Last checked at 
(Adds comment from GlaxoSmithKline CEO, more on new marketmodels)
DAVOS, Switzerland, Jan 21 (Reuters) - More than 80international drug and biotech firms urged governments to workwith them to combat drug-resistant superbugs which could killtens of millions of people within decades unless progress ismade and new antibiotics found.
In a declaration at the World Economic Forum in Davos, theycalled for coordinated efforts to cut unnecessary use ofantibiotics and support development of new ones, including bycreating new economic models and investing in research.
GlaxoSmithKline Chief Executive Andrew Witty saidthe difficulty of finding new antibiotics was highlighted by thefact that mass screenings of hundreds of millions of chemicalsat GSK and two other large firms over nine years had yieldedzero potential new drugs.
"That's not because we are all really stupid. It's becauseit is a really, really difficult space to make progress in," hesaid in Davos.
The 83 pharmaceutical companies urged governments around theworld to commit money "to provide appropriate incentives".
Since new antibiotics will likely be kept in reserve foremergencies, possible new market models could include upfrontpayments that would delink profits from sales volumes.
Any use of antibiotics promotes the development and spreadof so-called superbugs - multi-drug-resistant infections thatcan evade the medicines designed to kill them.
International alarm about the superbug threat is risingafter the discovery in China of a gene called mcr-1 that makesbacteria resistant to all known antibiotics.
"For the world to continue to have new antibiotics, we needinvestments in basic science and novel incentive models forindustry R&D, and to protect our existing treatments, we neednew frameworks for appropriate use," said Paul Stoffels, chiefscientific officer of Johnson & Johnson.
Former Goldman Sachs chief economist Jim O'Neill was askedin 2014 by Britain's prime minister to conduct a full review ofthe problem and suggest ways to combat it.
In his initial report, he estimated antibiotic and microbialresistance could kill an extra 10 million people a year and costup to $100 trillion by 2050 if it is not brought under control.
While the problem of infectious bugs becoming drug-resistanthas been a feature of medicine since the discovery of the firstantibiotic, penicillin, in 1928, it has grown in recent years asdrugmakers have cut back investment in the field.
In their Davos declaration, the companies pledged toencourage more appropriate use of new and existing antibiotics,including more judicious use of the drugs in livestock.
They also promised to increase investment in R&D "that meetsglobal public health needs" and work to ensure affordable accessto antibiotics all over the world, at all levels of income.
Other companies signing up to the declaration include Merck, Pfizer, Sanofi, Novartis and AstraZeneca. (Reporting by Kate Kelland in London and Ben Hirschler inDavos; Editing by Dominic Evans and Peter Graff)
