The Effect of High- Vs Low- to Medium-Efficacy Treatments on PIRA Compared in ECTRIMS 2024 Study

Study results presented at the 40th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) demonstrated that high-efficacy disease-modifying treatments (HE-DMTs) significantly reduced progression independent of relapse activity (PIRA) rates compared with low- to moderate-efficacy disease-modifying treatments (LM-DMTs) in individuals with relapsing remitting multiple sclerosis (RRMS). Recent evidence indicates that PIRA is a frequently occurring form of disability worsening in individuals with RRMS, and these results suggest that early initiation of HE-DMTs may reduce PIRA rates in these patients.

Researchers analyzed data from the Swedish Multiple Sclerosis Registry associated with individuals diagnosed with RRMS (N=4358), including 1968 individuals who received first-line HE-DMTs and 2390 individuals who received first-line LM-DMTs. Post-baseline PIRA rates between the HE-DMT and LM-DMT groups were compared using propensity score matched negative binomial regression.

During the observation period, 982 confirmed disability worsening (CDW) events were observed in the HE-DMT group, and 1474 CDW events were observed in the LM-DMT group. Most of the CDW events were classified as PIRA; relapse-associated worsening (RAW) accounted for only 9.7% and 12.1% of CDW events in the HE-DMT and LM-DMT groups, respectively.

• There was a significantly higher unadjusted rate of CDW in the LM-DMT group (9.98 events per 100-person years [py]; 95% CI, 9.48 to 10.51) compared with that found in the HE-DMT group (9.19 events per 100-py; 95% CI, 8.62 to 9.78; P=.0439).
• There was a significantly higher unadjusted rate for RAW in the LM-DMT group (1.21 events per 100-py; 95% CI, 1.04 to 1.40) compared with in the HE-DMT group (0.89 events per 100-py, P=.0141).