Puretech Ownership
Product Candidate
Initial Indication(s)
Stage of Development
21.0% Equity plus Royalties

Weight management

FDA Cleared,
European CE Mark Granted

Adolescent weight management

Seeking FDA input for expanding Plenity label to treat adolescents6

Weight management in type 2 diabetes (T2D)/prediabetes

Phase 2

Non-alcoholic steatohepatitis/Non-alcoholic fatty liver disease

Phase 2 Ready6

Functional constipation

Phase 3

4. These product candidates are regulated as devices and their development has been approximately equated to phases of clinical development.

5. Products are investigational and have not been cleared by the FDA for use in the United States.

6. Contingent on FDA review of the research plan.


Gelesis' investigational product candidates

Targeting the GI pathway to potentially alter the course of chronic diseases

Gelesis is developing oral therapeutics based on a novel, superabsorbent hydrogel technology platform to treat excess weight and other chronic diseases related to the gastrointestinal (GI) pathway. Gelesis’ proprietary approach is designed to act mechanically in the GI pathway to potentially alter the course of chronic diseases. Gelesis' investigational product candidates includes potential therapies for Non-alcoholic Fatty Liver Disease (NAFLD)/Non-alcoholic Steatohepatitis (NASH), weight management in T2D/prediabetes and functional constipation.

  • Program Discovery Process by the PureTech Team
    • PureTech was interested in creating an effective and safe therapy for obesity given the tremendous need, significant health implications and failure of prior approaches to effectively engage and serve the breadth of the population affected. PureTech consulted with leading obesity experts to brainstorm on the characteristics of an ideal approach, which it decided was an orally-administered mechanically acting device, and then conducted a worldwide search for compelling technologies meeting these criteria. PureTech identified and in-licensed the core intellectual property from one of its academic collaborators in October 2008, and PureTech subsequently co-invented additional intellectual property around a novel class of biocompatible, superabsorbent hydrogels. One of the core PureTech team members involved in the initial identification and development process subsequently assumed the role of chief executive officer of Gelesis, successfully attracted financing and built a strong development and commercial leadership team. The Gelesis advisory team is comprised of leading experts in obesity and its related comorbidities, clinical research and development and advanced biomaterials, including Caroline Apovian, MD, professor of medicine and pediatrics at Boston University School of Medicine; Louis J. Aronne, MD, FACP, director of the Comprehensive Weight Control Center at Weill Cornell Medicine; Arne Astrup, MD, head of the Department of Nutrition, Exercise and Sports at University of Copenhagen; Ken Fujioka, MD, director of the Nutrition and Metabolic Research Center and the Center for Weight Management at the Scripps Clinic; James Hill, PhD, chairman of the Department of Nutrition Sciences, director of the Nutrition Obesity Research Center at University of Alabama; professor of medicine and pediatrics at University of Colorado; Lee M. Kaplan, MD, PhD, director of the Obesity, Metabolism and Nutrition Institute at Massachusetts General Hospital; Bennett Shapiro, MD, co-founder and non-executive director at PureTech and former executive vice president of Research for Merck; and Angelo Tremblay, PhD, professor at Laval University.
  • Patient Need & Market Potential
    • Excess weight is growing rapidly in prevalence worldwide, with approximately 70 percent of American adults struggling with overweight and obesity. Globally there are more than 1.9 billion adults 18 years of age or older who are overweight and 600 million who have obesity.
    • Obesity-related conditions, such as heart disease, stroke, type 2 diabetes, non-alcoholic steatohepatitis (NASH)/non-alcoholic fatty liver disease (NAFLD) and certain types of cancer, are some of the leading causes of preventable death.
    • Functional constipation and NASH/NAFLD affect approximately 35 million and 80 to 100 million, respectively, in the United States.
    • Type 2 diabetes and prediabetes affect approximately 30 million and 84 million individuals, respectively, in the United States.
    • Current treatments for overweight and obese patients begin with lifestyle modification, such as diet and exercise. When healthy eating and physical activity fail to produce the desired results, physicians may consider pharmaceutical therapies, device implantation or surgical treatments, such as gastric bypass and gastric banding (for patients with more severe obesity). These approaches are associated with safety concerns, lifestyle impact, complexity of use, high cost and compliance issues that have limited their adoption.
  • Innovative Approach to Solving the Problem
    • Gelesis is developing oral therapeutics based on a novel, superabsorbent hydrogel technology platform to treat excess weight and other chronic diseases related to the gastrointestinal (GI) pathway. Gelesis’ proprietary approach is designed to act mechanically in the GI pathway to potentially alter the course of chronic diseases.
    • Given challenges associated with pharmacological and invasive surgical treatments for obesity, Gelesis designed an approach with an oral, non‑invasive, non‑systemic mechanism of action and a highly favorable safety and efficacy profile. Gelesis’ product candidates work in the GI tract and pass through the body without being absorbed. They are synthesized from two naturally derived building blocks (citric acid and cellulose) that form a novel, patent‑protected three‑dimensional structural composition and occupies volume in the stomach and small intestine to promote satiety and fullness. Because Gelesis’ technology acts mechanically and is not systemically absorbed, the product candidates are treated as devices for regulatory approval purposes.
  • Milestones Achieved
    • Gelesis initiated a Phase 3 study of GS500 in functional constipation in 2020.
    • Data from a pilot study of GS200 demonstrated that administration of GS200 ten minutes prior to a meal increased fullness throughout the entire day (p=0.012).
    • A pilot study of 40 individuals showed that a prototype of GS500 demonstrated a significant reduction in colonic transit time in patients with functional constipation by approximately 16 hours (approximately 31 percent) compared to baseline (p=0.02 compared to placebo).
  • Expected Milestones
    • In 2021, Gelesis expects topline results from a Phase 2 study of GS200 in weight management and glycemic control in adults with type 2 diabetes and prediabetes.
    • In the first half of 2021, Gelesis expects to initiate a Phase 2 study of GS300 in NASH/NAFLD.
    • Gelesis plans to seek FDA input on requirements for expanding Plenity label to treat adolescents.

