Federal regulators this week are expected to approve a new antibiotic designed to combat antimicrobial-resistant bacteria. While experts applaud the pending arrival of the new tool to fight the rising public-health
threat, they say more needs to be done to encourage drugmakers to invest in such drugs.
Massachusetts-based Cubist Pharmaceuticals expects the U.S. Food and Drug Administration
to approve on Friday the sale of Sivextro for the treatment of severe bacterial skin and soft-tissue infections such as Methicillin-resistant Staphylococcus aureus, or MRSA, a bacterium known to be resistant to a number of antibiotics, including most forms of penicillin and cephalosporins.
Sivextro would be the second antibiotic the FDA has approved this year. The other, Dalvance—approved last month for the treatment of MRSA-related infections—was the first to be designated as a Qualified Infectious Disease Product under the Generating Antibiotic Incentives Now (GAIN) Act of 2012. The designation is granted to antibacterial and antifungal drugs intended to treat serious or life-threatening infections.
Sivextro also was granted the QIDP designation, giving it expedited FDA review, as well as an extra five years of market exclusivity.
But even with such advantages, not many companies are researching and developing antibiotics, said Steven Gilman, Cubist executive vice president and chief scientific officer.
“It's kind of an odd thing, because this is an area where I would like to see more competition,” Gilman said. “On one hand it could be bad for us as a company, but it would be good for society to have more people in this game.”
Health experts and public-health officials have warned for years of the double threat posed by growing numbers of antibiotic-resistant pathogens combined with a dearth of new antibiotics on the market and in the pipeline to effectively treat such infections.
Of particular concern is the lack of antibiotics to effectively combat a class of bacteria known as gram-negative bacteria, which are extremely virulent and increasingly resistant to most available drugs.
“We have a situation where we have more and more patients with infections that cannot be adequately treated with existing drugs,” said Allan Coukell, senior director of drugs and medical devices for the Pew Charitable Trusts. “We are always potentially one mutation away from a very serious public health crisis.”
According to a 2013 study conducted by the Infectious Diseases Society of America, published in the journal Clinical Infectious Diseases
, the number of new antibiotics approved annually in the U.S. has been in decline for more than two decades. Only two new antibiotics were approved between 2008 to 2012, compared with 16 between 1983 and 1987.
That's largely because there are few financial incentives to develop such drugs. Instead, many of the world's largest pharmaceutical firms are investing in drugs that produce better returns, according to Amanda Jezek, vice president for public policy and government relations for the IDSA.
“So many more fields of pharmaceuticals present many more opportunities for companies to recoup the losses from the R&D to make a profit,” Jezek said. “I think that's been a big hurdle for antibiotics.”
Unlike other drugs where companies stand to make millions in ongoing profits because of a patient's continuous use of the product, patients are encouraged to use antibiotics sparingly, to reduce the risk that more strains of bacteria will become resistant to them. Overprescribing of antibiotics has been cited as one of the main causes for the rise in resistance.
Concerns about exacerbating drug resistance also mean a new antibiotic coming on to the market may not be used right away, leading to product stockpiles and losses for its maker.
There are an estimated 2 million cases each year of U.S. residents acquiring infections that are resistant to antibiotics, which result in about 23,000 deaths, according to a Centers for Disease Control and Prevention report (PDF)
released last September.
Health costs associated with the treatment of such infections has been estimated between $21 billion and $34 billion annually, according to the IDSA.
A Pew analysis found that, as of February, there were a total of 45 antibiotics in various stages of development. The analysis concluded however, that only one in five will ever be approved for sale.
The IDSA released a set of proposed guidelines
on Thursday to aid health professionals in diagnosing and managing skin and soft-tissue infections. But as Cubist's Gilman pointed out, “Resistance can still happen even when you do everything right.”Follow Steven Ross Johnson on Twitter: @MHsjohnson