This is a randomized, double-blinded, placebo-controlled, 2-arm study with an open label extension period following double-blind treatment, to investigate the anti-pruritic efficacy and safety of Nalbuphine Extended Release (ER) (NAL ER) tablets. Subjects will be randomized to NAL ER (2-week titration followed by 162 mg twice daily [BID] for 12 weeks) or matching placebo (14 weeks duration), with the primary endpoint evaluation at Week 14. During the open label extension, subjects who received NAL ER will continue on NAL ER total treatment duration 52 weeks including titration and subjects who received placebo will crossover to Nalbuphine ER Upon discontinuation of investigational product, all subjects will complete a 2-week off treatment Safety Follow-up Period, regardless of when and why the subject discontinued study treatment.
To investigate the anti-pruritic efficacy and safety of Nalbuphine Extended Release (ER) (NAL ER) tablets in Prurigo Nodularis. Subjects will be randomized to NAL ER (or matching placebo) with the primary endpoint evaluation at Week 14. During the open label extension, subjects who received NAL ER will continue on NAL ER and subjects who received placebo will crossover to NAL ER.