Oncternal Therapeutics Announces Interim Clinical Data on TK216 in Ewing Sarcoma to Be Presented at the CTOS 2019 Annual Meeting

Oncternal Therapeutics, Inc. (Nasdaq: ONCT), a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies, today announced that interim data on TK216 – an investigational targeted small molecule inhibitor of ETS transcription factor oncoproteins – will be presented at the Connective Tissue Oncology Society (CTOS) 2019 Annual Meeting in Tokyo, Japan, on November 16, 2019. The oral presentation (abstract 3250355) titled “A Phase 1 Dose Escalation Study of Intravenous TK216 in Patients with Relapsed or Refractory Ewing Sarcoma” will be given by Paul A. Meyers, M.D., Chief, Pediatric Sarcoma Service and Vice Chair for Clinical Affairs of Memorial Sloan Kettering Cancer Center.

About TK216

TK216 is an investigational, potentially first-in-class small molecule that is designed to inhibit the biological activity of E26 transformation-specific (ETS) transcription factor oncoproteins, including fusion proteins. Tumorigenic gene fusions involving ETS factors are frequently found in tumors such as Ewing sarcoma and prostate cancer, and ETS factors are often overexpressed in many other tumors, including prostate cancer and acute myeloid leukemia (AML). TK216 was developed based on discoveries of Jeffrey Toretsky, M.D., and his team at Georgetown University, who discovered inhibitors of EWS-FLI1 using a novel chemical screening assay. In preclinical models, TK216 binds to EWS-FLI1 and blocks the interaction between ETS family members and RNA helicase A leading to tumor cell apoptosis.

About the Study

TK216 is being evaluated in a Phase 1 clinical study as a single agent and in combination with vincristine in patients with relapsed or refractory Ewing sarcoma, a rare pediatric cancer that has historically been very challenging to treat effectively, particularly for recurrent and metastatic disease. A dose-finding arm of this study is nearing completion, after which Oncternal intends to begin enrolling patients in an expansion cohort of the study to evaluate the clinical response of treatment with TK216 in combination with vincristine, an approved chemotherapy agent. This multi-center study is actively enrolling patients at six clinical trial centers across the U.S. Additional information about the TK216 study may be accessed at ClinicalTrials.gov (NCT02657005).