Combining pre-operative radiation with Abemaciclib and Letrozole for breast cancer

RADIANT Study: Pre-op Radiation With Abemaciclib Andletrozole in Early Stage Breast Cancer

Phase 1 Interventional Rutgers, The State University of New Jersey · NCT06139107

This study is testing if giving radiation therapy together with two medications, Abemaciclib and Letrozole, is safe and effective for people with hormone receptor positive/HER2 negative breast cancer before surgery.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment15 (estimated)
Ages60 Years and up
SexFemale
SponsorRutgers, The State University of New Jersey Academic / other
Drugs / interventionschemotherapy, radiation
Locations4 sites (Belleville, New Jersey and 3 other locations)
Trial IDNCT06139107 on ClinicalTrials.gov

What this trial studies

This phase 1b study investigates the safety and feasibility of using pre-operative radiation therapy alongside CDK4/6 inhibitors in patients with hormone receptor positive/HER2 negative breast cancer. The research focuses on the concurrent administration of these treatments to assess their combined effects and tolerability. Participants will undergo thorough evaluations, including clinical assessments and imaging studies, to monitor treatment responses and any potential side effects. The goal is to gather valuable data that could inform future clinical applications of this combination therapy.

Who should consider this trial

Good fit: Ideal candidates are post-menopausal women with HR+/HER2- breast cancer who have a tumor size of at least 1.5 cm and meet specific eligibility criteria.

Not a fit: Patients with metastatic disease or those who do not meet the inclusion criteria will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could improve treatment outcomes for patients with HR+/HER2- breast cancer by providing a novel therapeutic strategy.

How similar studies have performed: While this approach is novel, other studies have explored CDK4/6 inhibitors in breast cancer, indicating potential for success in this area.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Histologically and/or cytologically confirmed diagnosis of invasive (ductal, lobular or mixed histology), Clinically inapparent tumor that is not palpable. (cT1-T2N0)disease. Minimum tumor size of 1.5 cm
* Expression of ER or progesterone receptors (PR)and negative expression of HER2 per American Society of Clinical Oncology, (ASCO) Common Alerting Protocol (CAP) guidelines
* Oncotype diagnosis (DX) Breast Recurrence score of less than 25 on core biopsy specimen
* Post-menopausal status defined:
* age \<60 with amenorrhea for at least 12 months in the absence of prior chemotherapy, tamoxifen, toremifene, or ovarian suppression and estradiol and FSH (follicle stimulating hormone) in postmenopausal range.
* No clinical suspicion of metastasis disease
* Eastern Cooperative Oncology Group (ECOG) performance status of follicle stimulating hormone (PFS) ≤2
* Eligible to undergo surgery, either lumpectomy or mastectomy for local treatment of the breast cancer
* Able to swallow oral medications
* Adequate organ function for all of the following:

Absolute Neutrophil (ANC) \>1.5 x 10/L Platelets \>100 x 10/L Hemoglobin \>8 g/dL - May receive erythrocyte transfusions to achieve this level Total Bilirubin \<1.5 x Upper Limit of Normal (ULN) Alanine Aminotransferase (ATL) and Aspartate Aminotransferase (AST) \<3 x ULN

* HR positive/HER2 -negative breast cancers are allowed as long as no other exclusions exist

Exclusion Criteria:

* History of ipsilateral breast cancer
* Prior treatment with CDK4/6 inhibitors or aromatase inhibitors
* History of chest wall or ipsilateral breast radiation
* Inflammatory breast cancer
* Needs neoadjuvant chemotherapy
* Presence of distant metastatic disease
* Contraindication for surgery
* Uncontrolled hypertension (systolic blood pressure \>190 mm Hg or diastolic blood pressure \>100 mm Hg)
* Any condition including the presence of laboratory abnormalities, which, in the opinion of the investigator places the subject at unacceptable risk if he/she were to participate in the study
* Life expectancy \< 12 weeks
* History of allergy or hypersensitivity to any of the study drugs
* Any significant medical condition, laboratory abnormality, or psychiatric illness
* Serious and/or uncontrolled preexisting medical condition
* Has had major surgery within 14 days prior to enrollment
* Has received an experimental treatment in a clinical trial within the last 30 days or 5 half-lives, whichever is longer, prior to enrollment, or is currently enrolled in any other type of medical research
* Has active systemic bacterial infection
* Personal history of any of the following conditions: syncope of cardiovascular etiology, ventricular arrhythmia of pathological origin (including, but not limited to, ventricular tachycardia and ventricular fibrillation), or sudden cardiac arrest

Where this trial is running

Belleville, New Jersey and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Breast CancerPre-op radiationCDK4/6 inhibitorsPositive/HER2 negative breast cancerAbemaciclibCombination of abemaciclib and radiationPost-menopausal womenNode-negative hormone-receptor positive/ human epidermal growth factor receptor 2
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.