Precision Targeted Therapy with BLU-667 for RET-Driven Cancers

Area of Science:

• Oncology
• Molecular Biology
• Drug Development

Background:

• Receptor tyrosine kinase (RET) alterations drive various cancers, including non-small cell lung cancer (NSCLC) and thyroid cancer.
• Current treatments rely on multikinase inhibitors (MKIs) with limited efficacy and significant off-target toxicities.
• There is a critical need for targeted therapies specifically designed to inhibit RET.

Purpose of the Study:

• To evaluate the preclinical and clinical efficacy of BLU-667, a novel selective RET inhibitor.
• To assess BLU-667's potency and selectivity against oncogenic RET variants and resistance mutations.
• To validate selective RET inhibition as a therapeutic strategy in RET-driven cancers.

Main Methods:

• In vitro assays were used to compare BLU-667's potency against RET variants and resistance mutants relative to approved MKIs.
• In vivo studies involved NSCLC and thyroid cancer xenografts driven by RET alterations to assess BLU-667's anti-tumor activity and selectivity (VEGFR2 inhibition).
• First-in-human clinical trials evaluated BLU-667's safety, tolerability, RET signaling inhibition, and clinical response in patients with RET-altered NSCLC and MTC.

Main Results:

• BLU-667 demonstrated at least 10-fold greater potency than approved MKIs against oncogenic RET variants and resistance mutants in vitro.
• BLU-667 effectively inhibited the growth of RET-driven NSCLC and thyroid cancer xenografts in vivo without affecting VEGFR2.
• First-in-human trials showed significant RET signaling inhibition and durable clinical responses in patients with RET-altered NSCLC and MTC, with minimal off-target toxicity.

Conclusions:

• BLU-667 is a potent and selective RET inhibitor with demonstrated efficacy in preclinical models of RET-driven cancers.
• Clinical studies validate BLU-667's ability to inhibit RET signaling and induce durable responses in patients with RET-altered NSCLC and MTC.
• Selective RET inhibition represents a clinically validated and effective therapeutic strategy for patients with RET-driven malignancies.