The US Glatiramer Acetate (GA) Trial is the longest evaluation of continuous immunomodulatory therapy in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to evaluate up to 15 years of GA as a sole disease-modifying therapy. Two hundred and thirty-two patients received at least one GA dose since study initiation in 1991 (mITT cohort), and 100 (43%, Ongoing cohort) continued as of February 2008.Patients were evaluated every 6 months using the Expanded Disability Status Scale (EDSS). Mean GA exposures were 8.6 +/- 5.2, 4.81 +/- 3.69, and 13.6 +/- 1.3 years and mean disease durations were 17, 13, and 22 years for mITT, Withdrawn and Ongoing cohorts, respectively. For Ongoing patients, annual relapse rates (ARRs) maintained a decline from 1.12 +/- 0.82 at baseline to 0.25 +/- 0.34 per year; 57% had stable/improved EDSS scores (change < or = 0.5 points); 65% had not transitioned to secondary progressive multiple sclerosis (SPMS); 38%, 18%, and 3% reached EDSS 4, 6, and 8. For all patients on GA therapy (the mITT cohort), ARRs declined from 1.18 +/- 0.82 to 0.43 +/- 0.58 per year; 54% had stable/improved EDSS scores; 75% had not transitioned to SPMS; 39%, 23%, and 5% reached EDSS 4, 6, and 8. In conclusion, multiple sclerosis patients with mean disease duration of 22 years administering GA for up to 15 years had reduced relapse rates, and decreased disability progression and transition to SPMS. There were no long-term safety issues.
Kappos L, Kuhle J, Multanen J, Kremenchutzky M, Verdun di Cantogno E, Cornelisse P, Lehr L, Casset-Semanaz F, Issard D, Uitdehaag BM. Factors influencing long-term outcomes in relapsing-remitting multiple sclerosis: PRISMS-15. J Neurol Neurosurg Psychiatry. 2015; 86:1202-7.
About 56% of those followed up had dropped off beta interferon and only 12% had been continuously on the same drug and dose.
The relapse rate dropped to about one every 3 years on average and between 21%-52% converting to secondary progression. So not that dissimilar from the copaxone data. Therefore being on DMT is a good thing as about 80% of MSers may have converted if they took nothing.