Phase 3 trial of Ceplene in acute myeloid leukemia meets primary trial endpoint

May 12 2004

Maxim Pharmaceuticals has announced the results of an international Phase 3 clinical trial testing the combination of Ceplene (TM) plus interleukin-2 (IL-2) in 320 patients with acute myeloid leukemia (AML) in complete remission. The primary endpoint of the Phase 3 trial was achieved using intent-to-treat analysis, as patients treated with the Ceplene/IL-2 combination therapy experienced a statistically significant (p=0.026) increase in leukemia-free survival compared to patients in the control arm of the trial.

AML is the most common form of acute leukemia in adults. AML patients are typically treated with chemotherapy to achieve disease remission, but the majority of patients will ultimately relapse. The prognosis for AML patients after relapse is dismal, with few long-term survivors. The Ceplene therapy treats patients during remission (after chemotherapy) with the goal to increase their remission period and prevent relapses.

In Maxim's Phase 3 trial, 320 AML patients in complete remission in Europe, North America, Israel, New Zealand and Australia were randomized to receive Ceplene plus IL-2 or the current standard-of-care (no treatment). The aim of treatment with Ceplene/IL-2 was to prevent leukemia relapse, and the primary trial endpoint was leukemia-free survival. All patients randomized to the trial were followed for at least three years.

Maxim today is reporting first data with regard to the trial's primary endpoint, leukemia-free survival. Patients treated with Ceplene and IL-2 in the intent-to-treat population (i.e. all patients randomized) had a statistically significant improvement of leukemia-free survival compared to patients in the control group, as assessed by the stratified log-rank test (p=0.026). More detailed results from the Phase 3 trial will be presented at upcoming hematology meetings. Ceplene is an investigational drug and has not been approved by the U.S. Food and Drug Administration (FDA) or any international regulatory agency.

"The high rate of recurrence of leukemia in AML patients is a major clinical challenge," said Dr. Mats Brune, M.D., PhD. of the Hematology Unit, Sahlgrenska University Hospital in Goteborg, Sweden, and Study Chairman of the trial. "It is very gratifying that treatment with Ceplene/IL-2 appears to be associated with long-term leukemia-free survival, which suggests that the treatment may cure a significant proportion of AML patients."

"Maxim currently plans to use the results from the Phase 3 AML trial to pursue expanded labeling for the Ceplene/IL-2 combination after the potential approval of Ceplene for the treatment of advanced malignant melanoma," stated Larry G Stambaugh, Chairman and CEO. "The positive results from this acute myeloid leukemia Phase 3 trial as well as the previous results form our malignant melanoma cancer Phase 3 trial represent important achievements for the Ceplene therapy and for patients. We hope to expand the testing of Ceplene in other cancers such as renal cell carcinoma and colorectal cancer."

Overview of Ceplene

In cancer diseases, including leukemias such as AML, the ability of the immune system to destroy cancer cells is frequently compromised. Ceplene therapy has been developed to maintain the integrity of pivotal immune cells, in particular T cells and natural killer (NK) cells, in patients with cancer. Ceplene treatment aims at facilitating immune-mediated destruction of cancer cells, including leukemic cells, and also at improving the efficiency of T and NK cell-activating agents such as IL-2. Research regarding histamine, the active agent underlying Ceplene, and related clinical results has been the subject of more than 80 presentations at major scientific and clinical meetings, and has been published in more than 300 scientific and clinical articles. More information on Ceplene's mechanism of action, including a short animation, can be viewed on the Company's website at www.maxim.com.