A phase 2 trial of high-dose immunosuppressive therapy (HDIT) and autologous hematopoietic cell transplant (HCT) for severe relapsing-remitting multiple sclerosis (RRMS) resulted in a high rate of remission that was sustained at 5 years.
Richard Nash, MD of the Colorado Blood Cancer Institute in Denver, CO and colleagues presented the extended results of HALT-MS at the 2016 CMSC Annual Meeting in National Harbor, MD.
Patients included in the study had more than 2 relapses despite conventional therapy in the previous 18 months and an Expanded Disability Status Scale (EDSS) score of 3.0 to 5.5, indicating moderate to severe disability. Primary endpoint or treatment failure was defined as MS disease activity in the form of worsening disability (EDSS increase >0.5), relapse, new MRI lesions, or death.
The study included 25 patients (median age 37 years) who received prednisone and G-CSF to obtain the autograft for CD34 selection. In total, 24 patients with RRMS were treated with HDIT and HCT and followed for a median of 62 months.
In the first 3 years, adverse events included 93 grade 4 and 121 grade 3 events, with a majority defined as gastrointestinal and hematological events. After the third year, 15 grade 3 adverse events were reported. Death occurred in 3 participants but was not attributed to the study intervention.
At the end of the study, the probability of no disease activity on MRI was 88.2% (90% CI: 67-96.2%), 86.3% for relapse-free survival (90% CI: 68.7-94.5%), 90.9% for progression-free survival (90% CI: 73.7-97.1%), and 69.2% for event-free survival (90% CI: 50.2-82.1%). T2-weighted lesion volume decreased significantly at 6 months compared to baseline and was maintained for 5 years (median change -1.208 mL, P<.001). Notably, T1 lesion volume was increased at 5 years (median change: 0.094 mL; P= .041).
Overall, high-dose immunosuppression therapy and autologous hematopoietic cell transplant resulted in a high rate of MS disease activity remission that was sustained at 5 years with no maintenance therapy. The authos pointed out that the majority of adverse events were expected given the treatment regiment.
Disclosures: Hutton, Racke, Stuve, Arnold, Wundes, and Bowen report relationships with pharmaceutical companies.
Nash RA, Hutton GJ, Racke MK, et al. Abstract DX05. Five-Year Outcomes of Halt-MS: High- Dose Immunosuppressive Therapy and Autologous Hematopoietic Cell Transplantation for Severe Relapsing- Remitting Multiple Sclerosis. Presented at: 2016 CMSC Annual Meeting. June 1-4, 2016; National Harbor, MD.