AB Science SA announced that it has received authorization from the Russian Health Ministry to resume patient enrollment in the phase 2 masitinib study of COVID-19 (AB20001). This latest authorization signifies that the measures proposed by AB Science to reinforce patient safety related to cardiac risk are adequate for all three of its ongoing masitinib studies. Authorizations to resume patient enrollment have already been received from European and National agencies for the confirmatory Phase 3 study in amyotrophic lateral sclerosis and the confirmatory Phase 3 study in mastocytosis. Study AB20001 is a randomized (1:1), double-blind, Phase 2 clinical trial to evaluate the safety and efficacy of masitinib combined with isoquercetin in hospitalized patients with moderate and severe COVID-19. Many patients with moderate and severe COVID-19 develop a “cytokine storm” that leads to severe pulmonary inflammation and various thrombotic events associated with acute respiratory distress syndrome and potentially death. The combination of masitinib and isoquercetin may prevent the development of these two complications. Study AB20001 plans to enroll 200 patients) with a primary objective to improve the clinical status of patients after 15 days of treatment. The Data and Safety Monitoring Board have met twice since the beginning of the study and have recommended continuation of the study on both occasions. Of major relevance to the development of masitinib in COVID-19 is the recent publication of research article in the journal Science that demonstrated the effectiveness of masitinib as an anti-SARS-CoV-2 drug in animals. Mice infected with SARS-CoV-2 and then treated with masitinib showed >200-fold reduction in viral titers in the lungs and nose, as well as improved overall lung pathology and significantly reduced levels of key pro-inflammatory cytokines. Overall, results showed that masitinib rapidly and effectively reduced SARS-CoV-2 viral load in mice, reduced inflammatory signatures, and showed potential benefits for survival and clinical scores. Remarkably, masitinib was also effective, in vitro, against all tested variants of concern, including the rapidly spreading Alpha, Beta and Gamma variants.