Vical shares climb on HIV vaccine news [The San Diego Union-Tribune]
Oct. 12--Shares of gene therapy company Vical rose as much as 22 percent yesterday after federal researchers said they will advance development of a potential "global" HIV vaccine that uses the San Diego company's technology.
The National Institute of Allergy and Infectious Diseases' Vaccine Research Center, or NIAID, plans to enroll about 500 volunteers in several countries to test whether a novel, two-pronged vaccine strategy can halt the spread of the deadly virus that causes AIDS. Federal researchers said the midstage, Phase 2 study marks an important step in the advancement toward an AIDS vaccine. "This is the first Phase 2 study of a vaccine candidate that is broadly relevant to the global AIDS pandemic because it combines components of HIV strains found throughout the world," said VRC Director Dr. Gary Nabel.
While Vical enjoyed a run-up in its share price yesterday, the stock settled at the close of trading at $6.05, up 68 cents, or 12 percent. The NIAID vaccine approach will take years to develop, and no HIV vaccine has yet been proven to be effective. There are dozens of other HIV vaccine trials involving other drugs that are being conducted worldwide.
The latest study will test a strategy that combines two separate vaccine technologies that are designed to teach the immune system to recognize and kill the invading HIV virus.
Both technologies, developed separately by San Diego's Vical and Gaithersburg, Md.-based GenVec, combine modified elements of four HIV genes found in subtypes of the virus. Those subtypes are found commonly in Africa, the Americas, Europe and parts of Asia, and account for about 85 percent of the HIV infections worldwide, according to federal researchers.
The two vaccines will be given in a one-two punch: Vical's vaccine, which contains "naked" HIV gene fragments, will first "prime" the immune system to recognize the virus. Then a second vaccine that incorporates GenVec's technology, which uses a weakened type of respiratory virus to carry non-infectious HIV gene fragments into the body, provides an additional
virus-recognizing boost. Half of the participants in the Phase 2 study will receive three injections of Vical's DNA
vaccine, followed by one injection of the GenVec booster vaccine. The other half will receive a placebo vaccine of sterile saltwater. In animal studies and a small safety study in humans, the prime-boost strategy stimulated a strong, broad immune response, according to federal researchers.
Both Vical and GenVec referred questions to NIAID. NIAID did n
ot return telephone calls. Vical and GenVec both have HIV vaccine development contracts with NIAID, and the biotechs retain certain commercial rights to the use of their technologies if the combination vaccine proves effective.
Vical has already received about $12 million in orders from NIAID to produce its HIV vaccine. |
