Madrigal Pharmaceuticals has entered into a partnership with Suzhou Ribo Life Science, a Chinese biotechnology company, to develop six investigational small interfering RNA (siRNA) programs targeting liver diseases. The agreement includes an upfront payment of $60 million from Madrigal and potential milestone payments totaling up to $4.4 billion across all programs. Ribo, through its subsidiary Ribocure Pharmaceuticals, will also be eligible for royalties on net sales.
The collaboration aims to explore combination regimens of these siRNA therapies with Madrigal’s drug Rezdiffra, which became the first FDA-approved treatment for metabolic associated steatohepatitis (MASH) in March 2024. Madrigal plans to begin IND-enabling activities for initial candidates from the Ribo deal in 2026.
SiRNAs are short strands of non-coding RNA that bind to target mRNA molecules and prevent their translation into proteins. This approach allows for targeted gene silencing in the liver, which could be beneficial in treating MASH.
“SiRNAs are highly liver targeted, and there are several genes implicated in MASH that could be addressed with an mRNA-knockdown approach,” said Chief Medical Officer David Soergel. He added that combining this technology with Rezdiffra “has the potential to create the next generation of MASH treatment.”
Details about Ribo’s preclinical siRNA candidates were not disclosed by Madrigal. The specific genes or disease pathways targeted by the collaboration remain unspecified. However, Madrigal noted that it now has more than ten molecules addressing different aspects of MASH due to this new partnership.
Rezdiffra remains central to Madrigal’s pipeline and is currently being evaluated in a late-stage study for compensated MASH cirrhosis, with results expected in 2027 according to the company’s third quarter 2025 presentation. In 2024, Rezdiffra was used by over 11,800 patients and generated net sales of $180.1 million. By the third quarter of 2025, its net revenues had increased significantly to $287.3 million compared to $62.2 million during the same period the previous year. Madrigal is scheduled to report its full-year 2025 earnings on February 19.
Another key asset in Madrigal’s pipeline is ervogastat, an oral DGAT protein blocker acquired from Pfizer last month through a $50 million upfront licensing deal. Ervogastat is currently in mid-stage development for MASH and may offer a complementary mechanism of action alongside Rezdiffra. Pfizer may receive additional milestone payments under this agreement.
A correction was issued on February 11 clarifying that the total potential value of the deal with Ribo is $4.4 billion rather than $4.4 million.
