Antibiotic moxifloxacin as a new treatment for tuberculosis

Oct 17 2005

A Johns Hopkins infectious disease expert will lead two international studies of the effectiveness of the antibiotic moxifloxacin as a new treatment for tuberculosis, the highly contagious bacterial disease that kills more than 2 million people worldwide each year and is the leading cause of death of people living with HIV and AIDS. Moxifloxacin is currently approved in more than 100 countries, including the United States, as a treatment for bacterial respiratory infections, such as bronchitis, sinusitis and pneumonia.

“Defeating the spread of tuberculosis in the United States and the developing world will require scientists to take bold and creative new approaches because there has not been a new therapy for tuberculosis in more than 40 years,” says tuberculosis expert Richard Chaisson, M.D., a professor of medicine, epidemiology and international health at The Johns Hopkins University School of Medicine.

Chaisson will conduct the research as part of a series of studies on moxifloxacin that are being coordinated by the nonprofit Global Alliance for TB Drug Development (GATB) in collaboration with Bayer Healthcare AG, the drug’s maker. His research will assess the ability of moxifloxacin to shorten the treatment period required to cure the disease.

One of Chaisson’s studies will take place in Brazil, with support from the U.S. Food and Drug Administration’s Office of Orphan Product Development. He will co-direct the second study with Susan Dorman, M.D., an assistant professor at Hopkins, and John Johnson, M.D., of Case Western Reserve University. The study will take place in five countries - the United States, Canada, Brazil, Spain, South Africa and Uganda - with funding support from the U.S. Centers for Disease Control and Prevention’s TB Trials Consortium. (Maryland is one of the 10 U.S. states where the second study will take place.)

The overall research program, expected to last two to three years and enroll close to 2,500 patients worldwide, was to be announced today at a news conference during the 36th annual World Conference on Lung Health in Paris, France. Other related studies of moxifloxacin will be led by Stephen Gillespie, M.D., of the University College-London, and Andrew Nunn, M.D., of the British Medical Research Council.

The GATB estimates that 1 billion people worldwide will be infected with tuberculosis by the year 2020, of whom 200 million will fall ill and 35 million will die. The group is developing moxifloxacin and other drugs in an effort to cure more patients by shortening the length of time it takes to treat the disease.

“Shortening the time required to cure the disease could save millions of lives in the coming years,” Chaisson says.

Chaisson has more than two decades of experience researching the tuberculosis epidemic, especially its impact on the health of people in developing countries, where most of the 9 million new cases of the disease occur each year. Current treatments for tuberculosis, Chaisson says, consist of a regimen of four antibiotic drugs usually, but not always, given in view of a caregiver. Called Directly Observed Therapy Short-Course, or DOTS, the drugs must be taken several times daily for six to eight months. Although DOTS cures 95 percent of those treated, the lengthy treatment period has proven a problem for patients, who sometimes miss taking their drugs on time, minimizing the therapy’s effectiveness.

Chaisson notes that multidrug-resistant strains of the tubercle bacillus, formally known as Mycobacterium tuberculosis, are spreading at a rate of 300,000 newly diagnosed cases each year that cannot be treated by current drugs. “New options are needed, and they need to be both effective and easier for patients to tolerate,” he adds.

Chaisson says that substituting moxifloxacin for one of the key ingredients in DOTS could shorten the treatment period by nearly two months, to three to four months, making the form far less costly overall.

As part of the research program, Bayer has agreed to donate supplies of moxifloxacin for all of the trial sites, including those in Tanzania and Zambia that are part of a third study not involving Hopkins. The TB Alliance will coordinate the trial and cover study costs, with additional support from the European and Developing Countries Clinical Trials Partnership.

In addition to the moxifloxacin study, Chaisson directs the Hopkins-based Consortium to Respond Effectively to the AIDS/TB Epidemic, called CREATE, an international effort to control the spread of tuberculosis and treat the disease in countries hit most hard by the duel epidemics. CREATE, which is sponsored by the Bill and Melinda Gates Foundation, has three community-based studies under way in Africa and Brazil.

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