New Hope: From the Clinic and Research Laboratory
Pelotonia funds support clinical and translational research with the goal of improving cancer care
BY DARRELL E. WARD
Clinical research” is research that involves patients, and it usually refers to clinical trials. “Translational research” encompasses studies that use genes, cells and animal models to solve problems related to medical treatment. The two types of investigation are closely linked: The ultimate goal of translational research is to apply the findings to humans in a clinical trial.
Pelotonia funds support both clinical and translational studies at the OSUCCC – James. We present an example of each below. The first is a clinical trial proposed by an OSUCCC – James physician researcher to evaluate a new drug for chronic lymphocytic leukemia (CLL). CLL is the most common form of leukemia in the nation, with about 15,000 new cases and 4,400 deaths occurring annually. It is currently incurable.
Second is an example of translational science by OSUCCC – James researchers working to improve the treatment of tamoxifen-resistant breast cancer.
A Clinical Trial That Met Two Needs
Ibrutinib is an experimental drug that works by inhibiting a chemical pathway that CLL cells need to survive. The drug was tested in phase I and phase II clinical trials at Ohio State and a few other centers with exciting results.
“Early ibrutinib trials indicated that the agent was highly active in CLL and well-tolerated by patients, with many durable responses and few serious side effects,” says Kami Maddocks, MD, assistant professor in the Division of Hematology and a CLL specialist.
The success of the early trials prompted Pharmacyclics, Inc., the biopharmaceutical company that developed the drug, to plan a phase III trial, which is needed for the drug to earn approval by the U.S. Food and Drug Administration.
Between the close of the early trials and the start of the phase III trial, however, the drug would be unavailable to those relapsed CLL patients. To cover that period, Maddocks proposed a new phase II trial to answer an important question while also making ibrutinib available to more patients. Maddocks worked with OSUCCC – James CLL specialist John C. Byrd, MD, director of the Division of Hematology, professor of Medicine, Medicinal Chemistry and Veterinary Biosciences, and the D. Warren Brown Designated Chair in Leukemia Research.
The new trial focused on patients with a particular cytogenetic abnormality in their CLL cells. Patients with this “17p deletion” don’t respond well to standard treatment. They have shorter remissions and a decreased survival. Maddocks’ trial would compare CLL patients with the deletion to patients without it.
“The company generously agreedto provide the drug for this trial, but we had to provide the funding for the trial,” Maddocks says. “That’s where the Pelotonia funds came in. They made this trial possible.”
Her trial – A Phase 2 Study of the Bruton’s Tyrosine Kinase Inhibitor, PCI-32765, in Relapsed and Refractory Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma and B-cell Prolymphocytic Leukemia – opened in May 2012. By March 2013, it had accrued 67 of the target 68 participants.
“This trial gave almost 70 more patients, many without any other treatment options, access to a drug that’s been very effective and that otherwise would not have been available during that time frame,” Maddocks says.
“Clearly, along with the important data it will provide, this trial has made a huge difference in the lives of several patients by making this drug available to them,” she says, “and Pelotonia funds played a huge part in our ability to open that trial here.”
From Research Bench to Patient Bedside
Breast cancer was expected to strike some 230,000 women in the United States in 2012 and to kill almost 40,000 of them. More than two-thirds of breast cancer cases show high levels of the estrogen receptor (ER).
Doctors treat these ER-positive tumors in part using the drug tamoxifen. “Tamoxifen has improved the disease-free survival of people with ER-positive breast cancer by 50 percent,” says OSUCCC – James breast cancer specialist and medical oncologist Bhuvana Ramaswamy, MD, “but 30 to 40 percent of patients who take tamoxifen become resistant to it after about five years.
“Currently, treatment options for patients with tamoxifen-resistant breast cancer are very limited, and most end up receiving chemotherapy, which can have
significant side effects,” she says. But Pelotonia funds are supporting work by Ramaswamy and collaborator Sarmila Majumder, PhD, research assistant professor in the Department of Molecular and Cellular Biochemistry at Ohio State, to better understand tamoxifen-resistant breast cancers and to develop targeted therapies that effectively treat them.
In 2012, Ramaswamy, Majumder and a group of colleagues published findings in the journal Cancer Research showing how tamoxifen-resistant breast-cancer cells grow and proliferate. They also identified an experimental agent that might offer a new therapy for these tumors.
Cells transmit signals from the outside world to the inside of the cell using biochemical pathways. When estrogen contacts an ER-positive cancer cell, it activates a particular pathway that causes the cells to proliferate.
Majumder and Ramaswamy discovered that when tamoxifen shuts down the pathway activated by estrogen, a different pathway, called hedgehog (Hhg), takes over. When the Hhg pathway turns on, tamoxifen therapy stops working, and the tumor grows in spite of it. Another signaling pathway, called PI3K/AKT, is also involved.
By analyzing more than 300 human tumors, the researchers also learned that patients with an active Hhg pathway in their tumor cells had worse outcomes.
Finally, Majumder, Ramaswamy and colleagues showed that an experimental drug called vismodegib, which blocks the Hhg pathway, inhibits the growth of tamoxifen-resistant human breast tumors in an animal model. The drug is in clinical trials testing for other types of cancer.
“Using this drug to target the hedgehog pathway alone or in combination with the PI3K/AKT pathway could be a novel therapeutic option for treating tamoxifen-resistant breast cancer,” says Majumder.
With this body of laboratory and animal evidence in hand, Ramaswamy and Majumder are preparing to complete the translational-research circle. “We now want to organize a clinical trial to evaluate vismodegib in patients with tamoxifen-resistant breast cancer,” Ramaswamy says.
The researchers are working with the National Cancer Institute (NCI) to design a clinical trial using the hedgehog inhibitor in patients with tumors resistant to hormone therapies such as tamoxifen, aromatase inhibitors and faslodex.
“Pelotonia funding helped support many of our laboratory and preclinical studies,” Ramaswamy notes. “Now we are using Pelotonia funds to study this target in triple-negative breast cancer (TNBC).” TNBC typically strikes younger women and has few treatment options and poor outcomes.
“Pelotonia support has been crucial in helping us understand this potential therapy, first in estrogen-resistant patients, and now Pelotonia funds are helping us obtain the data and translate the findings for a clinical trial in triple-negative breast cancer.”