Blockade of CD49d-mediated lymphocyte trafficking has been used therapeutically for certain autoimmune diseases, such as multiple sclerosis (MS). In addition to negative effects on the trafficking of ...mature lymphocytes to sites of inflammation, CD49d blockade in mice and monkeys rapidly mobilizes hematopoietic stem/progenitor cells (HSPCs) capable of short- and long-term engraftment. Here we aimed to ascertain the effects of treatment with antifunctional anti-CD49d antibody in humans (MS patients receiving infusions of the CD49d-blocking antibody natalizumab) on levels of circulating HSPCs after a single dose of antibody or after long-term treatment. On average, 6-fold elevated levels of circulating CD34+ cells and colony-forming unit-culture (CFU-C) were achieved within 1 day of the first dose of natalizumab, and similar levels were continuously maintained under monthly natalizumab infusions. The blood of natalizumab-treated subjects also contained SCID-repopulating cells. The fate of these circulating HSPCs and their clinical relevance for MS patients remains to be determined.
OBJECTIVE:To evaluate the safety, efficacy, and durability of multiple sclerosis (MS) disease stabilization after high-dose immunosuppressive therapy (HDIT) and autologous hematopoietic cell ...transplantation (HCT).
METHODS:High-Dose Immunosuppression and Autologous Transplantation for Multiple Sclerosis (HALT-MS) is a phase II clinical trial of HDIT/HCT for patients with relapsing-remitting (RR) MS who experienced relapses with disability progression (Expanded Disability Status Scale EDSS 3.0–5.5) while on MS disease-modifying therapy. The primary endpoint was event-free survival (EFS), defined as survival without death or disease activity from any one ofdisability progression, relapse, or new lesions on MRI. Participants were evaluated through 5 years posttransplant. Toxicities were reported using the National Cancer Institute Common Terminology Criteria for Adverse Events (AE).
RESULTS:Twenty-five participants were evaluated for transplant and 24 participants underwent HDIT/HCT. Median follow-up was 62 months (range 12–72). EFS was 69.2% (90% confidence interval CI 50.2–82.1). Progression-free survival, clinical relapse-free survival, and MRI activity-free survival were 91.3% (90% CI 74.7%–97.2%), 86.9% (90% CI 69.5%–94.7%), and 86.3% (90% CI 68.1%–94.5%), respectively. AE due to HDIT/HCT were consistent with expected toxicities and there were no significant late neurologic adverse effects noted. Improvements were noted in neurologic disability with a median change in EDSS of −0.5 (interquartile range −1.5 to 0.0; p = 0.001) among participants who survived and completed the study.
CONCLUSION:HDIT/HCT without maintenance therapy was effective for inducing long-term sustained remissions of active RRMS at 5 years.
CLINICALTRIALS.GOV IDENTIFIER:NCT00288626.
CLASSIFICATION OF EVIDENCE:This study provides Class IV evidence that participants with RRMS experienced sustained remissions with toxicities as expected from HDIT/HCT.
IMPORTANCE: Most patients with relapsing-remitting (RR) multiple sclerosis (MS) who receive approved disease-modifying therapies experience breakthrough disease and accumulate neurologic disability. ...High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic cell transplant (HCT) may, in contrast, induce sustained remissions in early MS. OBJECTIVE: To evaluate the safety, efficacy, and durability of MS disease stabilization through 3 years after HDIT/HCT. DESIGN, SETTING, AND PARTICIPANTS: Hematopoietic Cell Transplantation for Relapsing-Remitting Multiple Sclerosis (HALT-MS) is an ongoing, multicenter, single-arm, phase 2 clinical trial of HDIT/HCT for patients with RRMS who experienced relapses with loss of neurologic function while receiving disease-modifying therapies during the 18 months before enrolling. Participants are evaluated through 5 years after HCT. This report is a prespecified, 3-year interim analysis of the trial. Thirty-six patients with RRMS from referral centers were screened; 25 were enrolled. INTERVENTIONS: Autologous peripheral blood stem cell grafts were CD34+ selected; the participants then received high-dose treatment with carmustine, etoposide, cytarabine, and melphalan as well as rabbit antithymocyte globulin before autologous HCT. MAIN OUTCOMES AND MEASURES: The primary end point of HALT-MS is event-free survival defined as survival without death or disease activity from any one of the following outcomes: (1) confirmed loss of neurologic function, (2) clinical relapse, or (3) new lesions observed on magnetic resonance imaging. Toxic effects are reported using National Cancer Institute Common Terminology Criteria for Adverse Events. RESULTS: Grafts were collected from 25 patients, and 24 of these individuals received HDIT/HCT. The median follow-up period was 186 weeks (interquartile range, 176-250) weeks). Overall event-free survival was 78.4% (90% CI, 60.1%-89.0%) at 3 years. Progression-free survival and clinical relapse-free survival were 90.9% (90% CI, 73.7%-97.1%) and 86.3% (90% CI, 68.1%-94.5%), respectively, at 3 years. Adverse events were consistent with expected toxic effects associated with HDIT/HCT, and no acute treatment-related neurologic adverse events were observed. Improvements were noted in neurologic disability, quality-of-life, and functional scores. CONCLUSIONS AND RELEVANCE: At 3 years, HDIT/HCT without maintenance therapy was effective for inducing sustained remission of active RRMS and was associated with improvements in neurologic function. Treatment was associated with few serious early complications or unexpected adverse events.
Introduction
Diroximel fumarate (DRF) is an oral fumarate for relapsing multiple sclerosis (MS) with the same active metabolite as dimethyl fumarate (DMF). DRF has a safety/efficacy profile similar ...to DMF but with improved gastrointestinal (GI) tolerability and low (< 1%) treatment discontinuation due to GI adverse events (AEs). Efficacy and safety outcomes in patients who switched to DRF from other disease-modifying therapies (DMTs) have not been evaluated.
Methods
EVOLVE-MS-1 is an ongoing, 2-year, open-label, phase 3 study of DRF in adults with relapsing–remitting MS. Patients either entered as newly enrolled to DRF trials, or from the 5-week, randomized, head-to-head, phase 3 EVOLVE-MS-2 study of DRF and DMF. This analysis evaluated safety and GI tolerability in patients continuing on DRF (DRF-rollover) or switching from DMF (DMF-rollover) following EVOLVE-MS-2. Safety and efficacy were evaluated in a subset of newly enrolled patients who had received prior glatiramer acetate (GA; GA/DRF) or interferons (IFN; IFN/DRF) as their most recent DMT, prior to switching to DRF in EVOLVE-MS-1.
Results
As of September 1, 2020, 1057 patients were enrolled in EVOLVE-MS-1, including 166, 182, 239, and 225 patients in the GA/DRF, IFN/DRF, DRF-rollover, and DMF-rollover groups, respectively. Treatment discontinuation due to GI AEs was < 1% in all groups. GA/DRF and IFN/DRF patients experienced improvements from baseline in clinical and radiological efficacy outcomes, including significantly reduced annualized relapse rates. Rollover patients had low rates of new or recurrent GI AEs (DRF-rollover, 26.8%/4.2%; DMF-rollover, 27.1%/4.9%).
Conclusion
After 2 years of DRF exposure, patients with prior GA, IFN, or fumarate treatment had safety outcomes consistent with previous fumarate studies. Efficacy in patients with prior GA or IFN treatment was consistent with previous fumarate studies. The data suggest that transition to DRF from GA, IFN, or DMF is a reasonable treatment strategy, with low rates of discontinuation due to GI AEs.
Trial Registration
ClinicalTrials.gov (NCT02634307).
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