THURSDAY, Jan. 9, 2014 (HealthDay News) -- A new combination of drugs might prolong life in certain older leukemia patients, a new study suggests.
The research, led by German scientists, included nearly 800 older people (average age 73) who had been diagnosed with chronic lymphocytic leukemia. CLL is a cancer of the blood and bone marrow, the tissue inside bones in which blood cells are created.
The study was published online Jan. 8 in the New England Journal of Medicine. Study participants -- none of whom had received treatment for their illness before the start of the research -- were randomly assigned to one of three groups.
One group received an oral medication called chlorambucil (also known by the brand name Leukeran), the standard chemotherapy drug for older patients with CLL.
The second group received chlorambucil plus a drug called rituximab (Rituxan). This drug has been used effectively in combination with other forms of chemotherapy for more than a decade to treat younger, fitter patients with CLL, an expert said.
The third group received chlorambucil plus a pricey new antibody drug called obinutuzumab. The rituximab and obinutuzumab were given intravenously.
The researchers, whose study was funded by the manufacturer of both obinutuzumab and rituximab, reported that the obinutuzumab-chlorambucil combination improved outcomes for the older CLL patients better than the other two treatment options.
The most common side effects for obinutuzumab are infusion reactions, low blood cell counts, fever, cough and musculoskeletal disorders, according to the manufacturer Genentech's website.
The drug isn't cheap either: According to Genentech, which markets obinutuzumab under the brand name Gazyva, the medicine costs about $41,300 for a six-month course of treatment.
Dr. William Wierda, a professor in the department of leukemia at the University of Texas MD Anderson Cancer Center, said older patients don't tend to tolerate intensive chemotherapy with rituximab as well as younger patients. That has left older CLL patients with limited drug options, including chlorambucil, he said.
"We've been wanting to find a treatment that is effective and well tolerated in the elderly population," said Wierda, who was not involved with the new research. "A standard treatment for older patients with CLL has been chlorambucil, a type of chemotherapy that's been used for many years."
"The trial shows improvement in outcome remission rates and duration favoring patients who got chlorambucil and obinutuzumab," he said. "This was a head-to-head comparison of the two antibody arms of the study -- the rituximab and the obinutuzumab -- and obinutuzumab won out."
There also was an improvement in overall survival among the patients who received the obinutuzumab-chlorambucil combination treatment versus those who received chlorambucil alone, Wierda said.
Leukemia strikes both men and women, and the cause is unknown. In 2013, there were nearly 16,000 new cases of CLL diagnosed in the United States, according to the American Cancer Society. Statistics from the U.S. National Cancer Institute show the five-year survival rate for CLL is about 83 percent.
Lee Greenberger, chief scientific officer of the Leukemia & Lymphoma Society, said, "Chronic lymphocytic leukemia has been an incurable disease that has typically manifested in patients who have a median age of 72."
Greenberger said elderly patients can't tolerate the most aggressive treatment therapies due to other health issues, so this study is good news.
"This focuses on a very significant improvement in therapy for elderly people with CLL," he said. "It could become the new standard of care for elderly patients. That's very exciting news for these patients."
Although the study results are positive, Greenberger cautioned that the new drug cocktail is not a cure. It only delays the progression of the disease.
"But there are many other therapies for CLL in development," Greenberger said. One drug in particular, called ibrutinib, which is currently in phase 3 drug trials, is showing great promise, he said.
Visit the American Cancer Society to learn more about chronic lymphocytic leukemia.
SOURCES: William Wierda, M.D., Ph.D., professor, department of leukemia, University of Texas MD Anderson Cancer Center, Houston; Lee Greenberger, Ph.D., chief scientific officer, Leukemia & Lymphoma Society; Jan. 8, 2014, New England Journal of Medicine, online
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