Novel Treatment for MRSA Submitted for Review to US FDA

*Updated on 11/10/2016 at 10:30 AM EST

The development of new antibiotic drugs has fallen sharply since the 1980s, leaving healthcare practitioners with fewer ways to treat infections caused by antibiotic-resistant bacteria. However, novel treatments are slowly emerging, and a recent announcement pertaining to a New Drug Application to the US Food and Drug Administration (FDA) may signal that a promising new antibiotic is on the way to treat methicillin-resistant Staphylococcus aureus (MRSA) and other skin infections.

MRSA is best known as the bacterial culprit plaguing hospitals and causing hard-to-treat skin infections in patients. With more than 80,000 people in the United States contracting severe MRSA infections each year, and more than 11,000 annual deaths caused by the pathogen, the Centers for Disease Control and Prevention has it on their list of “biggest threats” of drug-resistant bacteria. MRSA often begins as a red, swollen, and painful bump that is full of pus and can be mistaken for a spider bite. As the infection progresses, the wound can become a deeper abscess with the potential to become life threatening. Its resistance to a broad range of antibiotics and its reputation as a major threat to hospital patients has put pressure on the medical research community to develop new treatments to fight MRSA infections.

In a recent press release, drug maker Melinta Therapeutics outlined what they say is a promising new antibiotic treatment for acute bacterial skin and skin structure infections, such as MRSA. They’ve submitted their New Drug Applications to the FDA for both oral and intravenous Baxdela, an investigational antibiotic in the fluoroquinolone class called delafloxacin. Following two Phase III, multicenter, randomized, double-blind, active-controlled trials to test intravenous and oral Baxdela, the drug showed non-inferiority to the current recommended treatment of vancomycin plus aztreonam for acute bacterial skin infections. Results of thet trial showed that the drug was able to reduce lesion size in 48 to 72 hours and meet the objective of investigator assessment of clinical cure.

“What makes it effective is probably the same thing that’s true of any antibiotic—the structure obviously plays a role,” Don Levine, MD, Professor Emeritus of Medicine, Division of Infectious Disease at Wayne State University, said in an interview with Contagion when describing delafloxacin. “The kind of molecule that it is, and the way it’s designed and hits the target, is what gives it such a low minimum inhibitory concentration and makes it so active against MRSA.”

“Baxdela, if approved, represents a potentially attractive treatment option for the nearly 3 million patients hospitalized annually in the US with serious skin infections,” said Eugene Sun, MD, Melinta’s Chief Executive Officer, in the press release. “These patients have a high rate of treatment failure, and frequently have underlying medical conditions that pose challenges to the choice of antibiotic. Baxdela has been tested in over 2,600 patients to date, and current results showed that it was well-tolerated with fewer than 1% of Baxdela-treated patients discontinuing due to treatment-related adverse events.”

Curbing the growing issue of antibiotic resistance requires that doctors show restraint in antibiotic administration to avoid unnecessary usage, while researchers also develop new drugs that can fight bacteria that have developed broad resistance. “The shape of the antibiotic plays a role in what mutational steps are needed to create resistance, and it just so happens that based on the unique structure of delafloxacin, it will require many more steps to develop resistance,” Dr. Levine stated. “It’s not that resistance won’t or can’t develop, but that it’s harder because of the structure.”

The development of Baxdela was, in part, made possible by the 2012 passage of the Food and Drug Administration Safety and Innovation Act, which included a provision called Generating Antibiotic Incentives Now (GAIN) meant to keep new antibiotics moving through the pipeline. The provision gives drug makers developing new antibiotics an additional five years of market exclusivity without competition from generics, priority review, and eligibility for fast-track status. A study conducted by the Tufts Center for the Study of Drug Development found that today it costs more than $2.5 billion to develop a new drug, so the GAIN rule extending the time until new antibiotic generics are available has been a strong incentive for companies previously unwilling to make the development investment.

Since Baxdela has been designated a Qualified Infectious Disease Product by the FDA, the drug is a candidate for priority review and may receive a decision as soon as mid-2017.