New clinical trial to test novel approach to treat triple-negative breast cancer

ScienceDaily (June 2, 2011) — A multicenter clinical trial led by a researcher at the University of Maryland Marlene and Stewart Greenebaum Cancer Center will evaluate a new approach to treat triple-negative breast cancer, an often-aggressive type of cancer that is more common among African-Americans and young women. The study will help researchers determine if an experimental drug, entinostat, can reprogram tumor cells to express a protein called an estrogen receptor to make them sensitive to hormone therapy.

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Saranya Chumsri, M.D., an oncologist at the Greenebaum Cancer Center and assistant professor of medicine at the University of Maryland School of Medicine, is the principal investigator of the newly opened National Cancer Institute-funded study. The trial is based on laboratory studies by Angela H. Brodie, Ph.D., an internationally recognized University of Maryland breast cancer researcher, and her colleagues. Their research, recently published in the journal Cancer Research, found that entinostat can cause triple-negative breast cancer cells to become sensitive to a hormone therapy such as an aromatase inhibitor. Dr. Brodie pioneered the development of aromatase inhibitors, a class of breast cancer drugs that reduces the level of estrogen produced by the body, thereby cutting off the fuel to cancer cells.

In this Phase II trial, doctors will treat newly diagnosed postmenopausal patients with entinostat and an aromatase inhibitor called anastrozole (Arimidex) before they have surgery to remove their cancer. Researchers will analyze tissue from the tumor and blood samples to evaluate whether the treatment is effective. After surgery, patients will receive standard treatment, such as chemotherapy and radiation.

"We hope that entinostat will make the tumor cells more sensitive to the drug anastrozole, causing the tumor to shrink or, at the very least, stop growing," Dr. Chumsri says. "For patients with triple-negative breast cancer, chemotherapy is currently the only drug treatment option, and it has a lot of side effects compared to hormone therapies like anastrozole."

Triple-negative breast cancer is unique in that it lacks three common receptors in the cell -- estrogen, progesterone or human epidermal growth factor 2 (HER2), which are the targets of drugs widely used today to treat breast cancer. As a result, this cancer can be very difficult to treat; it doesn't respond to therapies that target estrogen and progesterone receptors, such as tamoxifen (Nolvadex), fulvestrant (Faslodex) and aromatase inhibitors (Femara, Arimidex and Aromasin), or to HER2-targeted therapies such as trastuzumab (Herceptin) and lapatinib (Tykerb).

About 15 to 20 percent of breast cancers are triple-negative. For unknown reasons, there is a higher prevalence of this type of breast cancer among African-Americans, young women and women with the BRCA1 gene mutation. African-American women are twice as likely as white women to have this type of cancer, which can be very aggressive and spread to other parts of the body, such as the lungs, liver and brain.

The clinical trial is based on laboratory studies by Dr. Brodie, a professor of pharmacology and experimental therapeutics, and Gauri J. Sabnis, Ph.D., an assistant professor of pharmacology and experimental therapeutics, at the University of Maryland School of Medicine, in collaboration with Saraswati Sukumar, M.S., Ph.D., a professor of oncology and pathology at the Johns Hopkins University School of Medicine. Their research showed that entinostat can sensitize triple-negative breast cancer cells to treatment with an aromatase inhibitor, and when combined with an aromatase inhibitor, also reduce the growth and spread of tumors in animal models.

"Adding to her long list of remarkable achievements, Dr. Brodie has continued her research into aromatase inhibitors, searching for ways to overcome tumors' resistance to treatment," says E. Albert Reece, M.D., Ph.D., M.B.A., vice president of medical affairs at the University of Maryland and dean of the University of Maryland School of Medicine. "This multicenter clinical trial led by Dr. Saranya Chumsri is an excellent example of how our scientists turn discoveries made in the lab into new treatments that may benefit patients."

Entinostat is an oral, selective histone deacetylase (HDAC) inhibitor. This anti-cancer agent is being developed by Syndax Pharmaceuticals, Inc., and is being investigated in other clinical studies for the treatment of advanced estrogen receptor-positive breast cancer, advanced non-small-cell lung cancer, advanced colorectal cancer and Hodgkin's lymphoma.

Triple-negative breast cancer patients in this clinical trial will take entinostat weekly and anastrozole once daily for two to four weeks while they are waiting to have surgery. Researchers will use blood tests and tissue analysis of tumors to evaluate the effectiveness of the combination therapy.

Researchers hope to enroll a total of 41 patients at 20 sites, including the University of Maryland Greenebaum Cancer Center. The centers involved in the study are affiliated with the University of Chicago Phase II study research consortium and the California Cancer Consortium.

