Drug combination slows progression of treatment resistant bone marrow cancer
Combining a newly formulated drug with one that is already a standard treatment slows the progression of multiple myeloma, an advanced cancer of the bone marrow cells, according to a clinical trial led by a University of North Carolina at Chapel Hill School of Medicine researcher.
The phase III trial included 646 patients from 18 countries with relapsed or refractory multiple myeloma, a condition in which cancerous cells continue to multiply despite treatment. Patients in the trial were randomly assigned to receive the drug bortezomib (Velcade), standard therapy for relapsed multiple myeloma, or a combination of Velcade and Doxil, a chemotherapy drug (doxorubicin) delivered via liposomes, or microscopic fat bubbles.
An interim analysis of study participants who received the combination treatment showed a better response in the combination group than in participants who received standard treatment. The combination group's median time to progression - the time interval between the response to treatment and the time the disease starts to show evidence of growing or recurring - was 9.3 months, while those on Velcade alone progressed after 6.5 months.
The three-month improvement is an important step forward in treatment for multiple myeloma, said Dr. Robert Orlowski, Lenvel Lee Rothrock associate professor in the department of hematology/oncology at the School of Medicine, and a member of the UNC Lineberger Comprehensive Cancer Center.
Orlowski presented the trial's early results on Monday (Dec. 11), at the meeting of the American Society of Hematology in Orlando, Fla. The study was supported by Johnson & Johnson, which owns Ortho Biotech, the maker of Doxil, and also has a financial interest in Velcade.
"The data for time to progression were so positive and encouraging that we decided to announce this information earlier than anticipated so more people could be aware of the benefits of this combination," said Orlowski.
"This study establishes that this combination is one of the standards of care for relapsed, refractory multiple myeloma," Orlowski said. "It does provide some added hope for patients and their families."
The interim analysis also showed an early trend toward increased survival for patients taking the combination treatment, Orlowski said. Additional data on survival and the complete results of this analysis, as well as other factors such as quality of life, will be reported at a later date.
More than 11,000 people in the United States will die of multiple myeloma in 2006, according to the American Cancer Society. Because it affects white blood cells, multiple myeloma suppresses the immune system, so patients can develop sometimes-fatal infections. Other complications include kidney failure, bone pain, anemia, and bleeding.
Doxil is a liposmal version of an older drug, doxorubicin, which means the drug is encapsulated in a microscopic pouch made of lipids, or fats. The formulation seems to produce fewer cardiac side effects and is more convenient to administer.
Orlowski and others first found that doxorubicin and Doxil may complement Velcade in studies of cells in culture, and of mice. "We've been able to take findings from the laboratory and move them on to patients in early, phase I clinical trials, and now in this phase III trial," Orlowski said. "It's an excellent example of how support of basic and translational laboratory research can, in a short time period, result in tangible benefits to patients."