Sutro Biopharma, Inc. has announced the initiation of the REFRαME-P1 trial, a registration-directed study evaluating luveltamab tazevibulin (luvelta) for pediatric patients with CBFA2T3::GLIS2 (CBF/GLIS) acute myeloid leukemia (AML). This global study aims to address the unmet need for effective treatments for this rare and aggressive form of leukemia in infants and young children.
Anne Borgman, M.D., Sutro’s Chief Medical Officer, stated, “We are excited to announce the initiation of our second pivotal trial, the registration-enabling clinical trial of luvelta in infants and toddlers with a rare and aggressive form of leukemia. We look forward to bringing this promising targeted therapy to a pediatric patient group with limited effective treatment options.”
Luvelta: Targeting FRα in CBF/GLIS AML
Luveltamab tazevibulin (luvelta), formerly known as STRO-002, is an antibody-drug conjugate (ADC) that targets Folate Receptor-α (FRα). CBF/GLIS AML is a rare and highly lethal leukemia subtype found almost exclusively in infants and young children, with an average onset age of 18 months. Conventional chemotherapy is often ineffective, with induction failure rates exceeding 80%, leading to a dismal two-year survival rate for affected children. Recent studies have indicated that FOLR1, the gene encoding FRα, is uniquely induced by the CBF/GLIS gene fusion, making it a promising therapeutic target.
Compassionate Use Data
In December 2023, Soheil Meshinchi, M.D., Ph.D., presented data from the compassionate use of luvelta in 25 pediatric patients with relapsed/refractory CBF/GLIS AML at the American Society of Hematology Annual Meeting and Exposition. The data demonstrated meaningful clinical responses, including complete remission in 42% of patients with ≥5% blasts. Furthermore, luvelta treatment prolonged overall survival, enabling some patients to undergo hematopoietic stem cell transplant, a potentially curative therapy.
Dr. Meshinchi commented, “Beginning this trial is an important next step in the clinical development pathway for luvelta, as it has the opportunity to address the unmet need in many types of cancer that express Folate Receptor-α (FRα) beyond ovarian. With my focus on the biology of AML, I am honored to have been a part of making this medicine available to patients in dire need via a compassionate use mechanism sponsored by Sutro, through which we have seen encouraging results in this devastating disease.”
REFRαME-P1 Trial Design
The REFRαME-P1 trial is designed to evaluate the efficacy and safety of luvelta in infants and children under 12 years of age with CBF/GLIS AML. This registration-enabling study will be conducted globally, with the majority of clinical sites expected to be open for enrollment by the end of the year. The trial aims to provide a targeted therapy option for a patient population with limited effective treatment alternatives.
Luvelta has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA) for Ovarian Cancer, as well as Orphan and Rare Pediatric Disease designations for CBF/GLIS Pediatric AML.
