Targeting CD33+ Acute Myeloid Leukemia with GLK-33, a Lintuzumab-Auristatin Conjugate with a Wide Therapeutic Window.

CD33 (Siglec-3) is a cell surface receptor expressed in approximately 90% of acute myeloid leukemia (AML) blasts, making it an attractive target for therapy of AML. Although previous CD33-targeting antibody-drug conjugates (ADC) like gemtuzumab ozogamicin (GO, Mylotarg) have shown efficacy in AML treatment, they have suffered from toxicity and narrow therapeutic window. This study aimed to develop a novelADCwith improved tolerability and a wider therapeutic window.

Trastuzumab-MMAU Antibody-Auristatin Conjugates: Valine-Glucoserine Linker with Stabilized Maleimide Conjugation Improves In Vivo Efficacy and Tolerability.

Antibody-drug conjugates (ADC) have shown impressive clinical activity with approval of many agents in hematologic and solid tumors. However, challenges remain with both efficacy and safety of ADCs. This study describes novel trastuzumab-auristatin conjugates with the hydrophilic monomethylauristatin E (MMAE) prodrug MMAU, and optimization of a glycopeptide linker leading to a wider therapeutic window.

Hydrophilic Auristatin Glycoside Payload Enables Improved Antibody-Drug Conjugate Efficacy and Biocompatibility.

Antibody-drug conjugates (ADCs) offer a combination of antibody therapy and specific delivery of potent small-molecule payloads to target cells. The properties of the ADC molecule are determined by the balance of its components. The efficacy of the payload component increases with higher drug-to-antibody ratio (DAR), while homogeneous DAR = 8 ADCs are easily prepared by conjugation to the four accessible antibody hinge cystines.