April 13, 2022

BrightPath Presents Preclinical Data on a CD73 antagonist antibody
at AACR 2022
-New data from pre-clinical development of CD73 antagonist antibody, BP1200
that ameliorates tumor microenvironment.

Tokyo, Japan - April 13, 2022/ -- BrightPath Biotherapeutics (TSE Growth: 4594), a clinicalstage biotech company dedicated to the discovery and development of novel immunotherapies
today announced data presentations from its immuno-oncology pipeline at the American
Association for Cancer Research Annual Meeting (“AACR 2022”) on April 8-13. The abstract
featuring data on a CD73 antagonist therapeutic antibody, BP1200 will be shared in a virtual
poster viewing session.
BrightPath’s abstract is as follows:
Title: A novel therapeutic antibody against CD73 that ameliorates the tumor
microenvironment and improves the efficacy of cancer immunotherapy (987P)
Noriko Matsumoto, Yuji Mishima, at BrightPath Biotherapeutics
The abstract for this presentation is available on the websites of the AACR and BrightPath.

* BP1200 completely regressed colon-adenocarcinoma cells transplanted in mousein combination with PD-1 antibody. Tumor cells re-challenged to the mice werecompletely rejected, suggesting the enhancement and establishment of tumorspecific immunity by BP1200.
* BP1200 induces internalization of the cell surface CD73, thereby down-regulates theexpression level of CD73 as well as inhibiting the enzyme activity.
* BP1200 induces proliferation, cytokine production, and cytotoxic activity of T cells evenin the immunosuppressive condition, suggesting that BP1200 enhances the T cell
immunity in tumor micro-environment (TME).
* BP1200 shows preferable PK/TK profiles without remarkable organ toxicity in rodents
and primates.
*The novel anti-human CD73 antibody, BP1200, ameliorates immunosuppressive TME
caused by adenosine and enhances antitumor immune responses. The combination of1

BP1200 and immune-checkpoint inhibitors for cancer treatment will be a promisingtherapeutic option in clinical practice.

BP1200 is a humanized antibody that is a potentially best-in-class immune checkpoint inhibitor
targeting CD73 expressed on tumor and immune cells. CD73 is a cell surface enzyme that isexpressed on tumor cells and converts extracellular adenosine monophosphate (AMP) into
immunosuppressive adenosine. Adenosine production inhibits T cell and NK cell cytotoxicity,
cytokine production, and proliferation as well as suppression of antigen presenting cells andmacrophage M2 polarization, which enables tumor growth and disease progression. BP1200
ameliorates the suppressive tumor microenvironment by attenuating adenosine production andreestablishes a broad anti-tumor response mediated by tumor infiltrating T cells which includes
enhancement of proliferation, cytokine production, and cytotoxicity of T cells. BP1200 in
combination with other complementary immune pathways such as PD-1/PD-L1, is a key
strategy to enhance the anti-tumor cytotoxic potential of immunotherapy.
About BrightPath:
BrightPath Biotherapeutics is an immuno-oncology focused biotech company dedicated toimproving treatment and clinical outcomes for patients through cancer vaccine, therapeutic
antibodies, and cell therapy that harness the immune system to fight cancer.
BrightPath’s clinical-stage product, GRN-1201 is a new cancer vaccine in phase 2 trial inpatients with melanoma and lung cancer in US. BP2201 in-collaboration with RIKEN, Japan is
an iPSC (induced pluripotent stem cell)-derived NKT therapy and the phase 1 trial is currently
ongoing in Japan.
BrightPath’s broad pipeline of immunotherapy includes several potentially first-in-class and bestin-class clinical and preclinical candidates in cancers with high unmet medical need.
BrightPath has been a pioneer in immunotherapy by cancer vaccine and has expanded its
expertise in the tumor microenvironment and immune cell development as well as antibody
engineering. This innovative approach has resulted in a diversified proprietary portfolio ofcancer vaccine, therapeutic antibody, and immune-cell therapy.
Based in Tokyo, Japan, BrightPath is listed on Tokyo Stock Exchange in Japan. For more
information, visit www.brightpathbio.com.
Forward-Looking Statements:
This news release contains forward-looking statements that are based on the current
expectations and beliefs of BrightPath. All statements, other than statements of historical fact,
are statements that could be deemed forward-looking statements. BrightPath cautions thatthese forward-looking statements do not guarantee our future financial results but involve risks
and uncertainties that could cause actual results to differ materially from those discussed in theforward-looking statements. These forward-looking statements speak only as of the date of thispress release and BrightPath assumes no duty to update forward-looking statements, except as
may be required by law.

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Investor and Media Contact:+81-3-5840-7697
irpr@brightpathbio.com
www.brightpathbio.com

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