Efficacy and safety of intranasal peptide YY3-36 for weight reduction in obese adults

Context: The gastrointestinal peptide hormone, peptide YY3-36 (PYY3-36), is implicated to be a postprandial satiety factor. Objective: The aim of this study is to assess the safety, tolerability, and efficacy of intranasal PYY3-36 to induce weight loss in obese patients. Design: The study was designed as a randomized, 2-wk, single-blind placebo run-in followed by a 12-wk double-blind, placebo-controlled treatment period. Setting: The study was set within a private and institutional practice. Patients: A total of 133 obese patients ( body mass index, 30-43 kg/m(2); age, 18-65 yr) participated in the study. Intervention: Placebo or 200- or 600-mu g PYY3-36 was administered as an intranasal spray 20 min before breakfast, lunch, and dinner in conjunction with a hypocaloric diet and exercise. Main Outcome Measure: Body weight was the main outcome measure. Results: The number of patients completing 12 wk on the drug was 38 of 43 (88%), 31 of 44 (70%), and 12 of 46 (26%) for placebo, 200 mu g three times a day (t.i.d.) and 600 mu g t.i.d., respectively. In the 600 mu g t.i.d. group, 27 of 46 ( 59%) patients discontinued due to nausea and vomiting. Among all randomized patients who took at least one drug dose and had a postbaseline measurement, the mean body weight change from baseline was -2.8, -3.7, and -1.4 kg for placebo, 200 and 600 mu g, respectively. The least squares mean difference (95% confidence interval) between placebo and 200 mu g was -0.9 (-2.6, 0.7) kg (P= 0.251). A difference of 2.11 kg was sought. No meaningful inference can be drawn from the few patients who completed the study on 600 mu g. Conclusions: Intranasal PYY3-36 as administered at these intervention doses and preprandial timing is not efficacious in inducing weight loss in obese patients after 12 wk of treatment.