Breakthroughs Blog: Antimicrobial resistance

At the recent Union World Conference on Lung Health, TB Alliance presented the results of a Phase 2 clinical trial showing that the novel antibiotic candidate sorfequiline has the potential to improve tuberculosis (TB) treatment when combined with pretomanid and linezolid in people with drug-sensitive TB. The regimen was more effective than the current standard of care, and sorfequiline also demonstrated greater activity than bedaquiline, a key component of the BPaL regimen, a previous breakthrough that drastically reduced treatment time for most drug-resistant TB. This new treatment could shorten TB therapy even further. TB Alliance is working with partners ahead of the launch of a Phase 3 trial next year. Researchers at the University of California San Diego and partners have developed a new method to combat antibiotic-resistant bacteria, which could pave the way for developing alternatives to traditional antibiotics for treating a wide range of deadly infections, as the global threat of antimicrobial resistance continues to grow. The researchers used bacteriophages (or phages), which are viruses that infect and kill bacteria. Phages have been used to treat bacterial infections for more than 100 years but are usually limited in the bacterial strains they can successfully target. Researchers overcame this by allowing the pages to evolve alongside bacteria in a controlled laboratory setting for 30 days, enabling the phages to adapt their bacterial defenses, becoming more effective at killing a wide variety of bacterial strains, including drug-resistant ones, and better at suppressing bacterial growth for extended periods. Researchers at Indiana University have developed a molecular test that can simultaneously detect three dangerous fungi much faster than traditional methods, helping patients receive accurate, timely treatment against this growing global challenge. The test works by targeting genetic regions unique to each fungus, and it was much faster and more accurate than standard methods, a key advance as fungal infections are often mistaken for other respiratory illnesses. While the test still needs to be clinically validated in further studies, the research team believe it could eventually fill a major gap in fungal diagnostics. 

A team of chemists from the University of Warwick and Monash University has identified a promising, potent new antibiotic that seems to be much more effective than existing drugs against deadly superbugs like MRSA and shows no signs of resistance so far, encouraging news as the global threat of antimicrobial resistance continues to grow and the pipeline of new antibiotics continues to fall short. The molecule had been overlooked for decades as an intermediate chemical in the natural process to produce another known antibiotic, methylenomycin A, which was discovered 50 years ago, and despite having been synthesized multiple times, the synthetic intermediates have seemingly not been tested before for antimicrobial activity. The new antibiotic is much more potent than methylenomycin A itself—100 times more active against a range of serious bacteria. It could not only be a powerful new tool against rising drug resistance, but this work could also pave the way for new approaches to antibiotic discovery. A team of researchers has developed an antivenom using antibodies from a llama and an alpaca that can neutralize venom from some of the world’s most venomous snakes. Snakebites are a neglected public health issue that kill around 20,000 people in sub-Saharan Africa yearly. Current antivenom treatments are usually specific to a single snake species, and it can be difficult to identify which of the many types of venomous snakes is behind a bite, making timely, effective treatment difficult to achieve. The researchers exposed an alpaca and a llama to venoms from 18 of the most dangerous snake species in sub-Saharan Africa, isolated the antibodies that the animals produced against the venom, and then combined some of those antibodies in a single cocktail. In mice, the treatment protected against toxins from 17 African snake species and reduced skin damage. Many scientists previously thought that developing a broad-spectrum antivenom would require too many antibodies to be practical because some venom can contain up to 100 toxins, but this study shows that a combination of just a handful of antibodies can neutralize the venom of many snake species, paving the way for the development of similar broad-spectrum antivenoms for other areas where snakebites are a common public health challenge. Last week, Cepheid announced that its Xpert MTB/XDR test for tuberculosis (TB) drug resistance has been prequalified by the World Health Organization (WHO), enabling procurement through international agencies and greater access in areas with a high TB burden. The test is designed to detect resistance to multiple first- and second-line TB drugs from patient samples. It also delivers results quickly, within 90 minutes, allowing health care providers to make quicker, more reliable treatment decisions and have a better understanding of drug resistance, especially in regions with a high TB burden where timing and accuracy are critically important. 

Last week, the World Health Organization (WHO) published its latest reports on the new antibacterial agents and diagnostics in the pipeline, seeking to encourage research and development (R&D) to invigorate the sparse pipeline of tools to address the growing global threat of antibiotic resistance. The report highlights a lack of innovation in the antibacterial pipeline and major gaps in antibacterials targeting the most critical bacterial threats and addressing needs like pediatric formulations and oral treatments for outpatient use. There are similar persistent gaps for diagnostics, including a lack of new tests that are affordable, robust, and easy to use in low-resource settings. A new study, led by Imperial College London and supported by the Coalition for Epidemic Preparedness Innovations (CEPI) found that vaccines designed to protect against a wide range of coronaviruses, including a novel sarbecovirus, the type of coronavirus that includes the viruses that caused SARS and COVID-19, could be a gamechanger in a future global coronavirus pandemic, dramatically reducing deaths and disruption. A broad vaccine like this could be manufactured and stockpiled before an outbreak arises and quickly rolled out when a new outbreak is identified, providing protection to high-risk populations 60 years and older. This immediate protection could be a powerful stopgap while a new vaccine targeting the specific virus behind the outbreak is developed. An international research team has developed a simple, affordable HPV test that delivers results in less than an hour outside of a specialized laboratory, which could be a breakthrough for improving access to cervical cancer screening for women in low-resource settings. Cervical cancer continues to cause more than 350,000 deaths every year, particularly in low- and middle-income countries with limited regular access to cervical cancer screening. The test uses a swab sample and a battery-operated portable device, projected to cost less than $8 each, and it was found to be highly accurate compared to the reference standard. 

A Phase 1 clinical trial testing an experimental monoclonal antibody for malaria found that the highest dose of the treatment studied was highly effective in preventing malaria. Researchers from the University of Maryland, Sanaria, the Vital Narrative consultancy, and the Gates Medical Research Institute tested the monoclonal antibody, MAM01, in 37 adults who had never been exposed to malaria, who received either a single dose of varying sizes or a placebo, and then were infected by the bites of infected mosquitoes. None of the three recipients who received the highest dose had malaria parasites in their blood after infection. The monoclonal antibody could prove to be an important treatment option that provides immediate, high-level, and long-lasting protection with just one doseA Japanese research team has isolated natural compounds from marine sponges that demonstrate an ability to kill parasites that cause leishmaniasis, which affects approximately 12 million people around the world. Current treatments are highly toxic, cause serious side effects, and can be prohibitively expensive, leaving patients, particularly in low-income communities, which face a disproportionate burden of leishmaniasis, unable to access or complete treatment. Drug resistance is also complicating leishmaniasis treatment efforts. These findings could guide research into new treatment approaches and could potentially also be applied to other protozoan diseases like Chagas disease and African sleeping sickness. A new CRISPR-based RNA test could help track the parasites that spread Human African trypanosomiasis, or sleeping sickness, which affects around 500 people per year and many more livestock animals. The test can identify parasite species living in an animal’s blood, helping public health workers carry out targeted treatment of infected animals and prevent transmission to humans. This One Health approach to zoonotic or parasitic diseases could also be rolled out to address other diseases, such as Chagas disease or leishmaniasis.