The research of Star Therapeutics has spawned two startup subsidiaries, each with a clinical-stage program. Now the startup creator has $90 million to continue clinical development and to form new biotech companies in hematology and immunology.

The Series C financing announced Tuesday was led by Sofinnova Investments.

The business model of South San Francisco-based Star is unconventional but not unprecedented. Yes, the company conducts research with the aim of developing novel drugs for unmet medical needs. But rather than keeping all of its research under the same roof, Star forms startup subsidiaries around certain drugs. When Star emerged from stealth last year, CEO Adam Rosenthal told MedCity News that Star’s structure enables these new companies to focus on an asset as well as the flexibility to seek separate financing. BridgeBio Pharma, Cullinan Oncology, and Roivant Sciences are among the companies that operate similar business models.

Star’s first biotech startup was Electra Therapeutics, a company developing antibodies that target signal regulatory proteins, or SIRPs, on the surface of immune cells. Electra’s most advanced program, ELA026, is a potential treatment for the rare inflammatory disorder secondary hemophagocytic lymphohistiocytosis. The antibody has reached early clinical development. Electra also has preclinical research with an immuno-oncology drug candidate addressing an undisclosed target. Electra has since gone on to raise an $84 million Series B round of financing.

Late last year, Star unveiled its second startup, Vega Therapeutics. Vega is developing treatments for blood disorders. Its initial focus is von Willebrand disease, an inherited bleeding disorder caused by the deficiency or dysfunction of the condition’s namesake clotting protein. Vega drug candidate VGA039 is intended to restore proper blood clotting. The antibody has reached Phase 1a/1b testing.

The targets of Star’s research remain undisclosed but the company said the new biotech companies it forms will focus on developing novel antibody therapies for multiple diseases in hematology and immunology. The latest financing brings Star’s funding total to more than $190 million. The Series C round included new investors Qatar Investment Authority, Catalio Capital Management, Agent Capital, Soleus Capital, and NYBC Ventures. Also participating are earlier investors Westlake Village BioPartners, OrbiMed, Redmile Group, RA Capital Management, New Leaf Venture Partners, Cormorant Asset Management, and Cowen Healthcare Investments.

“Our outstanding syndicate of seasoned life sciences investors is ideally suited to support our growth and mission to develop life-changing therapies for as many patients as possible, building on our success to date with novel therapeutic approaches in hematology and immunology,” Rosenthal said in a prepared statement. “To date, we have unveiled two biotech companies that have rapidly advanced antibodies from idea stage to the clinic, and we aim to replicate this success with additional biotech companies in the Star portfolio.”

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