With Siran Biotechnology under its fold, GSK will have access to a long-acting siRNA therapy that could induce weight loss while preserving lean mass, in addition to addressing other weight-related comorbidities.
GSK has gone on another shopping trip to China, this time dropping up to just over $1 billion to pick up RNA developer Siran Biotechnology to advance an investigational siRNA therapy for cardiovascular and metabolic diseases.
The deal, announced by SiranBio Wednesday, fits with the pharma’s strategy to address the downstream health consequences of weight gain.
The $1 billion sum covers the upfront payment and future development, regulatory and commercial milestones, though the companies didn’t provide a more detailed financial breakdown for the deal. SiranBio will also be entitled to tiered royalties on global sales outside of the greater China region.
In return for its investment, GSK will gain access to SA030, SiranBio’s long-acting siRNA oligonucleotide that targets the ALK7 receptor, which has been shown in animal models to play a role in various metabolic pathways, including sugar control and weight loss. SiranBio will carry SA030 through ongoing Phase 1 development, after which GSK will take charge.
By targeting ALK7, SA030 could lower abdominal fat while preserving lean mass, according to SiranBio, in turn improving insulin sensitivity and blood lipid levels. SA030 could also tamp down fat cell-related inflammation. “SA030 has a complementary and distinct mechanism to GLP-1 agonists,” the Chinese company said on Wednesday, “supporting future combination approaches.”
This mode of action fits well with GSK’s overall cardiometabolic strategy of avoiding the GLP-1 modality, which in recent months has gotten increasingly competitive. “I think it’s going to be very crowded,” CEO Luke Miels told reporters in February. “Our focus is more on the downstream effects of obesity rather than addressing the actual obesity itself,” he continued, pointing to weight-related comorbidities such as kidney and heart conditions.
“People, when they’ve been obese for a very long time, they get fatty liver and then ultimately, if things remain that way, they can get fibrosis of the liver,” Miels said.
Wednesday’s SiranBio acquisition helps GSK build its portfolio in this direction, as does its May 2025 pick-up of Boston Pharmaceuticals’ efimosfermin alfa, an FGF21 analog primed for late-stage testing for metabolic dysfunction-associated steatohepatitis (MASH). That deal cost the pharma $1.2 billion upfront and up to $800 million in milestones.
GSK has been dealing outside the cardiometabolic space, too, marked by its January partnership with South Korea’s Alteogen. For $20 million upfront and $265 million in milestones, the pharma gained access to the biotech’s platform to enable subcutaneous delivery of the PD-1 blocker Jemperli. In December, GSK linked up with CAMP4 Therapeutics—another RNA developer—to advance multiple candidates for neurodegenerative and kidney disorders.
