Scientific American (08.05.2013)
Researchers have discovered a synthetic compound that shows promise as a new and different type of TB treatment. Kevin Pethe, a microbiologist at the Pasteur Institute in Korea, and colleagues researched more than 120,000 substances throughout a five-year period to find compounds that could kill Mycobacterium tuberculosis, the bacteria that causes TB. They infected mouse immune cells called macrophages with TB bacteria and observed which of the substances stopped the bacteria’s growth. The researchers found one successful substance, which they selected for further study.
The synthetic compound worked in a different way from current TB drugs. It prevented the synthesis of adenosine triphosphate, a chemical used by cells for energy, thus blocking the bacteria’s growth. Laboratory tests showed that the compound successfully treated TB in mice. The researchers hoped it would be harder for TB to develop resistance to this substance, since it worked differently from existing drugs. However, before researchers approve the new synthetic substance to treat humans, they must subject it to clinical trials to test for safety and tolerability.
The high cost of clinical trials will be another issue to resolve. State-funded institutions such as the Pasteur Institute normally focus on discovery, while pharmaceutical companies work on drug development. For this compound, the Pasteur researchers will conduct the clinical trials with funding from the Korean government and a company called Qurient, which is a spinoff of the Pasteur Institute. Meanwhile, Pethe and colleagues will continue to investigate new molecules to find more TB drug prospects.
The full report, “Discovery of Q203, a Potent Clinical Candidate for the Treatment of Tuberculosis,” was published in the journal Nature Medicine (2013; doi:10.1038/nm.3262).