Spero Therapeutics is on the hook for up to $1.1 billion in an exclusive license deal with Innovent Biologics for SP001, a third-generation anti-CD40L antibody. Innovent gets an upfront payment, R&D and commercial milestones stacking to that $1.1 billion figure, plus tiered royalties on net sales. Neither company disclosed the upfront split.
Here’s what Spero actually gets: global rights outside Greater China to a Phase 2-ready antibody with Phase 1b data already in hand from a Sjögren’s disease trial in China. Spero’s own Phase 2 push targets IgG4-related disease, starting Q2 2027. Innovent keeps China, where it’s running a Sjögren’s Phase 2 starting early 2027.
The financing mechanics are the real story. Spero doesn’t have $1.1 billion sitting around, so it borrowed $105 million from Healthcare Royalty, pledging a chunk of future royalties from GSK-partnered antibiotic Utebzi, approved by the FDA last month for complicated UTIs. That buys runway into the second half of 2029 without touching equity.
This is the small-biotech version of the immunology land grab. AbbVie just paid $10.9 billion, or $135.11 a share, for Apogee Therapeutics and its IL-13 antibody zumilokibart, and Biogen dropped up to $1 billion on RayThera’s preclinical assets in mid-June. Spero can’t outbid AbbVie, so it’s financing an in-license against an approved asset’s cash flow instead of diluting shareholders.
Watch Q2 2027 for the IgG4-related disease readout that decides whether this bet pays off.
Diana Kowalski