Activated matriptase as a target to treat breast cancer with a drug conjugate

Area of Science:

• Oncology
• Pharmacology
• Biotechnology

Background:

• Triple-negative breast cancer (TNBC) remains a challenging malignancy with limited targeted therapy options.
• Activated matriptase is frequently overexpressed in various epithelial cancers, presenting a potential therapeutic target.

Purpose of the Study:

• To evaluate the antitumor efficacy of a novel antibody drug conjugate (ADC) targeting activated matriptase.
• To assess the ADC's activity against TNBC cell lines and xenografts, both in vitro and in vivo.

Main Methods:

• Synthesis of an ADC comprising an anti-matriptase antibody (M69) linked to monomethyl auristatin-E via a cleavable linker.
• In vitro cytotoxicity assays against activated matriptase-positive cancer cell lines.
• In vivo studies using human TNBC xenografts in immunosuppressed mice, including combination therapy with cisplatin.

Main Results:

• The ADC demonstrated significant cytotoxicity against multiple activated matriptase-positive epithelial carcinoma cell lines in vitro.
• Marked inhibition of TNBC xenograft growth was observed in vivo.
• The ADC showed potent antitumor activity, superior to the unconjugated antibody, and enhanced efficacy when combined with cisplatin.

Conclusions:

• The novel ADC targeting activated matriptase exhibits potent antitumor activity against TNBC and other solid tumors.
• Activated matriptase may serve as a predictive biomarker for ADC response.
• This ADC, alone or in combination with cisplatin, holds potential for improving treatment outcomes in TNBC and other matriptase-overexpressing cancers.