Biotechnology startup Rakuten Medical announced on January 8 that it has raised $100 million in a Series F funding round.
Rakuten Medical aims to develop cancer treatments based on photoimmunotherapy, a therapeutic approach described below.The company is headquartered in San Diego, California, and has a Japanese subsidiary located at the same site as Rakuten Group’s headquarters in Tokyo.
A Photoimmunotherapy Discovered Through Mikitani’s Father’s Illness
Rakuten Medical’s core technology, photoimmunotherapy, was developed by Dr. Hisataka Kobayashi, a Senior Investigator at the U.S. National Cancer Institute (NCI). The therapy works by administering a drug that binds to cancer cells and then irradiating the target area with light of a specific wavelength, selectively destroying and eliminating cancer cells.
Rakuten Medical was originally known as Aspyrian Therapeutics. In 2016, Hiroshi Mikitani, founder and CEO of Rakuten Group, invested in the company in a personal capacity. In 2018, Rakuten Group itself also invested, and the company was renamed Rakuten Medical.
This development is closely tied to Mikitani’s personal background. His father, Ryoichi Mikitani, suffered from pancreatic cancer in his later years. While searching for treatment options for his father, Mikitani encountered Kobayashi’s photoimmunotherapy technology. By the time of this encounter, however, his father’s cancer had already progressed significantly, and he passed away in 2013, prior to Mikitani’s investment.
Nevertheless, Mikitani was convinced of the potential of photoimmunotherapy and decided to invest in the technology independently of his father’s illness.
Ryoichi Mikitani was an economist who served as president of the Japan Society of Monetary Economics.
Toward Global Expansion, Following Approval in Japan
Rakuten Medical’s photoimmunotherapy technology has been branded as the Alluminox Platform. The therapy has already received regulatory approval in Japan for the treatment of recurrent head and neck cancer.
As discussed later, the company is now seeking regulatory approvals outside Japan as well.
Targeting U.S. Approval by 2028
Of the $100 million raised in the Series F round, $70 million came from newly issued shares, while the remaining $30 million was raised through convertible bonds with stock acquisition rights. The lead investor was venture capital firm TaiAx Life Science Fund. New investors participating in the round included Daiwa Securities Group, Mitsui Sumitomo Insurance, Sumitomo Mitsui Banking Corporation, ABIES Capital, and Nexus CVC.
The funds will be used to obtain regulatory approval in the United States for the treatment of recurrent head and neck cancer. Rakuten Medical stated that it is aiming for U.S. approval by 2028.
Commenting on the funding round, Mikitani said:
“Through this fundraising, we will further accelerate clinical development, expand globally starting with the United States, and move into the next phase of growth.”
