Monrovia-based biotech company CytoImmune Therapeutics Inc., which is developing natural killer cell therapies to treat diseases, opened a manufacturing plant in Puerto Rico in March that will make natural killer cell lines.
Natural killer, or NK, cells are naturally occurring immune cells that have the ability to kill tumor and virally infected cells.

CytoImmune was founded in 2017 by cell scientist Michael Caligiuri, longtime biomedical industry executive Will Rosellini and former NetJets Inc. executive Richard Santulli. The company has been developing a natural killer cell drug pipeline to treat various cancers, including acute myeloid leukemia, lung cancer, multiple myeloma and solid tumors.
CytoImmune’s lead drug is being developed in combination with a monoclonal antibody to treat specific types of lung cancer.

In its early years, CytoImmune did most of its manufacturing of natural killer cells at its Monrovia headquarters. But as the company has expanded the types of cancer it’s seeking to treat, it needed more manufacturing capacity. So the company formed a Puerto Rican subsidiary in 2020 and initially hired 40 employees to support additional cell therapy manufacturing activities in the territory.

CytoImmune leased a 37,000-square-foot facility in Toa Baja, a city on the northern coast of Puerto Rico, and proceeded to invest $28 million to convert the building into a research and development and manufacturing facility. Much of the money was spent on acquiring the machinery needed to make the natural killer cells. The Puerto Rican subsidiary eventually intends to staff up to about 100 when the manufacturing facility hits full operation.