New antibiotic approved for acute bacterial skin infections

Delafloxacin (Baxdela, Melinta Therapeutics) has been FDA-approved for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible bacteria.

Baxdela is the newest member of the fluoroquinolone antibiotic class and exhibits activity against both gram-positive and gram-negative bacteria.

Cammarata

Approximately 3 million patients are hospitalized each year in the United States with ABSSSI. These patients often present treatment challenges owing to their underlying medical conditions, making optimal antibiotic selection difficult, explained Sue Cammarata, MD, Melinta chief medical officer.

Baxdela is available in both intravenous (IV) and oral formulations. The 450-mg tablet is bioequivalent to and interchangeable with the 300-/mg IV dose, and can be dosed without regard to food. The only drug-drug interaction expected with Baxdela is the co-administration with chelating agents, such as antacids.

As for the differences between Baxdela and previously approved fluoroquinolones, Camarrata explains that Baxdela is the only fluoroquinolone that can be used in MRSA infection; and unlike the others, it is not associated with QT prolongation or photosensitivity.

“Unlike many recent antibiotics approved for serious skin infections, Baxdela can also treat gram-negative bacteria, which can be seen in patients with complicated medical histories, such as those with diabetes, renal disease, vascular disease and obesity” Cammarata said. “Baxdela has both IV and oral formulations, which increases the options for physicians who are treating these complicated patients.”

The approval of Baxdela is based on two phase 3 clinical trials in patients with ABSSSI. Results of the trials determined that IV and oral Baxdela monotherapy was statistically non-inferior to the combination of vancomycin and aztreonam in the primary end point of early clinical response at 48 to 72 hours, as well as the secondary end point of clinical success at Day 14.

Baxdela was given priority review by FDA due to its designation as a Qualified Infectious Disease Product (QIDP) under the Generating Antibiotic Incentives Now (GAIN) Act of 2012. This qualifies Baxdela for incentives related to the development of new antibiotics, including a five-year extension of any non-patent exclusivity period awarded to the drug.

In trials, Baxdela was well tolerated with a 0.9% discontinuation rate due to adverse reactions. The most common adverse reactions associated with the use of Baxdela in clinical trials were nausea, diarrhea, headache, transaminase elevations, and vomiting.

Serious adverse reactions associated with the use of all fluoroquinolones include tendinitis and tendon rupture, peripheral neuropathy, and central nervous system effects. If these occur, patients are to immediately discontinue Baxdela and avoid use of any fluoroquinolone. It should be noted that there were no events of tendon rupture in Baxdela clinical trials.