To: CEO, Access Pharmaceuticals, Inc.
Access Pharmaceuticals to release HTLV Vaccine
Virologix was a privately held pharmaceutical company focused on the development of vaccines to prevent HTLV-I and HTLV-II infection. Working primarily with Rockefeller University and the University College Dublin, Virologix’ had substantially completed the preclinical studies of its HTLV vaccines; here's a release about the development of its HTLV vaccine program in 1996:
While it is less well characterized than HTLV-I, infection with HTLV-II has also recently been associated with HTLV-associated myelopathy. HTLV-II has also been linked to large granular lymphocytic leukemia, the cutaneous T lymphocyte neoplasm mycosis fungoides, and certain autoimmune diseases. In addition, HIV-positive individuals carrying HTLV-II have a significantly increased incidence of AIDS-associated non-Hodgkin's lymphoma and acquired ichthyosis (scaling of the skin) than do HIV-positive patients without HTLV-II. Prevention of Infection and the Role of Vaccination Current knowledge of the modes of transmission of HTLV-I have permitted the use of public health measures to reduce the rates of infection in some areas, e.g. by elimination of breast feeding and safe sex practices. However, this is not feasible in some instances and such interventions are unlikely to succeed in the long term, particularly in developing countries. Effective vaccines against HTLV-I and HTLV-II would be of significant clinical value. The viruses are widespread; HTLV-associated diseases can be life-threatening, debilitating and incurable; and the risk of developing a serious clinical disease (about 2-5%) is comparable to other viruses for which vaccines are widely used. Furthermore, the development of such vaccines is scientifically and technically feasible. The feasibility of such a vaccine is rooted in several findings. Perhaps most importantly, there appears to be natural immunity to HTLV-I infection in humans, as evidenced by the placental transmission of maternal antibodies to the fetus with subsequent protection of the newborn from viral transmission in the mother's breast milk. Preliminary studies in animals have also demonstrated that protection can be achieved by appropriate immunization strategies. Another critical point is that the viral components which appear to be the leading vaccine candidates remain genetically and serologically stable in the population, unlike those on HIV. Indeed, the genomes of all the strains of HTLV-I isolated thus far in Japan, Africa, the Caribbean, and Central and South America are 98 percent identical. Hence, a vaccine generated against one strain of HTLV-I will likely protect against the majority of strains, although there can be no such assurance. The Company believes that the similarity between HTLV-I and HTLV-II make the development of an effective HTLV-II vaccine equally feasible. The Company's Vaccine Candidates for HTLV-I and HTLV-II On the basis of the information described above, investigators at Rockefeller have developed vaccine candidates for HTLV-I and HTLV-II using recombinant DNA techniques. The leading candidates for vaccine formulation against HTLV-I infection are the surface glycoproteins. These proteins are so named because of the carbohydrates, or sugars, which the virus has attached to the proteins in strategic places. The Company has genetically engineered a novel version of one of these glycoproteins in a manner which produces large, previously unattainable quantities of the desired protein in either a glycosylated (with sugars) or non-glycosylated form. Both forms are easily purified for use as a vaccine. Initial studies with rabbits immunized with a modified non-glycosylatedform of the HTLV-I glycoprotein have demonstrated 100 percent protection against challenge with HTLV-I-infected cells. While the glycosylated forms more closely resemble the glycoproteins naturally produced by the virus, these results indicate that glycosylation is not required to confer protection. Nevertheless, the Company is continuing to evaluate both glycosylated and non-glycosylated vaccine candidates for HTLV-I. The Company's vaccine candidate for HTLV-II is based on a modified glycosylated form of the HTLV-II glycoprotein. This subunit vaccine was recently tested in a rabbit model of HTLV-II infection. In the studies, 22 rabbits were immunized at 0, 4, 8 and 16 weeks and were challenged with virus at 18 weeks or 6 months. In all 22 animals, the vaccine elicited high antibody titers and protection against viral infection. Following further animal studies to optimize both vaccines and determine routes of administration, the Company intends to begin human trials in Rio de Janeiro, Brazil. The Company believes it has identified a suitable population for Phase I safety and immunogenicity trials and expects that these Phase I trials will begin in Brazil in the first half of 1997.
After that release, Virologix was purchased by Access Pharmaceuticals, Inc and the HTLV vaccine program disappeared. The purpose of this...
