ONO-2952

ONO-2952 is a novel, selective small molecule antagonist of the translocator protein 18 kDa (TSPO), also known as the peripheral-type benzodiazepine receptor. It has high selectivity for TSPO over other receptors, transporters, ion channels, and enzymes. ONO-2952 exerts anti-stress effects by inhibiting excessive activation of the noradrenergic system in the brain without causing amnesic effects. Preclinical studies have shown that it reduces stress-induced defecation and visceral hyperalgesia in animal models. In clinical trials, ONO-2952 has been investigated primarily for irritable bowel syndrome with diarrhea (IBS-D), where it demonstrated some evidence of efficacy in reducing IBS-related symptoms but did not reach statistical significance compared to placebo. The drug was well tolerated with a safety profile similar to placebo[1][4][6][8].