Supplementary Methods, Table S1, and Figures S1-S6 from Selective and Concentrated Accretion of SN-38 with a CEACAM5-Targeting Antibody–Drug Conjugate (ADC), Labetuzumab Govitecan (IMMU-130)

Supplementary Table S1. Extraction efficiency for isolation of SN-38 in buffer with or without human serum albumin (HSA) or from the ADC with or without acid hydrolysis followed by extraction; Supplementary Figure S1. Schematic depiction of the conjugation of CL2A-SN-38 to mildly reduced IgG yielding site-specifically coupled SN-38 to 8 well-defined sites; Supplementary Figure S2. CL2A-SN38 amide capped with N-acetylcysteine; Supplementary Figure S3. SDS-Page gels comparing profiles for labetuzumab (unconjugated hMN-14 IgG) and labetuzumab govitecan (CL2A-SN-38 conjugated hMN-14 IgG; IMMU-130); Supplementary Figure S4. In vitro cell binding assay performed on LS174T cells, evaluating the binding of unconjugated hMN-14 IgG and SN-38-conjugated hMN-14 IgG (IMMU-130); Supplementary Figure S5. Stability of IMMU-130 in serum from different sources; Supplementary Figure S6. Evaluation of lactone ring stability of the CL2A-linked SN-38 compared to SN-38 at pH 7.4.