Ocrelizumab use in multiple sclerosis: a real-world experience in a changing therapeutic scenario

Introduction: CD20-depleting therapies are a real milestone in the treatment of multiple sclerosis (MS). This study examined the ocrelizumab (OCR) use in patients with primary progressive (PP) and relapsing remitting (RR) MS, also evaluating the predictors of treatment response.

Methods: Patients with MS treated with OCR between 2017 and 2022 were included, and OCR use trends examined. The patients' characteristics were assessed at baseline and after 24 months of OCR to assess the NEDA-3 status.

Results: This study included 421 patients: 33 (7.9%) with PP and 388 (92.1%) with RR MS. Among these, 67 (17.3%) were naïve, while switchers from first- and second-line disease-modifying therapies (DMTs) were 199 (51.3%) and 122 (31.4%), respectively. An increasing trend in OCR use was reported. For six patients treated with rituximab, OCR was chosen to improve tolerability; for 390 switcher patients, the choice was due to ineffectiveness; and for 25, as an exit strategy from natalizumab due to JC virus positivity. NEDA-3 status was calculated for subjects exposed to 24 months of OCR and was achieved by 163/192 (84.9%) RR patients and 9/16 (56%) PP patients, with younger age (p = 0.048) and annualized relapse rate in the year previous to OCR (p = 0.005) emerging as determinants. For the 25 patients who switched to OCR after natalizumab, no clinical or MRI activity after 12 months was reported.

Conclusion: OCR has been confirmed to be a highly efficacious option for patients with PP and RR MS, even proving to be a valid exit strategy for natalizumab.