KW-7158

KW-7158 is a tricyclic compound with a non-cholingergic mechanism of action for the treatment of "urinary urgency," "frequent urination" and "urinary incontinence" associated with bladder overactivity (involuntary abnormal contraction of the bladder). As the aging of population progresses, an increasing number of people are likely to suffer from urinary incontinence. Bladder overactivity, the indication for this compound, is estimated to affect around 2.4 million people in Japan and around 20 million in the US and Europe combined. We consider that the market for this therapeutic domain, which is characterised by the predominance of untreated patients, tends to grow. The current mainstay of treatment for bladder overactivity is anti-cholinergic agents, which, however, are associated with high incidences of adverse reactions such as thirst and urination disorder. The development of a new type of drugs, particularly those causing fewer side effects, is thus anticipated.

The therapeutic effects of KW-7158 in overactive bladder may be due to the activation of A-type K(+) channels which regulate afferent neuron excitability and firing properties in the dorsal root ganglion neurons. It is proposed that KW-7158 acts uniquely on the peripheral sensory nerves to control bladder activities by shortenining the action potential duration in DRG neurons.