August 9, 2019

Announcement on the Results of a Phase I Clinical Trial in Melanoma for Cancer
Peptide Vaccine GRN-1201
Tokyo, August 9, 2019 — BrightPath Biotherapeutics Co., Ltd., an immuno-oncology company,
announced that a Phase I clinical trial of cancer peptide vaccine GRN-1201 in patients with melanoma,
which was conducted in the U.S. (hereinafter the “Trial”), has confirmed safety and tolerability, which
are the primary endpoints, as well as an immune response, which is the secondary endpoint.
GRN-1201 is a cancer peptide vaccine consisting of four HLA-A2-compatible peptides derived from thetumor-associated antigens (TAA). HLA-A2 is a type of HLA* largely found in European and Americanpopulations. The Trial was conducted as monotherapy and enrolled a total of 18 melanoma patients who
had resected, histologically proven, cutaneous melanoma determined to be Stage II or III.
Regarding the primary endpoints, a safety and tolerability profile was confirmed. Four grade 3 treatmentrelated adverse events were reported including face edema, pruritus and urticaria in 1 of the 6 subjects(16.7%) in the low-dose group, and headache in 1 of the 6 subjects (16.7%) in the middle-dose group.
All other adverse events were grade 2 or lower, with no grade 4 or higher adverse events and no deaths
occurring.
Since the main objective of the Trial is to evaluate safety, it was designed to have a limited number ofdoses, in contrast to the ongoing Phase II clinical trial whose objective is to evaluate the clinical efficacyof GRN-1201 in combination with pembrolizumab. Under these circumstances, the immune response
seen in the Trial was positive in 2 of the 9 measurable subjects (22%) before vaccine administration andin 4 of the 10 measurable subjects (40%) after vaccine administration.
Immune response (Cellular immunity)
Dose
Before vaccine administration

Nos. ofNos. of positiveGroup

Dose/ measurable

After vaccine administration

Positive rate

subjects

positive /measurable

Positive rate

subjects

Low dose (n=6)

0.1mg

1/3

33.3%

1/3

33.3%

Middle dose (n=6)

1mg

1/2

50.0%

2/4

50.0%

High dose (n=6)

3mg

0/4

0.0%

1/3

33.3%

2/9

22.2%

4 / 1040.0%

Total

The above-described ability of GRN-1201 monotherapy to induce cellular immunity is considered to be1

equivalent to the clinical research results of Kurume University.
While the above results were obtained using GRN-1201 as monotherapy, the ongoing Phase II clinical
trial uses GRN-1201 in combination with pembrolizumab, and it is expected that vaccine-induced
cytotoxic T cells specific to GRN-1201 antigens will be avoided from tumor-induced immunosuppression
through PD1/PD-L1 signaling, thereby inducing stronger cancer immunity than in the case ofmonotherapy and leading to a better clinical outcome. The Phase II trial is currently enrolling subjects,
and BrightPath is encouraged by the clinical results obtained to date.

[Glossary]* HLA (Human Leukocyte Antigen): HLA is a marker that distinguishes between “self” and “non-self.” A
wide variety of HLA types exist in order to distinguish “non-self” from “self.” Peptides bind to specific,
but not to incompatible, HLA types.
BrightPath
BrightPath is a clinical stage biopharmaceutical company focused on the development of novel cancer
immunotherapies to transform cancer treatment for progressive or refractory cancers that cannot betreated using conventional standard therapies. In addition to the cancer peptide vaccines currently inclinical trials in the United States, BrightPath is actively involved in developing cell therapies,
immunomodulatory antibodies and new drugs targeted toward cancer-specific neoantigens.
Inquiries
Administration, BrightPath Biotherapeutics Co., Ltd.
Tel

: +81-3-5840-7697

E-mail: irpr05@brightpathbio.com

Web: https://www.brightpathbio.com/english/index.html

Source: BrightPath Biotherapeutics Co., Ltd.

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