New TB test can simultaneously detect resistance to first- and second-line drugs
The Foundation for Innovative New Diagnostics (FIND) and Cepheid have announced the launch of the new Xpert MTB/XDR test, which enables expanded drug-resistance tuberculosis (TB) profiling in less than 90 minutes. The Xpert MTB/XDR can be used to empower clinicians to quickly prescribe treatment regimens for extensively drug-resistant TB (XDR-TB), according to a release from Cepheid.
Able to detect TB that is resistant to multiple first- and second-line TB drugs, the test could help fill a critical gap that is currently jeopardizing global TB elimination targets. By contrast, current methods for identifying drug-resistance profiles for XDR-TB are very complex to perform, can take up to 16 weeks to deliver results, and as a result are often completely unavailable to patients.
XDR-TB is the most complicated form of TB, with the worst outcomes. Mortality has been reported as high as 41 percent in some cohorts. The scientific community has been focused on coordinating innovation to improve both diagnosis and treatment of XDR-TB for years. The World Health Organization (WHO) recommends rapid molecular testing and detection of drug-resistant TB as an essential condition for the implementation of new treatment regimens.
"An ordinary TB diagnosis is awful, but XDR-TB is the worst nightmare of every TB doctor and every patient," said Catharina Boehme, CEO of FIND. "Recent treatment advances are already making a huge impact, but for the best chances of survival, patients need to be able to start on treatment as soon as possible – and the only way for that to happen is through rapid diagnosis. By providing test results in just a few hours, the Xpert MTB/XDR test will save lives."
Xpert MTB/XDR leverages Cepheid's new 10-color technology, which enables the detection of multiple mutations across several genes, from a single sample. Xpert MTB/XDR can detect resistance to isoniazid, ethionamide, fluoroquinolones, amikacin, kanamycin and capreomycin. Access to testing that can reliably identify resistance towards isoniazid, as well as to fluoroquinolones and amikacin, will help enable clinicians to quickly select the most appropriate MDR-TB treatment for each individual patient.
"Rapid testing of resistance to isoniazid and fluoroquinolones is a critical step towards ensuring those who are ill with drug-resistant TB, and in particular XDR-TB, can access treatment and care early – in line with the latest WHO guidelines on the treatment of drug-resistant TB," said Tereza Kasaeva, Director of the WHO Global TB Programme. "WHO is looking forward to receiving all relevant data on the GeneXpert MTB/XDR cartridge from Cepheid and partners to rapidly proceed with an evaluation of the new test."
The test runs on Cepheid GeneXpert systems equipped with 10-color multiplexing modules. GeneXpert 10-color modules are capable of processing the already widely used Xpert MTB/RIF^ and Xpert MTB/RIF Ultra tests for diagnosis of TB and rifampicin resistance.
