12 Dec 2007

High hopes for TB treatment

A new therapy for treating tuberculosis could cut the current six-month treatment time in half, expand the numbers of patients and save millions of lives, the Global Alliance for TB Drug Development said Monday.

The Alliance and Bayer HealthCare AG announced a partnership to coordinate clinical trials of the combination therapy for about 2 500 patients in South Africa, Uganda, Brazil, the United States, Canada, Spain, Tanzania and Zambia. Some trials have already been conducted or are under way in South Africa and Uganda.

The initiative addresses the leading cause of death for people infected with HIV, the virus that causes Aids, and is an example of the new public-private partnerships that are focusing attention on so-called "neglected diseases" in the developing world.

Dr Maria C. Freire, president and chief executive officer of the Alliance, said the new treatment, which could be approved in five years, has the potential to reduce the six months of treatment for tuberculosis by two to three months, lower the risks of developing resistant strains and expand the number of patients receiving treatment.

May save millions of lives
"Our model of what shorter therapy means is that it literally will save millions of lives," Dr Mel Spigelman, the head of research and development for the Alliance, said in a telephone interview.

Currently about 9 million new active cases of the disease develop and about 2 million people die of the disease each year. According to current projections, 200 million more people will fall ill with TB by 2020 and 35 million will die.

In Africa and other places in the developing world where medical infrastructure can be primitive, Freire said shortening the treatment time will have a major impact on adherence and on reducing the number of infections from resistant strains. The Alliance said about 400 000 new cases of TB infection each year are multi-drug resistant. Resistant strains develop when patients do not adhere to the arduous six-month treatment until they are cured.

Antibiotic combined with TB drugs
The trials will test the effectiveness of using the antibiotic moxifloxacin in combination with existing tuberculosis drugs. Moxifloxacin has already been approved in 104 countries for treatment of bacterial respiratory and skin infections. The tests seek to have it registered as a treatment for tuberculosis.

The HIV pandemic is responsible for much of the explosion in the numbers of new tuberculosis cases each year and is the reason the World Health Organization now says the Millennium Development Goal of reversing the growth in TB by 2015 will not be achieved. There are an estimated 12 million people infected with both HIV and TB.

Dr Wolfgang Plischke, head of the pharmaceuticals division at Bayer HealthCare, said some of the drugs currently used to treat tuberculosis react adversely with the anti-retroviral cocktails used to treat HIV.

Antibiotic used with ARVs
"Moxifloxacin doesn't have that problem," said Plischke, who added that the antibiotic has been used successfully to treat other infections in people taking anti-retrovirals for HIV. "There is no reason to think it will react with anti-retrovirals."

Plischke said about 2 billion people worldwide are infected with the tuberculosis bacteria, which can lay dormant in its victims for years. About a third of those infected develop active cases. It flares up and kills people with compromised immune systems such as the elderly, Aids patients and others stricken with disease.

"That number is mushrooming," said Plischke.

Freire said if the new therapy successfully cuts the treatment time by two to three months as studies indicate, the goal of reversing the growth in TB infections by 2015 will be met.

In the trials, Moxifloxacin will be substituted for either ethambutol or isoniazid, two drugs used in the current treatment that was developed more than 40 years ago.

Commercial, academic partnership
The clinical trials are part of a growing trend of partnerships under which contributions from companies and academic centres are coordinated and which now account for three-quarters of the neglected-disease drug projects.

Under terms of this partnership, Bayer will donate moxifloxacin for each trial site and cover the costs of regulatory filings. The TB Alliance and its partners are helping to cover the cost of the trials and will manage the trial programme. The trials will be conducted by the US Centres for Disease Control TB Clinical Trials Consortium, John Hopkins University and the University College London working with the British Medical Research Council.

The Alliance and Bayer have agreed that if the treatment is registered, they will make the treatment available at affordable prices in the majority of the world's low and lower-middle income countries as defined by the World Bank. - (Sapa-AP)