BioWorld International Correspondent

LONDON - Oxxon Pharmaccines Ltd. moved its hepatitis B vaccine into a Phase II trial, giving the company three products in Phase II, with a fourth due to enter Phase II before the end of 2002. At the same time, Oxxon is seeking to raise £10 million to £15 million (US$23.2 million) in a third-round funding.

CEO Deirdre Gillespie told BioWorld International, "We are trying to raise money at present but it is a calamitous market." She is confident of getting funding, but said, "It is difficult to push the valuation, despite the fact that in the 18 months since our last funding we have put two more projects into the clinic and got them through Phase I."

Not only that, but two of the company's Phase II vaccines, against HIV and malaria, have charitable funding. "HIV is completely supported by the International AIDS vaccine initiative, while malaria is more or less completely funded by the Malaria Vaccine Initiative, with support from us around the edges.

"Two or three years ago we would have been public by now, given the strength of our pipeline. But you have to live with the market," Gillespie said.

Oxxon's vaccines, or pharmaccines as it calls them, use sequential immunization with two different vectors carrying the gene for the same antigen. The two-stage regimen primes the immune system and then boosts the immune response, generating cytotoxic T lymphocytes.

"The Phase I trials proved this works in terms of immunological response; now we have to push forward to get clinical proof of principle. In fact, we are starting to see a clinical effect in malaria," Gillespie said.

The Phase II trial in HBV will take place in the Gambia, Africa, and will involve 32 HBV carriers who are currently healthy, with safety and viral load as the endpoints. "We will then move on to patients with a higher viral load and increase the dose in sicker groups," Gillespie said.

The data from the first stage of the trial are expected before the end of the year and will aid in the design of a European Phase II trial expected to start in the fourth quarter of 2002.

Treatments are available for HBV, but they suppress, rather than clear, the virus. "The potential of pharmaccines is that they will clear the viral load," Gillespie said.

Oxford-based Oxxon's preventive vaccine for AIDS is in a Phase II multicenter trial involving 120 healthy volunteers in the UK. Following that it will progress to a Phase II trial in Kenya. The International AIDS Vaccine Initiative, which like the Malaria Vaccine Initiative is backed by the Bill and Melinda Gates Foundation, put in $4 million to fund Phase I and is fully funding Phase II.

Two Phase II challenge trials of the malaria vaccine are in progress, and a field trial is expected to start before the end of the year in Africa.

A fourth product, a melanoma vaccine, recently completed Phase I. "We have not released the data yet, but they are so good we are planning a bigger Phase II," Gillespie said. That one will have tumor burden, time to disease progression and survival as endpoints, the company said.