Matthew Goetz, M.D.

Study Co-Chair

Ciara O'Sullivan, M.B., B.Ch.

Study Co-Chair

Breast Cancer: PROMISE Study

A Prospective Study to evaluate the role of Tumor Sequencing in Women Receiving Palbociclib for Advanced Hormone Receptor (HR)-Positive, Breast Cancer (PROMISE), will open at all three Mayo Clinic campuses and is designed to further individualize treatment for patients with metastatic breast cancer. The PROMISE study combines drug treatment, blood and tumor sequencing, and the development of patient derived xenografts (PDX) for women with HR-positive, human epidermal growth factor receptor 2-negative (HER2-negative) metastatic breast cancer.

Endocrine resistance is common in breast cancer patients, and while the drug palbociclib in combination with endocrine therapy has provided substantial improvements in progression free survival in women with metastatic breast cancer, the majority of patients will experience disease progression. The PROMISE Study will use participants' biopsies to obtain detailed information regarding the genetic makeup of a tumor as well as the host (germline), with the goal of developing personalized treatment approaches to improve patient outcomes.

The PROMISE Study:

  • Obtains patient biopsies prior to the beginning of treatment, after 2 months of treatment and at disease progression
  • Extracts DNA and RNA from patient tumor biopsies for sequencing by TEMPUS
  • Identifies genetic alterations in germline and tumor DNA
  • Collects participants' blood samples prior to, during and at discontinuation of treatment to identify circulating tumor DNA (liquid biopsies)
  • Develops PDXs which will be used by Mayo investigators to study new drug therapies designed to overcome resistance to palbociclib


PROMISE Study investigators will recruit 250 subjects to be enrolled over 36 months and followed for at least 12 months after the close of enrollment.

Eligible participants:

  • Are at least 18 years of age
  • Female
  • Have been recommended first line endocrine treatment with palbociclib and letrozole for HR-positive, HER2-negative metastatic breast cancer or 2nd line therapy with palbociclib and fulvestrant (for women whose cancer progressed after first line endocrine treatment)
  • Willing to undergo a standard of care core biopsy of recurrent or metastatic breast cancer at baseline to document that the tumor is HR+ and HER2negative
  • Willing to undergo a mandatory research biopsy after 2 months of therapy and at disease progression (optional)

The results of participants' tumor and blood sequencing will be made available to patients and their healthcare providers. This information may assist treatment decisions going forward.


Patients and referring physicians can contact our PROMISE study chairs for more information:

You can also contact the Center for Individualized Medicine for information on other studies and trials.

Support this study

Generous donors and benefactors make this study possible. Your gift supports research in new treatments for breast cancer.

You can direct your gift to laboratory research, clinical care or genomic sequencing. Your support helps the PROMISE Study team develop new therapies for breast cancer.

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