GAITHERSBURG, Md.--()--VIRxSYS Corporation, a privately held company developing vaccines and RNA therapies for serious human diseases such as HIV and cardiovascular diseases, announced results from its prophylactic HIV vaccine (VRX1023) study in Rhesus Macaque monkeys during a presentation today at the 2010 Annual Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco, CA. The study has demonstrated that the VIRXSYS vaccine, VRX1023, is capable of achieving significant control of viral load over the course of four months following a challenge with a highly pathogenic simian immunodeficiency virus (SIV), a virus found in non-human primates and similar to HIV. In addition, monkeys vaccinated with VRX1023 demonstrated an improved immune response. VIRxSYS is currently preparing an Investigational New Drug Application for the therapeutic use of their HIV vaccine candidate in HIV infected patients.
“Obviously, the HIV vaccine field has been hit with a number of disappointing trial results over the past several years”
“We are extremely encouraged by the results of this study. The combination of strong immune responses, viral control, and CD4 preservation is tremendous. In addition, contrary to most viral vectors currently in development, our lentiviral vector elicits nominal anti-vector responses and therefore can be successfully re-administered,” said Dr. Franck Lemiale, Ph.D., Director of Immunology for VIRxSYS. “It will be very interesting to see how it performs as a therapeutic vaccine in humans.”
“Obviously, the HIV vaccine field has been hit with a number of disappointing trial results over the past several years,” said Dr. Joep Lange, Head of the Amsterdam Institute for Global Health and Development, Professor of Medicine at the Academic Medical Center, University of Amsterdam, President Emeritus of the International AIDS Society, and member of the VIRxSYS medical advisory board for HIV. “The results from this trial are very impressive and I believe could provide real excitement in the world of HIV vaccines.”
VIRxSYS’ vaccine candidate differs from other HIV vaccine candidates in that it employs an engineered HIV-based lentiviral vector to deliver the vaccinating antigens. The study results demonstrate the VIRxSYS vaccine candidate achieves remarkably high levels of T-cell responses, resulting in a 95% reduction of viral load in Rhesus monkeys which received lentiviral vaccination, as compared to non-vaccinated control animals in this study. The investigators also observed a strong and durable immune response without the requirement of a DNA prime and a major preservation of CD4+ T cell compartment as measured by the percentage of CD4+ T cells to total lymphocytes. The lentiviral-based vaccine also elicited high levels of CD107a expression in T cells, which have recently been described as having an important role in the control of SIV/HIV. Importantly, no adverse reactions have been observed in any of the vaccinated animals following multiple infusions of the lentiviral vaccine.
The Company described its intriguing data in Rhesus monkeys, which were divided into two groups receiving either the lentiviral vector vaccine or a mock vaccination as a control. Both groups were infected with a highly pathogenic SIV six months after the last immunization.
“We could not have wished to achieve better results with our lentiviral-based HIV vaccines,” said Gary McGarrity, PhD, Executive Vice President of Scientific and Clinical Affairs for VIRxSYS. “We believe that this lentiviral vector is an excellent HIV therapeutic vaccine candidate to move to human clinical trials. The potential impact of a series of simple injections to treat patients who are currently taking complex and often toxic multi-drug regimens, particularly in the developing world, is enormous. VRX1023 is designed to work against all clades of HIV.”
The VIRxSYS results were presented at CROI on Thursday, February 18, 2010 in San Francisco. In addition, Phase II results for VRX496™, the Company’s investigational RNA therapy for the treatment of HIV/AIDS, also were presented by the University of Pennsylvania School of Medicine on Thursday, February 18, 2010 in San Francisco (poster number 388).
Founded in 1998, VIRxSYS is a private biotechnology company that focuses on the development of novel lentiviral gene delivery platform and RNA technologies for the treatment of serious diseases. The Company has exclusively licensed its patented, proprietary lentiviral technology platform from The Johns Hopkins University (JHU) in Baltimore, Maryland, and obtained its SMaRT™ technology from Intronn Inc. More information regarding VIRxSYS can be found at www.virxsys.com.
About VIRxSYS’ HIV Vaccine Program
VIRxSYS’ lentiviral vector vaccine candidate against HIV is an investigational product in preclinical studies conducted in mice and non-human primates. This vaccine candidate has shown encouraging results, including induction of long-lasting cellular and humoral response against SIV. Based on non-human primate studies conducted by VIRxSYS, the vaccine appears to produce stronger anti-HIV immune responses compared to most other viral vectors, including adenoviral vectors similar to those that have been extensively tested in human subjects.
VRX496™ is an investigational RNA therapy for the treatment of HIV/AIDS. Current therapies for HIV-infected patients require daily drug regimens and have well documented side effects. It is anticipated that VRX496™ will require only a minimal number of infusions. To date VRX496™ has been infused in 65 patients, which represent an accumulative safety time period of 211 therapy years. VRX496™ also is different from previous gene therapies because it uses a lentiviral vector derived from HIV-1 itself. Unlike other viral vectors, lentiviral vectors appear to sustain expression of the delivered genes of interest for a longer period of time and do not appear to elicit an inflammatory immune response.
This announcement contains, in addition to historical information, certain forward-looking statements that involve risks and uncertainties, in particular statements related to the research and development of VIRxSYS Corporation's therapies. Such statements reflect the current views of VIRxSYS and are based on certain assumptions. Actual results could differ materially from those currently anticipated as a result of a number of factors, including risks and uncertainties related to drug development activities. There can be no assurance that such development efforts will succeed, that the products will receive required regulatory clearance or, even if such regulatory clearance is received, that the subsequent products will ultimately achieve commercial success. Further, any forward-looking statements contained in this announcement speak only as of the date hereof, and VIRxSYS expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as otherwise may be required by applicable law or regulation.