Led by scientists at Johns Hopkins, researchers announced yesterday the first effective treatment for severe cases of sickle cell anemia.
The researchers stopped a national study involving 300 patients four months early so other patients could use the drug, hydroxyurea, which was proven to halve severe sickle cell's disabling attacks.
Two Baltimore men began taking the drug 12 years ago, under the direction of researchers at the Johns Hopkins University School of Medicine. They were among the first in the world to take hydroxyurea, a drug used to treat cancer and a rare blood disease, for sickle cell. Both men had spent most of their time in the hospital. But gradually their painful attacks lessened.
Now, the controlled national study has duplicated those results.
"Seeing something go from an idea in a test tube to the bedside -- this is a very gratifying moment," said Dr. George Dover, a pediatrician and professor at Hopkins medical school who has been researching sickle cell for 20 years.
Doctors say the inherited disease, which primarily affects African-Americans, shortens the lives of black patients by roughly 30 years, so most people with the disease die in their 40s.
Until now, people who suffered from severe cases of sickle cell had few options -- they either took pain medications or underwent blood transfusions. But the new study showed that daily doses of hydroxyurea reduced the frequency of painful episodes, hospitalizations, transfusions and a life-threatening chest syndrome by 50 percent.
But Dr. Samuel Charache, the study's lead investigator and a professor of medicine at Hopkins, cautioned that the drug is not a cure and that researchers do not know whether it can be used in children or pregnant women. Long-term side effects are unknown, and it is unclear whether hydroxyurea will be used for the majority of sickle cell patients, who have milder cases.
But for about 15 percent of the 72,000 Americans with sickle cell, including about 1,000 in the Baltimore area, the drug could slowly turn around lives. That is what happened for the two Baltimore men who volunteered to try the drug before much was known about it.
John Paul, 42, used to find himself in the hospital about 24 times a year. He tried hydroxyurea because he was willing to risk unknown side effects for a more normal life.
And gradually, his "crises" -- episodes of intense pain that can last hours or days -- struck further apart. One day he was in the emergency room and realized that he had not been there for three years.
William Thorn Jr., 57, has traveled as far as Venezuela and put together his social work career since he started using the drug. "I really started having a ball," he said.
Yet both men struggle, because hydroxyurea cannot repair damage from the disease, such as the degeneration of both men's hip joints.
While researchers know that the drug is stopping painful attacks and other complications, they do not know if hydroxyurea is slowing the organ damage caused by sickle cell.
But experts are calling the findings significant.
Dr. Duane Bonds, leader of the Sickle Cell Disease Scientific Research Group of the National Heart, Lung and Blood Institute, compared the results to the discovery of insulin for diabetes or penicillin for infections.
"This is the first drug that gets at the heart of what causes the sickle cell problem," said Dr. Bonds.
What happens inside the red blood cells of sickle cell patients is well-known: Molecules of sickle cell hemoglobin knock into each other and stick together, making blood cells rigid. That means instead of having the flexibility of balloons filled with water that can squeeze through tiny blood vessels and carry in needed oxygen, the red blood cells take on the shape of sickles and plug up the blood supply. Sometimes quietly, others with intense pain, the damaged cells kill tissues.
Researchers say hydroxyurea turns on a switch that stimulates the production of fetal hemoglobin, which interferes with the blood damaging process. Doctors say patients would take the drug daily, possibly for the rest of their lives, and must be closely monitored.
But some adult patients may face barriers. While the drug can be prescribed for sickle cell patients, it has not been approved by the Food and Drug Administration, so insurance companies may not pay for the drug, which costs about $100 a month.