New Drug May Help Fight Rare Bone Marrow Disorder
While the drug, marketed in the United States under the brand name Jakafi, won't cure myelofibrosis, it can help ease symptoms, improve quality of life, and possibly improve survival according to the studies.
"This is probably the most thrilling development I have seen in my career. The drug delivers rapid, durable benefit which makes a great difference to patients' lives," said the lead author of one of the studies, Dr. Claire Harrison, a consultant hematologist at Guy's Hospital in London.
And, the lead author of the other study, Dr. Srdan Verstovsek, an associate professor in the leukemia department at the M.D. Anderson Cancer Center in Houston, said his team's study "shows that ruxolitinib provides a significant durable clinical benefit in terms of spleen-size reduction and myelofibrosis-related symptom improvement that leads to an overall survival benefit."
Results of both studies are published in the March 1 issue of the New England Journal of Medicine.
Verstovsek's study was funded by Incyte, the manufacturer of Jakafi, which was approved by the U.S. Food and Drug Administration in November 2011. Harrison's study was funded by Novartis, the company that will market the drug outside the United States. The drug is not currently approved in Europe.
The drug is expensive, costing about $84,000 a year.
Myelofibrosis is a bone marrow disorder that causes scar tissue to develop in the place of bone marrow. When the bone marrow becomes scarred, it can't produce enough blood cells any more. This causes a number of problems including an enlarged spleen, a feeling of fullness, bone pain, bruising, easy bleeding, tiredness and shortness of breath when exercising, according to the U.S. National Library of Medicine.
Estimates of the prevalence of myelofibrosis in the United States vary, but one study from the Mayo Clinic calculates that about 30,000 Americans have the disorder.
There is no specific treatment approved to cure myelofibrosis, though bone marrow transplants may be successful, according to Dr. Alan Astrow, director of hematology and medical oncology at the Maimonides Medical Center in New York City.
But, for those who don't qualify for a bone marrow transplant, treatment is directed to relieving symptoms, such as blood transfusions to help relieve fatigue, excessive bleeding and shortness of breath.
Verstovsek's study included 299 people with myelofibrosis defined as intermediate-2 or high-risk myelofibrosis, a group that represents about 80 percent of people with myelofibrosis, according to the author. Half the group was randomly chosen to receive ruxolitinib twice daily, while the other half was given an inactive "placebo" twice daily.
Almost 42 percent of those on ruxolitinib had a significant reduction in the size of their spleens at 24 weeks of therapy, compared with less than 1 percent of the group receiving the placebo. About 46 percent receiving the drug reported a significant reduction in their symptoms versus about 5 percent of those on placebo, according to Verstovsek's study.
His team also found the risk of death during the study was decreased by 50 percent for those taking the medication.
Harrison's study included 219 people with the same level of myelofibrosis. Of those, 146 people were randomly chosen to receive ruxolitinib and 73 were given standard treatments to relieve symptoms.
After 48 weeks, 28 percent of those on ruxolitinib had a significant reduction in their spleen size, while no one in the standard treatment therapy achieved this goal. Those in the ruxolitinib group reported more symptom relief and better quality of life than those receiving usual care, according to the study. Harrison's study didn't find an effect on overall survival.
The drug appeared to be well tolerated in both studies, and both study authors agreed that the benefits of the medication outweighed any potential risks.
Maimonides' director Astrow said, "Ruxolitinib appears to be useful for patients who have symptoms related to large spleens, who aren't candidates for bone marrow transplant. This drug appears to be effective in significantly reducing the size of the spleen and in helping patients feel better. Their appetites improved, they had less pain and they had more energy. Overall, the results seem to show improved quality of life. But, it's not a cure," he added.
"We hope this is a first step toward improved treatment for people with this disease that currently has no curative therapy aside from allogeneic bone marrow transplants for some patients," Astrow said.
The wholesale cost of Jakafi in the United States is about $7,000 a month, according to Incyte, the drug's manufacturer. Astrow said that once someone is on this medication, they generally stay on it. He said if the drug is stopped, symptoms often return, sometimes "suddenly and severely."
Learn more about myelofibrosis from the U.S. National Library of Medicine.
Posted: February 2012
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