Oral Meds for MS Have Higher Adverse Effect Rates in 'Real World' vs. Clinical Trials

Oral Meds for MS Have Higher Adverse Effect Rates in 'Real World' vs. Clinical Trials
Oral Meds for MS Have Higher Adverse Effect Rates in 'Real World' vs. Clinical Trials

VANCOUVER, BC—In the “real world,” patients with multiple sclerosis (MS) who experienced relapses while on oral medications did so at a rate comparable to that of clinical trials; however, adverse effects were higher than those observed in clinical trials, a study presented at the 68th AAN Annual Meeting has found.

NgocHanh Vu, MD, and colleagues reported their patients' experiences with the oral MS therapies fingolimod, dimethyl fumarate, and teriflunomide—all approved in the past 5 years—at the Vanderbilt Multiple Sclerosis Center in Nashville, TN. The retrospective chart review included examining “medication efficacy in preventing clinical and MRI relapses as well as common side effects and their impact on the duration/discontinuation of therapy,” the investigators reported.

The team also recorded 25ft walk and expanded disability status score (EDSS) score prior to switching to an oral agent, the reason for switch, 25ft walk and EDSS post-switch, number of clinical and brain MRI relapses on oral agents, reason(s) for discontinuation of therapies, among other parameters. A clinical relapse was defined as a change in neurological examination with an EDSS increase of 1 point or an increase of functional system score (FSS) of 2 points. Brain MRI relapse was defined as presence of contrast enhancing lesions (CEL).

A total of 98 patients were treated with teriflunomide for 20.2 ± 13.3 months; 78 were female and age was 49 ± 9.3 years. Of these patients, 17 (17%) had clinical relapses and 9 (9%), MRI relapses, with 22 (22%) discontinuing treatment due to side effects that included gastrointestinal (GI) (36%), rash (14%), hair loss (9%), infections (9%), hypertension (9%), and paresthesia (9%). In addition, 1 patient reported “tongue pain” as the reason for discontinuation.

Of the 192 patients treated with dimethyl fumarate for 16 ± 9 months, 146 were female and age was 43 ± 11 years. Clinical relapses occurred in 33 patients (17%) and MRI relapses in 10 (5%). A total of 38 patients (20%) discontinued due to side effects that included GI upset (71%), flushing (10%), rash (5%), leukopenia (2%), headache (2%), and mood change (2%).

Fingolimod treatment was administered to 206 patients for 20.7 ± 16 months; 151 were female and age was 41 ± 9.4 years. Of these, 22 (11%) had clinical relapses and 8 (4%), MRI relapses. Side effects among the 26 patients (13%) who discontinued fingolimod included lymphopenia (absolute lymphocyte count <300, 23%), elevated liver function tests (9%), headache (5%), hypertension (2%), cough (2%), macular edema (1%), bradycardia (1%), and rash (0.5%).

Dr. Vu stated that GI side effects of disease modifying therapies are not as well tolerated as agents without GI effects, "leading to poor compliance and early discontinuation."

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