SAN DIEGO, CA--(Marketwire - May 04, 2010) - REGiMMUNE Corporation said today that data from a preclinical study showed enhanced immune suppression when ToleroVax (RGI-2001), its lead product candidate for the prevention of acute Graft-versus-Host Disease (GvHD), is combined with anti-thymocyte globulin (ATG). The study found that the combination of the two drugs showed a robust synergy and induced proliferation in more than 70% of regulatory T cells (Tregs), a T cell subset that plays a central role in inducing and maintaining immune tolerance. These data are being presented today in a podium presentation: "Robust Synergy between a Liposomal alpha-Galactosylceramide (RGI−2001) and Anti-Thymocyte Globulin in the Induction of Tolerogenic Tregs In Vivo" at the 2010 American Transplant Congress in San Diego.
"The results imply that ToleroVax in combination with ATG may offer a basis to develop novel therapeutic strategies to prevent graft rejection by effectively inducing Treg-mediated transplantation tolerance," explained Haru Morita, President and Chief Executive Officer of REGiMMUNE.
ToleroVax is a proprietary liposomal formulation of KRN7000, a synthetic derivative of alpha-galactosylceramide. ToleroVax promotes transplantation tolerance by inducing Tregs. Most immunosuppressants used in the clinic suppress T cells in general; however, the effect on Tregs varies. Previous studies demonstrated synergistic effects of rapamycin with ToleroVax. The study presented today by REGiMMUNE scientist Omar Duramad, Ph.D., investigated the effects of anti-thymocyte globulin (ATG) and tacrolimus (TAC), a calcineurin inhibitor, on Treg activation by ToleroVax.
The study was designed to evaluate the effects of ATG or TAC on ToleroVax-induced activation of the tolerogenic cellular cascade, including regulatory dendritic cells (DCregs) and CD4+Foxp3+ Tregs. While both ToleroVax and ATG each have activity to stimulate Tregs as a single agent, when combined the two drugs were synergistic and stimulated proliferation of a majority ( > 70%) of Tregs. Investigation of dendritic cell (DC) subsets revealed increases in a tolerogenic DC subset, while an immunogenic DC subset decreased. The results together indicate that the combination of ToleroVax and ATG potently drives immune responses towards a tolerogenic direction by activating DC and T cells with tolerogenic functions. In contrast, addition of TAC suppressed proliferation of Tregs. Collectively, the data suggest that the combination of ToleroVax and ATG may lead to the development of novel therapeutics to prevent graft rejection by stimulating the tolerogenic cellular cascade.
ToleroVax is in late preclinical development for the prevention of acute GvHD associated with bone marrow transplantation and REGiMMUNE expects to begin a Phase I study the third quarter of 2010.
REGiMMUNE is a biotechnology company focused on the discovery, development and commercialization of immune regulatory therapeutics to treat life-threatening and debilitating conditions, including allergies, autoimmune diseases and transplantation. The company's proprietary platform technology, reVax, induces immune tolerance in an antigen-specific manner through pharmacological induction of regulatory T (Treg) cells. Using its reVax technology, REGiMMUNE is developing ToleroVax, which may be the first drug in the class of Treg-inducing agents.
The company is also applying its reVax technology to develop a range of pipeline products, including its RGI-1000 series for allergy and its RGI-3000 series for autoimmune diseases. Additionally REGiMMUNE is developing its RGI-4000 series for vaccine adjuvants. The company is headquartered in Tokyo, Japan and has a U.S. subsidiary in Mountain View, California. For more information, visit www.regimmune.com.