Adherence to weight management treatments is suboptimal. The Gelesis Loss Of Weight (GLOW; NCT02307279) pivotal trial data were used to assess treatment adherence impact on weight loss. The primary objectives of the GLOW study were to assess the effects of an oral superabsorbent hydrogel (OSH) on weight loss (targeted difference of ≥ 3%) and ≥ 5% weight loss responder status in subjects with a body mass index of 27-40 kg/m2. A total of 436 subjects were randomized to 3 capsules twice per day of OSH or placebo taken with 500 mL (16 oz) of water before lunch and dinner while on a hypocaloric diet (-300 kcal/day) for 24 weeks. There were 172 OSH- and 152 placebo-treated subjects who completed the study. Capsules counted at each study visit every 2-4 weeks were used to calculate overall percent treatment adherence (PTA) after the final visit. The PTA impact on weight loss was assessed using ANCOVA models with baseline BMI, fasting glucose and sex as covariates. A logit model with the same covariates was also used to assess the impact of PTA ≥ 95% or < 95% in subjects who achieved ≥ 10% or < 10% weight loss at 24 weeks. In the OSH group, mean PTA for was 97.61% ± 4.68% (SD) ranging from 70% to 111%, and all but 1 subject had PTA ≥ 80%. A significant interaction of ≥ 5% weight loss responder status and PTA was found (P=0.039); therefore, separate ANCOVA models were fit. PTA predicted weight loss at week 24 among the OSH group ≥ 5% responders, but not the ≥ 5% non-responders. Also, a PTA increase of 1 day/week predicted an additional 3.5% weight loss (β = 0.-25 ± 0.11 SE, P=0.024). PTA did not predict weight loss in the placebo group. OSH-treated subjects with ≥ 95% PTA were 4 times more likely to achieve ≥ 10% weight loss compared to those with < 95% PTA (P=0.027, odds ratio=4.27, 95%CI=1.18 to 15.41). These findings suggest that OSH has a binary impact on the treated subjects rather than a uniform effect. Increased PTA during OSH treatment predicted increased weight loss in patients responding to therapy with ≥ 5% weight loss, and not in non-responders or the placebo group.
L. E. Urban: Employee; Self; Gelesis. C. Apovian: Board Member; Self; Abbott, Allergan plc, Gelesis, Novo Nordisk, Nutrisystem, Tivity Health, Xeno Bioscience, Zafgen, Inc. L. Aronne: Other Relationship; Self; Allurion, Eisai & Janssen Pharmaceuticals, ERX Pharmaceuticals, Gelesis, Jamieson Wellness, Myos Corp, Intellihealth Corp, Novo Nordisk, Pfizer Foundation, Real Appeal, Research Support; Self; Astrazeneca, Aspire Bariatrics. H. Leider: Employee; Self; Gelesis.