Impact of an anti-infective screening and monitoring protocol together with infectious disease consultation in preventing infective adverse events in patients treated with anti-CD20/CD52 agents for multiple sclerosis.

Background: Monoclonal antibodies have been a milestone in the treatment of multiple sclerosis (MS). Infective complications have been observed in patients on agents targeting lymphoid cells' surface antigens, namely anti-CD52 (alemtuzumab) and anti-CD20 agents (ocrelizumab and rituximab). Despite increasing emerging data, there is no standardized consensus regarding pre-treatment testing, vaccinations, and patient education before and during MS therapy or optimal infection-control strategies.

Methods: We led a retrospective/prospective real-life study to evaluate the effectiveness of a program of screening and prophylaxis for infective adverse events in patients with multiple sclerosis and related disorders treated with drugs directed against CD20/52 antigens. All patients referring to the MS Clinical Care and Research Center, University of Naples "Federico II", who started on alemtuzumab, ocrelizumab or rituximab (off-label use) from 1 November 2015 to 30 June 2019 were recruited. From the 1st of February 2018 patients underwent a microbiological screening and were evaluated by an infectious disease specialist (IDs) before monoclonal antibodies infusion to rule out active infections. We evaluated incidence of infective complications and predictors before (retrospectively)and after (prospectively) the introduction of the above-mentioned anti-infective program.

Results: We enrolled 275 patients, 104 retrospectively (pre-intervention group, PRE) and 171 prospectively (post-intervention group, POST). In PRE group, most patients were treated with alemtuzumab (58% vs 32%, p < 0.001), were more frequently DMT naïve (48% vs 36%, p = 0.044) or had received fingolimod in the past (48% vs 28%, p = 0.044) and the follow-up period was longer than in POST group (750 vs 191 days, p < 0.001). In POST group, patients were older (median age 47 vs 42 years, p = 0.030) and mostly received OCR (54% vs 14%, p < 0.001). Lymphopenia at baseline was significantly more commonly observed in PRE arm (47% vs 8%, p < 0.001). A total of 39 patients (38%) in PRE arm and 42 patients (25% in POST) group experienced one or more infections (p = 0.022); severe infections were significantly more common in PRE patients (23% vs 14%, p = 0.022). Our anti-infective program was associated with a lower IAE incidence both at univariate and multivariate analysis (aHR of infective events in PRE group: 3.652 [CI: 9.03-94.19], p < 0.001). Moreover, DMT naïve patients significantly experienced fewer infective complications (aHR: 0.470, [CI: 1.02-2.55], p = 0.040).

Conclusions: A risk mitigation program including infectious disease consultation and standardized screening and prophylactic protocols was effective in reducing infective adverse events in patients receiving anti CD20/CD52 agents for MS.