Why some ER-positive breast cancers stop responding to CDK4/6 inhibitor drugs

Regulation of resistance to CDK4/6 inhibitor in breast cancer

NIH-funded research George Washington University · NIH-11284101

This project looks at whether a protein sugar tag called O-GlcNAcylation helps ER-positive breast cancers stop responding to CDK4/6 inhibitor drugs and aims to find ways to restore drug sensitivity.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionGeorge Washington University NIH-funded
Lab location1 site (Washington, United States)
Project IDNIH-11284101 on NIH RePORTER

What this research studies

Researchers will use high-throughput drug combination screens and lab models of ER-positive (hormone receptor–positive) breast cancer to pinpoint how cells become resistant to CDK4/6 inhibitors. They focus on an enzyme called OGT that adds O-GlcNAc sugar tags to proteins and will study how this modification changes cancer cell behavior and drug response. Work includes detailed molecular experiments in cell lines and follow-up tests of promising drug combinations that reverse resistance. If human tumor samples are used, findings could help guide future clinical trials to test new combination treatments for patients whose tumors stopped responding.

Who could benefit from this research

Good fit: Patients with ER-positive (hormone receptor–positive) advanced or metastatic breast cancer who have received CDK4/6 inhibitors and experienced primary or acquired resistance would be the most relevant candidates.

Not a fit: Patients with non–ER-positive breast cancers (for example triple-negative disease), those not treated with CDK4/6 inhibitors, or whose tumors have different resistance mechanisms may not benefit from findings focused on O-GlcNAcylation.

Why it matters

Potential benefit: Could lead to new combination therapies that help patients with ER-positive breast cancer overcome resistance to CDK4/6 inhibitors.

How similar studies have performed: CDK4/6 inhibitors are already standard for ER-positive advanced breast cancer but resistance is common; targeting O-GlcNAcylation is a relatively new approach with limited prior clinical validation.

Where this research is happening

Washington, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Conditions Breast CancerBreast Cancer CellBreast Cancer PatientCancer BiologyCancers
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.