LIVERPOOL, England – Data from an ongoing trial presented today indicates patients with extensively drug resistant tuberculosis for whom other treatments had failed showed signs of full recovery from disease following a six-month regimen of two recently developed tuberculosis drugs and one repurposed drug.
Extensively drug-resistant tuberculosis, or XDR TB, defined as tuberculosis resistant to at least two first line drugs used to treat the disease, and two drugs used to treat patients with strains of disease resistant to multiple drugs, is so difficult to cure that only about one in five XDR TB patients survive their illness beyond five years, said researchers presenting interim data from the Nix-TB study of the new, combined regimen.
The regimen consisted of bedaquiline, which in 2012 became the first new anti-tuberculosis drug in 50 years to receive regulatory approval, pretomanid an investigational drug developed by TB Alliance, and linezolid, a repurposed drug used normally for other resistant infections. All of the medicines are delivered in pills, simplifying treatment that can involve painful injections.
Current, non-experimental regimens for XDR-TB consist of “the kitchen sink approach,” lead investigator Dr. Francesca Conradie of Witswatersrand University said this morning, “giving every possible treatment you can think of to save the patient’s life.”
For the 51 patients enrolled so far in the Nix-TB study that began in April 2015, those options had been exhausted. Half of them were co-infected with HIV. A total of four died within the first seven weeks of the study from their disease. Of the 33 who have completed treatment, none showed any evidence of tuberculosis in their sputum after four months. After completing six months of treatment, 20 have been followed for six more months and showed no evidence of illness. Treatment is ongoing for 14. Only the linezolid was noted to cause side effects, which were manageable in the clinical trial setting, Dr. Conradie said.
“This is a phenomenal breakthrough in the treatment for XDR TB,” Dr. Conradie said.
The results she said, were rewarding for physicians as well as patients. “Doctors practice medicine because they don’t want patients to die,” she said.
She described one patient, a young woman hospitalized for a year, who already had seen her sister die of XDR-TB. When she learned that her tests no longer showed signs of infection, Dr. Conradie said, “they thought in the ward that she had gone crazy. In fact she was praying, and praising God.”