by Erica Lessem
December 28, 2012, was a historic day for the one million people around the world with strains of tuberculosis (TB) that are particularly difficult to treat. For the first time in forty years, the United States Food and Drug Administration (FDA) approved a new drug, bedaquiline for TB. This approval follows the first ever public hearing to review a new drug for TB, in which the expert panel unanimously found the drug effective at fighting multidrug-resistant (MDR) TB. (MDR-TB is defined as a strain of Mycobacterium tuberculosis that is resistant to at least isoniazid and rifampicin, two of the four first-line drugs that are used to treat TB.) Currently, MDR-TB patients have to endure up to two years of treatment with toxic existing drugs, only to have just a fifty percent chance of surviving. The FDA’s decision sets both a precedent around the world for other regulatory authorities, and the tone for the future of the TB drug pipeline.
New drugs are urgently needed in order to get to zero deaths, new infections, and suffering from TB. Less than five percent of the million people with MDR-TB receive appropriate treatment. Among the tiny proportion able to access care, fewer than half are cured. Even treatment success can mean hearing loss, liver damage, and psychosis.
In the past decade, after years of stagnation, TB drug research has undergone a renewal. Bedaquiline (also known as TMC207, or by its trade name, Sirturo) is the first novel drug candidate coming out of this renewal to be approved. Based on results from early-and middle-stage research studies in people with MDR-TB, combining bedaquiline with existing TB drugs clears the bacteria more quickly than existing drugs alone. This means that including bedaquiline could make MDR-TB treatment shorter and more effective.
There is, however, some concern about the drug’s safety. As such, Mark Harrington, the Executive Director of Treatment Action Group (TAG), urged the FDA advisory committee in his public testimony, “Be bold. Make history. But do it stringently.” The FDA has granted accelerated approval for bedaquiline (meaning before results from larger, phase III trials are available), and therefore must require bedaquiline’s sponsor to carry out a phase III trial quickly, as well as conduct other necessary studies into the drug’s safety, suitability in children and people with HIV, and potential for use along with other novel drug candidates such as delamanid, which is following closely on bedaquiline’s heels.
In order for a real renaissance in TB treatment to occur, the world needs more than just one new FDA-approved drug. Other countries need support and urging to build their infrastructure to approve and introduce new drugs such as bedaquiline in a timely fashion, and to make them available for urgent cases on a pre-approval basis. Additionally, only with other safe and effective new options to fight TB can we ensure new drugs’ effectiveness in the long-term by preventing resistance, and stop unnecessary suffering from current toxic and ineffective drugs. However, as illustrated by TAG’s recently released 2012 Report on Tuberculosis Research Funding Trends, 2005-2011, TB drug research still faces a shortfall of nearly half a billion dollars. By not only approving bedaquiline but also ensuring that proper follow-up studies are completed soon, the FDA could demonstrate to MDR-TB patients and providers that they matter, signal to other regulatory authorities around the world that TB is a priority, encourage developers and investors that there is a market and clear approval pathway for TB drugs, and ultimately herald a new era in TB treatment.