Return to main press room page Therion Biologics and the National Institute of Allergy and Infectious Diseases, NIH, Initiate Human Clinical Trials of Preventive Smallpox Vaccine -- Phase I Clinical Trial of TBC-MVA Smallpox Vaccine Begins -- Cambridge, MA, December 19, 2002 -- Therion Biologics Corporation and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), have initiated a Phase I clinical trial of TBC-MVA, Therion�s preventive smallpox vaccine. Therion derived TBC-MVA from modified vaccinia Ankara (MVA), a highly attenuated vaccinia virus that has been previously used in human vaccination against smallpox. TBC-MVA offers the potential for improved safety as compared to the currently available smallpox vaccine, Dryvax®. The trial, which is being conducted by the NIAID with TBC-MVA provided by Therion, is the first clinical trial in the United States to evaluate the use of MVA for smallpox prevention. �For more than ten years, Therion has built extensive experience with pox viruses, which we use in our proprietary therapeutic cancer vaccines,� commented Mark Leuchtenberger, President and Chief Executive Officer of Therion Biologics. �This expertise uniquely positions the company to contribute to the national effort to develop a safe and effective vaccine against smallpox.� �Even with the current supply of the existing smallpox vaccine, it is important to develop a method of immunization that minimizes the potential for adverse side effects over the currently available option,� said Dennis L. Panicali, Ph.D., Chief Scientific Officer of Therion Biologics. �Previous clinical experience has shown that MVA is well-tolerated in children, the elderly and those with skin conditions.� TBC-MVA is a non-recombinant derivative of MVA. MVA was originally prepared from the Ankara vaccinia strain CVA. In the mid-1950s, CVA was used in Germany as a smallpox vaccine. In 1958 CVA was used to develop an attenuated vaccine strain, resulting in a safer replication-defective virus, designated MVA. Over 120,000 humans have been safely vaccinated with MVA by intradermal, subcutaneous, and intramuscular routes of administration. TBC-MVA Study Design This Phase I clinical trial will be conducted by NIAID�s Vaccine Research Center to evaluate the safety of TBC-MVA in healthy volunteers who have never received a vaccination for smallpox. A secondary objective is to determine if vaccinia-specific immune responses elicited by TBC-MVA are comparable to those elicited by Dryvax alone. A third objective of the study is to assess TBC-MVA�s potential efficacy against poxvirus infection. Following vaccination with TBC-MVA, the volunteers will receive Dryvax, a live, replicating vaccinia virus that is closely related to variola, the cause of smallpox. Protection against infection with Dryvax may indicate that TBC-MVA may be effective against smallpox. The study, which involves 105 healthy volunteers, is randomized, placebo-controlled and double-blinded. Background on Smallpox Smallpox is a serious, highly contagious, and sometimes fatal infectious disease. There is no specific treatment for smallpox, and the only prevention is vaccination. Once a widespread disease with a mortality rate of nearly 30%, smallpox was eradicated during the twentieth century, with the last known naturally occurring case documented in Somalia in 1977. In 1972, the declining smallpox rate in the world, coupled with the rate of life-threatening complications incurred from then-available vaccines, led the Centers for Disease Control and Prevention to recommend that routine smallpox vaccinations be discontinued. The availability of a new vaccine with a lower rate of complications is of great interest to researchers. Dryvax®, used in mass smallpox vaccination programs, is currently the only licensed smallpox vaccine available in the U.S. While this vaccine is effective, it may cause significant side effects in a small percentage of recipients if used in a mass vaccination program. The development of a safer smallpox vaccine for biodefense is a top priority for the U.S. government. About Therion Biologics Corporation Therion Biologics Corporation develops therapeutic vaccines for cancer and preventive vaccines for AIDS. The company has three lead programs involving multiple clinical trials: PROSTVAC-VF/TRICOM™ for prostate cancer; CEA/MUC-1-VF/TRICOM™ for pancreatic cancer; and VF/TRICOM™ for melanoma. Therion is also applying its technology platform to develop vaccines to treat breast cancer and other solid tumors. The company�s strategic partners include the National Cancer Institute, a global network of leading clinical institutions, and Aventis Pasteur, Ltd., which is developing ALVAC-CEA/B7.1, a clinical candidate for colon cancer. Therion is headquartered in Cambridge, Massachusetts. ### Back to the top Main Page News Release Archive Media Coverage Copyright © 2002 by Therion Biologics Corporation.