Prescriber utilization of dalfampridine extended release tablets in multiple sclerosis: a retrospective pharmacy and medical claims analysis

Abstract

Purpose

This study aimed to characterize the prescribing of dalfampridine extended release (D-ER) 10 mg tablet treatment in people with multiple sclerosis (MS).

Methods

A retrospective cohort study was performed using Medco pharmacy and medical claims. Medical claims were used to identify MS patients with more than one prescription for D-ER with 1 year of prior continuous enrollment (n=704). These patients were matched 2:1 on age, sex, and health insurance source with a comparison group of MS patients who were treatment naïve for D-ER (n=1,403). Categorical data were analyzed by χ² test; ordinal data by Wilcoxon rank sum test; and continuous data by Student’s t-test.

Results

Most patients were women aged 45–64 years. In the year preceding D-ER initiation, the prevalence of seizure and renal impairment was numerically lower in the D-ER cohort relative to those who were D-ER naïve (seizure: 3.1% versus 4.7%, respectively; renal impairment: 4.3% versus 5.1%, respectively); however, prescriptions for antiepileptic drugs in the two cohorts were comparable. In the year preceding treatment initiation, 62% of the D-ER cohort was prescribed MS-specific disease-modifying therapies relative to 45% who were D-ER naïve.

Conclusion

Seizure and renal impairment rates among D-ER-naïve patients were consistent with published literature, yet rates among those prescribed D-ER during the year preceding treatment initiation were slightly lower than rates among D-ER-naïve patients. Given that D-ER is contraindicated in patients with history of seizure or moderate or severe renal impairment, lower rates may indicate that risk-minimization strategies contributed to the lower prevalence.

Keywords:

• disease-modifying therapy
• database
• seizures
• renal impairment
• pharmacoepidemiology

Acknowledgments

This research was supported by Acorda Therapeutics, Inc. Editorial assistance was provided by The Curry Rockefeller Group, LLC, Tarrytown, NY, which was supported by Acorda Therapeutics, Inc, Ardsley, NY.

Disclosure

MJ and MS are employees and stockholders of Acorda Therapeutics, Inc; HH was an employee and stockholder of Acorda Therapeutics, Inc, at the time of this study. The authors report no other conflicts of interest in this work.