Rubius raises $100M in crossover round as cell therapies near human testing

Torben Straight Nissen
Rubius CEO Torben Straight Nissen. (Rubius)

Rubius Therapeutics has pulled in another $100 million to fund the advance of its red blood cell therapies. The crossover round, which brings Rubius’ nine-month haul up to $220 million, comes as the Flagship Pioneering startup races to get its manufacturing and clinical development activities up and running.

Cambridge, Massachusetts-based Rubius is built upon technology that turns donors’ hematopoietic stem cells into enucleated, protein-expressing red blood cells. Expressing certain proteins on the cell surface results in anticancer therapies. If two or more proteins are expressed on the surface, the cell becomes a standalone immuno-oncology cocktail designed to deliver one-two punches such as the lowering of tumor defenses and orchestration of immune attacks. 

Alternatively, Rubius can express the proteins inside the cell to protect them from the immune system and thereby provide long-lasting treatment of enzyme deficiencies. Autoimmune disorders are also on Rubius’ radar.

Rubius has yet to learn how its idea holds up in the clinic. But the completion of two major, near back-to-back financing rounds means it is equipped financially to start finding out.

Sticking with the M.O. it established when it raised cash last year, Rubius is keeping details of its investors close to its chest. Flagship and undisclosed institutional investors drove Rubius to the earlier $120 million round. New and existing investors backed today’s $100 million follow up. Rubius called the round “highly oversubscribed” but opted against providing the names of the investors. 

RELATED: Flagship-backed Rubius raises $120M

The money is earmarked for clinical development and manufacturing, which is central to the value of Rubius’ pipeline prospects. Whereas the first generation of CAR-T therapies are produced through a complex process that starts with a patient’s own cells, Rubius plans to make its candidates at large scales in bioreactors. This could drive down costs and result in patients being treated sooner. 

On the clinical front, Rubius will use the cash to move candidates toward clinical proof of concept. Management plans to start the first clinical trial within the next year. Rubius previously said the $120 million round equipped it to get lead programs to clinical proof of concept. 

That suggests Rubius is well set to take multiple programs a decent way down the pipeline. But the framing of the latest investment as a crossover round implies the startup is looking to add to its haul a little way down the line. Many biotechs in recent years have gone from crossover rounds to IPOs in a matter of months. Rubius is refusing to be drawn on the timing of its plans, stating that the IPO is a “strategic consideration” and for now it is “focused on executing on [the] business plan.”