Synlogic Presents Data Describing a Solid Oral Formulation Process for Synthetic Biotic™ Medicine SYNB1618 for the Treatment of PKU at the 22nd Annual Meeting of the American Society of Gene & Cell Therapy (ASGCT)

– Synlogic’s robust and reproducible lyophilization process provides
a solid formulation of SYNB1618 with improved quality attributes,
stability and minimal loss of viability compared to liquid formulation –

CAMBRIDGE, Mass.–(BUSINESS WIRE)–lt;a href="https://twitter.com/search?q=%24SYBX&src=ctag" target="_blank"gt;$SYBXlt;/agt; lt;a href="https://twitter.com/hashtag/ASGCT19?src=hash" target="_blank"gt;#ASGCT19lt;/agt;–Synlogic,
Inc., (Nasdaq: SYBX) a clinical stage company applying synthetic
biology to beneficial microbes to develop novel, living medicines, today
announced that data demonstrating its development of a robust and
reproducible process to generate a solid oral formulation of its
Synthetic Biotic medicine, SYNB1618, are being presented
today at the 22nd Annual Meeting of the American Society of Gene & Cell
Therapy (ASGCT). Synlogic is developing SYNB1618 for the treatment of
phenylketonuria (PKU).

“We have developed a process to generate a solid formulation of SYNB1618
for oral use that makes it more patient-friendly and provides a
stability profile suitable for eventual commercialization,” said Antoine
Awad, Synlogic’s head of technical operations. “The data presented at
the ASGCT meeting demonstrate that we can generate a solid preparation
of SYNB1618 with minimal impact on cell viability and activity and
improved quality attributes compared to the liquid formulation that is
being used in our ongoing clinical trial. We plan to apply our solid
formulation expertise across our pipeline products.”

“We recognized that development of a solid formulation process was
critical to advancement of our orally administered Synthetic Biotic
medicines through clinical development toward commercialization,” said
Aoife Brennan, M.B. Ch.B., Synlogic’s president and chief executive
officer. “We made a strategic decision to develop this process in
parallel with clinical testing of an early liquid formulation in our
first two programs. Our clinical experience with the liquid formulation
has enabled the rapid achievement of proof-of-mechanism, as well as an
understanding of the translation of the medicines’ activity from
preclinical models to humans. Following the readout from our Phase 1/2a
study in patients with PKU later this year, we will be integrating the
solid oral formulation into the SYNB1618 development program.”

SYNB1618 is designed to function in the gastrointestinal (GI) tract and
has been engineered with two enzyme pathways to consume phenylalanine
(Phe), an essential amino acid that can accumulate to harmful levels in
patients with PKU with severe health consequences. SYNB1618 metabolizes
Phe to harmless compounds including trans-cinnamic acid (TCA) in the
blood which is further metabolized in the liver and excreted as hippuric
acid (HA) in the urine. TCA and HA, therefore, represent specific
biomarkers of SYNB1618 activity. Synlogic has conducted a Phase 1 /2a
study in healthy volunteers who were treated with an early formulation
of SYNB1618 (frozen liquid) and is currently evaluating the same
formulation in single and multiple dose expansion cohorts in patients
with PKU, with data expected mid-2019. Dose-dependent production of TCA
in the serum and HA in the urine were observed in SYNB1618-treated but
not placebo-treated healthy subjects demonstrating proof of mechanism.
The data were announced in September 2018 and confirmed preclinical data
published earlier in Nature
Biotechnology. In future clinical studies, Synlogic plans to use
a solid formulation of SYNB1618 which is more patient-friendly and will
enable outpatient clinical trials of longer duration that will be
required to demonstrate efficacy.

As described in the ASGCT
presentation, Synlogic’s scientists have successfully developed a
process that demonstrates:

• batch to batch reproducibility in cell viability and activity at the
  30L production scale
• improved physical quality attributes of the product; and
• a solid formulation that:
  • is similarly active to frozen liquid in terms of consumption of
    Phe or production of TCA/HA in an in vitro gut simulation
    model and in vivo in non-human primates and a mouse model
    of disease
  • in initial studies is stable for >90 days at 2-8^◦C
    and >30 days at room temperature (Synlogic intends to generate
    shelf-life data over two years).

As a solid oral formulation with improved stability and convenience
SYNB1618 has potential as a new therapy for managing blood Phe levels in
patients with PKU.

About Synlogic
Synlogic is pioneering the development of a
novel class of living medicines, Synthetic Biotic medicines, based on
its proprietary drug development platform. Synlogic leverages the tools
and principles of synthetic biology to genetically engineer beneficial
microbes to perform or deliver critical functions missing or damaged due
to disease. Synthetic Biotic medicines are designed to act locally and
have a systemic effect to address disease in patients. Synlogic’s two
lead programs, SYNB1020 and SYNB1618, are orally administered and target
hyperammonemia as a result of liver damage or genetic disease, and
phenylketonuria, respectively. Synlogic is also developing SYNB1891 as
an intratumorally-administered Synthetic Biotic medicine for the
treatment of cancer. In addition, the company is leveraging the broad
potential of its platform to create additional Synthetic Biotic
medicines for the treatment of liver disease, as well as inflammatory
and immune disorders including Synlogic’s collaboration with AbbVie to
develop Synthetic Biotic-based treatments for inflammatory bowel disease
(IBD). For more information, please visit www.synlogictx.com.

Forward-Looking Statements
This press release contains
“forward-looking statements” that involve substantial risks and
uncertainties for purposes of the safe harbor provided by the Private
Securities Litigation Reform Act of 1995. All statements, other than
statements of historical facts, included in this press release regarding
strategy, future operations, future financial position, future revenue,
projected expenses, prospects, plans and objectives of management are
forward-looking statements. In addition, when or if used in this press
release, the words “may,” “could,” “should,” “anticipate,” “believe,”
“estimate,” “expect,” “intend,” “plan,” “predict” and similar
expressions and their variants, as they relate to Synlogic may identify
forward-looking statements. Examples of forward-looking statements,
include, but are not limited to, statements regarding the potential of
Synlogic’s platform to develop therapeutics to address a wide range of
diseases including: inborn errors of metabolism, liver disease,
inflammatory and immune disorders, and cancer; the future clinical
development of Synthetic Biotic medicines; the approach Synlogic is
taking to discover and develop novel therapeutics using synthetic
biology; the potential of Synlogic’s technology to treat hyperammonemia,
phenylketonuria and cancer. Actual results could differ materially from
those contained in any forward-looking statement as a result of various
factors, including: the uncertainties inherent in the preclinical
development process; the ability of Synlogic to protect its intellectual
property rights; and legislative, regulatory, political and economic
developments, as well as those risks identified under the heading “Risk
Factors” in Synlogic’s filings with the SEC. The forward-looking
statements contained in this press release reflect Synlogic’s current
views with respect to future events. Synlogic anticipates that
subsequent events and developments will cause its views to change.
However, while Synlogic may elect to update these forward-looking
statements in the future, Synlogic specifically disclaims any obligation
to do so. These forward-looking statements should not be relied upon as
representing Synlogic’s view as of any date subsequent to the date
hereof.

Contacts

Media Contact:
Courtney Heath, 617-872-2462
[email protected]
or
Investor
Contact:
Elizabeth Wolffe, Ph.D., 617-207-5509
[email protected]