In the current standard six-month course of tuberculosis treatment, patients need to take four drugs daily for two months followed by two drugs daily for four months – around 360 tablets over a six-month period. The RIFAQUIN trial assessed whether a combination treatment of six or four months duration that included rifapentine (a rifamycin) and moxifloxacin (a quinolone) could reduce the frequency of taking tablets by patients in a six-month treatment by introducing a weekly treatment, or reducing the length of treatment from six months to four months.
The study, led by Dr Amina Jindani (INTERTB Consortium at St George’s, University of London), enrolled 827 patients in trial sites in Botswana, South Africa, Zambia and Zimbabwe. Study participants were assessed 12 months after finishing their treatment. The results show that 95% of patients taking the six-month rifapentine and moxifloxacin combination were cured, which was similar to the standard regimen. Unfortunately, the four-month treatment proved less effective than the six-month treatment.
The new once-weekly drug combination, therefore, could make treatment adherence easier. Dr Jindani said: “Fewer tablets means there is a higher chance of the patient completing their treatment. It also makes it easier for clinics to supervise treatment. This is particularly important for countries where clinics are severely under resourced and where it is not uncommon for patients to travel many miles in order to receive treatment.”
According to the researchers, a number of considerations need further investigation before health services could prescribe the new treatment combination. These include the cost effectiveness of the proposed regimen and the effectiveness of the proposed regimen in HIV-positive patients, who are particularly at risk of tuberculosis.