Attenuation of antibody response to SARS-CoV-2 infection in patients with multiple sclerosis on ocrelizumab: A case-control study

Objective: Ocrelizumab (OCR) is a monoclonal antibody directed at B-cells that is FDA approved for treatment of RRMS and PPMS. Prior studies have raised concerns about patients' ability to form antibodies in response to various antigens, especially SARS-CoV-2. The objective of this study is to determine whether OCR attenuates the antibody response to SARS-CoV-2 in patients with MS as compared with other disease modifying therapies. Methods: This is a case-control study looking at the odds of developing antibodies to SARS-CoV-2 in patients treated with OCR versus other disease modifying therapies. From May 13, 2020 through March 1, 2021, patients with a RT-PCR-confirmed infection to SARS-CoV-2 were tested for presence of antibodies and the data was recorded. Outpatients with MS at the Methodist Hospitals Comprehensive MS Center were selected who had a prior infection with COVID-19 as demonstrated by RT-PCR in the electronic health records. Odds ratios were calculated to compare rates of antibody formation with OCR exposure vs other DMT. Results: 24 patients had evidence of COVID-19 and had antibody testing available at the time of analysis. Patients who received OCR had decreased odds of forming antibodies (OR 0.045, p = 0.011, 95% CI (0.004,0.488)). Conclusions: Patients who received OCR within the prior 6 months of COVID-19 infection had decreased odds of developing antibodies as compared with other DMTs. This suggests that OCR may attenuate the antibody response to SARS-CoV-2. Additional studies should analyze the odds of spike protein antibody formation in response to SARS-CoV-2 vaccines for patients on OCR.