Leukemia Drug Eyed for Kaposi's Sarcoma
Gleevec can shrink skin tumors linked to HIV/AIDS
FRIDAY, Feb. 11, 2005 (HealthDay News) -- New research suggests that a breakthrough leukemia drug could do double-duty as a treatment for Kaposi's sarcoma, a disfiguring disease that often strikes people with AIDS.
The findings, from a study of just 10 men, are preliminary. But if they hold up, the drug, known as Gleevec, could help patients with the most severe cases of the disease, said study co-author Dr. Henry B. Koon, an instructor of medicine at Beth Israel Deaconess Medical Center/Harvard Medical School, in Boston.
Indeed, the drug "could eventually be used in any Kaposi's sarcoma patient," Koon said. "That's our question now: Who is this treatment effective for? That's what we're trying to find out."
Kaposi's sarcoma, a type of cancer, is best known for causing severe lesions on the faces and skin of AIDS patients. Formerly an obscure disease striking mainly elderly men in the Mediterranean region, Kaposi's became more prevalent during the AIDS epidemic as it began to emerge in individuals with immune systems weakened by HIV.
The condition is rarer now in the U.S. because a new generation of drugs has made AIDS patients stronger and more resistant to disease. However, Kaposi's still affects some HIV-positive patients, especially those who were diagnosed late or haven't stuck with their AIDS drug regimens.
"Kaposi's sarcoma is still a stigma," Koon said. "It's disfiguring and a significant component of their HIV in terms of their quality of life."
Kaposi's sarcoma also remains a major problem in Africa and other areas of the world where proper AIDS treatment is scarce. In some cases, the cancer strikes internal organs and leads to death.
"It's not like a classical cancer that begins in one place and metastasizes," said Dr. Don Ganem, a professor of medicine at the University of California at San Francisco. "It occurs in multiple sites all over the body."
In many cases, doctors treat Kaposi's sarcoma by removing tumors, but they sometimes need to turn to chemotherapy. Even that doesn't always work, Ganem said.
In the new study, Koon and his colleagues studied 10 HIV-positive patients with Kaposi's sarcoma on their skin. All continued to remain ill with the disease despite treatment with chemotherapy, antiretroviral drugs or both.
The researchers treated the patients with Gleevec (imatinib mesylate), usually used to treat a rare blood cancer called chronic myeloid leukemia.
The findings appear in the Feb. 10 issue of the Journal of Clinical Oncology.
The Kaposi's sarcoma tumors shrank in five of the 10 patients, the researchers report. "Some of the responses were very rapid, within one to two weeks," Koon said. The major side effect was diarrhea, which caused six patients to reduce their doses.
Gleevec appears to work by targeting a signaling pathway that contributes to the growth of the tumors, he said.
The next Gleevec study will look at 25 patients, Koon said. For now, Gleevec is only federally approved for the treatment of leukemia, although doctors can use it for other purposes.
To learn more about Gleevec, try the U.S. Center for Drug Evaluation & Research.