Sutro Biopharma Starts REFRαME-P1 Trial for Pediatric CBF/GLIS AML with Luvelta

SOUTH SAN FRANCISCO, CA, USA, November 01, 2024 - Sutro Biopharma, Inc., a clinical-stage oncology company, has commenced enrollment for its pivotal study of luveltamab tazevibulin (luvelta) targeted at pediatric patients with the CBFA2T3::GLIS2 (CBF/GLIS; RAM phenotype) subtype of acute myeloid leukemia (AML).

Anne Borgman, M.D., Sutro’s Chief Medical Officer, expressed enthusiasm about the initiation of their second major trial, which aims to provide a promising treatment for young children with this aggressive leukemia variant. This effort is particularly significant for this patient group, who have few effective treatment options.

Soheil Meshinchi, M.D., Ph.D., highlighted the critical nature of this trial in the development of luvelta, indicating its potential in addressing needs across various cancers expressing Folate Receptor-α (FRα). Dr. Meshinchi, focusing on AML biology, has been instrumental in providing access to this medication under compassionate use, showing positive outcomes in combating this severe disease.

In December 2023, Dr. Meshinchi presented data at the American Society of Hematology Annual Meeting, demonstrating the effectiveness of luvelta in treating 25 pediatric patients with relapsed or refractory CBF/GLIS AML. The findings revealed that 42% of patients experienced complete remission, with some achieving prolonged survival, allowing for subsequent stem cell transplants, offering a potential cure.

This particular AML subtype is rare and deadly, predominantly affecting infants and young children, typically diagnosed around 18 months. There are currently no approved therapies specifically targeting this leukemia form, and it shows high resistance to conventional chemotherapy, with an induction failure rate exceeding 80%. Due to the lack of effective treatments, children with this diagnosis face a bleak two-year survival outlook. Recent research has shown that FOLR1, the gene that encodes FRα, is normally inactive in blood cell formation but is uniquely activated by the CBF/GLIS gene fusion.

The REFRαME-P1 study is designed to assess the safety and efficacy of luvelta in children under the age of 12 with CBF/GLIS AML. It is set to be a global trial, with most sites expected to be operational by the end of the year.

Luveltamab tazevibulin, known as luvelta, is an antibody-drug conjugate (ADC) targeting FRα, developed for a broad range of patients, including those with ovarian cancer who have lower FRα expression and are not eligible for other treatments. Using Sutro’s XpressCF® platform, luvelta is engineered to efficiently deliver cytotoxins to tumors while maintaining systemic stability. Besides the REFRαME-P1 study, Sutro is conducting several other trials, including a Phase 2/3 study for platinum-resistant ovarian cancer and studies assessing luvelta in combination treatments for other cancer types. The U.S. Food and Drug Administration (FDA) has granted luvelta Fast Track designation for ovarian cancer and Orphan and Rare Pediatric Disease designations for CBF/GLIS pediatric AML.

Sutro Biopharma, based in South San Francisco, is dedicated to developing precise cancer treatments, leveraging their XpressCF® technology to enhance patient outcomes and experiences. Their pipeline includes several clinical-stage candidates and benefits from strategic collaborations and partnerships within the industry.