DALLAS – Patients with relapsing emitting multiple sclerosis who discontinued treatment after a period of disease inactivity had a similar time to next event, compared with those who remained on treatment, results from a single-center study showed.
In addition, being over the age of 45 years was associated with a better disease course after treatment discontinuation.
“Being clinically and radiologically stable for more than 2 years can be a potential milestone to regard the discontinuation of DMT [disease-modifying therapy] as a reasonable option in a subset of patients, especially patients who are nondisabled,” lead study author, said in an interview at the Americas Committee for Treatment and Research in Multiple Sclerosis.
According to Dr. Yano, a research fellow at the Ann Romney Center for Neurologic Diseases and Partners Multiple Sclerosis Center in Boston, relapsing remitting multiple sclerosis (RRMS) patients without relapse for long periods on treatment may consider discontinuing DMT, but there is limited information regarding the impact of discontinuation, especially in terms of MRI activity.
In an effort to investigate the impact of DMT discontinuation on clinical and radiologic outcomes in RRMS patients, he and his colleagues identified 70 patients from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women’s Hospital () study, which was initiated in 2000 and has enrolled more than 2,400 patients cared for at the Partners Multiple Sclerosis Center. Relapse date, symptoms, and Expanded Disability Status Scale (EDSS) were evaluated at 6-month intervals for each patient during the time of clinic visits by the treating neurologist. Additionally, brain MRIs were performed annually.
Next, the researchers matched the patients with 70 patients who remained on DMT identified by age, sex, treatment, treatment duration, disease duration, and EDSS. They used univariate and multivariable Cox proportional hazard models to test the differences between DMT discontinuation status with time to clinical relapse, MRI event, disability progression, and any inflammatory event (either clinical relapse or MRI event).
The mean age of patients was 45 years, 87% were female, their mean disease duration was about 13 years, and they had been receiving treatment for a mean of about 6 years. In adjusted analyses, the 70 pairs of patients who discontinued DMT and patients who continued DMT had similar outcomes in time to clinical relapse (hazard ratio, 0.93; P = .84), MRI event (HR, 1.01; P = .98), disability progression (HR, 1.33; P = .43), and any inflammatory event (HR, 0.93; P = .85). In a subgroup analysis, which compared the impact of DMT discontinuation between patients over the age of 45 years and those aged 45 years and younger, the researchers observed a statistically significant difference in effect of discontinuation on time to clinical relapse (P = .032), time to MRI event (P = .013), and time to any inflammatory event (P = .0005), all favoring patients over the age of 45 years.
“This finding makes sense since age has been reported as one of the factors that negatively impacts on the inflammatory activity in patients with RRMS,” Dr. Yano said. “However, our study is the first study [to find] that the impact of discontinuing DMT on RRMS patient prognosis may differ based on the age at the discontinuation. In short, stopping DMT at a younger age has a statistically significant higher risk on inflammatory activities, compared to [stopping DMT at an] older age.”
He acknowledged certain limitations of the study, including its small sample size and single-center design. However, Dr. Yano said that a key strength of the analysis was the inclusion of MRI activity prior to DMT as the definition of stable state, “which is an integral piece of information when physicians and patients consider DMT discontinuation in a ‘real world’ clinical setting. We also used MRI activity as an outcome measure, which is lacking in prior discontinuation studies.”
Dr. Yano reported that he has received a research grant from Yoshida Scholarship Foundation in Japan. His coauthors reported having numerous financial ties to industry.
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