Researchers have revealed that interim results from an ongoing phase 2 trial of the experimental drug TMC207 for the treatment of multidrug-resistant tuberculosis (MDR-TB) have shown promise.
Experts running the trial have revealed that the addition of TMC207 for eight weeks to a 5-drug background regimen, in patients with MDR-TB, resulted in a significant increase in the proportion of patients achieving a negative sputum culture and a shorter time to sputum culture conversion compared with the background regimen alone.
"The results of this study are highly encouraging news for the treatment of tuberculosis," the New England Journal of Medicine quoted Dr. Peter Donald, Professor Emeritus, Stellenbosch University in Capetown, South Africa, as saying.
"Not only is this an agent with a radically different means of action, but it shows potential to shorten the treatment of tuberculosis in the foreseeable future, something the tuberculosis community has been hoping for years," he added.
The researchers are investigating TMC207 as part of a combination therapy for the treatment of MDR-TB. The results reported are from the first stage of a two-stage Phase II randomised placebo-controlled trial.
The researchers said that they randomised 47 hospitalised patients with newly diagnosed multidrug-resistant pulmonary TB to receive TMC207 daily for 2 weeks, followed by 200 mg three-times weekly for 6 weeks, or placebo in combination with a standardized 5-drug background second-line antituberculosis regimen.
Six subjects discontinued the study prematurely. This first stage was conducted in South Africa, where the prevalence of MDR-TB is particularly high.
The results of bacterial culture of sputum showed more patients were TB culture-negative at 8 weeks in the TMC207 group, 47.6 per cent versus 8.7 per cent in the placebo group.
The researchers also found that TMC207 reduced the time to culture conversion.
Most adverse events were mild to moderate and only nausea occurred more frequently with TMC207 than with placebo.
One subject in each treatment group experienced a serious adverse event, neither of which was considered to be related to the study medication.
The data obtained validate ATP synthase as a viable target for the treatment of TB.
"The nearly half a million estimated new cases of MDR-TB annually highlights the urgent need for a paradigm shift in the way this disease is being tackled. The development of TMC207 is a tribute to the dedication of our scientists, to innovation and to the commitment of our company to accelerating the development of new drug regimens for tuberculosis," said Roger Pomerantz, President, Tibotec Research and Development.
The safety and efficacy of TMC207 are being further evaluated in ongoing and future trials.