Sutro Biopharma initiates REFRaME-P1 trial of luvelta in AML

Sutro Biopharma (STRO) announced that REFRaME-P1, the registration-directed study of luveltamab tazevibulin for pediatric patients with CBFA2T3::GLIS2 acute myeloid leukemia, has been initiated and is open for enrollment. In December 2023, Dr. Meshinchi presented data on anti-leukemic activity from the compassionate use of luvelta in 25 pediatric patients with relapsed/refractory CBFA2T3-GLIS2 acute myeloid leukemia at the American Society of Hematology Annual Meeting and Exposition. Data demonstrated that treatment with luvelta produced meaningful clinical responses, including complete remission in 42% of patients with greater than or equal to5% blasts, and prolonged overall survival, enabling some patients to receive hematopoietic stem cell transplant, a potentially curative therapy. CBF/GLIS subtype AML is a rare and highly lethal form of leukemia found exclusively in infants and young children, with the average age of onset at 18 months. There are no therapies specifically approved to target this form of leukemia and it is resistant to conventional chemotherapy, with an induction failure rate of over 80%2. Due to a lack of effective treatment, children diagnosed with the disease have a dismal two-year survival rate3. Recent studies have shown that FOLR1, which encodes for FRalpha, is silent in normal hematopoiesis, but is uniquely induced by the CBF/GLIS gene fusion. REFRaME-P1 is a registration-enabling study evaluating the efficacy and safety of luvelta in infants and children under 12 years of age with CBF/GLIS AML. This will be a global study, with the majority of sites planned to be open by the end of the year.