A phase I dose-escalation and dose-expansion study of tibremciclib, a novel CDK4/6 inhibitor, monotherapy and in combination with fulvestrant in HR-positive/HER2-negative advanced breast cancer.

ABSTRACT:

Background

Tibremciclib (BPI-16350) is a novel potent selective inhibitor of cyclin-dependent kinase 4 and 6 (CDK4/6). This phase I, first-in-human study assessed the tibremciclib monotherapy and combined with fulvestrant in advanced breast cancer (ABC).

Patients and methods

This open-label, phase I study (NCT03791112) comprised dose escalation (phase Ia) and expansion (phase Ib). In phase Ia, Chinese patients with advanced solid tumors received tibremciclib monotherapy (50-500 mg orally once daily). Based on the tolerability and preliminary antitumor activity from phase Ia, two dose cohorts (300 or 400 mg orally once daily) were selected in phase Ib to combine with fulvestrant in patients with hormone receptor (HR)-positive/human epidermal growth receptor 2 (HER2)-negative

SUBMITTER: Zhang J 

PROVIDER: S-EPMC12148727 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature