SYDNEY, Australia - The share price of a small Australian biotech company, Virax Ltd., has skyrocketed on news of a successful animal trial of a new HIV vaccine that features a two-pronged approach to priming the immune system.
The share price in Melbourne-based Virax, which holds the licenses for technology called Co-X-Gene (gene co-expression), closed at A$1.29 (US$0.82) Monday, which is about six times its share price before the Australian media publicized the results of the animal trials involving parts of the technology last week.
Virax's share price was little more than A$0.20 earlier this month, but closed at A$0.64 on Friday, following some initial publicity. Monday, the share price doubled, following additional publicity on the trials and the technology in Australia's weekend newspapers.
The successful trials involved four monkeys at the MacFarlane Burnet Centre, in Melbourne, using aspects of the treatment Virax plans for humans. The vaccine completely protected the monkeys against the virus.
In a subsequent letter to Virax shareholders sent last week, Virax's CEO, David Beames, said only four animals were involved, so the trial is of limited statistical significance. But the findings "are so encouraging that we expect the scientific world to take particular notice."
He said the company plans Phase I/IIa trials of a vaccine which uses Co-X-Gene and is designed to treat the disease. The trial will include 36 patients who have the HIV virus but who are still in the early stages of infection. It will start in hospitals in Sydney and Melbourne in April of next year.
The patients will be divided into three equal groups, with one group as the control and the other two receiving variants of the vaccine treatment. Participants will be given three injections over three months, then monitored over nine months. The data will take another three months to collect. This timetable means the trials will not be completed until the second half of the year 2000.
Technology used in the treatment was devised by Ian Ramshaw, of the John Curtin School of Medical Research, which is attached to the Australian National University, in Canberra, and Stephen Kent, of the MacFarlane Burnet Centre. It uses fowlpox virus to deliver two genes into the patient's skin and muscle.
One gene codes for an HIV antigen, to make the immune system produce T cells keyed to a highly conserved part of the HIV virus. The other codes for the cytokine human interferon gamma, which will boost T cell production.
Beames said the Co-X-Gene technology can be used for a range of other treatments, including cancer treatments. He said the company is applying to overseas entities for funding for the more expensive, and larger, tests for a variation on the treatment as a straight preventive vaccine. However, he declined to say which bodies the company is approaching, or how much it is asking to do the tests.
In addition, the company has built a small facility at the John Curtin School to make the vaccine required for the trials. The company received a grant of A$700,000 from the Australian government's Industrial Research and Development Board in April.