SOUTH SAN FRANCISCO, CA, USA I August 22, 2024 I Sutro Biopharma, Inc. (Sutro or the Company) (NASDAQ: STRO), a clinical-stage oncology company pioneering site-specific and novel-format antibody drug conjugates (ADCs), today announced that REFRαME-L1, the global Phase 2 study of luveltamab tazevibulin (luvelta) for patients with non-small cell lung cancer (NSCLC) whose tumor expresses Folate Receptor-α (FRα), has been initiated and is open for enrollment. Initial data from this study is expected in the first half of 2025.

“The initiation of REFRαME-L1 is an important milestone in our efforts to expand the application of luvelta to a broad range of patients with FRα expressing cancers. We have generated compelling preclinical evidence that luvelta can provide an important new treatment option for NSCLC, driven by its precise design, wide therapeutic window, and ability to treat patients with lower FRα expression profiles,” said Anne Borgman, M.D., Sutro’s Chief Medical Officer.

Lung cancer is the leading cause of cancer-related deaths worldwide1. More than half of patients have metastatic disease at diagnosis, which has a 5-year survival rate as low as 8%2. Despite a variety of treatment strategies, most patients with advanced NSCLC eventually become resistant to treatment and have less treatment options as their disease progresses to later lines of treatment.

FRα has been found in multiple cancer types including NSCLC, but exhibits limited expression in normal tissue3,4,5. Approximately 30% of patients with adenocarcinoma NSCLC have FRα expression, making FRα an attractive therapeutic target for treatment of advanced NSCLC and providing patients an opportunity for a targeted therapy.

REFRαME-L1 is a Phase 2 trial evaluating the safety and efficacy of luvelta in adult patients with previously treated advanced or metastatic NSCLC with FRα expression ≥25% Tumor Proportion Score (TPS). Patients are expected to be dosed with 4.3 mg/kg of luvelta every three weeks.

*1: Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. Cancer J Clin. 2021;71(3):209.
*2: National Cancer Institute (NCI). Surveillance, Epidemiology, and End Results program. SEER*Stat Database. Bethesda, MD: National Cancer Institute; 2021. https://seer.cancer.gov/statfacts/html/lungb.html.
*3: Cheung A, Bax HJ, Josephs DH, Smith J, Jones A, Lewis K, et al. Targeting folate receptor alpha for cancer treatment. Oncotarget. 2016;7(32):52553-52574.
*4: Nunez MI, Behrens C, Woods DM, Lin H, Suraokar M, Kadara H, et al. High expression of folate receptor alpha in lung cancer correlates with adenocarcinoma histology and EGFR [corrected] mutation. J Thorac Oncol. 2012;7(5):833-40. Erratum in: J Thorac Oncol. 2012 Jun;7(6):1065.
*5: O’Shannessy DJ, Yu G, Smale R, Fu YS, Singhal S, Thiel RP, et al. Folate receptor alpha expression in lung cancer: diagnostic and prognostic significance. Oncotarget. 2012;3(4):414 425.

About Luveltamab Tazevibulin
Luveltamab tazevibulin, abbreviated as “luvelta” and formerly known as STRO-002, is a FRα-targeting antibody-drug conjugate (ADC) designed to treat a broad range of patients with ovarian cancer, including those with lower FRα-expression who are not eligible for approved treatment options targeting FRα. Developed and manufactured with Sutro’s cell-free XpressCF® platform, luvelta is a homogeneous ADC with four hemiasterlin cytotoxins per antibody, precisely positioned to efficiently deliver to the tumor while ensuring systemic stability after dosing. REFRαME-O1, a Phase 2/3 registration-directed study for patients with platinum-resistant ovarian cancer is ongoing. The Company has additional ongoing trials in patients with endometrial cancer, non-small cell lung cancer, and in combination with bevacizumab in patients with ovarian cancer. The Company expects to initiate REFRαME-P1, a Phase 2/3 registration-directed study for patients with CBF/GLIS2 acute myeloid leukemia, a rare subtype of pediatric cancer, in the second half of 2024. The U.S. Food and Drug Administration (FDA) has granted luvelta a Fast Track designation for Ovarian Cancer, as well as Orphan and Rare Pediatric Disease designations for CBF/GLIS2 Pediatric AML.

About Sutro Biopharma
Sutro Biopharma, Inc., is a clinical-stage company relentlessly focused on the discovery and development of precisely designed cancer therapeutics, to transform what science can do for patients. Sutro’s fit-for-purpose technology, including cell-free XpressCF®, provides the opportunity for broader patient benefit and an improved patient experience. Sutro has multiple clinical stage candidates, including luveltamab tazevibulin, or luvelta, a registrational-stage folate receptor alpha (FolRα)-targeting ADC in clinical studies. A robust pipeline, coupled with high-value collaborations and industry partnerships, validates Sutro’s continuous product innovation. Sutro is headquartered in South San Francisco. For more information, follow Sutro on social media @Sutrobio, or visit www.sutrobio.com.

SOURCE: Sutro Biopharma