The University of Tokyo

Organization and Innovation

Japanese Creation to Worldwide Sensation: the Making of a Novel Peptide Drug


Crystal structure of a MATE multidrug transporter and bound peptides, featured in a Nature article in 2013 (data provided by Suga Lab & Nureki Lab, Graduate School of Science)

The name of this company is Peptidream. The second half of the name comes from “dream,” of course, but how about “pepti,” which is short for peptide? What exactly is a peptide?

Chief Executive Officer Kiichi Kubota provides the following explanation: “In simple terms, a peptide is a string of multiple amino acids. These strings control bodily functions. As peptides grow, they become polypeptides, and these polypeptides grow further to become proteins. So in other words, a peptide is a small protein.”

For example, one peptide that works to inhibit blood sugar is insulin, which, if it ceases to function properly, causes diabetes and needs to be injected into diabetic patients. A peptide that works to lower blood pressure naturally could be used as a treatment for hypertension. If we were able to create peptides that could manage bodily functions properly, they could be used as effective medicines. However, current pharmaceutical products are predominantly low-molecular drugs or antibody preparations; there are still very few drugs that use peptides.

“Putting peptides to practical use has been difficult,” Mr. Kubota explains. “Even if they are given as medication, they are almost immediately broken down inside the body. However, the technology developed by Professor Hiroaki Suga (currently of the Graduate School of Sciences) finally has helped to resolve this disadvantage of peptides.”


President Kubota shares a firm handshake with his partner, Professor Hiroaki Suga. “We want to launch a new drug before the Tokyo Olympics,” they say.)

That technology, called “Flexizyme,” makes it possible to easily link non-standard amino acids, a process which before had been extremely difficult. Flexizyme enabled the creation of special peptides that are not easily broken down in the body, thus opening up a range of new possibilities for peptide-based drugs. In 2006 Professor Suga met with Mr. Kubota, who was running the bio-incubation program of Kyoto University, and the two hit it off right away. They both shared the same dream to “engage in work that makes those suffering from illness say, ‘thank you.’” In this way Peptidream was born.

“What we added to Flexizyme were technologies capable of creating a library of special peptides and efficiently screening trillions of special peptides. Flexizyme combined with these technologies forms the basis of our drug development platform system. Using this system we are collaborating with major pharmaceutical companies to develop new drugs.”

Mr. Kubota estimates that it will be around 2020 when a special peptide drug can come into the market that can be used to treat disorders on which low-molecular drugs and antibody preparations are ineffective. When that day comes it will be proof that Mr. Kubota and Professor Suga’s work has not just been a mere “dream,” but rather a “target” to be achieved.

Kiichi Kubota

Kiichi Kubota

Peptidream, Inc.