Definition

A bispecific ligand drug conjugate targeting both human folate receptor alpha (FR alpha; FOLR1) and transient receptor potential cation channel subfamily V member 6 (TRPV6; CaT1; CATL) and conjugated to monomethyl auristatin E (MMAE), an auristatin derivative and potent microtubule disrupting agent, with potential antineoplastic activity. Upon administration of FR alpha/TRPV6 bispecific ligand drug conjugate CBP-1008, the bispecific ligand moiety targets and binds to FR alpha and/or TRPV6, which are overexpressed in certain tumor types. After internalization of the agent, the MMAE moiety is released and binds to tubulin and inhibits its polymerization, which results in G2/M phase arrest and apoptosis. This inhibits the proliferation of tumor cells expressing FR alpha and/or TRPV6. FR alpha is a high-affinity folate-binding protein and a member of the folate receptor family; it is overexpressed in certain tumor types. The TRPV6 ion channel plays a key role in calcium homeostasis and is highly selective for calcium compared to other cations; it is overexpressed in a variety of tumors and initiates tumor cell growth, proliferation and metastases.