Randomized trial of two therapies for acute lymphocytic leukemia finds survival advantage


Orlando, May 16, 2005 -- A prospective, randomized trial comparing a novel regimen with a standard treatment for adult patients with acute lymphocytic leukemia (ALL) showed a distinct advantage that continued to show superior results at three-, four-, and five-year intervals in the investigational arm of the trial. The drugs were given as induction therapy, an initial chemotherapy treatment with the goal of putting a patient's leukemia into complete remission. Patients who received the investigational regimen, comprised of cytarabine with high-dose mitoxantrone, also experienced a higher frequency of complete remission compared with patients on a standard, vincristine plus prednisone-based regimen. Mark A. Weiss, MD, a leukemia specialist at Memorial Sloan-Kettering Cancer Center and lead author of the eight-year, multicenter study, presented the study results today at the annual meeting of the American Society for Clinical Oncology.

"There have been very few randomized trials in adult ALL. This is probably the first study in 20 years that focuses on induction therapy, and it appears to show that one treatment is superior to another in putting the disease in remission," explained Dr. Weiss. "Although the survival rates for these patients were initially similar in both arms, the results diverged after two years. Patients treated with cytarabine plus high-dose mitoxantrone appeared to have a survival advantage at three, four, and five years. The difference in survival rates seemed even more pronounced for the subset of ALL patients with the Philadelphia chromosome, a genetic predisposition that makes the disease more difficult to treat," he said.

The trial looked at two regimens to be used as induction therapy. One hundred and sixty-four patients with ALL, who were able to participate in the trial, were randomized to receive either a standard regimen (L-20) of vincristine, prednisone, cyclophosphamide, and doxorubicin or the ALL-2 regimen of cytarabine with high-dose mitoxantrone. After 24 months of treatment, 83 percent of the 78 patients who received the ALL-2 regimen achieved a complete remission versus 71 percent of the 86 patients on L-20. Median survival rates were comparable at 24 months for ALL-2 treated patients versus 22 months for patients treated with L-20.

However, the survival curve begins to show a change after patients undergo two years on the trial. This trend continues through five years following initiation of treatment.

  • After three years, 45 percent of the ALL-2 patients were alive versus 33 percent of the L-20 patients.
  • After four years, 35 percent of the ALL-2 patients were alive versus 24 percent of the L-20 patients.
  • After five years, 34 percent of the ALL-2 patients were alive versus 21 percent of the L-20 patients.

Therapy with the ALL-2 regimen also resulted in superior outcomes for the 30 ALL patients with the Philadelphia chromosome. It improved the frequency of complete remission and also appeared to result in superior survival rates after six years. Eighty-five percent of the patients with the Philadelphia chromosome on ALL-2 achieved a complete remission compared with 47 percent of patients on L-20. The six-year survival rate for patients with the Philadelphia chromosome was 26 percent for the ALL-2 patients, with no patients alive after six years on the other regimen.

In addition to Dr. Weiss, members of the ALL-4 Consortium, comprised of physicians from Memorial Sloan-Kettering Cancer Center, the Cleveland Clinic Foundation, Duke University Medical Center, Emory University Medical Center, the University of California, Los Angeles, the Stanford University Medical Center, and Westchester Medical Center participated in this study. The study was funded, in part, by grants from Victoria's Smile Foundation, Immunex (Amgen), Rhone-Poulenc (Sanofi-Aventis), Berlex, and OSI Pharmaceuticals.

Acute lymphocytic leukemia (also called acute lymphoblastic leukemia) is the most common type of leukemia found in children, but it is less common among adults. According to American Cancer Society estimates, approximately 3,970 people will be diagnosed with ALL this year, and 1,490 will die from the disease. Treatment approaches for adult leukemia typically include chemotherapy, and may include stem cell transplantation.

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