Discovery of Potent and Selective Covalent Inhibitors of HER2^WT and HER2^YVMA

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• HER2 (Human Epidermal growth factor Receptor 2) is a key driver in various cancers.
• HER2 mutations, like the YVMA insertion in exon 20, activate signaling pathways promoting tumor growth.
• Current treatments for HER2-mutant NSCLC are limited, with approved therapies like Enhertu and challenges in TKI development due to off-target effects.

Purpose of the Study:

• To identify and develop a tyrosine kinase inhibitor (TKI) with potent activity against both wild-type HER2 (HER2^WT) and common HER2 mutants.
• To ensure the developed TKI spares wild-type epidermal growth factor receptor (EGFR^WT) activity, minimizing off-target toxicities.
• To achieve oral bioavailability for improved patient administration and treatment convenience.

Main Methods:

• Structure-based drug design and medicinal chemistry approaches were employed.
• In vitro assays were used to assess the inhibitory activity against HER2^WT, HER2 YVMA mutant, and EGFR^WT.
• Pharmacokinetic studies were conducted to evaluate oral bioavailability and drug exposure.

Main Results:

• A potent, covalent inhibitor targeting HER2^WT and the HER2 YVMA insertion mutant was successfully developed.
• The inhibitor demonstrated robust efficacy against HER2-driven oncogenic signaling.
• Crucially, the inhibitor showed minimal to no inhibition of EGFR^WT, differentiating it from other TKIs.
• The compound exhibited favorable oral bioavailability characteristics.

Conclusions:

• The developed covalent inhibitor represents a significant advancement in targeting HER2-mutant NSCLC.
• This novel TKI offers a potential therapeutic strategy with improved selectivity and efficacy.
• The findings pave the way for a new class of targeted therapies for patients with specific HER2 alterations.