In this interview, John Mascarenhas, MD, Icahn School of Medicine at Mount Sinai, New York, NY, comments on the promising results observed with INCA33989, a novel monoclonal antibody targeting mutant calreticulin (mutCALR), in patients with essential thrombocythemia (ET). The Phase I studies (NCT05936359, NCT06034002) investigating this agent demonstrated encouraging safety and efficacy, with rapid and durable reductions in platelet counts and significant decreases in mutCALR variant allele frequency (VAF). Dr Mascarenhas expresses his excitement at this therapeutic approach, which holds disease-modifying potential for CALR-mutant myeloproliferative neoplasms (MPNs). This interview took place at the 30th Congress of the European Hematology Association (EHA) in Milan, Italy. These works are owned by Magdalen Medical Publishing (MMP) and are protected by copyright laws and treaties around the world. All rights are reserved.