TSL2109 is a novel CDK4/6-DYRK2 dual-target inhibitor developed by Jiangsu Tasly Diyee Pharmaceutical Co., Ltd. for solid tumor treatment. Preclinical studies confirm its selective targeting of CDK4/6 and DYRK2, a eukaryotic CMGC family kinase.
In palbociclib-resistant cell lines, TSL2109 downregulates cell cycle-related proteins and DYRK2 pathway ribosomal synthesis regulators (RRS1, CDK2), and upregulates p53, thus exerting synergistic antitumor effects and overcoming resistance to enzalutamide and palbociclib.
As a small-molecule inhibitor with novel targets, structure and mechanism, TSL2109 blocks tumor cell cycle progression independently of hormonal signaling. Preclinical studies show it overcomes AR inhibitor resistance, meeting unmet needs for prostate cancer patients progressing after AR inhibitor therapy. It also reduces CDK2 activity and blocks CDK4/6 compensatory mechanisms, reversing resistance to CDK4/6 inhibitors, providing a new option for HR+/HER2- advanced breast cancer patients.
Participants Dose-Escalation Phase: Advanced solid tumor patients, prioritizing metastatic castration-resistant prostate cancer (mCRPC) and HR+/HER2- advanced breast cancer.
Dose-Expansion Phase:
Cohort A/C: mCRPC; Cohort B/D: HR+/HER2- advanced breast cancer. Treatment Regimens C0 Cycle (3 days): Single oral dose on Day 1 morning under fasting, followed by 72-hour observation.
C1 Cycle (28 days): Daily fasting oral dosing (QD) for 3 weeks, then 1-week rest. Participants may continue treatment if no DLT and potential clinical benefit.
Dose escalation to a pre-established tolerable level is allowed per investigator-sponsor agreement if well-tolerated and likely beneficial. Treatment continues until disease progression, intolerable toxicity or new antitumor therapy. The Dose-Expansion Phase uses the same regimen as C1.
Missed Dose: Make-up within 8 hours; skip if delayed over 8 hours. Notes: Once MTD is determined, participants dosed above MTD will be adjusted to MTD. All doses are administered orally under fasting conditions.