New TB drug holds promise for shortened treatment
Washington: Data from a phase 2b clinical trial has shown that a new TB (tuberculosis) drug regimen eliminated more bacteria from sputum than standard therapy and did so at a faster rate.
The results were published just as the global phase 3 clinical trial, designed to bring this regimen through the last stage of testing, has begun, The Lancet reported.
PaMZ is a three-drug regimen comprising two candidate drugs that are not yet licensed for use against TB.
The therapy is intended for those patients whose TB infections are sensitive to the three drugs, including people with drug-sensitive and multidrug-resistant TB (MDR-TB).
"The results of this trial show the potential for the PaMZ regimen to improve treatment for tuberculosis," said Rod Dawson, head of the Centre for TB Research Innovation at the University of Cape Town in South Africa, and lead author of the paper.
Especially noted is the fact that PaMZ may have a unique application as a potentially shorter, injection-free regimen for a select sub-group of patients with MDR-TB, Dawson added.
The phase 2b trial tested PaMZ in an eight-week study that enrolled more than 200 patients and took place at eight sites in South Africa and Tanzania.
Nearly twice (71 percent) 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 compared to patients treated with standard therapy (38 percent).
Patients that tested the effectiveness of PaMZ on MDR-TB responded similarly to those with drug-sensitive TB.
"PaMZ is the first regimen under development to treat both drug-sensitive TB and MDR-TB," said the president and CEO of TB Alliance, the trial's sponsor, Mel Spigelmen.
If successful in the phase 3 trial, the PaMZ regimen would eliminate the need for injectable drugs and reduce the cost of MDR-TB therapy by more than 90 percent.
It also promises to be compatible with commonly used HIV drugs, helping the millions of people co-infected with TB/HIV.
Limitations in standard treatment remain a strong barrier to TB control. The treatment and cure of a typical case of drug-sensitive TB currently takes between six and nine months.
People with multidrug-resistant TB require a minimum of 18 to 24 months of treatment.
This more extensive therapy requires more than 14,000 pills and daily injections for at least six months.
The long duration of MDR-TB treatment combined with the pain and side effects that the treatment causes are major obstacles the new therapy intends to overcome.