To assess adherence to approved biologics among patients with NMOSD in the US.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune demyelinating disease characterized by relapses and risk of disability accumulation. Adherence to therapy among patients with NMOSD on approved biologics remains to be extensively characterized.

A retrospective cohort study was conducted among adult patients with NMOSD treated with approved biologics (inebilizumab, eculizumab, or satralizumab) using the Komodo Research Database (2020 – 2023). Adherence to treatment was assessed as percentage of days covered (PDC), measured as a continuous and binary variable (PDC≥80%=adherent), from treatment initiation to data availability. Difference in continuous PDC (ΔPDC) was assessed using fractional regression adjusting for demographic characteristics (age, sex, race, region, health plan) and NMOSD-associated conditions (neuropathic pain, bladder dysfunction, hemiplegia/paraplegia) at baseline.

In total, 111 patients were included in analyses: 45% inebilizumab, 28% eculizumab, 27% satralizumab. Patients were, on average, 43.0 years-old, 85.6% were female, and 34.2% were Black/African American. Common baseline NMOSD-associated conditions included neuropathic pain (43.2%), bladder dysfunction (18.0%), and hemiplegia/paraplegia(17.1%). Prevalent comorbidities during the study period included hypertension(36.9%), obesity(30.6%), and depression(29.7%). Mean duration of follow-up was 17.3±6.9 months and varied by treatment: inebilizumab (16.4±6.3 months), eculizumab (20.6±7.4 months), and satralizumab (15.5±6.6 months).

Adherence was substantially higher among patients on inebilizumab (mean PDC=85.2%±19.0; adherent=72.0%) than on eculizumab (mean PDC=73.2%±21.5; adherent=45.2%) and satralizumab (mean PDC=66.5%±30.0; adherent=53.3%). Fractional regression adjusting for covariates revealed patients on inebilizumab had significantly higher adherence as compared to satralizumab (ΔPDC=20.8%, p=0.005) and higher as compared to eculizumab (ΔPDC=10.2%, p=0.090).

Among patients with NMOSD treated with approved biologics, patients on inebilizumab had substantially higher adherence to treatment as compared to those on eculizumab and satralizumab. Further research assessing the impact of adherence on patient outcomes, including relapses and treatment persistence, can further elucidate important evidence to guide effective clinical decision-making.