Ipsen has become the newest entrant in the antibody-drug conjugate (ADC) race, handing over around $90 million in near-term payments to Sutro Biopharma in return for the global rights to a preclinical candidate.
The asset in question, dubbed STRO-003, targets the receptor tyrosine kinase-like orphan receptor 1 (ROR1) tumor antigen. ROR1 is overexpressed in various cancers—including solid tumors and blood cancers—and the target is also being chased by the likes of Boehringer Ingelheim and Merck & Co.
STRO-003 will become the first ADC in Ipsen’s armory, and the French company said the focus will be on getting the candidate into the clinic.
The deal is worth around $900 million in combined upfront, development, regulatory and commercial milestone payments and an equity investment in Sutro. As a result, Ipsen will take on responsibility for preparing STRO-003 for phase 1 trials and beyond.
“The potential for ADCs in oncology is well-documented and we are excited by the addition of STRO-003, Ipsen’s first ADC candidate with best-in-class potential,” Mary Jane Hinrichs, senior vice president and head of early development at Ipsen, said in an April 2 release.
“STRO-003 is a next-generation ROR1 ADC, leveraging Sutro’s site-specific technology to generate a highly stable conjugate, coupled with exatecan payloads, that have shown significant potential in solid tumors,” Hinrichs added.
Capitalizing on Ipsen's interest, Sutro announced plans this morning to bring in $75 million from an underwritten offering of 14.4 million shares of its common stock.
Ipsen isn’t the only biopharma that’s spotted potential in ROR1. The target was at the center of Boehringer Ingelheim’s $1.5 billion acquisition of NBE-Therapeutics back in 2020, the same year that Merck bought VelosBio for $2.8 billion for a ROR1 ADC.
In 2022, Astellas also bought into Sutro’s vision, handing over $90 million upfront to the South San Francisco-based biotech for the rights to three immunostimulatory ADCs, a modality designed to combine the best features of ADCs and personalized vaccine biology.
The ADC race heated back up toward the end of last year, with everyone from GSK to Eli Lilly and Bristol Myers Squibb fronting serious cash to pad out their pipelines over the space of a few months.