Promising Clinical Data from Pilot Study of Gelesis’ Novel Hydrogel GS500 Prototype for the Potential Treatment of Chronic Constipation Presented at Digestive Disease Week by Researchers from Massachusetts General Hospital and Brigham and Women’s Hospital

Investigational candidate developed by Gelesis demonstrated
significant 16 hour reduction in colonic transit time in patients with
chronic idiopathic constipation

First clinical study demonstrating super-absorbent hydrogel
platform’s potential in this common condition

BOSTON–(BUSINESS WIRE)–Gelesis,
a biotechnology company at the forefront of developing
mechanobiology-based therapies to treat chronic diseases related to the
gastrointestinal (GI) system, announced the presentation of data from a
clinical study demonstrating that GS500 prototype (GS500/CSP01) provided
a significant reduction in colonic transit time (CTT) in patients with
chronic idiopathic constipation (CIC) relative to placebo. The data were
presented at Digestive Disease Week 2019, held in San Diego, California.

“One out of seven adults throughout the world suffer from chronic
idiopathic constipation. This condition can have a significant negative
impact on quality of life,” said Dr. Braden Kuo, Gastrointestinal Unit
in the Massachusetts General Hospital (MGH) Department of Medicine. “The
safety and efficacy results of this study are intriguing and suggest
further clinical evaluation in this very common, treatment resistant
condition would be both warranted and welcome.”

Gelesis’ proprietary hydrogel product candidates are orally administered
and synthesized from two naturally derived building blocks – modified
cellulose cross-linked with citric acid – that create a
three-dimensional matrix designed to achieve specific mechanical
properties (high elastic response) through the gastrointestinal system.
In order to assess the potential therapeutic benefits of the hydrogel’s
specific mechanical properties, modified cellulose, the main building
block of GS500, was included as an active control. This modified
cellulose is a widely used soluble dietary fiber but lacks the three
dimensional structure of the superabsorbent hydrogel, and therefore
creates significantly lower elastic response.

“The wireless motility capsule monitoring system allowed us to
demonstrate that the superabsorbent hydrogel, in contrast to modified
cellulose alone or placebo, accelerated colonic transit time,” said Dr.
Kyle Staller, Center for Neurointestinal Health and Division of
Gastroenterology at Harvard-affiliated Massachusetts General Hospital.
“This finding suggests that the three-dimensional structure of Gelesis’
hydrogel technology and specific elastic response may have contributed
to the observed improvements in colonic transit time over the active
fiber control in this study.”

The primary end-point of this randomized, double-blind study was the
change in CTT from pre-treatment to post-treatment as measured by
wireless motility capsules. The test involves swallowing a small data
recording device which transmits information to a wireless data receiver.

Two populations were evaluated separately, 27 subjects with CIC and 13
subjects with irritable bowel syndrome with constipation (IBS-C).
Patients were randomized into three treatment groups to receive 21 days
of treatment with either GS500 (n=20), active control (modified
cellulose, n=11) or placebo (n=9). Each subject’s CTT was measured
during the third week of treatment and compared to their baseline,
collected during 7 days of pre-treatment. Secondary outcome measures
included improvement of relevant gastro intestinal (GI) symptoms.

In the CIC population on treatment, colonic transit time was reduced by
approximately 16 hours (~31%) compared to baseline (P=0.02 compared to
placebo). No statistically significant change was observed in the
placebo or the active control groups. No improvement was observed in the
IBS-C population, as well as no change in the reported GI symptoms which
were the secondary endpoints. Two randomized patients did not complete
the study, one in the treatment group due to a GI related AE, and one in
the placebo group due to a faulty monitoring device. No serious adverse
events were reported.

This pilot study of 40 subjects was powered to detect improvement in CTT
(the primary end-point). Recent data suggest that colonic transit time
influences gut health and a longer fecal retention time is associated
with CIC symptoms and less microbiome diversity. Further studies are
required to assess the effect of Gelesis’ hydrogel technology on symptom
improvement.

About Chronic Idiopathic Constipation
Chronic idiopathic
constipation (CIC) is a common gastrointestinal disorder. Its primary
symptom is a low frequency of bowel movements, which can cause
significant discomfort and negative impact on quality-of-life. CIC is
estimated to affect between 15 and 25 percent of the general population
in North America.

About Gelesis
Gelesis is developing a novel hydrogel
platform technology to treat overweight and obesity and chronic diseases
related to the GI pathway. Gelesis’ proprietary approach is designed to
act mechanically in the GI pathway to potentially alter the course of
chronic diseases. In April 2019, Gelesis received FDA clearance for its
lead product candidate, PLENITY™. Gelesis is preparing to initiate a
targeted U.S. launch of PLENITY in the second half of 2019 and
anticipates PLENITY will be broadly available by prescription in the
U.S. in 2020.

Additionally, Gelesis is developing its second candidate, Gelesis200, a
hydrogel optimized for weight loss and glycemic control in patients with
type 2 diabetes and prediabetes. Novel hydrogel mechanotherapeutics
based on the Gelesis platform technology are also being advanced through
a pipeline (GS300, GS400, GS500) in other GI inflammatory conditions
where gut barrier and gut permeability potentially play a role, such as
non-alcoholic steatohepatitis (NASH) and inflammatory bowel disease
(IBD). Recent preclinical data presented this year support the potential
role of this novel hydrogel platform technology in restoring gut barrier
function and intestinal tissue health.

The Gelesis executive and advisory team includes some of the world’s
leading experts in obesity, materials science, chronic disease research
and commercialization. Gelesis was co-founded by PureTech Health (LSE:
PRTC), a biopharmaceutical company focused on the Brain-Immune-Gut (BIG)
Axis. For more information, visit gelesis.com or
connect with us on Twitter @GelesisInc.

Contacts

Investors
Allison Mead Talbot
+1 617 651 3156
[email protected]

U.S. media
Tom Donovan
+1 857 559 3397
[email protected]