FDA okays Nabriva’s novel antibiotic Xenleta for pneumonia

Ireland-headquartered biotech Nabriva has picked up its first product approval, getting an FDA okay for antibiotic Xenleta as a treatment for community-acquired bacterial pneumonia (CABP).

Xenleta (lefamulin) – described as a first-in-class semi-synthetic pleuromutilin antibiotic – is the first intravenous and oral antibacterial with a novel mechanism of action to be approved in the US in nearly two decades, according to the company.

The drug has activity against gram-positive, gram-negative and atypical pathogens associated with CABP and is “another option” for treatment of these types of infections, according to Ed Cox, the head of the FDA’s Office of Antimicrobial Products.

US government figures suggest there are around a million cases of CABP every year, with around 50,000 Americans dying from the disease, and Nabriva says that there is a growing problem of resistance as well as safety concerns with currently-approved drugs such as fluoroquinolones.

“Without the discovery and development of new antibiotic classes like Xenleta, we could find ourselves returning to the dark days of the pre-antibiotic era,” said Nabriva’s chief executive Ted Schroeder on a conference call.

The new drug should be on the market in mid-September, he added, and Nabriva is hoping to position it as a first-line, empiric therapy for various CABP patient groups – such as those admitted to the emergency department or with complicating illnesses and limited treatment options. It has set a price of around $200 per day for the new drug.

Recent changes to reimbursement policies in the US Medicare and Medicaid systems may make that feasible, he said. Under the new plans, clinicians should find it easier to prescribe new drugs for suspected multidrug resistant (MDR) infections – and make it easier for antibiotic developers to get a return on their R&D investment.

Often new antibiotics are reserved for last-line use, which limits their sales and in part explains why so many drugmakers have been ducking out of anti-infectives R&D.

The US Centers for Medicare and Medicaid Services (CMS) recently finalised an alternative and simplified New Technology Add-on Payment (NTAP) pathway for antimicrobial products that – like Xenleta – have been designated as Qualified Infectious Disease Products (QIDPs).

QIDP status is given to drugs that are intended to treat serious or life-threatening infections, and means they get accelerated review by the FDA. Having an NTAP pathway should make it easier for hospitals to get reimbursement for prescribing new antibiotics.

According to Schroeder, current data suggest between 30% and 60% of Streptococcus pneumoniae – the most common cause of CABP in the US – are resistant to macrolides like clarithromycin or azithromycin which are a go-to first-line treatment for these infections.

Xenleta has shown no evidence of cross-resistance with macrolides as well as other antibiotic classes used in CABP, such as beta lactams, fluoroquinolones and tetracyclines, according to Nabriva.

Schroeder also said on the call that the company is planning to refile its other antibiotic Contepo (fosfomycin) for complicated urinary tract infections, which was turned down by the FDA earlier this year because of quality deficiencies at a contract manufacturer, in the fourth quarter.