April 11, 2022

BrightPath Presents New Data on Personalized Neoantigen
Vaccine at AACR 2022
-New data highlighting scientific advancements in immune-checkpoint antibody-directed
personalized neoantigen vaccine, BP1209.

Tokyo, Japan - April 11, 2022/ -- BrightPath Biotherapeutics (TSE Growth 4954), a clinicalstage biopharmaceutical company focused on developing novel immunotherapeutics, today
announced that preclinical data on BP1209(Personalized neoantigen vaccine) at the American
Association for Cancer Research Annual Meeting (“AACR 2022”) on April 8-13. The abstract
featuring data on a new platform for personalized neoantigen vaccine, BP1209 will be shared ina virtual poster viewing session.
BrightPath’s abstract is as follows:

TTitle: A novel computational pipeline supported with in vivo T cell induction datafor identification and validation of neoantigens（6389）
Kazushi Hiranuka at BrightPath Biotherapeutics
The abstract for this presentation is available on the websites of the AACR and BrightPath.
We have developed a robust computational pipeline to identify putatively actionableneoantigens from patients’ WES and RNA-Seq data. We generated NGS data from over 100
clinical samples and analyzed the data using our computational pipeline. From 27 patient
cases, 275 of HLA-A02:01-, A24:02-, B07:02-, or B35:01-predicted neoantigen epitopes weretested in HLA transgenic mice and confirmed that the rate of positively reacted epitopes
increased in a correlated manner to the prediction score. We further developed animmunogenicity prediction model trained with these experimental results and tested its
performance in additional clinical samples. By integrating it into the selection criteria, weachieved higher positive rate.
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 is1

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

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