Background:

IC50: Inhibitor of COX-1, COX-2 and 5-LOX with IC50 values of 0.16 M, 0.37 M and 0.23 M respectively in human.

Licofelone (ML3000), developed by the German pharmaceutical company - Merckle GmbH, is a potent suppressor of both COX and LOX. As the first member of this new class of analgesic and anti-inflammatory drugs, Licofelone is suggested as a novel treatment for osteoarthritis (OA), the most common form of arthritis. [1]

In vitro: The 5-LOX and COX inhibitory effect of licofelone was firstly identified via bovine thromobocyte intact cell assay and intact bovine PMN leukocytes. Licofelone was also reported to inhibit PGE2 in a dose-dependent manner in human whole blood assay. Moreover, Licofelone was found to suppress in vitro generation of reactive oxygen species and to reduce release of elastase from PMN leukocytes. All above findings revealed that Licofelone had an inhibitory effect on COX-1/-2 and 5-LOX. [1]

In vivo: The pharmacodynamic properties of Licofelone were evaluated in various animal models and compared with those of commonly used NSAIDs. Based on studies from a rat model of incisional pain, orally administration of Licofelone had a longer duration of action and was more effective than indomethacin and zileuton. [1]

Clinical trials: Two double-blind phase-II studies had been conducted to detect the efficacy of licofelone in OA. In the first study, 107 patients were treated with different doses of licofelone or placebo for 4 weeks. It was reported that licofelone at 200 or 400 mg twice a day could significantly ameliorate the symptoms of OA. In the second study, licofelone at doses of 100, 200 and 400 mg was administered to 404 patients twice a day, WOMAC pain subscore showed a notable decrease of 37%, 40% and 42% respectively. Licofelone at 400 mg twice a day was found to cause adverse events including diarrhea and abdominal pain. [1]

Reference:
[1]Kulkarni SK and Singh VP.  Licofelone-a novel analgesic and anti-inflammatory agent. Curr Top Med Chem. 2007; 7(3): 251-63.