Medroxyprogesterone acetate (MPA) was used for many years in women whose cancer was fueled by estrogen production. This type of breast cancer is referred to as hormone receptor positive (HR +). Recent laboratory studies suggested MPA may be effective in treating patients who are hormone receptor negative (HR-) meaning estrogen does not make their breast cancer grow. This phase II trial was conducted to evaluate the activity of MPA alone or in combination with low-dose chemotherapy in patients with metastatic, hormone receptor negative (HR-) breast cancer.
Translational Breast Cancer Research Consortium (TBCRC)
- Dana-Farber/ Harvard Cancer Center
- Duke University Medical Cancer Center
- Indiana University Simon Cancer Center
- University of Alabama, Birmingham
- University of California, San Francisco
- University of North Carolina, Chapel Hill
Date First Site Activated: September, 2006
Date Trial Closed to Enrollment: July, 2010
- Hormone Receptor negative (HR-)
- No more than three prior chemotherapy regimens for metastatic disease
- ECOG Performance status < 2
- Adequate organ function
- No blood clot within the last 12 months
- No extensive fluid in the chest or abdomen
- Eligible women were assigned as follows:
- Group 1 - MPA alone group
- Group 2 - MPA with low-dose chemotherapy group
- Each group would initially enroll 15 patients.
- If less than two of the 15 patients had clinical benefit, that group would close.
- If 2 or more patients had clinical benefit, an additional 10 patients would be enrolled to that group.
- Blood samples and skin biopsies were collected to measure MPA concentration and the effect of MPA on markers of metastasis and blood vessel growth
- 30 patients were enrolled.
- 14 were treated with MPA alone
- 16 were treated with MPA in combination with low-dose chemotherapy.
- There were no measurable responses in either group.
- Five patients had stable disease but disease control was maintained for > 6 months in only 2 patients.
- The MPA concentration achieved in our study was much less than anticipated and in most patients was less than the levels needed for activity based on the laboratory studies.
- The markers of metastasis and new blood vessel formation didn’t change consistently.
- MPA monotherapy had little clinical or biologic activity in patients with advanced HR-negative (HR-) metastatic breast cancer in this study.
- Despite real-time assessment of MPA through concentration and mid-cycle dose increase, few patients reached concentrations in the potentially therapeutic range.
- Though MPA will not continue in clinical trials, lessons from this trial will impact the design of future studies.
Vaughn,L.G., Li, L., Nabell, L., Rugo, H.S., Carey, L.A., Kimmick, G.G., Steeg, P.S., Miller, K. A phase II study of medroxyprogesterone acetate (MPA) in patients (pts) with hormone receptor-negative (HR-) metastatic breast cancer (MBC): Translational Breast Cancer Research Consortium trial 007. 2010 ASCO, Poster, Abstract #1074.
Miller,K.D., Althouse,S.K., Nabell, L., Rugo, H., Carey, L., Kimmick,G., Jones, D.R., Merino, M.J., Steeg, P.S. A Phase II Study of Medroxyprogesterone Acetate in Patients with Hormone Receptor Negative Metastatic Breast Cancer: Translational Breast Cancer Research Consortium Trial 007. Breast Cancer Res Treat 148 (1): 2014.
*This summary was reviewed by: Kathy Miller, M.D. This summary was also reviewed and approved by the members of the TBCRC Patient Advocate Working Group.