Today, the U.S. Food and Drug Administration (FDA) approved bedaquiline as the first new drug for tuberculosis (TB) in 40 years. This important news comes at a time when the incidence of multi-drug resistant (MDR) TB is growing worldwide and public health officials are in desperate need of better drugs
to contain the most dangerous strains.
There are many reasons why there has been such a drought in TB drug development. TB incidence declined dramatically following the introduction of antibiotics in the 1950s, and pharmaceutical companies stopped investing in the development of new therapies as a result.
But it’s been clear since the early 1990s that TB is on the rebound globally. Drug-resistant forms of the disease, and the high incidence of TB among people living with HIV, have fueled a surge in cases that are increasingly difficult to treat.
According to the most recent data from the WHO
, there were more than 300,000 patients with multi-drug resistant (MDR) TB worldwide in 2011, and only one in five of those cases received appropriate treatment with second-line drugs. And while TB is relatively well controlled in the United States, MDR TB knows no boundaries. Nearly 100 cases were detected nationwide in 2010
, requiring patients to enroll in 18 months of intensive treatment, including six months of daily injections.
First discovered in 2004
, bedaquiline kills TB bacteria by interrupting their energy production, which is an entirely new action mechanism. This means that there is no existing resistance to it. When added to existing treatments for MDR TB, the evidence presented to the FDA
suggests that bedaquiline can improve cure rates and reduce the chance of relapse as well.
The FDA review noted that there are still gaps in our knowledge about bedaquiline at this early point. Without careful monitoring, the drug could potentially cause some side effects
affecting the heart and liver, and these risks need to be better understood. Bedaquiline also has a very long half-life, meaning that it stays in the body for over 150 days, and it could interact with other medications. The drug’s manufacturer, however, has committed to launching a larger clinical trial to demonstrate the drug’s benefit and conduct additional safety and drug interaction studies.
Bedaquiline appears to be just the first step in an exciting renaissance for TB drug development. Another new drug, delamanid
, is currently in late clinical trials and has been submitted to the European Medicines Agency for review as a treatment for MDR TB.
The next important step is to pursue new combination therapies for TB that don’t rely on a single drug and could limit the emergence of resistance over time. A coalition of researchers, the FDA, and a public-private-nonprofit consortium called Critical Path to TB Regimens
(CPTR) are exploring the possibility of developing new combination therapies for TB that could be presented to the FDA for review and approval, and the Global Alliance for TB Drug Development
(TB Alliance) is currently conducting studies to explore combination therapies that could provide effective treatment of MDR and drug-sensitive TB.
It’s an exciting time for TB treatment, but much more needs to be done and more resources are needed. We need to focus not only on the discovery and development of new drugs, but also on ensuring that news drugs are delivered to those who need them and in combinations that can prevent the emergence of new types of drug resistance.