– SB-612111 is a novel and potent human opiate receptor-like orphan receptor (ORL-1) antagonist with a high affinity for hORL-1 (Ki = 0.33 nM). It exhibits selectivity for μ-, κ-, and δ-receptors with Ki values of 57.6 nM, 160.5 nM, and 2109 nM, respectively. SB-612111 effectively antagonizes the pronociceptive action of Nociceptin in an acute pain model[1].