MRSA Infection

Delafloxacin a Strong Anti MRSA Candidate

PharmaLive: Rib-X Pharmaceuticals Presents Data at ECCMID Demonstrating Potent In Vitro Activity of Radezolid and Delafloxacin Against Resistant Strains of Gram-positive Bacteria.

Delafloxacin was superior to multiple antibiotics currently used as standards of care for the treatment of MRSA infections. Radezolid was shown to be more potent than torezolid by at least two-fold against multiple strains of oxazolidinone-resistant bacteria,” said Scott Hopkins, M.D., Chief Medical Officer at Rib-X. Mark Leuchtenberger, President and Chief Executive Officer at Rib-X commented, “These data continue to support delafloxacin as a potential best-in-class fluoroquinolone antibiotic with outstanding activity against MRSA, including multiple strains from across Europe.

Delafloxacin being tested in combination for MRSA

Rib-X Advances Clinical Testing of Anti-MRSA Treatment - OrlandoSentinel.com.

A New Haven company founded by a Yale chemist announded today that it's starting a phase 2-B clinical trial of a combination of three drugs for the treatment of acute bacterial skin infections, including infections caused by drug-resistant staph, known as MRSA. One of the three drugs in the study by Rib-X Pharmaceuticals has been studied in about 1,000 subjects so far. That new drug, delafloxacin, is being licensed from Wakunaga Pharmaceutical Company. The other two are on the market, but have not been tested in combination with delafloxacin. The study will be a randomized double-blind trial to see how infections respond over five days to the drug cocktail, and will test 240 subjects around the United States.

Delafloxacin active against Staph - effective in low doses?

Contrasting effect of acidic pH on the extracellular and intracellular activity of anti Gram-positive fluoroquinolones (moxifloxacin and delafloxacin) against Staphylococcus aureus. -- Lemaire et al., 10.1128/AAC.01201-10 -- Antimicrobial Agents and Chemotherapy.

In contrast to currently marketed fluoroquinolones that are zwitterionic, delafloxacin is an investigational fluoroquinolone with anionic character that is highly active on Gram-positive bacteria. We have examined the effect of acidic pH on its accumulation in S. aureus and in human THP-1 cells, in parallel with its activity against extracellular and intracellular S. aureus. Moxifloxacin was used as comparator. Delafloxacin showed MICs 3-5 log2 dilutions lower than those of moxifloxacin for a collection of 35 strains with relevant resistance mechanisms, and proved also 10-fold more potent against intracellular S. aureus ATCC25923. In media at pH 5.5, this difference was further enhanced, with MIC decreasing by 5 log2 dilutions. In infected cells incubated in acidic medium, relative potency was 10-fold higher than at neutral pH and maximal relative efficacy reached a bactericidal effect at 24 h.