Ibrance (palbociclib)

P2, N=40, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Dec 2025 --> Dec 2026

P2, N=720, Recruiting, Canadian Cancer Trials Group | Trial primary completion date: Jan 2026 --> Dec 2026

P2, N=43, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Dec 2025 --> Jan 2027

To investigate this, we developed a fundamental in vitro model of cell cycle arrest and reentry based on reversible CDK4/6 inhibition (CDK4/6i) with palbociclib, compatible with quantitative single-cell live-imaging of a knock-in endogenous HES1 reporter...Preventing this dip at the point of release, by inducibly sustaining HES1 with a Tet-On system, upregulated the cell cycle inhibitor p21, impeded cell cycle reentry and induced cell death. These findings suggest that manipulating HES1 dynamics could represent a promising therapeutic approach to prevent reactivation of dormant tumor cells.

Furthermore, it discusses the emerging resistance mechanisms to PI3K inhibition, mitigation of adverse effects, and future directions for inavolisib in personalized oncology. As studies continue to demonstrate its clinical utility, inavolisib exhibits preferential activity against the mutated PI3Kα isoform, thereby enhancing therapeutic specificity for combination therapy.

P1, N=31, Active, not recruiting, Eisai Inc. | Trial completion date: Mar 2026 --> Mar 2027

This single-centre retrospective observational cohort study included patients with HR+/HER2- metastatic breast cancer treated with endocrine therapy and a CDK4/6 inhibitor (palbociclib or ribociclib) in the metastatic setting between January 2018 and May 2025. However, modelling BMI as a continuous variable revealed a non-linear (U-shaped) relationship, with increased risk at both the low and high ends of the BMI distribution. These findings suggest that the prognostic impact of BMI is non-linear and may be obscured by simple dichotomous categorisation.

We retrospectively analyzed 156 women with HR+/HER2- MBC (hormone-receptor-positive, Her2-negative metastatic breast cancer) who initiated ribociclib or palbociclib plus endocrine therapy between May 2020 and January 2024. Routine body composition assessment may refine risk stratification and identify candidates for supportive interventions. Prospective studies are needed to validate these findings.

We therefore evaluated cell cycle protein expression by immunohistochemistry (IHC) in 186 LGSOC cases, and evaluated the efficacy of the MEK inhibitor, trametinib, in combination with the CDK4/6 inhibitor, palbociclib, in preclinical models of LGSOC. Acquired drug resistance was linked to increased cyclin D1/E1 expression. This study confirms abnormal p16 IHC as a negative prognostic marker in LGSOC and establishes key determinants of sensitivity to CDK4/6 inhibitor-based therapy.

A total of 100 patients were evaluable 53 treated with palbociclib, 44 with ribociclib and 3 with abemaciclib. Pretreatment sTILs levels were associated with outcome in patients treated with palbociclib. Given the lack of interaction between treatment and sTILs our findings warrant validation in larger, independent cohorts and if confirmed propose sTILs as a simple and reproducible biomarker to aid patient selection for palbociclib.

The median duration of treatment for patients receiving an AI as an accompanying therapy was 15.1 (13.6-17.4) months and 7.9 months (5.8-12.6) for patients receiving fulvestrant, which may suggest endocrine resistance in the latter group. The PALCAN data provides insights into practice patterns and the effectiveness of palbociclib as a first-line therapy in female patients with HR+/HER2- breast cancer in the Canadian real-world setting.

Importantly, Q2 retained bioactivity, inducing cell-cycle arrest and suppressing tumor-cell growth, mirroring the activity of the parent inhibitor Palbociclib. Thus, Q2 is a ready-to-use chemical tool for real-time visualization of CDK4/6 dynamics and holds promise for improving the diagnosis and treatment of breast cancer.