Chugai Receives “The Imperial Invention Prize,” the Highest Honor of the FY2026 National Commendation for Invention — Recycling Antibody Technology Recognized for its Contribution to Pharmaceutical Research —

• An invention related to Chugai’s recycling antibody technology has received “The Imperial Invention Prize,” the highest honor of the FY2026 National Commendation for Invention
• The invention was recognized as a foundational technology that improves the sustained efficacy of antibody drugs and enables reduced burdens on patients and healthcare professionals, contributing to pharmaceutical research and medical care, and as an invention that makes a significant contribution to the promotion of science and technology in Japan and the development of the industrial economy
• This achievement demonstrates that Chugai’s proprietary drug discovery capabilities and technological strength have been recognized

TOKYO, May 26, 2026 -- Chugai Pharmaceutical Co., Ltd. (TOKYO: 4519) announced that its proprietary antibody engineering technology, the “recycling antibody technology,” has received “The Imperial Invention Prize,” the highest honor at the FY2026 National Commendation for Invention, organized by the Japan Institute of Invention and Innovation.

The National Commendation for Invention is Japan’s historic and prestigious invention prize program, conducted with a monetary grant bestowed by the Imperial Household. The program honors outstanding inventions with a high degree of originality that contribute to the advancement of science and technology and the development of industry in Japan. Among these prizes, “The Imperial Invention Prize” is conferred on inventions that are scientifically and technologically exceptional.

This marks Chugai’s first receipt of the Imperial Invention Prize, and represents recognition, within the invention prize system, of the strengths of the company’s research in proprietary antibody engineering technologies and its drug discovery platforms built over many years. This invention relates to recycling antibody technology, a technology for creating antibodies endowed with a recycling function, whereby a single antibody molecule can repeatedly bind to multiple antigen molecules by conferring pH‑dependent antigen-binding properties, thereby expanding the potential of antibody drugs and improving sustained pharmacological efficacy.

“We are deeply honored that our invention in recycling antibody technology has received the highest honor, ‘The Imperial Invention Prize,’ at the National Commendation for Invention. We believe this prize reflects the high regard for the efforts of our researchers, who have worked for many years to develop Chugai’s proprietary antibody engineering technologies. Going forward, we will continue striving to refine our world‑class drug discovery capabilities and to become a company where patients around the world expect that 'Chugai will surely create new treatments,'" said Dr. Osamu Okuda, Chugai’s President and CEO.

Chugai has long been committed to addressing unmet medical needs through the creation of innovative medicines, particularly antibody drugs. Chugai will continue to generate innovative medicines through ongoing research into proprietary drug discovery technologies and provide new value to patients and society.

Outline of the Award