Oral Versus Injectable Disease-Modifying Agents: Which Has Better Adherence?

Although oral fingolimod is more convenient than injectable disease-modifying agents (DMAs) in patients with multiple sclerosis (MS), it is unclear which option has a better adherence trajectory. According to a retrospective, longitudinal study comparing the two treatment options, oral fingolimod was correlated with better adherence.

Patients with MS aged ≥18 years were identified in the IBM MarketScan Commercial Claims and Encounters Database between 2010 and 2012 by ICD-9-CM: 340 had a DMA prescription. Eligible patients were stratified by whether they received oral fingolimod or injectable DMA per the index DMA. Annual DMA adherence trajectories were determined using the proportion of days covered (PDC), which was evaluated by using group-based trajectory modeling (GBTM) over the one-year period following treatment initiation. The relationship between the DMA route of administration and the adherence trajectory groups was analyzed by conducting multivariable multinomial logistic regression using stabilized inverse probability treatment weights (IPTW). A standardized difference threshold of 0.25 was used to balance covariates between the groups before and after IPTW.

A total of 1,700 patients with MS constituted the study group; most patients had initiated injectable DMAs (84.2%). The adherence rate (PDC ≥0.8) was higher in the oral group than the injectable group (64.7% vs. 50.8%). Using GBTM, patients were stratified into three adherence groups: rapid discontinuers (23.5%), complete adherers (49.9%), and slow decliners (26.6%). When the multinomial logistic regression model with stabilized IPTW was implemented, oral fingolimod users, compared with injectable DMA users, had greater odds of being a complete adherer (adjusted odds ratio [aOR], 2.78; 95% confidence interval [CI], 1.85-4.16) or slow discontinuer (aOR, 2.62; 95% CI, 1.70-4.05).

“Further research is warranted to evaluate the adherence trajectories with newer oral DMAs introduced in the last decade for MS,” the study authors concluded.