ctDNA Monitoring

Exploring the dynamics of ctDNA following neoadjuvant therapy with CDK4/6 inhibitors combined with endocrine treatment, and its potential to guide de-escalation of adjuvant chemotherapy

* This is a Phase II, multicenter, randomized clinical trial evaluating a ctDNA-guided approach to de-escalate adjuvant chemotherapy in patients with hormone receptor (HR)-positive, HER2-negative early-stage breast cancer. The study aims to determine if combining the CDK4/6 inhibitor Dalpiciclib with endocrine therapy can reduce the need for chemotherapy while maintaining clinical benefits. * Key Details ： 1. Participants: 393 women (aged 18-75) with early-stage HR+/HER2- breast cancer at high risk of recurrence (e.g., tumor size ≥2 cm, lymph node involvement, or high-grade tumors). 2. Design: Patients are randomized 1:4 to two groups: Group A (Chemotherapy) : Receives 4 cycles of taxane-based chemotherapy before surgery. Group B (Experimental) : Receives Dalpiciclib + aromatase inhibitor (AI) for 4 cycles pre-surgery. Post-surgery, treatment is adjusted based on ctDNA results. 3. Primary Goals ： Assess ctDNA clearance rate (conversion from detectable to undetectable ctDNA) after neoadjuvant therapy in Group B. Evaluate 3-year event-free survival (EFS) in Group B (e.g., freedom from cancer recurrence, progression, or death). Secondary Goals ： Safety of Dalpiciclib + endocrine therapy. Tumor response rates (e.g., complete cell cycle arrest, pathological remission). Correlation between ctDNA clearance and long-term outcomes. * Why This Matters ： Current guidelines recommend chemotherapy for high-risk HR+ breast cancer, but it often causes significant side effects. This study explores a personalized approach using ctDNA-a blood-based biomarker-to identify patients who may safely avoid chemotherapy without compromising survival. If successful, it could shift clinical practice toward less toxic, targeted therapies for eligible patients.

Exploring the dynamics of ctDNA following neoadjuvant therapy with CDK4/6 inhibitors combined with endocrine treatment, and its potential to guide de-escalation of adjuvant chemotherapy

* This is a Phase II, multicenter, randomized clinical trial evaluating a ctDNA-guided approach to de-escalate adjuvant chemotherapy in patients with hormone receptor (HR)-positive, HER2-negative early-stage breast cancer. The study aims to determine if combining the CDK4/6 inhibitor Dalpiciclib with endocrine therapy can reduce the need for chemotherapy while maintaining clinical benefits. * Key Details ： 1. Participants: 393 women (aged 18-75) with early-stage HR+/HER2- breast cancer at high risk of recurrence (e.g., tumor size ≥2 cm, lymph node involvement, or high-grade tumors). 2. Design: Patients are randomized 1:4 to two groups: Group A (Chemotherapy) : Receives 4 cycles of taxane-based chemotherapy before surgery. Group B (Experimental) : Receives Dalpiciclib + aromatase inhibitor (AI) for 4 cycles pre-surgery. Post-surgery, treatment is adjusted based on ctDNA results. 3. Primary Goals ： Assess ctDNA clearance rate (conversion from detectable to undetectable ctDNA) after neoadjuvant therapy in Group B. Evaluate 3-year event-free survival (EFS) in Group B (e.g., freedom from cancer recurrence, progression, or death). Secondary Goals ： Safety of Dalpiciclib + endocrine therapy. Tumor response rates (e.g., complete cell cycle arrest, pathological remission). Correlation between ctDNA clearance and long-term outcomes. * Why This Matters ： Current guidelines recommend chemotherapy for high-risk HR+ breast cancer, but it often causes significant side effects. This study explores a personalized approach using ctDNA-a blood-based biomarker-to identify patients who may safely avoid chemotherapy without compromising survival. If successful, it could shift clinical practice toward less toxic, targeted therapies for eligible patients.

The goal of this clinical study is to determine whether monitoring ctDNA and treating patients who become ctDNA-positive with abemaciclib can help prevent the recurrence of hormone receptor-positive, HER2-negative breast cancer after curative surgery and standard therapy. The study will also assess the safety of abemaciclib and the medical problems that may occur during treatment. Participants will receive routine follow-up after surgery, undergo regular blood tests to measure ctDNA, and, if ctDNA becomes positive, receive abemaciclib for a defined treatment period with scheduled clinic visits for examinations and safety assessments. Researchers will evaluate recurrence-free survival, distant recurrence-free survival, adverse events, the time between ctDNA positivity and clinical recurrence, and the rate of ctDNA clearance at the end of abemaciclib therapy.