Ocrelizumab in highly disabled progressive multiple sclerosis patients.

BACKGROUND

Ocrelizumab is a commonly used anti-CD20 monoclonal antibody with efficacy in the treatment of both relapsing-remitting (RRMS) and primary progressive (PPMS) multiple sclerosis. Real world use of ocrelizumab in MS patients with higher levels of motor disability requiring a walker or a wheelchair is not well characterized as these populations were excluded from initial studies. Higher levels of disability may be a barrier to treatment access. This study aimed to describe the access to, and tolerability and therapeutic outcomes of ocrelizumab in highly disabled MS patients in a real-world setting.

METHODS

As part of an ongoing study of ocrelizumab treatment access, barriers, and outcomes in MS patients at the Brigham MS Center, we retrospectively reviewed all patients with an Expanded Disability Status Scale (EDSS) of 6.5 or greater at the time of ocrelizumab initiation. All patients were started on ocrelizumab by their treating providers prior to this study initiation. Patients were excluded for recent rituximab exposure, co-treatment with more than one immunosuppressant, or alternative diagnoses contributing to high EDSS. Data was collected on incidence and severity of side effects while on ocrelizumab, persistence of treatment beyond one year, and MS stabilization versus progression while on this treatment.

RESULTS

Of the 1219 patients on ocrelizumab between 2017 and 2021, 113 (9.3 %) had EDSS of 6.5 or greater at the time of ocrelizumab initiation. Of the 113, 51 (45.1 %) were excluded: 6 (5.3 %) because they were duplicates or didn't receive ocrelizumab at our center, 25 (22.1 %) due to rituximab treatment in the previous year, 16 (14.2 %) due to lack of at least 1 year of follow up, and 4 (3.5 %) due to relevant comorbidities/treatment with other immunosuppressants. 62 patients were included in the final analysis. At ocrelizumab start, mean age was 62.1 +/- 8.7 years and median EDSS was 7.0 (range 6.5 to 9.5). Ocrelizumab was started in 26 of the included 62 patients (41.9 %) because of objective clinical disease worsening, in 17 (27.4 %) because of subjective worsening, in 8 (12.9 %) to prevent future progression. 32 patients (51.6 %) continued ocrelizumab throughout the study period, with average length of ocrelizumab use of 36.5 +/- 17.0 months. 29 patients (46.8 %) experienced no side effects during the study period. 29 (46.7 %) patients discontinued treatment, and of those, 9 (31.0 %) cited more than one reason for discontinuation: 17 (58.6 %) cited side effects, 12 (41.4 %) cited progression/lack of benefit, 6 (20.7 %) cited the Covid19 pandemic, and 1 (3.4 %) cited financial issues as a reason for discontinuation. Over the course of the study, 16 (25.8 %) patients had disability worsening by EDSS, 5 (8.1 %) had disability improvement, and 41 (66.1 %) remained stable, with a median end EDSS of 7.0 (range 6.5 to 9.5). Importantly, 18 patients (29.0 %) reported subjective disease stability while on ocrelizumab.

CONCLUSIONS

Ocrelizumab may lead to disease stabilization in a subset of highly disabled MS patients, but possible benefits need to be carefully balanced against the incidence of adverse events in this high-risk patient population.