Lab Canada

Stem cell mobilizer holds hope for potential use in allogeneic transplant for cancer patients

Vancouver, BC – AnorMED has announced preliminary results on AMD3100, its lead drug candidate for stem cell transplantation, which support its potential use as a single agent to mobilize stem cells from healthy donors for allogeneic stem cell transplantation in cancer patients. This data was reported at the 2004 American Society of Hematology conference (ASH) in San Diego.

Additional data presented at ASH continue to show that AMD3100, in combination with standard stem cell mobilization regimens, provides a rapid increase in the number of peripheral blood stem cells capable of engraftment, increases the proportion of patients reaching a peripheral blood stem cell target required for transplant, even in heavily pre-treated patients, and reduces the number of apheresis sessions required for patients to reach a target number of peripheral blood stem cells.

There are two types of stem cell transplantation, autologous and allogeneic. Autologous transplant, where a patient’s own stem cells are used for their transplant, is usually preferred for the treatment of multiple myeloma and non-Hodgkins lymphoma. Allogeneic transplant, where stem cells collected from a healthy donor (often a sibling) are used for transplantation into a cancer patient, is the preferred procedure for different types of leukemia.

The AMD3100 allogeneic study is being conducted by Dr Steven Devine, director of clinical research, division of oncology, section of bone marrow transplantation and leukemia and Dr John Dipersio, chief, division of oncology, section of bone marrow transplantation and leukemia, both at Washington University School of Medicine in St Louis.

Data reported at ASH shows that administration of AMD3100 to four healthy donors results in a modest but sufficient increase in CD34+ cell count within six hours of injection. Three of four donors collected an allograft containing greater than 2.0×10(6)/kg recipient weight after one or two apheresis sessions. AMD3100 administration was not associated with any significant side effects in the healthy donors. Two allogeneic transplants, using the AMD3100 mobilized stem cells, were performed, one in a patient with Acute Myelogenous Leukemia and another in a patient with non-Hodgkin’s lymphoma. Both patients engrafted promptly and are currently being followed as outpatients. These results are consistent with those obtained by Dr Richard Childs, and colleagues, at the National Institute of Health in Bethesda Maryland. In this study administration of AMD3100 to healthy donors allowed for mobilization and collection of cells suitable for transplant.

Additional data reported at ASH from a Phase II study of AMD3100 in combination with G-CSF continues to support AMD3100’s potential to become a standard new agent in stem cell mobilization and an effective alternative to chemotherapy/cytokine mobilization. All 20 non-Hodgkin’s lymphoma and multiple myeloma patients, including 14 who were heavily pre-treated with chemotherapy and/or radiation therapy, achieved the target number of cells for transplantation following the combination G-CSF AMD3100 therapy. Compared to historical studies of G-CSF alone, the combination may reduce the number of apheresis procedures needed to collect an adequate graft for rapid hematopoietic engraftment. The study is ongoing with accrual to date of 40 patients and is being conducted by a number of investigators including Dr Patrick Stiff, director of the bone marrow transplant program, Loyola University Medical Center, Chicago, who presented the results today.

Data from two other studies reported today at ASH: A poster presentation, given by Dr Michael Dugan, Indiana Blood and Marrow Transplantation, Indiana, on a Phase II study in showing that AMD3100 added to a chemo mobilization regimen increases CD34+ cells by greater than or equal to 2.0 fold and that in 13/13 NHL and MM patients transplanted cells demonstrated prompt and durable engraftment. This study also provides evidence that AMD3100 is effective post chemo-mobilization, as a rescue for patients who fail to mobilize. Another poster presentation, given by Dr Yair Gazitt, University of Texas, San Antonio, Texas, on a Phase II study of AMD3100 in combination with G-CSF in ten hard to mobilize NHL patients shows that use of AMD3100 increased the number of stem cells available for transplant and did not mobilize detectable lymphoma cells.

AMD3100 is a novel stem cell mobilizer, developed by AnorMED that blocks a specific cellular receptor triggering the movement of stem cells out of the bone marrow and into the circulating blood. Data from over 250 participants, from all clinical studies conducted by AnorMED on AMD3100 to date, show the drug candidate has a good safety profile.

Clinical studies on AMD3100 are being conducted at multiple transplant centers in the US, Canada and Europe. AnorMED has reached an agreement with the FDA on a special protocol assessment for the AMD3100 Phase III protocols. The company has initiated its Phase III studies and hopes to enrol the first patient early in 2005. AnorMED is conducting an ongoing Phase II program in transplant to evaluate AMD3100 in combination with different stem cell mobilizing regimens including chemotherapy, as well as in cancer patients with Hodgkin’s disease.

AnorMED is a chemistry-based biopharmaceutical company focused on the discovery, development and commercialization of new therapeutic products in the areas of hematology, HIV and oncology.