Cytomegalovirus vaccine TransVax trial data promising: Vical

TransVax, a vaccine targeting cytomegalovirus (CMV) in hematopoietic stem cell transplant (HCT) recipients, is showing encouraging trial results, according to the developer of the vaccine Vical Inc.

TransVax is a bivalent DNA vaccine containing plasmids (closed loops of DNA) encoding CMV phosphoprotein 65 (pp65) and glycoprotein B (gB) for induction of cellular and humoral immune responses.

TransVax is formulated with a proprietary poloxamer-based delivery system.

Vical’s phase 2 trial is evaluating the potential for TransVax to prevent CMV reactivation in CMV-seropositive HCT recipients, which could reduce antiviral usage and CMV-associated disease.

“We reported promising results in July for TransVax for clinical efficacy and immunogenicity endpoints at the four-month interim analysis point,” said Vijay B. Samant, Vical’s President and Chief Executive Officer.

Vical Incorporated has said that the company has completed the last scheduled follow-up visit for the final patient enrolled in a Phase 2 trial of its cytomegalovirus TransVax vaccine.

Vical expects to have TransVax data available in the first half of 2010.

In July, the company reported results from a four-month interim analysis in the Phase 2 trial favoring the TransVax vaccine over placebo across a broad range of clinical efficacy endpoints.

In October, the company reported that T-cell responses to both CMV antigens encoded by the vaccine were sustained through a seven-month data point, after the last of four scheduled injections, and noted a promising trend in the antibody response against CMV.
TransVax has orphan drug designation for HCT and solid organ transplant patients.

Vical has also reported that the immune responses were sustained through the seven-month data point.

What is cytomegalovirus?

Cytomegalovirus is a member of the herpesvirus family. Other members of the herpesvirus family cause chickenpox, infectious mononucleosis, fever blisters, and genital herpes. These viruses all share the ability to remain alive, but dormant, in the body for life.

Cytomegalovirus, or CMV, is a common virus that infects most people worldwide. CMV infection is usually harmless and rarely causes illness. A healthy immune system can hold the virus in check. However, if a person’s immune system is seriously weakened in any way, the virus can become active and cause CMV disease.

A first infection with CMV usually causes no symptoms. The virus continues to live in the body silently without causing obvious damage or illness. It rarely becomes active for the first time or reactivates (causes illness again in the same person) unless the immune system weakens and is no longer able to hold the virus in check.

Cytomegalovirus is not associated with food, water, or animals. Cytomegalovirus is spread from person to person. Any person with a CMV infection, even without symptoms, can pass it to others. In an infected person, the virus is present in many body fluids, including urine, blood, saliva, semen, cervical secretions, and breast milk.

CMV can be spread by any close contact that allows infected body fluids to pass to another person. CMV can spread in households and child-care centers through hand-to-mouth contact with infected body fluids. CMV can spread by sexual contact, blood transfusions, organ transplants, and breastfeeding. CMV can also be passed from an infected pregnant woman to her fetus or newborn.

Active infection in otherwise healthy children and adults can cause prolonged high fever, chills, severe tiredness, a generally ill feeling, headache, and an enlarged spleen.

People with weakened immune systems can have more serious, potentially life-threatening illnesses, with fever, pneumonia, liver infection, and anemia. Illnesses can last for weeks or months and can be fatal. In persons with HIV infection, CMV can infect the retina of the eye (CMV retinitis) and cause blindness.

In those who do, the time between exposure and symptoms is about 3 to 12 weeks.

Vical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. Potential applications of the company’s DNA delivery technology include DNA vaccines for infectious diseases or cancer, in which the expressed protein is an immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic growth factor.

Vical is developing certain infectious disease vaccines and cancer therapeutics internally. In addition, the company collaborates with major pharmaceutical companies and biotechnology companies that give it access to complementary technologies for greater resources. These strategic partnerships provide the company with mutually beneficial opportunities to expand its product pipeline.