New MDR-TB drug regimen works faster, shortens treatment

A new study published in The Lancet yesterday showed that a new tuberculosis (TB) drug regimen eliminated more bacteria from sputum and also acted faster than currently-prescribed drugs.

The journal published the results of a phase 2b clinical trial of the three drug regimen called PaMZ. The PaMZ regimen comprises two candidate drugs that are not yet licensed for use against TB -- pretomanid (Pa) and moxifloxacin (M) -- and one antibiotic called pyrazinamide (Z) that had been approved for use in TB treatment.

The PaMZ therapy is known for cutting down the number of drugs and also the period of treatment of a TB patient.

At present, patients with multi-drug-resistant TB, for instance, need to take numerous drugs over a two-year period, but the PaMZ, which has been extensively tested in South Africa, could potentially cut down these number drastically to four to six months.

India was yet to warm up to the PaMZ regimen due mainly to some doctors reporting widespread resistance among Indian patients to moxifloxacin and pyrazinamide.

Meanwhile, according to Dr Rod Dawson, the lead author of the study published in The Lancet, who is honorary senior consultant in the divison of pulmonology, in the department of medicine at the University of Cape Town, the trial showed the potential for the PaMZ regimen to improve treatment for tuberculosis. Dawson heads the Centre for TB Research Innovation at the University of Cape Town, South Africa.

According to the report, the results were published just as the global phase 3 clinical trial, designed to bring this regimen through the last stage of testing, had begun.

The therapy is intended for those patients whose TB infections were sensitive to the three drugs, including people with drug-sensitive and multidrug-resistant TB (MDR-TB).

The phase 2b trial tested PaMZ in an eight-week study that enrolled over 200 patients and took place at eight sites in South Africa and Tanzania.

The trials showed nearly twice (71 per cent) as many TB patients treated with PaMZ had no TB in their sputum when cultured at the end of the two-month course of the trial as against patients treated with standard therapy (38 per cent).

Patients that tested the effectiveness of PaMZ on MDR-TB responded in a similar fashion to those with drug-sensitive TB.

According to Mel Spigelmen, the president and CEO of TB Alliance, the trial's sponsor, PaMZ was the first regimen under development to treat both drug-sensitive TB and MDR-TB.