GAR

News and Events

28/01/2008 10:43:52

HIV patients get new drug in battle to keep AIDS at bay

A new class of drug for people with HIV is being introduced in Britain today, having been described by researchers as a huge step forward in treating the deadly infection.

Raltegravir, available as tablets to be taken twice a day, is approved for use with other antiretroviral drugs to treat HIV in about one in ten patients whose therapy has stopped working. Because of their potential to prolong life by decades, HIV drugs are considered cost-effective and raltegravir is likely to be available on the NHS for all infected patients.

Doctors believe that the drug could become standard treatment, potentially preventing HIV progressing into full-blown Aids. Three quarters of trial patients showed a significant reduction in viral load – the prevalance of the virus in their bloodstream – compared with 40 per cent taking current medication alone. Some patients had a marked improvement to the point where levels of the virus were “undetectable”, doctors said.

An estimated 73,000 people in Britain are infected with HIV, or human immunodeficiency virus, which culminates in Aids (acquired immunodeficiency syndrome). Although HIV infection is still considered serious, early diagnosis and appropriate treatment can allow for a relatively normal lifespan.

HIV continually changes and can become resistant to treatment, leading to a continuing search for new drugs. Raltegravir is the first in a new class of HIV treatments called integrase inhibitors, which it is hoped will avoid the risks of heart attack and cancer associated with existing medication. It works by blocking integrase, an enzyme that HIV relies on to replicate itself. It affects the ability of the virus to infect other cells, thus reducing the blood’s viral load.

During the trials, patients were given raltegravir or the dummy drug plus optimised background therapy (OBT), a regime of antiretroviral drugs tailored to individual patients.

One study published in The Lancet in April last year was based on 178 patients with advanced HIV. They had been taking regular antiretroviral drugs for about ten years but were not responding to them. Patients taking raltegravir had an average of a 98 per cent drop in their HIV ribonucleic acid (RNA) count, compared with 45 per cent in the dummy group. The number of CD4 cells, an indicator of the immune system’s ability to fight disease, was also boosted.

Made by the US-based company Merck, the drug is also known by the brand name Isentress. Mark Nelson, director of HIV services at the Chelsea and Westminster Hospital, London, said that it had already provided a life-line to 30 of his patients. “While this is not a ‘cure’ for HIV it does mean we can suppress the virus to where it is virtually undetectable.”

Dr Nelson added that the drug’s long-term safety record would be very important, given that more adverse effects from existing treatments were emerging after many years of therapy.

“Raltegravir is going to be popular because it’s very effective and it seems to have a good safety profile,” he said. “Previous drugs have done a terrific job keeping people alive. But now we have to start thinking about safety.”

Eight years and four different drug cocktails after Philippe B, 41, learnt that he had HIV, he almost gave up.

“Ten years ago nobody told you anything about the drugs or how to take them, so I stopped for a few months. I became resistant and had to change my combination. Every new combination meant new side effects – nausea, diarrhoea. Sometimes the fatigue was so bad, I couldn’t get out of bed.”

Philippe, who works for the Terence Higgins Trust, had a viral load of 500,000 (more than 100,000 is considered high) and was in hospital with toxoplasmosis, ulcers and paralysis. After three months, he started a new regime that was the first to work – his viral load is below 50.

Philippe says that he is lucky because he has yet to run out of drug options. “It’s very important that there are new drugs. HIV is not a death sentence any more but there’s still no cure. After you become resistant, you start running out of options.”




 

Sources: UNAIDS; Times database





Back to News and Events.