enalidomide safe as single therapy for elderly CLL patients

Drug shows activity against chronic lymphocytic leukemia in clinical trial

SAN FRANCISCO, 09 dec 2008 ― The oral medication lenalidomide is safe and well-tolerated for elderly patients with chronic lymphocytic leukemia, a group without a well-defined frontline therapy for their disease, researchers from The University of Texas M. D. Anderson Cancer Center reported today at the 50th annual meeting of the American Society of Hematology.

"Lenalidomide has a favorable toxicity profile and shows signs of activity against CLL in our phase II clinical trial to date," said study presenter Alessandra Ferrajoli, M.D., associate professor in M. D. Anderson's Department of Leukemia.

Patients start on a 5 mg dose of the drug in pill form and the dose escalates over time in 5 mg increments to a maximum of 25 mg. The median age of participants is 72. Chemo-immunotherapy therapy combinations that are effective in younger patients with CLL tend to be associated with a high rate of complications in patients older than 70, Ferrajoli said.

Of 43 patients enrolled in the study, 35 were evaluable because they had been treated for at least three months. Nineteen of these (54 percent) achieved a partial response, where the disease is diminished, 14 patients (40 percent) had stable disease and continue on therapy, and two had their CLL progress.

Lenalidomide also rapidly reduced the number of circulating lymphocytes – the hallmark of the disease – in the patients' blood. Ferrajoli said 47 percent achieved a blood complete response and 38 percent had at least a partial response.

Patients on the trial for at least two months were evaluated for the drug's potential side effects. Of those 39 patients, 10 (26 percent) had decreased bone marrow activity resulting in a decrease in the number of either white blood cells called neutrophils or of platelets. Three patients had infections, two had fever and one had pneumonia.

All patients registered in the study remain alive with 37 of the 43 continuing on treatment. Ferrajoli said the trial will include up to 60 patients.

Lenalidomide, a drug developed by Celgene Corp. known commercially as Revlimid®, attacks both malignant cells and the cellular environment that nurtures them. The U.S. Food and Drug Administration has approved the drug for treatment of multiple myeloma and some forms of myelodysplastic syndrome.

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The clinical trial is funded by Celgene.

Co-authors with Ferrajoli are Susan O'Brien, M.D., William Wierda, M.D., Ph.D., Stefan Faderl, M.D., Zeev Estrov, M.D., Kimberly Yerrow, R.N., Hagop Kantarjian, M.D., and Michael Keating, M.D., all of the Department of Leukemia; and Steven Kornblau, M.D. of the Department of Stem Cell Transplantation and Cellular Therapy and the Department of Leukemia.