San Diego’s Aspyrian Therapeutics Inc. has raised $15.1 million in a Series B-1 financing round. The company expects the round will increase to $19 million in the next few weeks.

The money comes from private investors including Hiroshi Mikitani, the CEO of Japan-based Rakuten Inc. and chairman of Aspyrian’s board.

The new round will go towards the company’s clinical development of an investigational drug called RM-1929 for the treatment of recurrent head and neck cancer. The company plans to start a Phase 1 trial in Japan this year, and to complete a Phase 2 study in the U.S. during the first half of 2018.

Aspyrian is focused on developing targeted therapies based on proprietary technology for cancer, pain and inflammation.

The company, founded in 2012, is using the near-infrared Photoimmunotherapy (PIT) platform exclusively licensed from the National Cancer Institute. PIT permits highly efficient and selective surgical removal of tumor cells while sparing damage to healthy organs adjacent to the tumor.