AVZO-023 + AVZO-021 + letrozole

This combination therapy consists of three orally administered agents: AVZO-023 (a potent, highly selective cyclin-dependent kinase 4 [CDK4] inhibitor), AVZO-021 (a potent, selective cyclin-dependent kinase 2 [CDK2] inhibitor), and letrozole (an aromatase inhibitor). The regimen is under clinical investigation for the treatment of advanced or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer and other advanced solid tumors. The combination aims to enhance antitumor activity by targeting key cell cycle regulators (CDK4 and CDK2) to overcome resistance seen with endocrine therapy and selectively lower estrogen production via aromatase inhibition. AVZO-023 and AVZO-021 are being developed by Avenzo Therapeutics; letrozole is an established drug for hormone-responsive breast cancer. This specific three-drug regimen is currently in Phase 1/2 clinical trials to assess safety, tolerability, and preliminary efficacy in relevant patient populations[1][3][5][8].