ERYTECH Presents New Preclinical Anti-Tumor Data on Erymethionase at AACR 2017

LYON, France–(BUSINESS WIRE)–Regulatory News:

ERYTECH Pharma (Paris:ERYP) (ADR:EYRYY), a French clinical-stage
biopharmaceutical company developing innovative therapies for rare forms
of cancer and orphan diseases based on its proprietary ERYCAPS platform,
encapsulating therapeutic drug substances inside red blood cells, today
announced the presentation of new anti-tumor data supporting the
Company’s preclinical product erymethionase (ERY-MET) at the upcoming
American
Association for Cancer Research (AACR) Annual Meeting
, being
held April 1 – 5, 2017 in Washington, D.C.

Results from the preclinical study demonstrate that erymethionase,
methionine gamma-lyase (MGL)-encapsulated in red blood cells using
ERYTECH’s proprietary encapsulation platform technology, represents a
promising new treatment approach against a broad range of cancers that
rely on methionine metabolism. The research will be presented by Dr.
Vanessa Bourgeaux, Program Leader at ERYTECH, during a poster session at
the conference.

Dr. Bourgeaux stated, Methionine dependence has emerged as a unique
target for anti-cancer activity during the last two decades. While
methionine gamma-lyase is a promising strategy for these cancers, its
very short half-life in the body prohibited all attempts to develop MGL
as cancer therapy. However, our work here shows that when encapsulated
in red blood cells using our ERYCAPS technology, MGL is protected from
degradation and overcomes the pharmacokinetic limitations resulting in
increased half-life in vivo for effective potential use in a broad-range
of methionine-dependent cancers.”

Gil Beyen, Chairman and CEO of ERYTECH, added,Erymethionase
represents a novel product candidate in our tumor starvation arsenal.
ERYTECH is progressively building its cancer metabolism platform with
this second product candidate to complement eryaspase (GRASPA®),
ERYTECH’s lead product candidate. The posters presented at two
immunotherapy medical meetings earlier this month and now promising data
with erymethionase at AACR underscore ERYTECH’s intention to develop the
scope of products and applications for its technology platform.”

Methionine is an essential amino acid, which is necessary for all cells
to grow and multiply. More specifically, fast-growing tumor cells
exhibit very high requirements of methionine to proliferate. The enzyme
methionine gamma-lyase (MGL) mediates tumor starvation via systemic
lowering of methionine levels. MGL is an enzyme with a short half-life
and is dependent on a co-factor, a Vitamin B6 derivative which is
naturally present in red blood cells, to demonstrate enzymatic activity.
The preclinical studies in mouse models of erymethionase aimed to
investigate the protection of MGL against degradation and immune
reactions through encapsulation in erythrocytes (red blood cells).

ERYTECH researchers demonstrated that encapsulation of MGL in red blood
cells both strongly improved the half-life of the enzyme and provided
active co-factor to increase MGL activity and therefore, tumor
starvation. The half-life of MGL increased from less than 24 hours when
free to more than 10 days when encapsulated in red blood cells, with no
toxicity reported. The preclinical study showed that combining a single
weekly intravenous injection of erymethionase with daily pyridoxine (PN)
supplementation led to a sustained methionine depletion in the plasma,
and an inhibition of tumor growth for 45 days following the fifth
erymethionase dose of 85% in the glioblastoma mouse model, and of 72% in
the gastric cancer mouse model. Repeated injections of ERY-MET were also
effective against established tumors in the gastric cancer model leading
to a complete tumor regression.

Full details of the AACR presentation follow:

Abstract
# 2134 / Poster # 3
: Use of methionine gamma-lyase-loaded
erythrocytes to induce effective methionine depletion of cancer therapy

Presenter:
Dr. Vanessa Bourgeaux
Poster Session/Section: PO.ET01.09 – New
Targets 2/Section 6
Date: Monday, April 3
Time: 1:00 – 5:00
p.m. EDT
Location: Convention Center, Halls A-C

