Bruton Tyrosine Kinase Degraders: Current Concepts

Area of Science:

• Oncology
• Pharmacology
• Biochemistry

Background:

• Bruton tyrosine kinase (BTK) is essential for B-cell signaling and a target for treating B-cell cancers.
• BTK inhibitors (BTKi) are effective but face challenges due to intrinsic and acquired resistance, often caused by BTK mutations (e.g., C481S).

Purpose of the Study:

• To evaluate novel Bruton tyrosine kinase (BTK) degraders as a therapeutic strategy to overcome BTK inhibitor (BTKi) resistance in B-cell malignancies.
• To assess the efficacy and safety of various BTK degraders in preclinical and clinical settings.

Main Methods:

• Development of proteolysis-targeting chimeras (PROTACs) designed to selectively degrade both wild-type and mutant BTK.
• Preclinical and early-phase clinical trials evaluating agents like NRX-0492, BGB-16673, NX-5948, NX-2127, HZ-Q1060, ABBV-101, and AC676.

Main Results:

• Several BTK degraders demonstrated significant BTK degradation (e.g., NRX-0492 >90%) and potent anti-cancer effects.
• BGB-16673 showed clinical responses in 67% of relapsed/refractory B-cell malignancy patients.
• NX-2127, which also targets immunomodulatory proteins, achieved partial and stable responses in chronic lymphocytic leukemia and non-Hodgkin lymphoma.

Conclusions:

• BTK degraders represent a promising new therapeutic approach for patients with BTKi-resistant B-cell malignancies.
• These agents exhibit favorable safety profiles and hold potential for enhanced treatment outcomes in personalized cancer therapy.