April 11, 2022

BrightPath Presents New Data on Preclinical Data onBP2301(HER2 CAR-T) at AACR 2022
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 BP2301(HER2 CAR-T) are presented at the American
Association for Cancer Research Annual Meeting (“AACR 2022”) on April 8-13. The data arebeing reported in a poster presentation entitled “Development of piggyBac transposonmediated HER2-CAR-T cells for the treatment of solid tumors（Ab No. 5570）”
The abstract for this presentation is available on the websites of the AACR and BrightPath.

Key findings are as follows:* A non-viral GMP manufacturing process of BP2301 has been optimized using piggyBac
transposon system with antigen presenting feeder cells.
* BP2301 exhibits stem cell memory phenotype and no significant T-cell exhaustion
markers.
* In vitro, BP2301 showed killing activity against the cell lines of sarcoma (RH30, RD-ES,SW-982), ovarian cancer (SK-OV-3) and endometrial serous adenocarcinoma (ARK1)
and demonstrated durable cytotoxicity and resistance to exhaustion in a sequentialkilling assay.
* In RH30 and SK-OV-3 xenograft models, BP2301 eradicated the inoculated tumors
completely without recurrence, suggesting that BP2301 persisted and maintained antitumor activity in these mice.

About BP2301
BP2301 (HER2 CAR-T cell) is a chimeric antigen receptor T (CAR-T) cell product targeting
HER2, which is highly expressed in various solid tumors.

The CAR transgene of BP2301 istransduced by a non-viral gene transfer method, piggyBac transposon system, and the productis successfully manufactured by using a method developed by the company, together withProfessor Yozo Nakazawa and Professor Shigeki Yagyu of Shinshu University . BP2301 exhibits
a dominant fraction of stem cell memory-like T cells (Tscm), which is less exhausted, having
potential to proliferate, and long-lived in vivo. Tscm has been reported to be correlated with
CAR-T clinical response in many literatures. An investigator-initiated Phase 1 clinical trial to1

evaluate the safety and efficacy of BP2301 in patients with recurrent or advanced
osteosarcoma, soft tissue sarcoma and gynecological cancer is going to be started in April-June
2022.
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 isan 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.
Investor and Media Contact:+81-3-5840-7697
irpr@brightpathbio.com
www.brightpathbio.com

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