#United States #San Diego #Breast Cancer #Biotheryx #BTX-9341

Biotheryx's BTX-9341 Clinical Trial Enrollment Completed

Biotheryx, Inc., a biopharmaceutical company dedicated to advancing cutting-edge treatments for cancer and inflammatory diseases, has announced a significant milestone in its clinical research. As of November 17, 2025, the company has completed the enrollment of participants in its Phase 1a clinical trial of BTX-9341, a novel treatment specifically targeting HR+/HER2- breast cancer patients.

About the Clinical Trial

This Phase 1a trial focuses on the administration of BTX-9341, a potent and selective degrader targeting CDK4/6 proteins, which play a crucial role in the progression of certain cancers, particularly HR+/HER2- breast cancer. Patients enrolled in the trial have previously received CDK4/6 inhibitors and are facing advanced or metastatic disease. The trial began with escalating doses of BTX-9341, initially as a standalone therapy, followed by a combination with fulvestrant.

The primary aims of this clinical trial include assessing the safety and tolerability of BTX-9341, along with evaluating its pharmacokinetics and pharmacodynamics. This crucial data will direct the subsequent dosing phases of the trial, where efficacy will be formally evaluated in a dose expansion stage.

Significance of BTX-9341

Dr. Leah Fung, CEO of Biotheryx, emphasized the importance of this trial: "Completing enrollment in the Phase 1a trial for BTX-9341 marks a significant step forward in advancing a very promising first-in-class treatment option for patients with HR+/HER2- breast cancer who have received prior CDK4/6 inhibitor therapy." She expressed gratitude towards the patients and investigators who contributed to this clinical endeavor and reaffirmed the company's commitment to improving the quality of life for patients battling this challenging disease.

BTX-9341 stands out due to its innovative approach as a first-in-class oral degrader of CDK4/6. In preclinical studies, BTX-9341 demonstrated distinct advantages over traditional CDK4/6 inhibitors, exhibiting superior degradation of these targets and significant efficacy in preclinical models. This differential mechanism could potentially overcome the resistance issues associated with current inhibitor therapies, providing new hope for patients who have exhausted other treatment options.

Biotheryx's Vision and Future Directions

Biotheryx’s journey reflects its dedication to pioneering a new class of therapies through research and innovation. With a strong pipeline that includes various first-in-class protein degraders, the company leverages its expertise in molecular glues and bifunctional degraders to address previously unmanageable cancer targets. This includes ongoing trials and preclinical work on additional novel compounds aimed at tackling various malignancies effectively.

Moving forward, the company is keenly anticipating the topline data readout from the Phase 1a trial, expected in the first quarter of 2026. As this research unfolds, Biotheryx remains focused on delivering transformative treatments that can change the landscape of cancer care for patients facing difficult diagnoses.

For further information, readers can explore Biotheryx’s offerings at www.biotheryx.com and follow their advancements on LinkedIn. As the company navigates this promising path, it embodies the hope and resilience of those battling breast cancer and aims to lead breakthroughs in oncology research.