GlobeImmune's Hepatitis C Product Candidate Improves End of Treatment Response in All IL-28 B Genotypes, With the Greatest Effect in the Hardest-to-Treat Patients
- Category: Vaccines
- Published on Monday, 19 April 2010 03:00
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IL-28 B Genotype Has Been Shown to Correlate Highly With Response to Pegylated Interferon Plus Ribavirin Standard of Care
Data Showing Correlation of GI-5005 Therapeutic Vaccine Treatment Response and IL-28 B Genotype Presented at 45th Annual Meeting of the European Association for the Study of the Liver
LOUISVILLE, CO, USA | April 19, 2010 | GlobeImmune Inc. announced Phase 2b data for GI-5005, the Company's investigational Tarmogen® product for hepatitis C virus (HCV) infection, correlating GI-5005 treatment response rate and IL-28 B genotype in patients with chronic HCV infection.
It was recently reported that variations in the human IL-28 B gene are predictive of spontaneous clearance of HCV infection (Thomas et al, Nature 2009), as well as response to treatment with standard of care, (SOC) pegylated interferon alpha plus ribavirin (Ge et al, Nature 2009). In the IL-28 B T/T genotypes, only a third as many patients respond to SOC as compared to the C/C genotype. The GI-5005 Phase 2b study demonstrated that all IL-28 B genotype subgroups receiving GI-5005 in addition to SOC saw an improvement in viral clearance as measured by PCR at the end of treatment (ETR) compared to patients receiving SOC alone. Patients with the hardest-to-treat T/T genotype in the GI-5005 arm of the study saw the greatest improvement in sustained virologic response (SVR -- defined as viral negativity 6 months off treatment and used to define successful treatment), with a 60 percent treatment effect compared to SOC alone. Patients carrying the T allele (form) (C/T or T/T) of the IL-28 B gene are at high risk for treatment failure with SOC and represent approximately 65 percent of the treatment naive population.
"Differences in the IL-28 B genotype determine how effectively a patient's immune system responds against the HCV virus," said John G. McHutchison, M.D., Associate Director of the Duke Clinical Research Institute at Duke University Medical Center, who presented the data on Saturday at the 45th Annual Meeting of the European Association for the Study of the Liver (EASL). "The data from the GI-5005 study are encouraging because there is a significant need for potential new strategies for the hardest to treat IL-28 B genotype patients."
Genetic analysis of the IL-28 B gene was performed retrospectively on 140 patients with chronic genotype 1 hepatitis C infection who were either treatment naive or prior non-responders as part of a Phase 2b study comparing GI-5005 plus SOC versus SOC. The data show:
* GI-5005 improved viral clearance as measured by PCR in all IL-28 B genotypes
* 100% (5/5) patients in the GI-5005 arm of the trial with the hardest-to-treat T/T genotype achieved viral negativity on treatment during the study
* 60% (3/5) of T/T genotype patients receiving GI-5005 went on to achieve SVR, compared to 0% (0/5) of patients receiving SOC
"Prior publications on the IL-28 B gene and this study demonstrate the importance of the immune response in HCV treatment," said David Apelian, M.D., Ph.D., chief medical officer at GlobeImmune. "These data suggest that a critical component of the future of HCV treatment lies in immune-stimulating therapies such as GI-5005."
Dr. McHutchison and Ira M. Jacobson, M.D., Vincent Astor Distinguished Professor of Medicine at NewYork-Presbyterian/Weill Cornell Medical Center, presented additional data from the Phase 2b study at the conference. The data demonstrated a 10 percent absolute improvement in SVR for treatment-naive patients receiving GI-5005 plus SOC versus SOC alone. Adding GI-5005 to SOC also resulted in a 67 percent relative improvement in the proportion of patients achieving normalization of ALT levels, and a 39 percent relative improvement in biopsy necroinflammatory scores, both measures of liver damage.
Tarmogens are whole, heat-killed recombinant S. cerevisiae yeast that express antigens from one or more disease-related proteins. GlobeImmune's GI-5005 Tarmogen is a therapeutic vaccine product candidate that contains conserved HCV proteins and is designed to generate an HCV specific T-cell response.
GlobeImmune Inc. is a private company developing active immunotherapies called Tarmogens for the treatment of cancer and infectious diseases. Tarmogens generate activated killer T cells that locate and eliminate cancer cells and/or virally-infected cells. The Company's lead product candidate, GI-5005, is a Tarmogen being developed for the treatment of chronic hepatitis C infection (HCV). GI-5005 is designed to complement both the current standard of care and emerging novel therapies for HCV. The Company's lead oncology program, GI-4000, targets cancers caused by mutated versions of the Ras oncoprotein. GI-4000 is being investigated in clinical trials for the treatment of pancreas cancer as well as other cancers that contain mutated Ras, including non-small cell lung cancer and colorectal cancer. In May 2009, the Company announced a global partnership with Celgene focused on the discovery, development and commercialization of multiple product candidates for the treatment of cancer.