Background

The TREAT-MS study (Paul-Ehrlich-Institut registry: 281) is assessing real-world effectiveness of alemtuzumab in relapsing-remitting multiple sclerosis (RRMS) patients in Germany.

Objectives

Subgroup analysis of TREAT-MS to investigate the effect of the number of prior disease-modifying therapies (DMTs) on the efficacy and safety of alemtuzumab 1 year after the 2nd treatment cycle with alemtuzumab.

Methods

TREAT-MS is a 5-year, observational, longitudinal, noninterventional, open-label, multicenter study of alemtuzumab-treated patients.

Results

As of February 2020, 883 patients were enrolled and 571 patients were observed for 2 years after treatment initiation. Of these, 565 (98.9%) patients entered the first treatment period, 538 (94.2%) patients entered two treatment periods. 13.3% of patients were treatment-naive at baseline, 83.7% had received prior DMTs, and in 3.0% pretreatment was unknown. The interim analysis focussed on the data of patients 1 year after the 2nd treatment phase and was differentiated by the number of previously received DMTs. Patients with 0, 1, 2, and ≥3 pretreatments had a mean number of 1.6, 1.7, 1.4, and 1.8 relapses, respectively, during the last 12 months before alemtuzumab treatment. After alemtuzumab treatment initiation, annualized relapse rate (ARR) in patients with 0, 1, 2, ≥3 pretreatments reached levels of 0.13, 0.18, 0.25, and 0.24. ARR after alemtuzumab initiation was significantly higher in patients who received 2 or ≥3 prior DMTs when compared with treatment-naive patients.

The majority of patients were relapse-free 1 year after the 2nd course of alemtuzumab. 82.2%, 77.0%, 66.5%, 73.1% of the patients with 0, 1, 2, ≥3 pretreatments, respectively, had no relapses during the observational period. The proportion of relapse-free patients 1 year after the second alemtuzumab course was highest in treatment-naive patients.

Mean expanded disability status scale (EDSS) score at baseline was 2.2, 2.4, 2.6, and 3.6 for those who received 0, 1, 2, and ≥3 prior DMTs, respectively, and changed by a mean EDSS value of –0.5, –0.2, –0.2, and –0.5 one year after the 2nd treatment phase.

Adverse events were reported for 64.5%, 66.9%, 66.9%, 73.6% of the patients treated with 0, 1, 2, and ≥3 DMTs. No new safety signals were observed.

Conclusions

The interim subgroup analysis of patients 1 year after the 2nd treatment cycle with alemtuzumab has shown that relapse rates were reduced, and EDSS scores were stable regardless of the number of prior DMTs received. These data confirm registration trial findings (CARE-MS I and II) in the real-world setting in patients with longer disease duration and varying treatment history.