BOSTON (Reuters) - Two major studies of Celgene Corp’s multiple myeloma drug Revlimid showed that when taken as maintenance therapy following stem cell transplantation it reduced the risk of disease progression by more than 50 percent.
According to preliminary data released ahead of the annual meeting of the American Society of Clinical Oncology, patients who took Revlimid on a continuous basis following a stem cell transplant kept their disease in check longer than those who took a placebo.
The data are important because they lend weight to the theory that giving patients Revlimid as a maintenance therapy, either after first receiving other drugs or after receiving a stem cell transplant, could improve outcomes.
Revlimid, known generically as lenalidomide, is already approved in combination with dexamethasone to treat patients with multiple myeloma who have received at least one prior treatment.
In one trial of 614 patients, known as IFM 2005-02, patients first underwent a stem cell transplant, then they received two cycles of Revlimid — about one a month. After that they either continued to take Revlimid, or were given a placebo.
After three years, almost twice as many patients — or 68 percent — in the Revlimid maintenance arm were able to keep their disease in check compared with 35 percent of patients in the placebo arm.
The results equate to a 54 percent reduction in overall risk of disease progression.
“Lenalidomide was shown to dramatically improve progression-free survival,” said Michel Attal, professor of hematology at Purpan Hospital in Toulouse, France, and lead author of the study, on a conference call with reporters.
Results from a similar trial led by the Cancer and Leukemia Group B (CALGB) showed a comparable reduction in the risk of disease progression. More than twice as many patients in the placebo arm saw their disease progress than in the Revlimid arm, according to a preliminary summary known as an abstract.
Of 418 patients in the trial, 29 patients on maintenance Revlimid had had their disease worsen, compared with 58 in the placebo arm. That equated to a reduction in risk of 58 percent.
“Both studies have information pointing in the same direction,” said Dr. Brian Durie, Chairman of International Myeloma Foundation, a non-profit patient advocacy group. “The medical community has been waiting for information on whether to put patients onto maintenance therapy once they have been transplanted. This may tip the balance where people say, here are two studies showing it is helpful.”
The outstanding question is whether a reduction in the risk of disease progression translates into an overall lower risk of death. Data from the IFM trial showed a similar death rate in the two arms of the trial. At 3 years, the overall survival rate for the Revlimid group was 88 percent, compared with 80 percent in the placebo group. After two years, overall survival was similar at 95 percent.
Attal said that could change over time.
“I would be surprised not to see an improvement in overall survival,” he said. “Each time we see a difference in progression-free survival it has been correlated over time with a difference in overall survival.”
Autologous blood stem cell transplantation is a procedure in which a patient’s own blood stem cells are removed, the patient is then treated with chemotherapy or radiation or both, and then the blood stem cells are put back into the patient.
Revlimid is a derivative of thalidomide, which is sold by Celgene as Thalomid. Revlimid is Celgene’s most important growth driver.
Reporting by Toni Clarke; editing by Carol Bishopric