Traws Pharma’s novel, proprietary, targeted multi-kinase CDK4-plus inhibitor narazaciclib is being evaluated in dose ranging Phase 1/2 clinical trials in patients with cancer, with or without co-administration of letrozole, with the aim to define the recommended phase 2 dose for further development in metastatic breast, endometrial and potentially other cancers. Pre-clinically narazaciclib has shown efficacy in breast cancer cells resistant to palbociclib, assumed due to targeting proteins such as CSF-1 and FGFR implicated in resistance to these agents. Targeting ARK-5 (also known as NUAK 1) suggests additional tumors can be studied when high expression of these proteins is correlated with resistance.