About ERYTECH and eryaspase (GRASPA®): www.erytech.com

Founded in Lyon, France in 2004, ERYTECH is a clinical-stage
biopharmaceutical company developing innovative therapies for rare forms
of cancer and orphan diseases. Leveraging its proprietary ERYCAPS
platform, which uses a novel technology to encapsulate therapeutic drug
substances inside red blood cells, ERYTECH has developed a pipeline of
product candidates targeting markets with high unmet medical needs.
ERYTECH’s initial focus is on the treatment of blood cancers, including
acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), by
depriving tumors of nutrients necessary for their survival. ERYTECH
plans to pursue regulatory approvals for its lead product candidate,
eryaspase, also known as ERY-ASP or under the trade name GRASPA®, having
achieved positive efficacy and safety results from its completed Phase
2/3 pivotal clinical trial in Europe in children and adults with
relapsed or refractory ALL. ERYTECH also has an ongoing Phase 1 clinical
trial of eryaspase in the United States in adults with newly diagnosed
ALL, and a Phase 2b clinical trial in Europe in elderly patients with
newly diagnosed AML, each in combination with chemotherapy. ERYTECH
believes that eryaspase also has the potential as a treatment approach
in solid tumors and is conducting a Phase 2 clinical trial in Europe in
patients with metastatic pancreatic cancer.

Eryaspase consists of an enzyme, L-asparaginase, encapsulated inside
donor-derived red blood cells. L-asparaginase depletes asparagine, a
naturally occurring amino acid essential for the survival and
proliferation of cancer cells, from circulating blood plasma. ERYTECH
produces eryaspase at its own GMP-approved and operational manufacturing
site in Lyon (France), and at a site for clinical production in
Philadelphia (USA). ERYTECH has entered into licensing and distribution
partnership agreements for eryaspase for ALL and AML in Europe with
Orphan Europe (Recordati Group), and for ALL in Israel with TEVA, which
will market the product under the GRASPA® brand name. The European
Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA)
have granted orphan drug designations for eryaspase for the treatment of
ALL, AML and pancreatic cancer.

In addition to eryaspase, ERYTECH is developing two other product
candidates that focus on using encapsulated enzymes to induce tumor
starvation. The company is also exploring the use of its ERYCAPS
platform for developing cancer immunotherapies and enzyme replacement
therapies.

ERYTECH is listed on Euronext regulated market in Paris (ISIN code:
FR0011471135, ticker: ERYP) and is part of the CAC Healthcare, CAC
Pharma & Bio, CAC Mid & Small, CAC All Tradable, EnterNext PEA-PME 150
and Next Biotech indexes. ERYTECH is also listed in the U.S. under an
ADR level 1 program (OTC, ticker EYRYY).

Forward-looking information

This press release contains forward-looking statements, forecasts and
estimates with respect to the clinical development plans, business and
regulatory strategy, and anticipated future performance of ERYTECH and
of the market in which it operates. Certain of these statements,
forecasts and estimates can be recognized by the use of words such as,
without limitation, “believes”, “anticipates”, “expects”, “intends”,
“plans”, “seeks”, “estimates”, “may”, “will” and “continue” and similar
expressions. They include all matters that are not historical facts.
Such statements, forecasts and estimates are based on various
assumptions and assessments of known and unknown risks, uncertainties
and other factors, which were deemed reasonable when made but may or may
not prove to be correct. Actual events are difficult to predict and may
depend upon factors that are beyond ERYTECH’s control. There can be no
guarantees with respect to pipeline product candidates that the
candidates will receive the necessary regulatory approvals or that they
will prove to be commercially successful. Therefore, actual results may
turn out to be materially different from the anticipated future results,
performance or achievements expressed or implied by such statements,
forecasts and estimates. Documents filed by ERYTECH Pharma with the
French Autorité des Marchés Financiers (www.amf-france.org),
also available on ERYTECH’s website (www.erytech.com)
describe such risks and uncertainties. Given these uncertainties, no
representations are made as to the accuracy or fairness of such
forward-looking statements, forecasts and estimates. Furthermore,
forward-looking statements, forecasts and estimates only speak as of the
date of this press release. Readers are cautioned not to place undue
reliance on any of these forward-looking statements. ERYTECH disclaims
any obligation to update any such forward-looking statement, forecast or
estimates to reflect any change in ERYTECH’s expectations with regard
thereto, or any change in events, conditions or circumstances on which
any such statement, forecast or estimate is based, except to the extent
required by law.

Contacts

ERYTECH
Gil Beyen
Chairman and CEO
or
Eric
Soyer

CFO and COO
+33 4 78 74 44 38
investors@erytech.com
or
The
Ruth Group

Lee Roth, +1 646 536 7012
Investor
relations
lroth@theruthgroup.com
or
Kirsten
Thomas,
+1 508 280 6592
Media relations
kthomas@theruthgroup.com
or
NewCap
Julien
Perez

Investor relations
or
Nicolas Merigeau
Media
relations
+33 1 44 71 98 52
erytech@newcap.eu