NEWTOWN, Pa., May 26, 2022 (GLOBE NEWSWIRE) — Onconova Therapeutics, Inc. (NASDAQ: ONTX), a clinical-stage biopharmaceutical company focused on discovering and developing novel products for patients with cancer, today announced the publication of an abstract at the American Society of Clinical Oncology (ASCO) Annual Meeting. Featured in the abstract are preclinical data from in vitro and cell-based assays that demonstrate how narazaciclib’s inhibitory profile differentiates it from the FDA-approved CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib.
Key data and conclusions from the abstract include:
- Narazaciclib, abemaciclib, palbociclib, and ribociclib each have strong affinity for CDK4/cyclin D1, with Kd values of 0.18 nM, 0.08 nM, 0.75 nM, and 1.3 nM, respectively.
- Narazaciclib and abemaciclib have similar affinities against CDK family members, including nM activity against CDK2/cyclin A, which may play a role in resistance to palbociclib and ribociclib.
- Narazaciclib’s inhibitory activity against GSK3β, a kinase whose inhibition putatively causes tolerability issues related to diarrhea, is ~29 times less than that of abemaciclib.
- Cellular kinase assays showed narazaciclib’s highest inhibitory activity to be against CDK4/6, CSF1R, (supports pro-tumor immune suppression), and NUAK1/ARK 5 (associated with poor prognosis in multiple cancers and implicated in cancer cell migration, invasion, and metastasis).
- Cellular Thermal Shift Assay (CETSA) and…
