Treadwell Therapeutics Announces A Presentation at the 2022 SABCS Annual Meeting Featuring a Clinical Trial Update on CFI-402257, a Best-in-Class TTK inhibitor

NEW YORK,Dec. 9,2022 -- Treadwell Therapeutics,a clinical-stage biotechnology company developing novel medicines for highly aggressive cancers,today announced that data presented on the ongoing CFI-402257-CL-001 clinical study of the Company's CFI-402257 program in advanced solid tumors,continued to show a tolerable safety profile and demonstrated clinical benefit both as a monotherapy as well in combination with fulvestrant. Data were presented at the 2022San Antonio Breast Cancer Symposium (SABCS) being held fromDecember 6-10,2022 at the Henry B. Gonzalez Convention Center in San Antonio,Texas.

"CFI-402257 is well-tolerated and showed signs of anti-tumor activity either as a monotherapy or in combination with Fulvestrant,including some patients who were with durable disease control after progression on prior CDK4/6 inhibitor therapy" said Dr. Philippe Bedard,Study investigator and Associate Professor of Medicine at the University of Toronto and Staff Medical Oncologist at the Princess Margaret Cancer Centre,Toronto,Canada.

"CFI-402257 continues to demonstrate an encouraging clinical profile,and we look forward to further developing the molecule for the treatment of ER+ breast cancer," added Dr. Michael Tusche,Treadwell co-CEO.

2022 SABCS Poster Presentations and Details:

An Update to a Phase I Trial of CFI-402257,an oral TTK Inhibitor,in Patients with Advanced Solid Tumors with HER2-Negative Breast Cancer Expansion Cohorts

Poster Number: P6-10-13

Date: December 9th,7:00 am CT

Data presented on CFI-402257,an oral,best-in-class TTK inhibitor,continue to show a tolerable safety profile at the recommended Phase 2 dose of 168 mg once daily with manageable,dose-dependent neutropenia being the primary toxicity. In this heavily pre-treated population (N=86),the overall response rate was 6% for monotherapy patients (4/66) and 10% for ER+/HER2- breast cancer patients treated in combination with fulvestrant (2/20). The clinical benefit rate (CR+PR+SD>6 months) for monotherapy and combination were 12% and 25%,respectively. Patients achieving stable disease or better stayed on treatment for a median of 242 days (range: 112 to 673). Significantly,several ER+ breast cancer patients who previously failed CDK4/6 inhibitors in the combination cohort remained on therapy for a year or more. The most common drug related toxicities of any grade,which occurred in greater than 10% of all patients,included fatigue (48%),nausea (48%),decreased appetite (34%),diarrhea (34%),vomiting (24%),constipation (21%) and headache (21%).

About Treadwell Therapeutics

Treadwell Therapeutics is a science driven,clinical-stage,multi-modality biotechnology company developing first-in-class and best-in-class medicines to address unmet needs in patients with cancer. The Company's internally developed clinical pipeline includes CFI-400945 (PLK4 inhibitor),CFI-402257 and CFI-402411 (HPK1 inhibitor). The company is also advancing a pre-clinical pipeline of first-in-class antibody and TCR-based cell therapy assets. For more information,please visit www.treadwelltx.com.

Contact

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