With so many disease modifying therapies available to treat MS, each with its own benefit risk profile, patients often switch among different drugs for reasons including perceived lack of efficacy, side effects, needle fatigue, etc. A study on disability progression in people switching from Tysabri to Gilenya or injectable therapies was recently presented at the 2014 annual meeting of the Consortium of Multiple Sclerosis Centers.1 It was found that transitioning from Tysabri to Gilenya or to injectable therapy (interferon beta or glatiramer acetate) was associated with an increased likelihood of reported disability progression.
Study investigators examined data from the North American Research Committee on Multiple Sclerosis (NARCOMS) registry to compare changes in patient-reported disability progression (measured by Patient-Determined Disease Steps [PDDS]) in participants who were treated with Tysabri and switched treatment versus those who remained on Tysabri. Data for 547 NARCOMS participants who had at least 2 years of continuous treatment with Tysabri and at least one year of follow up survey data with a PDSS assessment were included in the analysis. Change in PDSS score was examined for participants whose only treatment during follow up was Tysabri (n=406), and for those who switched to Gilenya (n=50) or to injectable therapies (n=71). While age, gender, and initial PDDS were similar between groups, the median months of total follow up were significantly different among groups (48 months for Tysabri-only, 54 months for those who switched to Gilenya, and 60 months for those who switched to injectables). Results of the study showed that adjusted mean PDDS was not different between groups after 2 years of Tysabri therapy (P=0.11), but at the end of follow-up, mean increase in PDDS was 0.31 points for Tysabri, 0.58 points for Gilenya, and 0.71 points for injectables. (An increase in PDDS indicates a worsening in disability.) The difference between Tysabri and injectables was significant (P=0.007). Additionally, there was a significant difference between groups in the proportion of participants with at least a 1-point increase in PDDS (Tysabri=30.8%, Gilenya=46.0%, Injectables=42.3%, P=0.03). While switching from Tysabri to Gilenya or injectables was associated with an increased likelihood of reported disability progression, causality can not be concluded. It should also be noted that this study was sponsored by Biogen Idec (the manufacturer of Tysabri, among other MS treatments).
There are several reasons why a person with MS may want to switch their current therapy, including an increase in relapses, more MS-related symptoms, the presence of new brain or spinal cord lesions, lack of tolerability, etc. There are benefits and risks associated with all MS treatments, moreover, there may be risks that are unique to switching between treatments. It’s important to keep an open dialogue with your doctor so you can make decisions about your treatment regimen that are right for you. Data from studies like this one can aid in these discussions.
Have you switched between treatments for your MS? Are you considering doing so? Please share your thoughts with us in the comments. Also, check out what Cathy had to say about deciding to switch or not to switch medication.