Disability Progression in Patients Who Switch from Natalizumab to Fingolimod or Injectable Therapies

DALLAS -- May 29, 2014 -- Transitioning from natalizumab to fingolimod was linked to a self-reported worsening of disability in patients with multiple sclerosis, according to data from a North American Research Committee on Multiple Sclerosis (NARCOMS) analysis presented by Stacey Cofield, PhD, at the 2014 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) and the Sixth Cooperative Meeting with Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS).

Cofield is Deputy Director of the CombiRx Statistical and Data Management Center and the NARCOMS Coordinating Center at the University of Alabama-Birmingham (UAB) School of Public Health.

In her presentation, titled “Disability Progression after Switching from Natalizumab to Fingolimod or Injectable Therapies: A NARCOMS Analysis,” Cofield, who is also an associate professor in the Department of Biostatistics at UAB, noted that natalizumab is a highly effective treatment for multiple sclerosis.

“However, the clinical outcomes of natalizumab-treated patients who have switched to other treatments are not well understood,” she noted.

The study was done to compare changes in patient-determined disease steps (PDDS) -- a patient-reported outcome of disability in patients with multiple sclerosis -- between natalizumab-treated patients who remained on natalizumab and patients who switched treatment after a minimum of two years. For the study, researchers collected information on 547 NARCOMS participants who were on at least 2 years of continuous natalizumab treatment.

“Scores from the first survey were compared between participants whose only disease-modifying treatment during follow up was natalizumab and patients who switched to treatment with fingolimod or injectable therapies,” said Cofield.

Injectable therapies included interferon beta or glatiramer acetate.

Adjusted mean PDDS was not different between groups after two years of natalizumab therapy, but at the end of follow up, the mean PDDS increase was 0.31 points for the natalizumab-only group, 0.58 for patients who switched to fingolimod, 0.71 for patients who switched to injectables.

The difference between natalizumab and the injectable therapies groups was significant (P = 0.007).

In addition, there was a difference between groups in the proportion of patients with a greater than one point increase in PDDS (30.8% of the natalizumab-only group, 46.0% of the fingolimod group, and 42.3% of the injectable therapies group; P = 0.03).

On average, patients who switched to treatment with injectable therapies reported larger disability increases than patients who remained on natalizumab.

Age, gender, and starting PDDS were similar in all groups, but median months of total follow up were significantly different (48 months for the natalizumab-only group, 54 months for the fingolimod group, and 60 months for the group that switched to treatment with injectable therapies).

“The study found that age, gender, and starting PDDS were associated with changes in PDDS (P < 0.03) and total follow up was not different between groups after 2 years,” said Cofield.

Switching from natalizumab to fingolimod or injectable therapy was associated with an increased likelihood of reported disability progression.

Since the study included self-reported data, “causality cannot be concluded,” Cofield said.