HAMPTON, N.J., Dec. 10, 2013 (GLOBE NEWSWIRE) -- Celldex Therapeutics, Inc. (Nasdaq:CLDX) announced today positive results from a preclinical combination study of CDX-301 (FMS-like tyrosine kinase-3 ligand or Flt3L) and Mozobil ® (Plerixafor injection, formerly AMD3100) demonstrating that the combination of these agents significantly increases hematopoietic stem cell mobilization in mice. The data support future clinical development of CDX-301 and demonstrate a novel potent cell mobilization regimen combining CDX-301 and Mozobil ® , which may have significant potential for use in autologous and allogeneic hematopoietic stem cell transplantation. Results were presented in an oral session entitled "FLT3L and AMD3100 Combination Increases Hematopoietic Stem Cell Mobilization and Leads to Improved Transplantation Outcome" on Tuesday, December 10, 2013 at 7:30 am CT at the American Society of Hematology 55 th Annual Meeting and Exposition (ASH). The studies were conducted in collaboration with Jianhua Yu, PhD, and Steven Devine, MD, and were presented by Shun He, PhD, all of The Ohio State University. "We need novel interventions to advance hematopoietic stem cell mobilization techniques and transplantation, and based on our studies to date, this could be a promising alternative approach for these patients," said Steven Devine, MD, Professor of Internal Medicine and Director, Blood and Marrow Transplant Program, The Ohio State University Comprehensive Cancer Center. "The data presented today further demonstrate the potential for CDX-301 to improve both autologous and allogeneic hematopoietic stem cell transplantation and, importantly, show the ability for CDX-301 to combine effectively with other cell mobilization agents," said Tibor Keler, PhD, Senior Vice President and Chief Scientific Officer of Celldex. "If what has been demonstrated in preclinical models can be applied to a clinical setting, this regimen could improve stem cell transplantation outcomes for patients across a broad range of indications. We plan to initiate a pilot clinical study evaluating CDX-301 alone and in combination with Mozobil ® in the transplant setting in early 2014 and look forward to seeing how this program progresses." Current standard of care mobilization treatments produce grafts, or transplanted tissues, that may not contain sufficient numbers of hematopoietic stem cells or may cause graft-versus-host disease (GVHD), a common complication following allogeneic transplantation in which the immune cells in the graft recognize the host, or recipient, as foreign and react by attacking the host's cells. This study found that the combination of CDX-301 and Mozobil ® mobilized the highest rate and amount of hematopoietic stem cells into peripheral blood compared to the mice treated with granulocyte colony-stimulating factor (G-CSF, an FDA-approved mobilization treatment) alone, or the combination of G-CSF with Mozobil ®. In a model of autologous stem cell transplantation, there was greater than 70% survival among mice exposed to an otherwise lethal dose of radiation that had received grafts mobilized with the combination of CDX-301 and Mozobil ® or CDX-301 alone, whereas survival was only 35% when grafts were mobilized by G-CSF combined with Mozobil ® , and there was no survival with either G-CSF or Mozobil ® alone. Further, in a mouse model of allogeneic stem cell transplantation, the combination of CDX-301 with Mozobil ® or CDX-301 alone again resulted in significantly greater survival at four months (80% and 66%, respectively) than did the combination of G-CSF with Mozobil ® (13%) or did either agent alone (0%). The better outcomes from the CDX-301 alone or in combination with Mozobil ® appeared to be due to suppression of GVHD and also better hematopoietic reconstitution of stem cells. Mozobil® is a registered trademark of Genzyme Corporation.