Cell-based therapies for COVID-19: A living systematic review

Rada, Gabriel; Corbalan, Javiera; Rojas, Patricio

OBJECTIVE: This living systematic review aims to provide a timely, rigorous and continuously updated summary of the available evidence on the role of cell-based therapies in the treatment of patients with COVID-19. DATA SOURCES: We conducted searches in PubMed/Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), grey literature and in a centralised repository in L-OVE (Living OVerview of Evidence). L-OVE is a platform that maps PICO questions to evidence from Epistemonikos database. In response to the COVID-19 emergency, L-OVE was adapted to expand the range of evidence it covers and customised to group all COVID-19 evidence in one place. All the searches covered the period until April 23, 2020 (one day before submission). ELIGIBILITY CRITERIA FOR SELECTING STUDIES AND METHODS: We adapted an already published common protocol for multiple parallel systematic reviews to the specificities of this question. We searched for randomised trials evaluating the effect of cell-based therapies versus placebo or no treatment in patients with COVID-19. Anticipating the lack of randomised trials directly addressing this question, we also searched for trials evaluating other coronavirus infections, such as MERS-CoV and SARS-CoV, and non-randomised studies in COVID-19. Two reviewers independently screened each study for eligibility. A living, web-based version of this review will be openly available during the COVID-19 pandemic. We will resubmit it every time the conclusions change or whenever there are substantial updates. RESULTS: We screened 1,043 records but no study was considered eligible. We identified 61 ongoing studies, including 39 randomised trials evaluating different types of cell-based therapies in COVID-19. CONCLUSIONS: We did not find any studies that met our inclusion criteria and hence there is no evidence to support or refute the use of cell-based therapies in the treatment of patients with COVID-19. A substantial number of ongoing studies should provide valuable evidence to inform researchers and decision makers in the near future. PROSPERO REGISTRATION NUMBER: CRD42020179711