OncoMatch/Clinical Trials/NCT05996107
Study of Ribociclib Administered Concurrently With Postoperative Radiation Therapy in Patients With High-Risk, HR+/HER2- Breast Cancer
Is NCT05996107 recruiting? Yes, currently enrolling (Jun 2026). This Phase 1 trial studies Ribociclib for breast cancer.
Treatment: Ribociclib — The purpose of this research study is to determine the safety, tolerability and dose of Ribociclib when combined with adjuvant radiation in women with high-risk ER+ breast cancer. Once enrolled on study, patients will begin treatment with Ribociclib 400 mg daily at the same time as they initiate standard of care adjuvant radiation therapy- 50 Gy in 25 fractions or 42.56 Gy in 16 fractions +/- 10 Gy boost including comprehensive nodal. Paitents will continue treatment with Ribociclib for up to 6 weeks.
Check if I qualifyExtracted eligibility criteria
Treatments studied
Targeted therapy
Cancer type
Breast Carcinoma
Biomarker criteria
Required: ESR1 overexpression (≥ 1% positivity)
ER and/or PR-positive (≥ 1% positivity as determined by local pathology laboratory)
Required: PR (PGR) overexpression (≥ 1% positivity)
ER and/or PR-positive (≥ 1% positivity as determined by local pathology laboratory)
Required: HER2 (ERBB2) wild-type
HER2-negative breast cancer
Disease stage
Grade: grade 3
Performance status
ECOG 0–1(Restricted strenuous activity)
Demographics
Prior therapy
Must have received: chemotherapy — neoadjuvant or adjuvant
Patients must have completed chemotherapy (either in neoadjuvant or adjuvant setting).
Cannot have received: CDK4/6 inhibitor
Prior history of CDK4/6 inhibitor therapy.
Cannot have received: radiation therapy
Exception: prior radiation therapy to other sites is permissible
Prior history of radiation therapy to the chest wall and/or regional nodes is not allowed (but prior radiation therapy to other sites is permissible).
Lab requirements
Blood counts
Absolute neutrophil count ≥ 1.5 × 10^9/L; Platelets ≥ 100 × 10^9/L; Hemoglobin ≥ 9.0 g/dL; INR ≤1.5 (unless the patient is receiving anticoagulants and the INR is within the therapeutic range of intended use for that anticoagulant within 7 days prior to the first dose of study drug).
Kidney function
Estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73m2 according to MDRD formula.
Liver function
Total bilirubin < ULN except for patients with Gilbert's syndrome who may only be included if the total bilirubin is ≤ 3.0 × ULN or direct bilirubin ≤ 1.5 × ULN. AST < 2.5 × ULN, except for patients with liver metastasis, who are only included if the AST is < 5 × ULN. ALT < 2.5 × ULN, except for patients with liver metastasis, who are only included if the ALT is < 5 × ULN.
Cardiac function
QTcF interval at screening EKG ≤ 450ms; Mean resting heart rate 50-90 bpm; LVEF < 50% excluded.
Adequate baseline hematologic, hepatic and renal function as indicated below: ... QTcF interval at screening EKG ≤ 450ms (QT interval using Fridericia's correction). Mean resting heart rate 50-90 bpm (determined from the EKG).
Structured fields extracted by AI. May contain errors — verify against the official protocol.
US trial sites
- University of Michigan · Ann Arbor, Michigan
- University of Michigan Health West · Wyoming, Michigan
- UHCMC Seidman Cancer Center · Cleveland, Ohio
Showing up to 5 US sites.
See all sites on ClinicalTrials.gov →Frequently asked questions
Is NCT05996107 currently recruiting?
Yes, this trial is currently recruiting patients.
Are there prior therapy exclusions?
Yes. Prior CDK4/6 inhibitor, radiation therapy disqualifies patients from enrollment.
Does this trial require ESR1?
Yes, ESR1 overexpression is a required biomarker for enrollment.
Does this trial require PGR?
Yes, PGR overexpression is a required biomarker for enrollment.
Does this trial require ERBB2?
Yes, ERBB2 wild-type is a required biomarker for enrollment.
Is this trial open to male patients?
No. This trial enrolls female patients only.
Could you qualify for this trial?
Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.
Check if I qualify