Nose Spray, 'Hot' Spheres
May Transform Cancer Therapy
By Maggie Fox
Reuters Health
ATLANTA - From nose drops that fight a cancer common in AIDS patients to tiny radioactive spheres that fight liver tumors while sparing the organ, new treatments may transform the way cancer is attacked, researchers said Sunday.
They described promising but highly experimental new ways to attack cancer that organizers of an annual conference of the American Society of Clinical Oncology (ASCO) described as some of the most exciting research being presented at the meeting.
"This is a bit of visionary stuff," Dr. Derek Raghavan, chief of medical oncology at the University of Southern California, told a news conference.
Dr. Parkash Gill and colleagues at USC combined two newly fashionable approaches to cancer " charging up the immune system to attack cancerous cells while also starving the tumors by blocking them from growing blood vessels to feed themselves, a process called angiogenesis.
They used a drug made by Seattle-based Cytran Inc., a privately held company, called IM862. It combines two amino acids, the building block of proteins, that block angiogenesis and at the same time stimulate the immune system.
Gill said his team chose to test it on Kaposi's sarcoma because it is marked by the creation of many blood vessels. One of the diseases that marks AIDS, Kaposi's sarcoma causes red, raised lesions on the skin, so it is easy to see and monitor.
Because IM862 is such a small molecule it can be absorbed right through the mucus membranes, so Cytran formulated it as nose drops. Gill's team gave it to 44 patients at two sites in Los Angeles and Boston.
Thirty-six percent of the patients had their tumors either disappear or shrink by at least 50 percent, Gill said.
"I expect this compound will have action in other tumors but unless that has been proven you have to have great caution in making that claim," Gill said.
Nose drops are a much more convenient way to take a drug, he said. The drug might eventually be added to standard chemotherapy to allow doctors to reduce the dose and possible side effects, he added.
Reducing toxic effects was the goal of another study done by Guy van Hazel and colleagues at the University of Western Australia in Perth, who tested tiny radioactive spheres in people whose colon cancer had spread to the liver.
The SIR-Spheres, made by Paragon Medical Limited, contain radioactive yttrium-90 and were injected into the hepatic artery, from which liver tumors get 80 percent of their blood. Healthy liver cells get most of their blood from elsewhere, so the idea was to hit tumor cells and spare healthy ones.
Van Hazel's team took 74 patients and either gave them standard chemotherapy for liver cancer, or chemotherapy plus the spheres.
Although the effects were modest, they were encouraging, Van Hazel said. Fourteen percent of the patients who got the spheres had their tumors shrink as opposed to 9 percent who got chemotherapy alone.
After two years, 39 percent of patients who got the spheres were still alive, as opposed to 29 percent of patients given standard therapy. It looks like the people who got spheres might survive better as more time goes by, Van Hazel said.
"This gives us reason to believe we are on the right track," Raghavan said.
Researchers also told of an experiment that dramatically extends the lives of patients whose cancer has spread to the liver and which doctors can start using right away.
Dr. Nancy Kemeny of Memorial Sloan-Kettering Cancer Center in New York found that infusing drugs directly into the hepatic artery had a much stronger effect than the standard approach, which is to put the drugs into the general circulation.
She used a pump made by Reading, Pennsylvania-based Arrow International, which is surgically implanted into the patients.
After two years, 85 percent of the patients who got the direct liver infusion were alive and in most, 89 percent, the liver tumors disappeared. This compared to 69 percent of patients who got only the general treatment.
"Generally, most of my patients don't survive two years," Kemeny said. "For me, a study that has an 85 percent two-year-survival is very exciting."