patients in the initial study were enrolled in the extension. In the late-breaker presentation, Dr. Karussis provided interim results on 23, of which all had been followed for at least another additional year. These patients had been treated with one to three intrathecal injects of MSCs at intervals of 3 to 6 months.
Of further gains during the extension, Dr. Karussis described gains in cognitive function, represented by a 3-degree improvement in the Symbol Digit Modalities Test (SDMT), a median 17% improvement in the 25-foot walk test, and an improvement in quality of life, captured in domains of both physical and mental function. All of these gains were statistically significant.
The clinical responses were supported by reductions in both serum neurofilament light chain (sNfL) levels and in the glial fibrillary acid protein (GFAP), which Dr. Karussis described as important biomarkers of disease progression. For sNfL, the reduction was 33.2% (P = .001), and there was further decline observed after repeated MSC injections.
The 22% (P < .0004) reduction in GFAP, which Dr. Karussis said has not been shown before, was observed in all 23 patients. Again, there was an additional reduction with repeated MSC treatments.
The safety and tolerability remained encouraging with longer follow-up. As in the original series, there were no serious adverse events. Headache and backache, which were more common among those receiving intrathecal injections of MSC in the original study, continued to be reported in the extension, but these were time-limited.
Although Dr. Karussis emphasized that these interim results await confirmation with longer follow-up and larger studies, he suggested that the consistency of benefit with early report provides “an additional hint of possible neuroprotective and neurotrophic effects.”