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Astellas and GO Therapeutics Enter into Strategic Research and License Agreement to Develop Novel Antibodies for Immuno-Oncology

Collaboration to Accelerate Next-Generation Cancer Treatment

TOKYO and Cambridge, Mass., June 1, 2022 – Astellas Pharma Inc. (TSE: 4503, President and CEO: Kenji Yasukawa, Ph.D., “Astellas”) and GO Therapeutics, Inc. (Co-Founder and CEO: Constantine Theodoropulos, “GO”) today announced that Xyphos Biosciences, Inc., (a wholly owned subsidiary of Astellas, “Xyphos”) and GO have entered into a strategic research collaboration and license agreement to develop novel Immuno-Oncology therapeutics.

GO is applying new advances in glycoproteomics to develop antibody-based cancer therapeutics that specifically target cancer cells. Xyphos holds a novel and proprietary ACCELTM technology platform that uses its convertibleCAR® (convertible Chimeric Antigen Receptor) on immune cells.

Under the terms of the agreement, the two companies will collaborate exclusively to identify novel antibodies with high affinity to two different glycoprotein targets and apply these antibodies to a range of therapeutic modalities. GO will lead the collaboration to discover high-affinity antibodies against the two targets, and Astellas will be responsible for research activities, clinical development and commercialization of the therapeutics derived from the antibodies provided by GO.

Under the terms of the agreement, Xyphos will pay GO Therapeutics US$20.5 million in upfront cash. Milestone and contingency payments could total up to another US$763 million.

“We are excited to collaborate with Astellas to develop a new class of Immuno-Oncology therapeutics,” said Constantine Theodoropulos, co-founder and CEO of GO Therapeutics. “The combination of GO’s targets and antibodies and Astellas’ ACCEL technology promises to create a new generation of cancer treatments that have a greater therapeutic index. This will enable oncologists to increase the efficacy of antibody-based immunotherapies for solid tumors with less damage to healthy tissues.”

Naoki Okamura, Chief Strategy Officer at Astellas said, “At Astellas, we have positioned Immuno-Oncology as one of the Primary Focuses of our R&D strategy. We believe that this collaboration will bring synergies between the two companies’ cutting-edge research, and will ultimately lead to the development of new therapeutics for patients with great unmet medical needs.”

About GO Therapeutics

GO Therapeutics is applying the latest advances in glycobiology to create cancer drugs that are more potent and less toxic. GO Therapeutics’ cancer specific antibodies against tumor-specific antigens can be used in a multimodal approach to killing cancer, such as antibody-drug-conjugates, bispecific T-cell engagers and immune-based cell therapies. The company’s scientific team includes some of the leading scientific researchers and applied biologists in glycoproteomics. GO Therapeutics is based in Cambridge, MA. For more information about the company, please visit

About Xyphos Biosciences, Inc., an Astellas Company.

Xyphos Biosciences, Inc., located at South San Francisco, Calif., is a wholly owned subsidiary of Astellas featuring ACCELTM technology, a CAR (chimeric antigen receptor) technology platform for immune cell therapies. ACCELTM technology combines a universal CAR on immune cells such as natural killer (NK) or T cells (convertibleCAR® cells) with bispecific antibody-based molecules (MicAbodies) to direct immune cell function against cancer cells. By replacing or using multiple MicAbodies according to the characteristics of the cancer cells to be attacked, convertibleCAR® cells can recognize different cancer antigens or multiple cancer antigens and attack various cancer cells. Xyphos Biosciences was launched in 2017, and the Company was acquired by Astellas Pharma in December of 2019. For more information about the company, please visit

About Astellas

Astellas Pharma Inc. is a pharmaceutical company conducting business in more than 70 countries around the world. We are promoting the Focus Area Approach that is designed to identify opportunities for the continuous creation of new drugs to address diseases with high unmet medical needs by focusing on Biology and Modality. Furthermore, we are also looking beyond our foundational Rx focus to create Rx+® healthcare solutions that combine our expertise and knowledge with cutting-edge technology in different fields of external partners. Through these efforts, Astellas stands on the forefront of healthcare change to turn innovative science into value for patients. For more information, please visit our website at

Astellas Cautionary Notes

In this press release, statements made with respect to current plans, estimates, strategies and beliefs and other statements that are not historical facts are forward-looking statements about the future performance of Astellas. These statements are based on management’s current assumptions and beliefs in light of the information currently available to it and involve known and unknown risks and uncertainties. A number of factors could cause actual results to differ materially from those discussed in the forward-looking statements. Such factors include, but are not limited to: (i) changes in general economic conditions and in laws and regulations, relating to pharmaceutical markets, (ii) currency exchange rate fluctuations, (iii) delays in new product launches, (iv) the inability of Astellas to market existing and new products effectively, (v) the inability of Astellas to continue to effectively research and develop products accepted by customers in highly competitive markets, and (vi) infringements of Astellas’ intellectual property rights by third parties.

Information about pharmaceutical products (including products currently in development) which is included in this press release is not intended to constitute an advertisement or medical advice.

Contacts for inquiries or additional information

Astellas Pharma Inc.
Corporate Advocacy & Relations

GO Therapeutics, Inc.
Jeffrey Krasner
Slowey McManus Communications