๐Ÿ›๏ธ Verified NIH Record โ€ข Updated 2026-08-05

Determinants of Resistance to Endocrine Therapy and a Cyclin-dependent Kinases 4 and 6 (CDK4/6) Inhibitor for HR+ MBC (NCT03439735)

Prospective Evaluation of Determinants of Resistance to Endocrine Therapy and a Cyclin-dependent Kinases 4 and 6 (CDK4/6) Inhibitor in Hormone Receptor (HR) Positive Metastatic Breast Cancer (MBC)

๐Ÿ”ต Active, Not Recruiting Phase2 ๐Ÿ’Š Investigational Drug / Biologic Sponsor: Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins

๐Ÿฉบ Plain-English Summary (8th-Grade Level)

The goal of this research study is to determine if the investigators can predict which participants will respond to endocrine therapy and a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor for metastatic breast cancer and which participants will not. Investigators will use information from the tumor tissue and serial blood samples. Investigators hope that a deeper understanding of which participants will respond to this combination and how resistance emerges will allow the investigators to better tailor therapies for metastatic breast cancer. Subjects will have archived tissue or new biopsy collected at study enrollment. This tissue will undergo special molecular testing. Subjects will also have blood collected at study enrollment and periodically thereafter. This blood will also undergo special molecular testing. Information from this testing will not be available to subjects or their treating physicians as the investigators do not know how this information should impact treatment. The investigators will collect information about which treatment the subjects receive and how their cancer responds. Any man or woman being seen at Johns Hopkins for treatment of newly diagnosed estrogen receptor positive (ER+) and/or progesterone receptor positive (PR+) metastatic breast cancer may be eligible.

Who can join: Review the eligibility criteria below.

Location: Johns Hopkins University โ€” Baltimore, Maryland

Age range: 18 Years to 100 Years

๐Ÿ“‹ "Do I Qualify?" โ€” 1-Minute Self Screener

Instant Checklist

Full eligibility criteria are available on the official NIH protocol. View the criteria โ†—

๐Ÿ“ All Participating Trial Locations (1 Sites)

  • Johns Hopkins University โ€” Baltimore, Maryland

๐Ÿ“ž Contact the Study Coordinator

Phone: (855) 694-6725

Coordinator details come directly from the registered NIH protocol. Confirm the study is still recruiting before traveling.

๐Ÿ’ฐ 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 ยง 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.

Explore by condition: All Breast Cancer clinical trials

๐Ÿ’ก How to Participate

  1. Check the checklist above to see if you may qualify.
  2. Contact the study coordinator using the phone/email above.
  3. Ask about the visit schedule, what is covered at no cost, and any travel support.
  4. Confirm with your own doctor before making a decision.
๐Ÿ›๏ธ View Official NIH Record โ†—