Background: Both interferon beta-1b (IFN-β-1b) and interferon beta-1a (IFN-β-1a) are immunomodulators that require regular subcutaneous self-administration by patients with multiple sclerosis (MS). However, no electronic autoinjector is available for IFN-β-1a in the US.
Objective: This retrospective cohort study investigated adherence to two subcutaneous disease-modifying therapies, IFN-β-1b and IFN-β-1a, during two periods (before and after the introduction of the BETACONNECT® autoinjector for IFN-β-1b).
Patients and methods: Data were evaluated from the MarketScan database for adults in the US with an MS diagnosis and a medical claim for subcutaneous IFN-β-1b or IFN-β-1a, either before (October 2013-September 2015) or after the introduction of BETACONNECT (October 2016-September 2018). Patient populations were propensity-score matched by demographic and clinical characteristics. Persistence was recorded, and adherence was evaluated by medication possession ratio (MPR).
Results: The study included 196 IFN-β-1b and 365 IFN-β-1a people with MS (PwMS) (pre-BETACONNECT period), and 126 IFN-β-1b and 223 IFN-β-1a PwMS (post-BETACONNECT period). In the pre-BETACONNECT period, the proportion with at least 80% MPR was higher for IFN-β-1a (90%) than for IFN-β-1b (83%), but in the post-BETACONNECT period the proportion with ≥ 80% MPR was higher for IFN-β-1b (92%) than for IFN-β-1a (86%). In the pre-BETACONNECT period, median persistence (in days) was higher for IFN-β-1a (199) than for IFN-β-1b (152), while in post-BETACONNECT period persistence was higher for IFN-β-1b (327) than for IFN-β-1a (229).
Conclusions: Following the introduction of BETACONNECT, this exploratory study suggested that PwMS taking IFN-β-1b were more adherent compared with those taking IFN-β-1a, with higher persistence, and more than 90% reached 80% MPR, a threshold commonly used to define good adherence.
© 2021. The Author(s).