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Cancer drug stuns doctors
16/05/2005 14:08 - (SA)
Orlando - Doctors were stunned when a drug they hoped would relieve the symptoms of a deadly blood disorder started treating the disease itself.
In nearly half of the people who took experimental drug Revlimid, the cancer became undetectable.
Specialists said Revlimid now looked like a breakthrough and the first effective treatment for many people with myelodysplastic syndrome, or MDS, which was even more common than leukaemia.
Dr David Johnson, a cancer specialist at Vanderbilt-Ingram Cancer Centre who was familiar with the research, but had no role in it said: "It may be, if not eradicating the disease, putting it into what I would call deep remission."
He said Revlimid "is not yet on the market, but almost certainly will be" because of these findings.
20 000 new cases in United States
MDS refered 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 were diagnosed each year in the United States alone.
People usually suffered anaemia and fatigue and need blood transfusions about every eight weeks to stay alive.
Dr Herman Kattlove, a blood disorder specialist at the American Cancer Society said: "It's a serious problem, it tends to occur in older people, and it's fatal for most."
Revlimid was similar to thalidomide, a drug notorious for the birth defects it caused decades ago, but that in recent years had proved effective against another blood cancer, multiple myeloma.
Researchers didn't really know how it worked other than that it boosted the immune system in a number of ways.
Chromosome abnormality 'causes the disease'
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 had the most common chromosome abnormality that caused the disease.
The study's leader, Dr Alan List of the H Lee Moffitt Cancer Centre in Tampa, Florida said after about six months on the drug, 66 percent no longer needed blood transfusions.
A year later, three-quarters of them still didn't need transfusions.
But, the big surprise was that signs of the genetic mutation fuelling the disease diminished in 81 patients and vanished in 51.
People with chronic myelogenous leukaemia
List said: "The chromosome abnormality completely disappeared, something we've never seen before" from a drug aimed just at boosting red blood cells.
Dr Bruce Johnson of the Dana-Farber Cancer Institute in Boston compared it to what doctors' saw in early tests of the drug Gleevec on people with chronic myelogenous leukaemia several years ago.
He said of the abnormality's disappearance: "If you extrapolate what they saw, it's one of the signs for long remission."
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.
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