Effect of ocrelizumab on rates of retinal atrophy in relapsing multiple sclerosis

Ganglion cell + inner plexiform layer (GCIPL) atrophy reflects global neurodegeneration and disability in multiple sclerosis (MS). The effect of ocrelizumab, an anti-CD20 monoclonal antibody and highly-effective disease modifying therapy (DMT), on rates of GCIPL atrophy in people with MS remains understudied.

To assess if ocrelizumab attenuates retinal atrophy rates, particularly GCIPL atrophy, and change in clinical measures in people with relapsing MS (PwRMS), and how this compares to natalizumab (another highly-effective DMT), as well as the related anti-CD20 therapy rituximab.

PwRMS receiving ocrelizumab, natalizumab, or rituximab, untreated people with progressive MS (PwPMS), and healthy controls underwent Cirrus HD-OCT, 100% and 2.5%-contrast letter acuity (LA) assessments longitudinally. MS participants underwent Expanded Disability Status Scale (EDSS) assessments. Statistical analyses used linear mixed-effects regression models adjusting for age, sex, race, disease duration, optic neuritis history, and interval between DMT initiation and OCT monitoring; accounting for within-subject, inter-eye correlations.

In ocrelizumab-treated PwRMS, GCIPL atrophy rate was -0.15 µm/year (SE = 0.03, p < 0.001, n = 88 [168 eyes]), similar to GCIPL atrophy in natalizumab- or rituximab-treated PwRMS, and healthy controls, although slower than in untreated PwPMS (-0.35 µm/year, SE = 0.04, p < 0.001, n = 40 [78 eyes]). EDSS and LA scores remained stable in ocrelizumab-treated PwRMS, and similar to natalizumab- or rituximab-treated PwRMS.

GCIPL atrophy is attenuated and clinical function relatively stable in PwRMS treated with ocrelizumab.