The results of two separate tuberculosis (TB) drug trials, both of which involved South African patients, could change the way doctors treat TB and save thousands of lives.
About 1,4 million people died of TB globally in 2015. In recent years, doctors have struggled to combat drug-resistant strains of the disease. Especially vulnerable are patients who have TB that is resistant to the two most common treatments (multi-drug-resistant or MDR-TB) and patients who are resistant to these as well as to second-line treatments (known as extensively drug-resistant TB or XDR-TB). According to the World Health Organisation less than 1 in 3 people with XDR-TB and only about half of those with MDR-TB are successfully treated.
But investigators on the Nix-TB trial, which involved 61 patients at two sites, in Cape Town and Johannesburg, achieved much better results when they treated patients with three relatively new drugs: Bedaquiline, Pretomanid and Linezolid (BPaL). In fact, only four patients died. The majority of the patients recovered, and did so earlier than doctors expected.
The vast majority of patients with XDR-TB or treatment intolerant MDR-TB that have completed six months of the BPaL treatment have negative cultures of their sputum by the end of four months of treatment. They are clinically well and are in follow up, and able to go home to their families and communities. — TB Alliance
The investigators concluded that the "current results of this greatly simplified and shortened all-oral regimen for drug-resistant TB are encouraging in terms of both efficacy and safety".
This cautious summation of the results is typical of medical researchers. When Dr. Francesca Conradie, president of the South African HIV Clinicians Society, spoke with Huffington Post South Africa over the phone, her assessment was much more effusive.
"It is a game changer," said Conradie. "I'm an investigator on the trial and I never expected these results. I thought, if we save 30 percent of the patients, we'd have done well. I have been completely flabbergasted."
"We had a young man who had XDR-TB for six or seven years and he came out of our site in tears. He got XDR-TB when he was 17, and he was cured on the Nix regiment. Every patient of ours has a story like that. It's really a game changer."
Patients involved in the trial took the three drugs in a total of 27 tablets a week. "This is really low. Normally a patient with XDR-TB takes 12 tablets a day," she said.
The medication worked quickly too. In many patients, doctors were no longer able to find evidence of TB in their sputum after just eight weeks of treatment.
Conradie says the next phase of the trial will try to refine the drug regimen.
The results of the trials were presented at the Conference on Retroviruses and Opportunistic Infections in Seattle, Washington, this week.
NC-005
Also presented at the conference were the results of the NC-005 trial. The NC-005 trial was carried out at 10 sites in South Africa, Tanzania and Uganda. It focused on patients with either drug-sensitive TB or MDR-TB and looked at how they responded to treatment with the drugs bedaquiline, pretomanid, moxifloxacin and pyrazinamide (referred to as BPaMZ).
The trial showed that treatment for patients with drug-sensitive TB could be lessened to about four months, from six months, and treatment for patients with drug-resistant TB could be reduced to about six months, from two years.
The BPaMZ regimen could help rationalize and dramatically improve TB treatment by offering countries a single, 4-6 month, injection-free regimen that could treat the vast majority (perhaps 99%) of patients.— TB Alliance
The non-profit group TB Alliance, which is geared towards developing better TB treatments, believes these regimens could dramatically improve the treatment of drug-resistant TB.
Currently, countries devise regimens to treat drug-resistant TB from nearly 20 drugs, many which are sub-optimal, produce harsh side effects, and some of which require daily injections. These results point to the potential for countries to procure just two regimens and treat all types of TB with all orally-taken drugs in no more than 6 months.— TB Alliance
TB Alliance CEO Mel Spigelman told the HuffPost SA that researchers still have more work to do. "We still need to do more studies, on more patients, but certainly based on the preliminary data this could truly have a transformative effect, not just on drug-resistant TB but on all TB," he said.
"We're not all the way there, certainly, but with these two regimens that's been presented we've made tremendous strides forward."
Spigelman says the new treatment has the potential to produce the "full package" for TB care that researchers have been seeking, namely to:
- Ensure that patients no longer require injections as part of their treatment, regardless of whether they have drug-susceptible TB or drug-resistant TB;
- Develop medication that is easy to administer and easy for patients to take; and
- Shorten TB treatment regimens to no more than six months, regardless of the type of TB a patient has.
Spigelman described the results of the two trials as a "quantum leap" in the treatment of TB. "A disease that until now has been highly fatal is now being stopped dead in its tracks," he said.