3. Important Safety Information: Plenity is contraindicated in patients who are pregnant or are allergic to cellulose, citric acid, sodium stearyl fumarate, gelatine, or titanium dioxide. Plenity may alter the absorption of medications. Read Sections 6 and 8.3 of the Instructions for Use carefully. Avoid use in patients with the following conditions: esophageal anatomic anomalies, including webs, diverticuli, and rings; suspected strictures (such as patients with Crohn’s disease); or complications from prior gastrointestinal (GI) surgery that could affect GI transit and motility. Use with caution in patients with active GI conditions such as gastro-esophageal reflux disease (GERD), ulcers or heartburn. The overall incidence of adverse events (AEs) in the Plenity group was no different than the placebo group. The most common side effects were diarrhea, distended abdomen, infrequent bowel movements, and flatulence. For the safe and proper use of Plenity, U.S. Instructions for Use or the EU Instructions for Use. 

Key Features

The proprietary Gelesis platform is the first and only superabsorbent hydrogel made exclusively from naturally-derived building blocks

Press Releases

PureTech Founded Entity Gelesis Presents Pre-Clinical Data Suggesting Proprietary Hydrogel (GS300 Prototype) Reverses the Damage to the Intestines Induced by a High Fat Diet

November 13, 2020

PureTech Founded Entity Gelesis Presents Plenity® Efficacy and Safety Data at the European and International Congress on Obesity 2020

September 4, 2020

PureTech Founded Entity Gelesis Announces Partnership for Commercial Launch of Plenity® in China

June 18, 2020

PureTech Founded Entity Gelesis Receives Approval to Market PLENITY™ in Europe as a Weight Loss Treatment 

June 2, 2020

PureTech Affiliate Gelesis Named One of the World’s Most Innovative Companies for 2020 by Fast Company

March 11, 2020

PureTech Health Affiliate Gelesis Announces Partnership with Ro to Support US Commercialisation of Plenity™

December 17, 2019

PureTech Health Affiliate Gelesis Secures Over $84 Million in New Capital to Support US Commercialisation of PLENITY™

December 9, 2019


PureTech Affiliate Gelesis Presents Additional Data Highlighting Therapeutic Benefits of Plenity at ObesityWeek 2019

November 5, 2019

PureTech Health Affiliate Gelesis Announces Promising Pilot Clinical Data From Prototype of GS500 In Development for Chronic Idiopathic Constipation

May 20, 2019

PureTech Health Affiliate Gelesis Announces $10.6 (€9.4) Million Grant to Support Commercial Manufacturing of PLENITY™

April 25, 2019


PureTech Health Affiliate Gelesis Announces Successful FDA Milestone for First Product, PLENITY

April 14, 2019

PureTech’s Affiliate Gelesis Presents Data at ENDO Demonstrating Lead Product Candidate’s Positive Effect on Patients With Prediabetes, Untreated Diabetes, and Elevated Insulin Resistance

March 25, 2019

PureTech Health Affiliate Gelesis Presents Preclinical Data Showing Pipeline Candidate Restores Gut Barrier Function

March 25, 2019

PureTech's Affiliate Gelesis Announces Three Presentations at Endocrine Society Annual Meeting

March 21, 2019

Pivotal Weight Loss Data for Gelesis100 Published in Obesity, Including Predictors of Response

November 13, 2018

PureTech's Gelesis to Present Expanded Pivotal Data for Lead Product Candidate at ObesityWeek 2018

November 5, 2018