Early Weight Loss While on Lorcaserin, Diet and Exercise as a Predictor of Week 52 Weight-Loss Outcomes

ObjectiveTo identify an early treatment milestone that optimizes sensitivity and specificity for predicting 5% weight loss at Week (W) 52 in patients with and without type 2 diabetes on lorcaserin or placebo. MethodsPost hoc area under the curve for receiver operating characteristic analyses of data from three phase 3 trials comparing lifestyle modification+placebo with lifestyle modification+lorcaserin. A total of 6897 patients (18-65 years; BMI, 30-45 or 27-29.9 kg/m(2) with 1 comorbidity) were randomized to placebo or lorcaserin 10 mg bid. Changes (baseline to W52) in cardiometabolic parameters were assessed. ResultsResponse (5% weight loss from baseline) at W12 was a strong predictor of W52 response. Lorcaserin patients with a W12 response achieved mean W52 weight losses of 10.6 kg (without diabetes) and 9.3 kg (with diabetes). Proportions achieving 5% and 10% weight loss at W52 were 85.5% and 49.8% (without diabetes), and 70.5% and 35.9% (with diabetes). Lorcaserin patients who did not achieve a W12 response lost 3.2 kg (without diabetes) and 2.8 kg (with diabetes) at W52. Responders had greater improvements in cardiometabolic risk factors than the modified intent-to-treat (MITT) population, consistent with greater weight loss. Conclusions5% weight loss by W12 predicts robust response to lorcaserin at 1 year.