Research Into TB Medications Strong, But Much More Work to Do
The next decade of research into TB medications could be "an exciting time."
A strong response to the call for the development of alternative treatments for tuberculosis (TB), particularly resistant TB, offer hope that this disease can be brought under control, but much more work needs to be done to achieve this goal, according to a review published recently in The New England Journal of Medicine.
Calling the next decade of research into new treatments an "exciting time," one of the review's authors, Dr C. Robert Horsburgh, Professor of Epidemiology and Infectious Diseases at Boston University, said that the response from foundations to look into new treatments against this global illness has been "robust."
In an interview with Infectious Disease Advisor, Dr Horsburgh summarized the review noting: “we have learned that treating TB is more complicated than we had previously thought; and that new drugs and new ways to monitor treatment hold the promise of shorter, more effective regimens ... we might finally begin to get this disease under control around the world.”
Regarding TB treatment, Dr Horsbough and his colleagues noted in the report that adverse events and treatment duration recommendations often pose a challenge for clinicians and their patients.
“A review of retrospective studies using similar definitions estimate that 3% to 13% of patients have hepatotoxic effects… a 15% incidence of adverse drug reactions resulting in interruption or discontinuation of one or more of the drugs," according to the review. Of these, researchers have reported a 7.7% chance of hospitalization, disability, or even death. Between 16 and 49% of patients do not complete the regimen due to adverse reactions, price, stigma and patients' false belief of cure when asymptomatic and no bacteria is found in sputum.1
Mycobacterium tuberculosis is associated with multiple drug resistant (MDR) infection and requires treatment by an expert physician. Centers for Disease Control and Prevention data note that “there is less evidence to support recommendations for treatment of drug-resistant disease than there is to support treatment recommendations for drug-susceptible disease.”2
The review emphasized the importance of the development of shorter drug regimens that are less toxic to treat TB, which will require more effective use of drugs that are currently available, as well as the development of new medications. Fortunately, studies looking into this area are already under way from private foundations as well as publicly-funded trial networks, according to the review.
Continuing challenges in treating TB include an ongoing need to develop a laboratory test to determine if patients could benefit from a shorter course of treatment and a better understanding of pharmokinetic data to see how well drugs penetrate into lung tissue.
A method to accurately and rapidly assess drug resistance, the development of new antimycobacterial agents, and the development of a safe treatment regimen for children are additional challenges researchers face, according to the review.
1. Horsburgh Jr CR, Barry III CE, Lang C. Treatment of tuberculosis. N Engl J Med. 2015; 373:2149-2160.
2. Centers for Disease Control and Prevention.Treatment for TB Disease. Updated December 9, 2011. Accessed December 12, 2015.