clinical trialMerLion Pharmaceuticals has presented detailed data from its Phase II study in patients hospitalized with complicated urinary tract infections (cUTI) and pyelonephritis showing that a 5 day course of its novel antibacterial, finafloxacin, was more effective than treatment with the current standard of care (ciprofloxacin).

The results were presented at the joint Interscience Conference of Antimicrobial Agents and Chemotherapy (ICAAC) and International Society of Chemotherapy (ISC) International Congress of Chemotherapy and Infection (ICC), currently taking place in San Diego.

Data from the Phase II study indicate that patients treated with a 5 day course of finafloxacin had a higher, more rapid and more sustained level of microbiological eradication and improved clinical outcomes than those treated with ciprofloxacin taken twice daily for 10 days. The trial’s primary and secondary endpoints were all successfully achieved. Finafloxacin was found to be both safe and tolerable, with only a small number of class-typical adverse events observed.

Safety and efficacy of finafloxacin were investigated in a double-blind, double-dummy Phase II study at 18 sites in Poland and Germany. In total, 225 adult patients diagnosed with cUTI and acute pyelonephritis were randomized to receive finafloxacin (800 µg once daily intravenously

[IV] or orally) either for a total of 5 (FINA Five Days) or 10 days (FINA 10 Days) or the current standard of care, ciprofloxacin (400 mg IV twice a day or 500 mg orally twice a day) for 10 days (CIPRO 10 Days), with a potential switch from initial IV to oral administration on day three or later. The most common pathogens in the study were the Gram-negative Escherichia coli and Klebsiella pneumoniae.

The study primary endpoint, known as Test of Cure, assessed the combined microbiological eradication and resolution of clinical symptoms at day 17 (the regulatory time-defined endpoint). For finafloxacin, the Test of Cure was 70% when dosed for 5 days or 68% when dosed for 10 days, compared with 57% for ciprofloxacin dosed for 10 days. In addition, FINA Five Days did not result in an increased rate of relapses on day 24 when compared with either CIPRO 10 Days or FINA 10 Days.

Eight per cent of the patients in the study had urine with a pH below 7. Finafloxacin activity was not affected by urine pH where, in the mITT population, within three days of starting treatment 88% bacterial eradication was seen in patients with urine pH <7 (n=102) and 92% eradication in those with urine pH ≥7 (n=25). In comparison, the antibacterial activity of ciprofloxacin was negatively influenced by acidic urine (73% eradication at pH <7 [n=45] versus 92% at pH ≥7 [n=12)]). Finafloxacin also showed very rapid activity against ciprofloxacin-resistant, as well as ESBL-producing, pathogens.

“These clinical data continue to support finafloxacin’s potential as a potent antibiotic to treat cUTI infections,” said David Dally, CEO of MerLion. “Given its very rapid activity against a wide variety of bacterial pathogens, including multidrug-resistant Gram-negative bacteria, and its potential as an IV-to-oral switch therapy, we believe that finafloxacin will offer physicians additional options when treating bacterial infections.”

Prof. Dr Kurt Naber (Technical University Munich, Germany) stated: “The data from this trial provides clear differentiation of finafloxacin from existing fluoroquinolones and from other antibiotics including those in development. The safety and tolerability profile will allow high once-daily dosing and it has an excellent PK profile and bioavailability. Importantly, the very rapid and sustained bactericidal effects of the product result in a low propensity for development of resistance which is a key characteristic. I am convinced that finafloxacin could become an important option in modern antibiotic therapy.”