EC50: 6.2 nM (hCB ₂ ).

A comprehensive in vitro profile of Olorinab (APD 371) (6) shows that single digit nanomolar potency and full intrinsic efficacy are maintained in all species assessed, and that Olorinab (APD 371) is highly selective for CB ₂ over CB ₁ in both binding and functional assays. Furthermore, Olorinab (APD 371) induces efficient receptor internalization (~106% relative to the CB1/2 agonist CP55,940) in CHO cells expressing HA-tagged rat CB ₂ suggesting that, according to the hypothesis, Olorinab (APD 371) would be able to drive agonist-induced receptor recycling.

Olorinab (APD 371) significantly increases paw withdrawal thresholds at doses ≥3 mg/kg PO (ED ₅₀ =2.3 mg/kg). In a separate experiment, a single dose of Olorinab (APD 371) (10 mg/kg, PO) inhibits paw withdrawal threshold for up to 4 hours after administration. Seperately, the analgesic effects of Olorinab (APD 371) are shown to be highly likely mediated via activity at CB ₂ receptors.