WASHINGTON -- After nearly 50 years, the drug development pipeline for new tuberculosis (TB) treatments is finally opening up again, according to infectious disease specialists.
The first drug to treat tuberculosis was developed in 1943, and for 20 years, only a handful of others were developed. Streptomycin was the last drug to be approved for treatment of the disease, and that was in 1963.
About 8.8 million people become infected with TB each year, and 1.4 million die from it, mostly in developing countries. And drug resistance has become an increasing problem -- in large part because between 20% and 30% of people who start the long, complex treatment course stop before it's complete.
But, although the National Institutes of Health (NIH) budget has been flat since 2008, funding within the agency for TB research has increased, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, told reporters at a Monday afternoon briefing on the state of TB research.
"For the first time in a very long time, the TB pipeline is showing significant progress," Janet Woodcock, MD, director of the FDA's Center for Drug Evaluation and Research (CDER), said at the briefing, which was sponsored by the TB Alliance.
Eradicating TB will rely on having novel therapies, not just the same drugs and diagnostics that have been around since the early 1900s, said Robert Clay, MD, deputy assistant administrator for the Global Health Bureau of USAID.
One trial seen as having potential is currently enrolling patients for its stage IIb phase. The trial is testing three drugs -- novel agents PA-824 and pyrazinamide, as well as the commonly-used drug moxifloxacin. It is taking place in Africa and South America among a mixed group of 250 TB patients, some of whom are drug-resistant, some of whom are drug-sensitive, and some of whom are neither.
The trial is being funded by the TB Alliance, Bayer, Novartis, and USAID, and draws on early research funded by the NIH, the TB Alliance, and the Bill and Melinda Gates Foundation, said Mel Spigelman, MD, president and CEO of the TB Alliance.
If the data pans out, the treatment regimen for TB could be reduced to a four-month, once-daily oral regimen and costs of treatment cut by 90%, he said.
Other ongoing trials also aim to cut treatment time down to as low as two months, but it would be a major advance in the field if a TB therapy were developed that cuts down treatment time to seven to 10 days, said Spigelman.
Fauci went further, saying he's hopeful there will be a vaccine for TB in the next decade. But, he noted, it's difficult to encourage companies to invest in TB because it's not a research area that is viewed as holding the potential for a blockbuster drug.
"Within the drug development world, TB is not cancer, diabetes, or heart disease," Fauci said.
"A lot of what we're doing is relying on a 19th century tool: the microscope," the USAID's Clay said. "Unless we have some new tools, we're not going to reach our goal of having a TB-free world in 2030."
One such tool was hailed as a major advance in the TB field with the publication in 2010 of results from a trial that found a two-hour molecular diagnostic test had high sensitivity in detecting tuberculosis.
The automated test represented a significant advance over the gold-standard culture methods for diagnosing active TB, which usually takes weeks.