Efficacy, safety and pharmacokinetics of ABT-594 in subjects with painful diabetic polyneuropathy were evaluated in a randomized, double-blind, placebo-controlled, parallel-group, multi-centre, 7-week Phase 2 study: subjects were approximately equally divided into four groups to receive BID regimens of placebo or 150, 225 and 300 ug of ABT-594. ABT-894 was evaluated in 2 separate randomized, double-blind, multicenter, placebo-controlled clinical trials in patients with diabetic peripheral neuropathic pain. Study 1 (280 patients randomized) tested 1, 2, and 4 mg ABT-894 twice daily compared with placebo and 60 mg duloxetine once per day over 8 weeks of treatment. Study 2 (124 patients randomized) tested 6 mg ABT-894 twice daily vs placebo for 8 weeks.

ABT-594 (30 uM) inhibits the release of calcitonin gene-related peptide from C-fibers terminating in the dorsal horn of the spinal cord, an effect mediated via nAChRs.