May 15, 2017
Press Release
CompanyGreenPeptide Co., Ltd.

Representative

Kenichi Nagai, President & CEO(Code: 4594 TSE Mothers)

Inquiries

Teruhiko Sakai, Director/CFO(TEL.: 03-5840-7697)

Decision to Grant a Patent Related to Antigenic Peptides Derived
from the T790M Point Mutation of Epidermal Growth Factor Receptor
GreenPeptide Co., Ltd. announces that a patent application for the cancer peptide
vaccine GRN-1301, a product developed by the company, has received a decision togrant a patent*1 in Japan, following an equivalent grant in the United States of America(USA), as described below.
1. Overview of the patent
Title of the invention
Patent application number
Patent holder

Antigen peptide originated from T790M
point-mutated*2 sequence of epidermal growth factor
receptor (EGFR)*3
Japanese Patent Application No. 2014-529551
GreenPeptide Co., Ltd.

Of patients with non–small-cell lung cancer, which accounts for 80% of all lungcancer types, those with epidermal growth factor receptor (EGFR) mutations are
typically prescribed with tyrosine kinase inhibitors (TKIs) as first-line therapy. However,with prolongation of their TKI treatments, approximately 60% of patients experience
the T790M point mutation, which induces TKI resistance in the EGFR. The peptide
vaccine GRN-1301, derived from the T790M point mutation, is designed to target theneoantigen*4 and exert longer-term treatment effects by suppressing the emergence ofTKI-resistant cancer cells associated with the mutation mentioned above. We have been
engaged in the research and development of this drug jointly with the Kanagawa
Prefectural Hospital Organization.
The peptide derived from this invention integrates the T790M point mutation, a“driver mutation” directly involved in the malignant transformation of cancer, so that itis recognized as a non-self in the patient’s immune system, thereby holding great
expectations for high immunogenicity. This peptide also has other characteristics, such1

as a low likelihood of an escape from immunological surveillance occurring due to aloss of cancer vaccine antigens in the cancer cell.
From the viewpoint of intellectual property rights, this decision to grant a patent willprotect the GRN-1301 cancer immunotherapeutic under development in a highly securemanner. This patent has already been registered in the USA.
2. Impact on projections for financial results
This decision to grant a patent will not have any impact on the company’s financial
results for the fiscal year ending March 31, 2018.

[Explanation of terms]*1: Decision to grant a patent: Results of an examination by each country’s patent office
to be notified when it has been determined that “the invention described in theapplication deserves being entitled a patent.” Payment of the patent fee uponreceipt of such decision will have the patent registered and its right established inrelevant countries.
*2: T790M point mutation: The mutation of the 790th amino acid of the EGFR, fromthreonine to methionine. This mutation is considered to eventually acquire drug
resistance to the first- and second-generation tyrosine kinase inhibitors extensively
used as first-line therapy, such as Tarceva and Iressa.
*3: Epidermal growth factor receptor (EGFR): The receptor that binds to the epidermal
growth factor, which regulates cell proliferation and growth, thereby mediating
signal transmission. The activation of this receptor will lead to cell differentiationand proliferation. The EGFR is found in many cells, and its mutation can trigger
canceration, infiltration, and metastasis in the cells.
*4: Neoantigen: An antigen that involves gene mutations (amino acid mutations) anddevelops with gene abnormalities unique to cancer cells. This cancer-specificantigen manifests only through gene mutations unique to cancer cells of individual
patients and does not exist in normal cells. It is expected that targeting aneoantigen, which is recognized as a “non-self” by the immune system, will
efficiently induce cancer cell-killing immunity.

2About GreenPeptide Co., Ltd.
GreenPeptide is a drug discovery venture company engaged in the development ofinnovative “cancer immunotherapy” as the fourth cancer treatment following surgery,radiotherapy, and chemotherapy. Clinical trials of the company’s cancer peptide
vaccines are being conducted in Japan and the USA. In addition, the company recently
started the development of a new T-cell therapy using the induced pluripotent stem cellregeneration of antigen-specific T cells, as well as the development of new drugs basedon neoantigens (gene mutation antigens), a highly innovative approach the world over.

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