Trial of all-oral XDR-TB treatment begins

Investigators have launched a clinical trial of a novel oral regimen used to treat patients with extensively drug-resistant tuberculosis, according to a press release.

The Nix-TB trial will assign patients with extensively drug-resistant tuberculosis (XDR-TB) in South Africa to the regimen, which has the potential to simplify XDR-TB management and reduce TB-related health costs, according to the release from TB Alliance.

The cohort of the open-label trial will include patients aged 14 years and older plus patients coinfected with HIV who have a CD4 count of 50 or more.

“The study is the first to test a novel and potentially transformative regimen for XDR-TB, which could be a valuable tool as we battle this problem on the front lines in South Africa and around the world,” Francesca Conradie, MD, investigator and clinical advisor at Sizwe Hospital in Johannesburg, South Africa, said in the release. “The strategic emphasis by our National Department of Health on clinical research for drug-resistant TB coupled with rigorous regulatory framework has enabled this trial to be conducted in South Africa.”

Francesca Conradie

The three-drug combination includes Sirturo (bedaquiline, Janssen Therapeutics), a regulatory-approved treatment in several countries with high-TB infection; pretomanid, TB Alliance’s antibacterial compound investigated in multiple clinical trials; and oxazolidinone, an off-label treatment of TB. Researchers anticipate the minimally resistant drug regimen will cure patients within 6 to 9 months of treatment, but will continue to monitor patients for 2 years.

Currently, patients with XDR-TB are assigned to drugs not intended for TB management or long-term use, according to TB Alliance. A recent study showed that few patients (16%) in South Africa were cured of XDR-TB after 2 years of treatment.

“TB must be treated in multidrug combinations or regimens to enhance efficacy and prevent the development of resistance,” Mel Spigelman, MD, president and CEO of TB Alliance, said in the release. “Therefore, the Nix-TB trial fills a critical gap and capitalizes on the availability of novel drugs by studying them together in the most vulnerable TB population, those with XDR-TB.”

Mel Spigelman

Other limitations in current XDR-TB treatment include the high costs for therapy, particularly in TB-endemic countries.

“We now see the possibility of a single TB regimen that can treat virtually all patients with active TB with a relatively simple and affordable regimen,” Spigelman said.
Researchers will incorporate improved treatments into the trial if they become available, according to the organization.

If the regimen is successful, it may be further evaluated as a treatment option for patients with MDR-TB and drug-sensitive TB.

For more information:

Pietersen E, et al. Lancet. 2014;doi: 10.1016/S0140-6736(13)62675-6.