Shorter TB combination therapy proven effective

Shorter combination therapy has proven to be just as effective as longer monotherapy for preventing progression in patients with latent tuberculosis, according to the results of a new trial.

The phase III PREVENT TB trial tested the effects of combination therapy using 8,000 patients with latent TB infection who were at high risk for progression, according to

Given three months of weekly rifapentine plus isoniazid under direct observation, the cumulative rate of TB was .19 percent. For those patients given nine months of only isonizaid on a self-administered basis, the cumulative rate of TB was .43 percent.

According to lead investigator Dr. Timothy R. Sterling, the difference between the two groups was well within the boundary set for noninferiority,  according to Sterling reported the results of the study at an international conference of the American Thoracic Society.

Although patients given the shorter combination therapy were more likely to stop treatment because of adverse events, they were still far more likely to finish than those with the longer treatment.

"3HP was as effective as 9H in this clinical trial, but in operational settings, 3HP could be more effective than 9H, particularly if 3HP is given under direct observation and 9H has completion rates of approximately 30 percent to 60 percent," Dr. Sterling said, according to "And, with greater effectiveness, there would be more tuberculosis prevented."

The U.S. Centers for Disease Control and Prevention and the American Thoracic Society plan to update their TB recommendations when the study is published, according to Dr. Sterling.

The shorter and more potent TB treatment may improve the chances that a patient will adhere to the entire protocol, Dr. Kenneth Castro said, according to Castro is the director of the Division of TB Elimination at the National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention at the CDC.

"As someone who has been in the business of fighting TB for a long time, I can’t tell you how pleased I am to be able to offer a three month regimen: 12 doses and you are done," Dr. Castro said, according to