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,"
said tuberculosis expert Richard Chaisson, a professor of
medicine,
epidemiology and
international health at The Johns Hopkins University's
School of Medicine and
Bloomberg School of Public Health.
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 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, an assistant professor at
Johns Hopkins, and John Johnson, of Case Western Reserve
University. The study will take place in six 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 announced last week at a news conference during the
36th annual World Conference on Lung Health, held in Paris.
Other related studies of moxifloxacin will be led by
Stephen Gillespie, of University College London, and Andrew
Nunn, of the British Medical Research Council.
The Global Alliance for TB Drug Development estimates
that 1 billion people worldwide will be infected with
tuberculosis by the year 2020; of these, 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
said.
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
said, 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 said 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," he said, "and they need to
be both effective and easier for patients to tolerate."
Chaisson said 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 the trial sites,
including those in Tanzania and Zambia that are part of a
third study not involving Johns Hopkins. The Global
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 Johns 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.