ORLANDO—For patients with relapsing-remitting multiple sclerosis (MS), MRI activity unaccompanied by any other clinical event may be the strongest predictor of switching from a first-line disease-modifying therapy (DMT), according to research presented at the Fifth Cooperative Meeting of the Consortium of MS Centers and the Americas Committee for Treatment and Research in MS. Individuals with MRI worsening alone may be 6.3 times as likely to switch DMTs than patients with one relapse.
In addition, worsening on the Expanded Disability Status Scale (EDSS) alone or EDSS and MRI worsening nearly tripled the odds of switching DMTs, compared with having one relapse, said Barbara Teter, PhD, Director of Research and Development at the New York State MS Consortium in Buffalo. Patients with two or more relapses as a first event following DMT initiation were 2.8 times as likely to switch DMTs, compared with patients with a single relapse.
A Retrospective Analysis of Longitudinal Registry Data
To identify clinical and demographic characteristics that predict switching to a new DMT among patients with relapsing-remitting MS, Dr. Teter and her colleagues conducted a retrospective study of longitudinal registry data from 14 MS Centers or neurology practices in the state of New York. The researchers analyzed data for patients enrolled in the registry from 1996 to 2009, and nine MS treatment centers participated in chart review follow-up.
Eligible study participants had three or more years of follow-up and used interferon beta or glatiramer acetate as an initial DMT. Suboptimal response to the first DMT was defined as a relapse, EDSS worsening, MRI worsening (eg, new gadolinium-enhancing or T2 lesions), or a combination of these events. Patients who discontinued their initial DMT and started another DMT within six to 12 months after the first MS event were considered to have switched therapies. The investigators used regression modeling to identify predictors of DMT switching.
Patients Who Switched DMTs Were More Likely to Be Younger
Patients who switched therapies were more likely to be younger at symptom onset and younger at DMT initiation than patients who did not switch. Among patients with MRI worsening alone, the mean time between DMT initiation and first MS event was longer among patients who switched DMTs (62.3 months) than among patients who did not switch (38.5 months).
Patients were less likely to switch therapies if they experienced combinations of one relapse plus EDSS worsening and one relapse plus EDSS worsening plus MRI worsening than if they had one relapse alone, said Dr. Teter. Combinations of two or more relapses plus EDSS worsening or MRI worsening did not predict a DMT switch, but the sample size was small.
“The likelihood and drivers of therapy switch may change with expanding therapy options,” said Dr. Teter. “At the time of this study, few therapy options were available.”
—Erik Greb
Senior Associate Editor