New flu drug could avoid antiviral resistance
A new type of flu drug that is active against the newest strains of the flu virus has been developed by an international team of scientists working in the UK, Canada and Australia.
The World Health Organization (WHO) estimates that influenza affects up to five million people globally each year, causing as many as 500,000 deaths. In some pandemic years, the figure rose to millions.
Whilst existing drugs are effective, there are fears that their over-use may cause the virus to develop resistance against them, rendering them useless.
A team of researchers, including scientists from the University of Bath, have identified drug molecules that work in a different way to traditional drugs, meaning that the virus is less likely to evolve resistance.
The drugs bind to the flu enzyme neuraminidase, which helps the virus to spread. However, unlike current antiviral drugs such as Tamiflu and Relenza, which bind competitively to the enzyme, these new drugs bind permanently to the flu protein and block its action.
The drugs have so far been very successful in animal models and will hopefully be going into pre-clinical trials soon.
The research, led by the University of British Columbia (Canada) and involving researchers from Bath and CSIRO Materials Science and Engineering (Australia), is published online in the journal Science at the Science Express website.
Dr Andrew Watts, Lecturer in Pharmacy & Pharmacology at Bath, said: “Antivirals have been very effective in stopping the spread of flu in the pandemics over the last few years; however new strains of the virus that are resistant to these drugs are emerging and represent a serious threat to our ability to effectively treat the disease.
“It is therefore vital that we develop new drugs that combat resistance. This new class of drug is based on the natural mechanism of the enzyme and so the virus can’t easily evolve to avoid its action.”
Professor Steve Withers, from the University of British Columbia (UBC), was senior author on the study. He explained: “Our drug agent uses the same approach as current flu treatments – by preventing neuraminidase from cutting its ties with the infected cell.
“But our agent latches onto this enzyme like a broken key, stuck in a lock, rendering it useless.”
The research was partly funded by the Medical Research Council through a strategic call for research into influenza.
Professor Doreen Cantrell, chair of the Immunity and Infections Board at the Medical Research Council, said: “This study in mice opens up the possibility of new types of drugs that could stop emerging flu viruses in their tracks.
“If these results are replicated in clinical trials and are shown to halt infection in flu patients, we will have turned a corner in the search for new antivirals that tackle the problem of resistance. The MRC has a long standing commitment to flu research, building on our landmark discovery in 1933 identifying the flu virus.”