China-based Tasly Pharmaceuticals (SHA: 600535) has announced that it has received approval from the National Medical Products Administration (NMPA) to conduct a clinical study for its third-generation antibody drug conjugate (ADC), STRO-002, in advanced malignant solid tumors.
STRO-002: A Third-Generation ADC Targeting FRα
STRO-002, originated by US firm Sutro Biopharma Inc., is a third-generation ADC that targets folate receptor α (FRα). The molecule is created by conjugating a novel cleavable 3-aminophenyl hemiasterlin linker-warhead (SC239) to the nonnatural amino acid para-azidomethyl-L-phenylalanine at specific positions within a high affinity anti-FolRα antibody using Sutro’s XpressCF+ technology. This results in a homogeneous ADC with a drug-antibody ratio (DAR) of 4. STRO-002 binds to FolRα with high affinity, internalizes rapidly into target positive cells, and releases the tubulin-targeting cytotoxin 3-aminophenyl hemiasterlin (SC209). SC209 has a reduced potential for drug efflux via P-glycoprotein 1 drug pump compared to other tubulin-targeting payloads.
Exclusive Licensing Deal and Market Potential
Tasly Pharma secured a USD 385 million licensing deal with Sutro in December 2021, obtaining exclusive development and commercialization rights to the drug for ovarian cancer, non-small cell lung cancer, and breast cancer indications in Greater China. This move positions Tasly/Sutro to compete with Immunogen, which received conditional approval for Elahere (luveltamab tazevibulin) for FRα-positive ovarian cancer in the US in November of the previous year.-Fineline Info & Tech
