Therapeutic HIV vaccine research in the USA

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Pharmexa receives approval to start Phase Ib trial in the US with

HIV vaccine

Summary: Pharmexa has received approval from US authorities to start

a Phase Ib trial with the HIV vaccine EP1090.The first patients will

be treated in the next few weeks.

Relevant US authorities have approved Pharmexa's application to

start a Phase Ib trial of the vaccine EP1090 in HIV-infected

patients. In this trial sponsored by Pharmexa, EP1090 is tested

using a needle-free injection device chosen to maximize delivery of

the vaccine, thus enhancing the vaccine's ability to stimulate the

immune system. The first patients will be treated in the next few

weeks.

The trial is a randomized, double blinded, placebo-controlled study

in 32 HIV-infected patients receiving antiretroviral therapy (ART).

Conducted at one US center with the AIDS Research Alliance (ARA) the

trial tests two equal-sized groups dosed with 1 mg or 4 mg of EP1090

administered with the Biojector® 2000. The 24-week trial will

consist of weekly vaccine doses for the first five weeks with a 20-

week follow-up after the last vaccination. The primary endpoints of

the trial are vaccine safety and immunogenicity. Results are

expected in the third quarter of 2007.

How does EP1090 work?

EP1090 has been designed to restore and amplify anti-viral immune

responses in patients who have been receiving ART. The ultimate

treatment goal is to provide a second treatment option to patients

that discontinue or fail on standard ART using EP1090 to stimulate

their natural immune suppression of HIV replication.

EP1090 is an epitope based DNA vaccine that activates so called

cytotoxic T-lymphocytes (CTL or " killer T cells " ) of the immune

system to attack HIV-infected cells. The vaccine is designed to

induce CTL responses but not helper T-lymphocytes (HTL), which are

readily infected by HIV. As such, this vaccine is unique because it

is specifically designed for therapy. EP1090 encodes 21 CTL epitopes

from multiple virus proteins found in all HIV subtypes carefully

selected using Pharmexa-Epimmune's patented EIS technology. The

epitopes selected are believed to be crucial to the fitness of all

HIV viral strains, with the result that the virus should be unable

to mutate away from immune responses targeted by EP1090. Such

mutation has presented an obstacle to conventional whole antigen HIV

vaccine development.

EP1090 has previously been successfully tested both in HIV-infected

patients and in healthy volunteers. In addition, EP1090 is currently

being tested in combination with the vaccine EP1043 in a large Phase

I trial sponsored by the United States' National Institutes of

Health (NIH), Division of AIDS (DAIDS) through the HIV Vaccine

Trials Network. This trial includes 120 healthy volunteers in the

United States and Peru. Results are expected towards the end of

2007.

Pharmexa's programmes in HIV

Through its US subsidiary Pharmexa-Epimmune, Pharmexa works with

both therapeutic and prophylactic vaccines against HIV. The company

has a broad portfolio of vaccine candidates in HIV, which are

developed in-house, in collaboration with the health authorities in

the United States or in collaboration with other companies. A number

of Pharmexa-Epimmune's programmes in HIV are financed in whole or in

part by the NIH.

The central hypotheses in Pharmexa's work on therapeutic HIV

vaccines is that the company's vaccines can stimulate a CTL-based

immune response that helps the patient control the virus after

infection has taken place. Pharmexa's most advanced project here is

the vaccine EP1090.

The central hypotheses in Pharmexa's work on prophylactic HIV

vaccines is that the company's vaccines can stimulate both a CTL and

a HTL based memory immune response that would be re-activated upon

HIV infection. The most advanced vaccines in the prophylactic

pipeline are the EP1090 + EP1043 combination product, and the EP1233

DNA vaccine which is designed for use with the viral vector vaccine

MVA-BN32, which has been developed in collaboration with the Danish

biotech company Bavarian Nordic.

Briefly on HIV

HIV and the ensuing disease AIDS has caused more than 25 million

deaths since the disease was first observed in 1981. HIV infection

threatens a large percentage of the population in many developing

countries. In 2005 there were almost 5 million new cases of HIV

infection, which brought the total number of HIV infected

individuals above 40 million world-wide, and more than 3 million

AIDS related deaths that year. The HIV epidemic has therefore not by

any standard been contained.

Antiretroviral drugs have seen a large increase in sales since 2000

and these drugs are now used for treating the HIV infected not just

in the western world but also in many low- and middle income

countries. In 2004 alone the global market for HIV antiretrovirals

exceeded USD 6 billion, with the United States comprising

approximately 70% of the market. The antiretrovirals have reduced

the mortality for the treated patients and made HIV infection a

chronic but manageable disease for some of the patients. However,

there is still a great need for preventive vaccines, particularly in

the non-western world and for vaccines that can help those patients

that do not respond optimally to the standard antiretroviral drugs.

Hørsholm, August 29, 2006

Jakob Schmidt

Chief Executive Officer

Note to editors: Pharmexa A/S is a leading company in the field of

active immunotherapy and vaccines for the treatment of cancer,

serious chronic and infectious diseases. Pharmexa's proprietary

technology platforms are broadly applicable, allowing the company to

address critical targets in cancer, rheumatoid arthritis, bone

degeneration and Alzheimer's disease, as well as serious infectious

diseases such as HIV, influenza, hepatitis and malaria. Its leading

programs are GV1001, a peptide vaccine that has entered phase III

trials in pancreatic cancer and is expected to enter a phase II

trial in liver cancer soon, as well as a number of HIV and hepatitis

vaccines in phase I/II. Collaborative agreements include H.

Lundbeck, Innogenetics, IDM Pharma and Bavarian Nordic. With

operations in Denmark, Norway and USA, Pharmexa employs

approximately 100 people and is listed on the Copenhagen Stock

Exchange under the trading symbol PHARMX.

The AIDS Research Alliance (ARA) is a not-for-profit medical

research organization, founded in 1990, whose mission is to find and

accelerate the development of promising treatments and vaccines for

HIV-1/AIDS.

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