MRI more sensitive for disease activity than relapses in SPMS

In both real-world and clinical trial setting, MRI activity was found to be a more sensitive tool to measure disease activity than relapses in secondary progressive MS (SPMS). Thus, the frequency of MRI monitoring is driving detection of disease activity. Even after 2 years without relapse and no MRI activity at baseline, disease activity returned in >50% of patients with previously ‘non-active’ MS on placebo [1].

Patients with SPMS are often categorised as active (aSPMS) or non-active (naSPMS) based on evidence of their disease activity, explained Prof. Gavin Giovannoni (Queen Mary University of London, UK). However, the relative contribution of MRI activity and/or relapses in defining disease activity is not well understood. Therefore, differences between aSPMS and naSPMS were evaluated. Data was used from the Adelphi real-world MS Disease Specific Programme (Adelphi MS DSP), and the phase 3 EXPAND study (NCT01665144).

Adelphi MS DSP is a non-interventional, real-world study of 37,318 MS patients, including 3,580 patients with SPMS who were surveyed between 2011 and 2019. This group was categorised into aSPMS (≥1 new lesion on the most recent MRI and/or ≥1 relapse in the last 12 months; n=1,889) and naSPMS (n=665). In the 1,651 participants of the EXPAND study, aSPMS was defined as ≥1 relapse in the 2 years prior to screening and/or ≥1 gadolinium-enhancing (Gd+) T1 lesion at baseline. According to this definition, 779 patients had aSPMS and 866 naSPMS.

“In patients from the real-world cohort categorised as having aSPMS, disease activity was more commonly detected via MRI than relapse activity,” Prof. Giovannoni observed. They were considered aSPMS based on relapse status alone (12.6%), on MRI status alone (59.1%), or on both MRI and relapse status (28.3%). In the past 12 months, naSPMS patients had a higher mean Expanded Disability Status Scale (EDSS) score versus aSPMS patients (4.6 and 5.2, respectively), were less frequently monitored with MRI (58.7% vs 87.7%), and had a lower number of MRIs per patient (0.87 vs 1.24). A higher proportion of naSPMS patients had moderate-to-severe disease, and were not on any DMT (45.1% vs 23.4%).

In EXPAND, 52.7% of naSPMS patients on placebo had on-study relapse and/or MRI activity: MRI (41.8%), relapses (4.6%), or both MRI and relapse (9.2%). “What's driving the detection of disease activity in this population is the frequency of MRI monitoring,” said Prof. Giovannoni. He concluded that incorrectly defining patients as naSPMS can result in reduced monitoring and decreases the chance to detect and treat any new disease activity in these patients.

1. Giovannoni G, et al. MRI activity versus relapses as markers of disease activity in SPMS: Data from real world and pivotal clinical studies. P001, ECTRIMS 2021 Virtual Congress, 13–15 October.

 

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Posted on 9 December, 202125 March, 2024