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Joshua Donaldson, MD, PhD

Oncology Fellow
Sidney Kimmel Comprehensive Cancer Center
Johns Hopkins University
Baltimore, Maryland
Conquer Cancer Foundation of ASCO

Current Research

  • Seeking to identify mechanisms of resistance to CDK4/6 inhibitor therapy and devise ways to improve patient response to this therapy.

  • Genetic screening is conducted in laboratory models to identify genetic-mediators of resistance to palbociclib.

  • Results from this study may improve the ability to identify patients who may become resistant to therapy and ways to overcome that resistance.

The majority of breast cancers require estrogen for growth. These cancers, called estrogen receptor (ER)-positive, are treatable with anti-estrogen therapies. In spite of this, many patients will experiene a recurrence or metastasis, sometimes many years after “successful” therapy.

Metasasis is an incurable but treatable disease. A new class of targeted drugs called CDK4/6 inhibitors have shown promise in extending the lives of patients with ER-positive metastatic breast cancer. However, as with other cancer therapies, these tumors inevitably become resistant to these drugs.

Understanding the specific mechanisms involved in resistance to CDK4/6 inhibitors will greatly improve their effectiveness and allow more patients to benefit.

Dr. Donaldson is conducting state of the art genetic screening in laboratory models of ER-postive breast cancer to identify genes that may be driving both acquired and inherent resistance to palbociclib.   Future studies are planned to validate his findings in tumor tissue and blood from patients enrolled in clinical trials with palbociclib.

The results from these studies will lead to new methods in selecting patients who will respond to new therapies, and in targeting pathways that lead to resistance.

Dr. Donaldson is conducting thes studies under the mentorship of BCRF investigator, Ben Ho Park


Dr. Joshua Donaldson is an oncology fellow at Johns Hopkins University, where his research focuses on targeted therapy for breast cancer. After graduating summa cum laude from The College of New Jersey, Dr. Donaldson completed his MD/PhD at Thomas Jefferson University. His thesis was mentored by Dr. John Williams and involved developing antibody prodrugs to reduce on-target, off-tumor effects to improve therapeutic index. Dr. Donaldson completed his internal medicine residency at Thomas Jefferson University Hospitals. His current research is mentored by Dr. Ben Park, and relates to translating the genetic data available for breast cancers into clinically relevant hypotheses aimed at tailoring therapy to improve response and address resistance.

BCRF Investigator Since


Area(s) of Focus