Sanofi has decided to end work on a STAT6 degrader from Nurix just two months after taking the inflammatory disease drug into the clinic.
A History of Multi-Million Dollar Collaboration
The two firms have been collaborating since 2019, when Sanofi paid $55 million to join forces with the biotech in order to develop novel methods of specifically targeting proteins for degradation using E3 ligases. One year later, the French pharma gave another $22 million to expand the collaboration, followed by another two years of collaboration in 2024, this time with a signal transducer and activator of transcription 6 (STAT6) degrader called SAR448272.
The partnership grew stronger last year, with Sanofi securing two more protein degrader programs aimed at STAT6 and an undisclosed target, respectively.
Phase 1 Trial Triggered Milestone Payment
Until recently, it seemed SAR448272 would go on to become a Phase 1 trial, with Sanofi taking the STAT6 degrader in August. Launching the study, which was aimed at type 2 inflammatory diseases, triggered a $10 million milestone payment to Nurix.
The executives of Nurix at the time said the trial launch was “further validat[ing] the productivity of our DEL-AI drug discovery platform in producing differentiated degrader medicines for immunology.”
However, Sanofi has since changed its mind. In a press release, Nurix revealed that Big Pharma has decided to terminate the trial and the program of SAR448272.
Nurix Leadership Responds and Highlights Pipeline
Today’s news is disappointing, but Nurix is in a good position with a significant cash runway ahead, three clinical stage programs in its wholly owned and partnered portfolio, and an exciting preclinical pipeline,” said Arthur Sands, Nurix’s CEO.
Roche-partnered BTK degrader bexobrutideg was mentioned by Sands in a phase 3 study in chronic lymphocytic leukemia. There is also a Gilead co-developed IRAK4 degrader in a phase 1 clinical trial for rheumatoid arthritis, and Nurix’s fully developed CBL-B inhibitor NX-1607 in phase 1 trials for multiple types of cancer.
Sanofi has yet to take any other drugs from its Nurix partnership into the clinic, but the California biotech said it would still be in line for milestones if that does occur.
Broader Pipeline Slimming at Sanofi
Nurix didn’t disclose the exact reasons behind Sanofi’s decision, but it comes in the wake of a significant pipeline restructuring at the Big Pharma under the oversight of recently installed CEO Belén Garijo.
While Garijo’s arrival was followed by a slimming down of the company’s pipeline—removing the likes of amlitelimab, balinatunfib and itepekimab—the pharma’s chief financial officer told journalists last week that there are “no plans for major restructuring.”
Sanofi Ends Nurix STAT6 Degrader Shortly After Trial Start
Sanofi has decided to discontinue the development of SAR448272, an oral STAT6 degrader licensed from Nurix Therapeutics, only months after the program entered clinical testing. The company stopped the Phase 1 first-in-human trial and terminated the program, marking a significant change for one of the early-stage assets in the collaboration. Nurix Therapeutics, Inc.
The Sanofi and Nurix partnership began in 2019 and focuses on using targeted protein degradation technology to develop new medicines. The collaboration was later expanded, with Sanofi licensing programs targeting transcription factors for autoimmune and inflammatory diseases.
SAR448272 entered the clinic in August 2026 for the treatment of type 2 inflammatory diseases. The start of the Phase 1 study triggered a $10 million milestone payment to Nurix. However, Sanofi announced its decision to end the trial and terminate the program in early November, bringing the asset’s development to a rapid close.
Nurix said the change does not affect its previously announced cash runway guidance and continues to advance other clinical and preclinical programs. The development highlights the challenges of early-stage drug research, where companies such as Sanofi regularly evaluate emerging scientific and development information when making pipeline decisions. Nurix Therapeutics, Inc.
