NIH-Funded Trial Will Assess New TB Drug
Investigators plan to compare oxazolidinone antibiotic with standard TB therapy (Dec. 11)
A clinical study will examine an investigational drug’s early bacteria-killing activity in patients newly diagnosed with drug-sensitive pulmonary tuberculosis (TB). The clinical trial — sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health — is being led by researchers at Case Western Reserve University in Cleveland and will be conducted in South Africa.
According to the World Health Organization, 8.7 million people worldwide had TB in 2011, and 1.4 million people died from the disease. Co-infection with TB causes one quarter of all deaths among persons infected with human immunodeficiency virus (HIV). South Africa has the highest TB infection rate in the world and accounts for 5% of the global TB burden. The country also has the highest TB/HIV co-infection rate at 73%.
“New, simplified treatments that cure TB infection more quickly are desperately needed,” said NIAID director Anthony S. Fauci, MD. “It has been nearly 50 years since a new drug specifically developed for TB was licensed. This is a relatively small study, but we hope it yields insights into whether this investigational drug shows promise in people who are newly diagnosed with TB, as laboratory and earlier clinical safety trials indicate it might.”
The clinical trial will assess an investigational oxazolidinone antibiotic (AZD5847) developed by AstraZeneca. In a laboratory setting, the drug proved active against a wide range of drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis — the bacterium that causes TB disease. In two preliminary human studies in the U.S., the oral drug was generally well-tolerated. Some study participants experienced gastrointestinal and blood-related adverse events at higher doses, but these effects were reversible and not serious.
The new study will enroll a total of 75 men and women aged 18 to 65 years with TB, including individuals who are also infected with HIV but who are not yet taking antiretroviral treatment.
The study volunteers will be randomly assigned to participate in one of five study groups, each with 15 participants. In four groups, the participants will receive a 14-day regimen of the experimental drug, but at different dosages and frequencies: 500 mg once daily; 500 mg twice daily; 800 mg twice daily; and 1,200 mg twice daily.
Participants in the fifth group will receive the standard TB therapy of 14 days of rifafour (a four-drug combination pill containing isoniazid, rifampin, ethambutol, and pyrazinamide), dosed according to the study participant’s body weight.
The study will last only 14 days because of the potential risk of drug resistance emerging in TB patients receiving a single drug for a prolonged period. At the end of the study period, all of the participants will receive standard TB drugs to treat their disease.