Dr. Chumsri says that if the results of this trial are positive, researchers plan to launch a larger study to test the combination therapy on women whose cancer has metastasized to other parts of the body. "These women have limited treatment options. Hopefully, this treatment would give them a longer period in which their cancer is not progressing, with only minimal side effects compared to chemotherapy," she says.

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Results of international Phase III clinical trial for newly diagnosed brain tumors announced

ScienceDaily (May 18, 2011) — RTOG reports on the largest trial to-date for patients with newly diagnosed glioblastoma demonstrating the importance and feasibility of prospective molecular analysis of tumor tissue although finding that patients received no additional benefit from dose-intensive temozolomide as compared to standard adjuvant temozolomide after combined temozolomide and radiotherapy. The integration of tumor analysis with the clinical trial and international collaboration, major components of this unprecedented study, will significantly impact future trial design, ultimately leading to advances in patient care.

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In the randomized trial, RTOG 0525 Phase III Trial Comparing Conventional Adjuvant Temozolomide with Dose-Intensive Temozolomide in Patients with Newly Diagnosed Glioblastoma, no significant improvement in overall patient survival or disease progression was observed for patients who received the dose-intensive (dose-dense) TMZ plus radiotherapy as compared to patients who received standard-dose TMZ plus radiotherapy. The trial did however prove the feasibility of collecting and analyzing tumor tissue prospectively in a multi-center setting.. The international trial was led by RTOG principal investigator Mark R. Gilbert, MD (University of Texas M. D. Anderson Cancer Center, Houston) and conducted in concert with the European Organization for Research and Treatment of Cancer (EORTC) and the North Central Cancer Treatment Group (NCCTG).

Four presentations will report study results at the 2011 American Society of Clinical Oncology (ASCO) Annual Meeting, June 3-7.

"Given the promising preliminary data of improved patient outcomes using an adjuvant dose-intensive schedule of temozolomide, the trial allowed us to robustly test whether this treatment strategy provides a significant benefit over standard-dose temozolomide treatment," says Gilbert. "While dose-dense temozolomide did not demonstrate improved efficacy for patients newly diagnosed with a glioblastoma, the study results confirmed the prognostic significance of MGMT gene methylation and demonstrated the feasibility of prospective tumor tissue collection, molecular stratification and collection of patient outcomes in a large transatlantic intergroup trial."

One hundred and eighty-five facilities in North America and 24 facilities in Europe enrolled 1173 study participants. Key study eligibility criteria required that tumor tissue, obtained at the time of biopsy or surgery and with patient consent, be sent for central pathology review to confirm the tumor as a glioblastoma and as adequate to perform MGMT gene methylation analysis and molecular risk classification (to assess whether a correlation exists between these biomarkers and study participant outcomes).

Upon pathology confirmation, eligible patients were enrolled in the trial and randomized into one of two adjuvant treatment arms: Arm 1 (standard arm: TMZ days 1-5 every 28 days for up to 12 cycles/months) or Arm 2 (experimental arm: TMZ days 1-21 every 28 days for up to 12 cycles/months).

Study participants were stratified to assess correlation of their outcome with three major criteria: (1) prognostic recursive partitioning (based upon age, performance status, extent of pretreatment surgery, neurologic function and mental status), (2) MGMT status (methylated, unmethylated, or indeterminate) and (3) radiation therapy treatment (US standard vs European).

Trial co-chair for neuropathology and correlative biology Kenneth D. Aldape, MD (M.D. Anderson Cancer Center, Houston), comments, "In this trial we've demonstrated the positive correlation between clinical outcomes and molecular classification of glioblastoma, which will enable improved future prognostic prediction, spur the development of specific therapies based on tumor biology, and ultimately lead to individualization of treatment." Aldape will present findings of the tumor tissue profiling at the 2011 ASCO Annual Meeting.

"This trial was a tremendous undertaking with the complexities of confirming the presence of the MGMT gene as an eligibility criteria -- the first time a molecular marker has been used in this manner -- and of conducting the trial internationally," says RTOG Group Chair Walter J. Curran, MD, FACR,(Winship Cancer Institute of Emory University, Atlanta). "The collaboration with EORTC and NCCTG significantly helped to expedite trial enrollment and consequentially to expediently report trial results."

The clinical trial also included longitudinal data collection to measure neurocognitive function, symptom burden and health-related quality of life, collectively called net clinical benefits. The important correlations of these measures with outcomes shown by the trial will also be reported at the ASCO meeting, along with seven presentations regarding other RTOG trials.

RTOG 0525 was supported by Award Number U10CA021661 from the National Cancer Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health. RTOG also received support from Merck to conduct this trial.

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