Originally described as receptor for capsaicin, the active ingredient of hot chili pepper, TRPV1 (transient receptor potential vanilloid 1) is meanwhile considered to be an important integrator for a multitude of different pain signals. Expressed on many neurons which participate in the complex process of pain signaling, TRPV1 is an ion channel responsible for pain transmission. While under normal conditions noxious (painful) heat is a major stimulus for the activation of this channel, chronic pain conditions result a sensitization towards other temperatures. Likewise, TRPV1 is able to amplify pain signals fueled into the body by other pain relevant receptor systems. Inhibition of the TRPV1 activity is suggested to be a powerful tool for the reduction of a variety of different pain conditions. A desensitizing TRPV1 agonist (i.e. capsaicin) has meanwhile been introduced as a pain drug for the treatment of neuropathic pain in a patch formulation. In contrast, low molecular TRPV1 antagonists have not yet reached the market.
Grünenthal is actively developing TRPV1 antagonists for the treatment of chronic pain conditions in cooperation with Medifron Digital Biotech (South Korea).