In 2005, Chugai launched Actemra^®, the first therapeutic antibody produced in Japan. 15 years since its introduction in Japan, Actemra^® has grown into a product sold in more than 110 countries worldwide through the channels of the Roche Group. The product is manufactured at the Utsunomiya Plant and shipped to patients worldwide, realizing the ambition incorporated in Chugai’s name at its founding: to provide Japanese pharmaceuticals overseas.

Chugai is focusing on the development of next-generation antibody technologies. Its innovative antibody engineering technology called Recycling Antibody^®, which prolongs the effect of a drug by binding to an antigen multiple times, was announced in Nature Biotechnology in October 2010. In addition, Sweeping Antibody^®, which was developed by applying Recycling Antibody^® technology, has the feature of being able to remove a large amount of antigens with fewer antibodies. In August 2020, Enspring^®, the first drug based on Recycling Antibody^® technology, was launched for the treatment of Neuromyelitis Spectrum Disorder (NMOSD), which has been designated as an incurable disease.

The breakthrough therapy designation of the U.S. FDA is aimed at expediting the development and review of drugs for the treatment of severe or life-threatening diseases or symptoms. A drug must be highly innovative to receive the designation, but receiving it is valuable for various reasons. For example, a drug with this designation receives priority review, which shortens the development period, bringing the drug to patients as quickly as possible. Six Chugai products have received nine breakthrough therapy designations.

While conventional antibodies only bind to the same antigen, “bispecific antibodies” can bind to two different antigens, allowing for an unconventional approach to drug discovery. Using this technology, we launched Hemlibra^® in May 2018. The strong desire of the developers to address unmet medical need was the driving force behind the drug discovery research, which resulted in an unprecedented treatment.

Although therapeutic antibody drugs offer a therapeutic approach not available with small molecule drugs, there are challenges. One challenge is “on-target toxicity,” in which toxicity increases once the antibody binds to the target molecule. One solution is the Switch Antibody^™ technology announced by Chugai in 2019. This technology focuses on a small molecule (switch molecule) which is present at high extracellular concentrations in tumors. The Switch Antibody^™ is designed to “switch on,” or bind to the target antigen only in a tumor microenvironment, but “switch off,” or not bind to the antigen in normal tissues. As a result, target molecules that have been undruggable due to the increase in toxicity can be made druggable, greatly extending the boundaries of drug discovery. Drug discovery projects using this technology are also in progress.