entinostat

This is an open-label, single-center, exploratory, Phase Ib/II clinical trial evaluating the safety and efficacy of entinostat combined with pyrotinib and endocrine therapy in patients with advanced hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-positive (HER2+) breast cancer who have failed prior trastuzumab-based therapy. The study consists of two parts: Part I (Phase Ib) employs a 3+3 dose-escalation design to determine the dose-limiting toxicity (DLT), maximum tolerated dose (MTD), and recommended Phase II dose (RP2D) of entinostat when given in combination with pyrotinib (400 mg daily) and endocrine therapy. Part II (Phase II) uses a Simon two-stage design to further evaluate the efficacy and safety of the combination at the RP2D. The primary efficacy endpoint is progression-free survival (PFS) based on RECIST v1.1. A total of approximately 79-94 participants will be enrolled.

* This study was an open, multicenter phase II clinical trial that enrolled 118 patients with HR+/HER2- with recurrent or progressive advanced breast cancer treated with CDK4/6 inhibitors; * The study adopted the Simon phase 2 design, and all 20 eligible patients were treated with entinostat + fulvestrant; The study was terminated if no more than 2 patients achieved objective response and continued to enter Phase 2 if no more than 3 patients achieved objective response. In Phase 2, qualified patients were randomly assigned at a ratio of 1:1.5 to either the entestasta + fluvestrus group (Group 1) or the anlotinib + entestasta + fluvestrus group (Group 2), with 39 patients enrolled in group 1 and 59 patients enrolled in group 2; All patients were treated until the subjects' treatment would continue until the subjects experienced disease progression, intolerable toxicity, active withdrawal from treatment, or other conditions specified in the protocol, whichever occurred first. * During the study period, efficacy evaluations will be conducted every 8 weeks in accordance with the Solid Tumor Efficacy Evaluation Criteria (RECIST) v1.1 until disease progression, the initiation of a new anti-tumor treatment by the subject, or the withdrawal of informed consent, whichever occurs first. * Continuous safety evaluations will be conducted during the study treatment period. All subjects who have received at least one study treatment will be required to undergo end-of-treatment visits and safety follow-up visits within 7 days and 30±2 days after the last study treatment, respectively. * The end of the study was defined as the occurrence of disease progression or the end of the study treatment in all subjects, or the early termination of the study for other reasons, whichever occurred first.

Brief Summary This is an open-label, randomized, phase II clinical study designed to evaluate neoadjuvant treatment regimens in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) early breast cancer. A total of 60 premenopausal, perimenopausal, and postmenopausal patients with HR+/HER2- breast cancer who meet the inclusion criteria will be enrolled. During the study, clinical information will be collected according to standard practice, including demographic data, tumor imaging, and pathological results (e.g., Ki-67). Investigator-assessed outcomes will be used as the final results. After 14 days of treatment, patients who provide consent will undergo a second biopsy to evaluate the rate of complete cell-cycle arrest. Safety assessments and imaging evaluations will be performed at treatment completion or upon study withdrawal. Informed consent must be obtained at each study center before participation. Treatment arms: Arm A (30 patients): Dalpiciclib 125 mg orally once daily on Days 1-21 of each 28-day cycle (3 weeks on, 1 week off), for 6 cycles Letrozole 2.5 mg orally once daily continuously for 6 cycles Entinostat 3 mg orally once weekly (Days 1-28 of each 28-day cycle), for 6 cycles Arm B (30 patients): Dalpiciclib 150 mg orally once daily on Days 1-21 of each 28-day cycle, for 6 cycles Letrozole 2.5 mg orally once daily continuously for 6 cycles Premenopausal and perimenopausal women will also receive ovarian function suppression (OFS), such as with a GnRHa agent. After signing informed consent, patients will begin neoadjuvant therapy with dalpiciclib plus entinostat and letrozole ± OFS. Ultrasound assessments will be conducted every two treatment cycles and before surgery under the same imaging conditions as baseline. Bone scans will be performed at the end of neoadjuvant treatment. MRI of the breast will be performed at baseline, after two cycles, and before surgery to assess treatment efficacy. Treatment discontinuation will occur if toxicity is intolerable, consent is withdrawn, or the investigator determines it is necessary. Adjuvant therapy: After surgery, patients will receive physician's choice of therapy (TPC). Safety follow-up: Patients will be followed until they start another anticancer therapy, all adverse events have resolved to Grade 0-1 or baseline level, or death-whichever occurs first.