A new drug has had its approval fast-tracked by the Food and Drug Administration after showing great promise in treating multi-drug resistant tuberculosis. However, a community health group are advising that further research needs to proceed cautiously in light of potentially serious adverse effects.
Bedaquiline is the first new drug to have been given approval to be used in the treatment of tuberculosis (TB) by the Food and Drug Administration in 40 years.
Studies have found that the drug is particularly effective against multi-drug resistant tuberculosis (MDR-TB), reducing the average time to a negative TB culture by a third and increasing the overall proportion of negative TB culture participants after 6 months from 58% to 79%.
These results are a vast improvement on current treatments for MDR-TB. While bedaquiline was found to be effective after 12 weeks on average, current treatments find improved outcomes when used for 18-24 months. Even then, their effectiveness varies dramatically, with a cure range of 11-79%.
A quicker and more effective method of treatment would improve matters greatly as it would reduce the burden on health care facilities, save on resources and mean that patients would no longer have to maintain a strict, and at times toxic, care routine for a long period of time.
MDR-TB is a particularly dangerous form of tuberculosis. The majority of TB cases can be cured when the right medication is available and administered correctly. Unfortunately, MDR-TB is often more difficult to diagnose than other cases of TB and is vulnerable to only very specific drugs which are often limited or not readily available.
MDR-TB occurs when an antibiotic fails to entirely kill off a strain of TB. That strain of TB goes on to develop a resistance to that form of antibiotic as well as others, making it much harder to kill in the future.
Some cases require extensive courses of chemotherapy to treat, which can be expensive and cause severely adverse reactions in patients.
A new drug that is specifically effective at tackling MDR-TB would be a very useful weapon to have, but the Community Research Advisors Group (CRAG) have argued in an article written for The Lancet that bedaquiline has several safety concerns that need addressing.
The authors from CRAG, an international community-based advisory board for the Centers for Disease Control and Prevention’s (CDC) Tuberculosis Trials Consortium, has said that these concerns need to be dealt with prior to the drug being tested on people who have developed drug-sensitive TB.
People with drug-sensitive TB have an effective drug treatment option available to them already, and, as a result, have different risk-benefit considerations that need to be addressed compared with people who have MDR-TB.
The authors highlight one particular study where significantly more participants who had been using bedaquiline died compared with participants who had been taking a placebo. Adverse effects from the drug could not be ruled out as a cause of death.
The authors from CRAG recommend that the drug be trialled in populations that have a high usage of alcohol and drugs and have Hepatitis B and C. These groups are identified by the authors as ones that would greatly benefit from a shortened treatment time, whilst also being at an increased risk from some of bedaquiline’s potential side effects.
CRAG also ask that Janssen, the developer of bedaquiline, make information available to public research groups about the drug’s safety.
CRAG co-chair Dorothy Namutamba acknowledges the promise that the drug shows, but urges that researchers do not pursue shorter treatment times at the expense of patient safety:
“The drug also shows potentially serious adverse effects ranging from liver toxicity, disruption of the heart’s electrical rhythm, and even death. As trials of this novel drug are considered in patients with drug-sensitive tuberculosis, researchers need to carefully balance the potential benefit of the new drug while making sure to always place the safety of the trial participants at the forefront of any considerations.”
The authors say that unless these questions are answered “[they] do not believe that researchers can approach the study of bedaquiline as a potential treatment for drug-susceptible tuberculosis from a position of true equipoise.”
Recently, Medical News Today reported on plans from the World Health Organization to eradicate TB in 33 countries, including the US. For further information about tuberculosis and MDR-TB, visit our Knowledge Center article about the condition.