Excitement over anticipated approval of T-20 is balanced by fears that it will be the most expensive HIV drug yet

T-20, the first of a new class of drugs, called fusion inhibitors, is expected to get European approval this year or early next year and production is already being increased to expand the drug’s early access programme to make it available to more people with advanced HIV disease.

The drug, which is administered by injection twice a day, has the generic name enfuvirtide and will be marketed as Fuzeon. It is expected to cost $10,000 to $15,000 per patient per year, twice the price of any current antiretroviral. There are fears that this could limit the number of patients able to get treatment on the National Health Service, privately or via AIDS drug assistance programmes in other countries.

Some American activists are asking Roche and Trimeris, who are producing enfuvirtide, for the “accounting costs” of the drug.

The actual price has yet to be announced by the companies, but enfuvirtide, a complex peptide, is unusually complicated to produce and observers believe the companies will be keen to earn as much as they can before similar, but orally administered, drugs are launched by Merck and Schering-Plough.

The excitement about enfuvirtide centres on its ability to lower viral loads in people who have HIV that is resistant to other drugs. Clinical trials show that when it is added to the regimens of people whose virus is resistant, they were twice as likely to see their viral load cut to undetectable levels, as people who didn’t add enfuvirtide.

Roche has built a special manufacturing plant in the US to produce enfuvirtide and expects to produce enough for 25,000 patients by the end of next year, and to step that up the following year to 40,000 people.

There are fears that demand could outstrip supply as the number of people with drug resistant virus continues to grow.

Enfuvirtide was developed by two researchers at Duke University, Dani Bolognesi and Tom Matthews, who subsequently founded Trimeris.

Enfuvirtide binds to the protein gp41 on HIV’s surface. Once it does this, the virus cannot successfully bind with the surface of T-cells, thus preventing it from infecting healthy cells.

Bolognesi is on record as saying that concerns about the price of the treatment are “premature” and that it would not “significantly” increase the overall price of treatment because it might replace one or more drugs in a patient’s regimen.

Martin Delaney, of Project Inform, the US advocacy organisation, said: “Everyone is so pleased about the drug itself, it is such a significant development, but we are terribly apprehensive about the cost.”

The international early access programme (EAP) makes the drug available free on compassionate grounds before it becomes commercially available, and includes patients in the UK. It is limited to people over 16 with HIV-1, a viral load > 10,00 copies/mL and a CD4+ T-cell count < 100 cells/mm3 while on HAART.

A Roche spokesman told HTB that the size of the EAP is determined by the availability of enfuvirtide. The companies are currently in discussions with the regulatory authorities, doctors and community advocates to establish procedures for the programme.

They estimate that by March 2003 a further 1,200 patients will be able to access enfuvirtide through the EAP, bringing the total number of people using the drug to more than 3,000. Specific numbers for the UK were yet to be announced as this issue of HTB went to press. The companies have also yet to announce contact details but doctors are advised to contact Roche.