Researchers who tested the safety and effectiveness of a new approach to tuberculosis treatment in recent global clinical trials are saying the results offer hope that a drug that could shorten the period during which patients can spread the disease to others, while addressing multi-drug-resistant infections.
Researchers are calling the development of a new drug for tuberculosis “a milestone.”
If the drug proves effective, it would be the first new class of TB drug in 40 years. According to researchers it could cut costs of treatment by reducing periods of quarantine. Tuberculosis bacteria disappeared from the sputum of nearly half the participants testing the drug with additional standard treatment within two months, while only 29 percent of the participants taking a placebo along with the standard treatment showed similar results. Previous studies have shown that patients undergoing standard treatment, when it is effective, can take longer than three months to clear bacteria from their sputum.
Tuberculosis patients are infectious during the period during which bacteria is present in sputum, and the need to isolate patients during that time is one of many factors complicating treatment in resource poor settings, said Lawrence Geiter, a vice president of Otsuka Pharmaceutical Company, which developed the drug.
Geiter was one of the authors of a study published in the New England Journal of Medicine, announcing the results of clinical trials for delamanid among 481 participants in nine countries: the Philippines, Peru, Latvia, Estonia, China, Japan, Korea, Egypt and the United States. The drug was not tested in Africa, home to some of the highest multi-drug-resistant TB rates in the world, and where the spread of the disease is speeded by the highest rates of HIV prevalence in the world, because of difficulty finding tuberculosis patients who were not also on antiretroviral treatment, Geiter said.
Drug interaction studies on healthy patients have since cleared the drug for testing on patients taking antiretroviral medicines, and the next trials will include patients in Africa who also are being treated for HIV.
A prolonged period between heartbeats was the most serious side effect noted in patients taking Delamanid, but it did not lead to health-threatening problems, Geiter said. Other side effects, including nausea, insomnia, headache, occurred at comparable rates among patients taking the drug with standard treatment, and those taking a placebo drug with standard treatment. Researchers are hoping the drug will be approved later next year and be available to patients shortly thereafter.
Announcement of the trial was accompanied in the NEJM by an editorial discussing the prevalence of resistant strains of tuberculosis in China, and the unmet need of treatment for MDR TB. The editorial, by Dr. Richard E. Chaisson and Dr. Eric Nuermberger, noted that rising rates of drug resistant tuberculosis strains are due largely to transmission of those strains, and called for the need to replace outdated diagnostic tests.