ORLANDO, Fla. - No one could have been more surprised than the doctors themselves. They were just hoping to relieve the symptoms of a deadly blood disorder — and ended up treating the disease itself. In nearly half of the people who took the experimental drug, the cancer became undetectable.
Specialists said Revlimid now looks like a breakthrough and the first effective treatment for many people with myelodysplastic syndrome, or MDS, which is even more common than leukemia.
"It may be, if not eradicating the disease, putting it into what I would call deep remission," said Dr. David Johnson, a cancer specialist at Vanderbilt-Ingram Cancer Center who is familiar with but had no role in the research.
Revlimid "is not yet on the market but almost certainly will be" because of these findings, he said.
MDS refers to a group of disorders caused by the bone marrow not making enough healthy, mature blood cells. About 15,000 to 20,000 new cases are diagnosed each year in the United States, and as many as 50,000 Americans have it now. They usually suffer anemia and fatigue and need blood transfusions about every eight weeks to stay alive.
"It's a serious problem, it tends to occur in older people, and it's fatal for most," said Dr. Herman Kattlove, a blood disorder specialist at the
American Cancer Society.
Revlimid is similar to thalidomide, a drug notorious for the birth defects it caused decades ago but that in recent years has proved effective against another blood cancer, multiple myeloma. Researchers don't really know how it works other than that it boosts the immune system in a number of ways.
In small studies, Revlimid also showed promise and with far fewer side effects. In a new study, doctors tested it on 115 people with MDS who have the most common chromosome abnormality that causes the disease.
After about six months on the drug, 66 percent no longer needed blood transfusions, said the study's leader, Dr. Alan List of the H. Lee Moffitt Cancer Center in Tampa, Fla. A year later, three-fourths of them still don't need transfusions.
But the big surprise was that signs of the genetic mutation fueling the disease diminished in 81 patients and vanished in 51.
"The chromosome abnormality completely disappeared, something we've never seen before" from a drug aimed just at boosting red blood cells, List said.
Dr. Bruce Johnson of the Dana-Farber Cancer Institute in Boston compared it with what doctors saw in early tests of the drug Gleevec on people with chronic myelogenous leukemia several years ago.
"If you extrapolate what they saw, it's one of the signs for long remission," he said of the abnormality's disappearance.
Dr. Jasmine Zain, a blood specialist from the City of Hope Cancer Center in New York, said the results warrant further testing on the drug.
"Nowhere do you see 60 to 70 percent responses," she said.
About one-third of people on the drug had temporary drops in other blood cells and clotting components, fixed by briefly interrupting treatment or lowering the dose.
The study was sponsored by Celgene Corp., which makes Revlimid. List is a consultant for the company and reported results Sunday at a meeting of the
American Society of Clinical Oncology in Orlando.