SYN-38

SYN-38 is a proprietary, functionalized version of **SN-38** (7-ethyl-10-hydroxycamptothecin) developed by **Synaffix** (a **Lonza** company) for use as a cytotoxic payload in **antibody-drug conjugates (ADCs)**. It is a central component of the **toxSYN™** platform, designed to be conjugated to antibodies using site-specific technologies such as **GlycoConnect™** and **HydraSpace™**. As a derivative of the active metabolite of irinotecan, SYN-38 acts as a potent **DNA topoisomerase I inhibitor**. Its mechanism involves stabilizing the transient covalent complex between the topoisomerase I enzyme and DNA, which prevents DNA ligation and results in lethal double-strand breaks during the S-phase of the cell cycle. This targeted delivery approach aims to maximize the anti-tumor efficacy of the camptothecin analog while minimizing systemic toxicity. SYN-38 is currently utilized in several ADC programs under development through licensing agreements with various biopharmaceutical partners.

Other names

functionalized SN-38SN-38 payloadSN38 payloadSN 38 payload