A two-prong approach combining ibrutinib and rituximab (Rituxin®) to treat aggressive chronic lymphocytic leukemia (CLL) produced profound responses with minor side effects in a Phase 2 clinical trial at the University of Texas MD Anderson Cancer Center.
Researchers presented the results today at the 54th annual meeting of the American Society of Hematology (ASH).
"This is a patient population with a great need for more targeted therapies," said Jan Burger, M.D., Ph.D., associate professor in MD Anderson's Department of Leukemia. Burger was lead author of the study.
"Many CLL patients, especially those with indolent or non-aggressive disease, do well on the standard treatment of chemotherapy and antibodies," he said. "But for a certain subset of high-risk patients, treatment often fails, and remissions, if they are achieved, are short."
According to the National Cancer Institute's Surveillance Epidemiology and End Results database, CLL is the most common type of adult leukemia in the United States. An estimated 16,000 new cases will be diagnosed this year, and about 4,600 people will die because of the disease. Median age of diagnosis is 72, and it is more common in men than women.
Although chemotherapy combinations have improved the cure rate for CLL, side effects often are severe. A sizeable number of CLL deaths are from secondary cancers caused by treatment.
Early studies showed potential
Ibrutinib, a tyrosine kinase inhibitor that thwarts B-cell receptor signaling, is a promising new targeted therapy for mature B-cell malignancies, including certain types of myeloma and lymphoma. It has been shown to be especially effective in CLL.
Over the past two years, Phase 1/2 trials at MD Anderson and other sites showed high-risk CLL patients responded as well as low-risk patients to ibrutinib. However, the response often is lessened because of persistent lymphocytosis, an increase in leukemia cells in the blood due to release of CLL cells from the tissues (lymph glands) into the blood stream. Rituximab, a well-established antibody, was added to capture the CLL cells in the blood and thereby accelerate and improve response.
"When we looked at how well the high-risk patients were doing on ibrutinib - even though it was a small number - we saw a great opportunity to find out if combining the two drugs would have a positive impact on these patients," Burger said.
Combination tolerated wellForty patients with high-risk CLL were enrolled in the study earlier this year. They received:
Preliminary results: 85 percent response rate
Of 20 patients evaluated for early response at three months, 17 achieved partial remission for an overall response rate of 85%. Three achieved partial remission with persistent lymphocytosis.
Interestingly, lymphocytosis peaked earlier and the duration was shorter than with ibrutinib alone.
Treatment was well tolerated, with 13 cases of grade 3 or grade 4 toxicities, including neutropenia, fatigue, pneumonia, insomnia and bone aches. Most side effects were unrelated and transient. Many patients reported improved overall health and quality of life after three cycles of treatment.
"Although this study has a short follow-up time, we are encouraged by the fact that the vast majority of patients are responding and are able to continue on treatment, Burger said.
Development of ibrutinib for CLL crucial
Researchers said these data, together with the previous Phase 1/2 studies, emphasize the need for rapid further development of ibrutinib for high-risk CLL patients.
Pharmacyclics, the company that is developing ibrutinib, is proceeding with a Phase 3 multi-center clinical trial, in which MD Anderson will participate. Additionally, MD Anderson researchers will conduct a follow-up study on their research in high-risk CLL patients.
Other research team members from MD Anderson's Department of Leukemia included Michael Keating, M.D.; William Wierda, M.D., Ph.D.; Julia Hoellenriegel, M.S.; Alessandra Ferrajoli, M.D.; Stefan Faderl, M.D.; Susan Lerner, M.S.; Gracy Zacharian; Hagop Kantarjian, M.D.; and Susan O'Brien, M.D. Also participating were Xuelin Huang, Ph.D., of the Department of Biostatistics at MD Anderson; and Danelle James, M.D. and Joseph Buggy, Ph.D., of Pharmacyclics, Inc, Sunnyvale, CA.
Support for the study was provided by Pharmacyclics and CLL Global Research Foundation.
About MD Anderson
The University of Texas MD Anderson Cancer Center in Houston ranks as one of the world's most respected centers focused on cancer patient care, research, education and prevention. MD Anderson is one of only 41 comprehensive cancer centers designated by the National Cancer Institute. For nine of the past 11 years, including 2012, MD Anderson has ranked No. 1 in cancer care in "America's Best Hospitals," a survey published annually in U.S. News & World Report.
Scott Merville | EurekAlert!
A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital
Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Physics and Astronomy
24.04.2017 | Materials Sciences
24.04.2017 | Life Sciences