Efficacy and safety of tixagevimab-cilgavimab (Evusheld®) in people with Multiple Sclerosis on Ocrelizumab: preliminary evidence

Background Evusheld (EVS) was authorized by FDA and EMA as pre-exposure prophylaxis (PrEP) in people at high risk of severe Covid-19 outcomes, including people with Multiple Sclerosis (pwMS) on B-cell depleting (BCD) therapies—such as Ocrelizumab (OCR). In this population, no data on possible adverse drug reactions (ADRs) to EVS, B-lymphocytes (CD20 +) counts pre- and post-EVS injection, and comparison of percentage increase of IgG antibodies directed against SARS-CoV-2 trimeric spike protein (anti-TSP IgG) post-EVS and Covid-19 vaccine was available. The aim of this study was to better characterize the efficacy and safety profile of EVS in pwMS on BCD agents. Methods 17 pwMS on OCR agreed to receive EVS as PrEP for Covid-19. Sera samples were collected before the first dose of Covid-19 vaccine (T0), 4 weeks after the second dose (T1), 4 weeks after third dose (T2), immediately before (T3) and 4 weeks after (T4) EVS. Results Covid-19 vaccine ADRs were mild-to-moderate, whereas no ADRs were reported after EVS injection. A significant increase of anti-TSP IgG was found only at T0-T1 (Z = -3.059, p = .002) and T3-T4 (Z = -3.621, p < .001) time-points. The median percentage increase between T3-T4 was significantly higher with respect to the T0-T1(Z = -3.296, p = .001) and T1-T2 (Z = -3.059, p = .002) time-points. Conclusions These results further support EVS safety and efficacy in boosting anti-TSP IgG titers in pwMS on OCR, with a statistically greater increase than that observed after completion of a full Covid-19 vaccine cycle, plus a booster dose.