Site-specific trastuzumab maytansinoid antibody-drug conjugates with improved therapeutic activity through linker and...

Area of Science:

• Oncology
• Pharmacology
• Biotechnology

Background:

• Antibody-drug conjugates (ADCs) represent a significant advancement in cancer therapy, with approved drugs like brentuximab vedotin and ado-trastuzumab emtansine demonstrating clinical efficacy.
• Maytansine analogs, such as DM1, are potent microtubule inhibitors but exhibit limited clinical utility and high systemic toxicity when used alone.
• Conjugating DM1 to antibodies like trastuzumab improves safety and clinical activity, as seen in trastuzumab-MCC-DM1 for HER2+ breast cancer.

Purpose of the Study:

• To enhance the therapeutic activity of trastuzumab maytansinoid antibody-drug conjugates (ADCs) through chemical modification of the linker-drug and antibody engineering.
• To develop novel ADCs with improved drug stability, reduced plasma drug release, and increased drug load.
• To create a homogeneous ADC with superior therapeutic efficacy compared to the clinically approved trastuzumab-MCC-DM1.

Main Methods:

• Chemical synthesis of highly stable linker-drug constructs.
• Engineering of antibodies to incorporate four cysteine residues for site-specific conjugation, enabling increased drug load.
• Development of homogeneous ADCs through precise chemical modification and antibody engineering.

Main Results:

• The novel ADCs demonstrated elimination of DM1 release in plasma, indicating enhanced stability.
• Increased drug load was achieved through antibody engineering with additional cysteine residues.
• The resulting homogeneous ADCs exhibited significantly increased therapeutic activity compared to the established trastuzumab-MCC-DM1.

Conclusions:

• Chemical modification of linker-drugs and antibody engineering can substantially improve the therapeutic activity of trastuzumab maytansinoid ADCs.
• The developed homogeneous ADCs offer a promising alternative with enhanced efficacy and potentially improved safety profiles for cancer treatment.
• These findings pave the way for next-generation ADCs with superior anti-cancer properties.