While it is less well characterized than HTLV-I, infection with HTLV-II has also recently been associated with HTLV-associated myelopathy. HTLV-II has also been linked to large granular lymphocytic leukemia, the cutaneous T lymphocyte neoplasm mycosis fungoides, and certain autoimmune diseases. In addition, HIV-positive individuals carrying HTLV-II have a significantly increased incidence of AIDS-associated non-Hodgkin's lymphoma and acquired ichthyosis (scaling of the skin) than do HIV-positive patients without HTLV-II. Prevention of Infection and the Role of Vaccination Current knowledge of the modes of transmission of HTLV-I have permitted the use of public health measures to reduce the rates of infection in some areas, e.g. by elimination of breast feeding and safe sex practices. However, this is not feasible in some instances and such interventions are unlikely to succeed in the long term, particularly in developing countries. Effective vaccines against HTLV-I and HTLV-II would be of significant clinical value. The viruses are widespread; HTLV-associated diseases can be life-threatening, debilitating and incurable; and the risk of developing a serious clinical disease (about 2-5%) is comparable to other viruses for which vaccines are widely used. Furthermore, the development of such vaccines is scientifically and technically feasible. The feasibility of such a vaccine is rooted in several findings. Perhaps most importantly, there appears to be natural immunity to HTLV-I infection in humans, as evidenced by the placental transmission of maternal antibodies to the fetus with subsequent protection of the newborn from viral transmission in the mother's breast milk. Preliminary studies in animals have also demonstrated that protection can be achieved by appropriate immunization strategies. Another critical point is that the viral components which appear to be the leading vaccine candidates remain genetically and serologically stable in the population, unlike those on HIV. Indeed, the genomes of all the strains of HTLV-I isolated thus far in Japan, Africa, the Caribbean, and Central and South America are 98 percent identical. Hence, a vaccine generated against one strain of HTLV-I will likely protect against the majority of strains, although there can be no such assurance. The Company believes that the similarity between HTLV-I and HTLV-II make the development of an effective HTLV-II vaccine equally feasible. The Company's Vaccine Candidates for HTLV-I and HTLV-II On the basis of the information described above, investigators at Rockefeller have developed vaccine candidates for HTLV-I and HTLV-II using recombinant DNA techniques. The leading candidates for vaccine formulation against HTLV-I infection are the surface glycoproteins. These proteins are so named because of the carbohydrates, or sugars, which the virus has attached to the proteins in strategic places. The Company has genetically engineered a novel version of one of these glycoproteins in a manner which produces large, previously unattainable quantities of the desired protein in either a glycosylated (with sugars) or non-glycosylated form. Both forms are easily purified for use as a vaccine. Initial studies with rabbits immunized with a modified non-glycosylatedform of the HTLV-I glycoprotein have demonstrated 100 percent protection against challenge with HTLV-I-infected cells. While the glycosylated forms more closely resemble the glycoproteins naturally produced by the virus, these results indicate that glycosylation is not required to confer protection. Nevertheless, the Company is continuing to evaluate both glycosylated and non-glycosylated vaccine candidates for HTLV-I. The Company's vaccine candidate for HTLV-II is based on a modified glycosylated form of the HTLV-II glycoprotein. This subunit vaccine was recently tested in a rabbit model of HTLV-II infection. In the studies, 22 rabbits were immunized at 0, 4, 8 and 16 weeks and were challenged with virus at 18 weeks or 6 months. In all 22 animals, the vaccine elicited high antibody titers and protection against viral infection. Following further animal studies to optimize both vaccines and determine routes of administration, the Company intends to begin human trials in Rio de Janeiro, Brazil. The Company believes it has identified a suitable population for Phase I safety and immunogenicity trials and expects that these Phase I trials will begin in Brazil in the first half of 1997.
After that release, Virologix was purchased by Access Pharmaceuticals, Inc and the HTLV vaccine program disappeared. The purpose of this...
Why is this important?
Virologix was a privately held pharmaceutical company focused on the development of vaccines to prevent HTLV-I and HTLV-II infection. Working primarily with Rockefeller University and the University College Dublin, Virologix’ had substantially completed the preclinical studies of its HTLV vaccines; however, once the company was purchased by Access Pharmaceuticals, the vaccine disappeared. The purpose of this petition is to ask Access Pharmaceuticals to allow the vaccine to be available so that it can used to save the lives of millions of men, women, and children.