The CDK4/6 Inhibitor Dosing Knowledge (CDK) Study (NCT06377852)
Comparing Oral Drug Dosing Strategies in Older Patients With Metastatic Breast Cancer to Maximize Tolerance and Reduce Discontinuation: The CDK4/6 Inhibitor Dosing Knowledge (CDK) Study
🩺 Plain-English Summary (8th-Grade Level)
The purpose of this study is to generate evidence on an alternative dosing strategy for CDK4/6 inhibitors to help more patients with Metastatic Breast Cancer (MBC) (age ≥ 65 years) tolerate side effects and stay on treatment longer, to derive the most clinical benefit from these drugs. The primary objective of the CDK Study is to compare time to treatment discontinuation (TTD) on the approved dosing for palbociclib (125 mg orally daily on days 1-21 of 28-day cycle) or ribociclib (600 mg orally daily on days 1-21 of 28-day cycle) vs. TTD using titrated dosing approach with the same schedule but starting at a lower dose of palbociclib (100 mg or 75 mg) or ribociclib (400 mg or 200 mg) and escalating the dose if well-tolerated in combination with provider/patient choice endocrine therapy (aromatase inhibitor (AI) or fulvestrant) in patients age 65 or older with HR+/HER2- MBC. The secondary and exploratory objectives will generate evidence needed to personalize treatment decisions by comparing patient-centric secondary outcomes and evaluating baseline factors. Together with their treating physician, participants will choose the CDK4/6 inhibitor (palbociclib or ribociclib) and which endocrine therapy (aromatase inhibitor or fulvestrant) of their choice but will be randomized to either Arm 1 (indicated dosing) or Arm 2 (titrated dosing). Note: Telehealth visits are allowed at any time per institutional guidelines. In addition, the study allows for remote consenting per institutional guidelines.
Who can join: Review the eligibility criteria below.
Location: Ironwood Cancer & Research Centers — Chandler, Arizona
Age range: 65 Years
🧪 Interventions in This Study
📋 "Do I Qualify?" — 1-Minute Self Screener
Instant ChecklistFull eligibility criteria are available on the official NIH protocol. View the criteria ↗
📍 All Participating Trial Locations (73 Sites)
Showing the first 25 of 73 sites.
- Ironwood Cancer & Research Centers — Chandler, Arizona
- Ironwood Cancer & Research Centers — Gilbert, Arizona
- Ironwood Cancer & Research Centers — Glendale, Arizona
- Ironwood Cancer & Research Centers — Goodyear, Arizona
- Ironwood Cancer & Research Centers — Mesa, Arizona
- Ironwood Cancer & Research Centers — Mesa, Arizona
- Ironwood Cancer & Research Centers — Phoenix, Arizona
- Ironwood Cancer & Research Centers — Scottsdale, Arizona
- University of Colorado Anschutz Medical Campus — Aurora, Colorado
- UCHealth Cherry Creek Medical Center — Denver, Colorado
- UCHealth Highlands Ranch Hospital — Highlands Ranch, Colorado
- Smilow Cancer Hospital Care Center - Derby — Derby, Connecticut
- Smilow Cancer Hospital Care Center - Fairfield — Fairfield, Connecticut
- Smilow Cancer Hospital at Glastonbury — Glastonbury, Connecticut
- Smilow Cancer Hospital Care Center - Greenwich — Greenwich, Connecticut
- Smilow Cancer Hospital Care Center - Guilford — Guilford, Connecticut
- Smilow Cancer Hospital at Saint Francis — Hartford, Connecticut
- Smilow Cancer Hospital - Yale New Haven Health — New Haven, Connecticut
- Yale University/Yale Cancer Center/Yale School of Medicine — New Haven, Connecticut
- Smilow Cancer Hospital Care Center - North Haven — North Haven, Connecticut
- Smilow Cancer Hospital Care Center - Torrington — Torrington, Connecticut
- Smilow Cancer Hospital Care Center - Trumbull — Trumbull, Connecticut
- Smilow Cancer Hospital Care Center - Waterbury — Waterbury, Connecticut
- Smilow Cancer Hospital - Waterford — Waterford, Connecticut
- Miami Cancer Institute — Miami, Florida
📞 Contact the Study Coordinator
Phone: (571) 483-1300
Email: CDKstudy@asco.org
Coordinator details come directly from the registered NIH protocol. Confirm the study is still recruiting before traveling.
💰 Cost, Insurance & Patient Rights
- 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
- Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
- Voluntary Participation: You may withdraw at any time without affecting your standard medical care.
More studies in Metastatic Breast Cancer
- Assessing the Time Demands of Cancer — Birmingham, Alabama
- Niraparib in Combination With Trastuzumab in Metastatic HER2+ Breast Cancer — Birmingham, Alabama
- A Phase 1b Study of T-DXd Combinations in HER2-low Advanced or Metastatic Breast Cancer — Commack, New York
- Palbociclib With Fulvestrant for Metastatic Breast Cancer After Treatment With Palbociclib and an Aromatase Inhibitor — Washington D.C., District of Columbia
- A Study of Abemaciclib (LY2835219) Plus Tamoxifen or Abemaciclib Alone in Women With Metastatic Breast Cancer — Tucson, Arizona
- Roll-over Study to Allow Continued Access to Ribociclib — Chandler, Arizona
Explore by condition: All Metastatic Breast Cancer clinical trials
💡 How to Participate
- Check the checklist above to see if you may qualify.
- Contact the study coordinator using the phone/email above.
- Ask about the visit schedule, what is covered at no cost, and any travel support.
- Confirm with your own doctor before making a decision.