Sanofi has discontinued an early-stage STAT6 degrader program licensed from Nurix Therapeutics, a decision analysts say is related to the asset itself or Sanofi’s strategic reprioritization rather than the drug class more broadly.
Nurix Therapeutics shares fell more than 30% after market close on Tuesday after the biotech disclosed that Sanofi was discontinuing development of a STAT6 degrader licensed from Nurix—but analysts don’t see the move as a critique of the drug class or as extremely damaging for the company.
“While NRIX has limited visibility into the full data package, initial discussions have pointed to molecule-specific attributes of SAR448272 rather than a target-related issue,” Truist Securities wrote in a Tuesday evening note.
Leerink Partners analysts, who spoke with investor relations (IR) representatives at Sanofi, also relayed that the discontinuation was specific to that asset.
“We connected with IR, who stated that the decision was based on ‘emerging nonclinical findings that did not warrant continued development in atopic dermatitis,’” the firm said in a Tuesday evening note.
The program cut comes just two months after Nurix collected a $10 million milestone payment from Sanofi as the pharma kicked off a Phase 1 trial for SAR448272 in type 2 inflammatory diseases.
Sanofi and Nurix linked up in 2019 to leverage the latter’s DEL-AI drug discovery platform to identify novel agents that use E3 ligases to induce the degradation of specified proteins. In 2025, the French pharma picked up a license extension option for two programs targeting transcription factors for autoimmune and inflammatory diseases, according to Nurix’s Tuesday release. One target was undisclosed. The other was STAT6.
Now, Sanofi has informed Nurix of its decision to discontinue a Phase 1 first-in-human trial of the STAT6 degrader SAR448272, and to terminate the program, the San Francisco–based biotech said on Tuesday.
Shares of Nurix fell by as much as 38% in post-market trading Tuesday, recovering only slightly to $16.15 per share in pre-market trading on Wednesday.
Truist viewed Nurix’s post-market stock drop as “an overreaction,” writing that while the discontinuation was “disappointing given the potential upside and upcoming peer data catalyst, STAT6 was not included in our valuation, limiting the direct impact on our base case.”
Oppenheimer, meanwhile, suggested that while the program cull may have been driven by STAT6 degrader safety signals, other possibilities include “robust/convincing” data from another Sanofi STAT6 collaboration and the pharma’s strategic reprioritization following its expanded partnership with Regeneron around long-acting IL13/IL13xIL4.
Early last month, Sanofi paid long-time partner Regeneron $1 billion upfront to advance four long-acting, next-generation antibodies for immune-mediated conditions in search of the next Dupixent, the partners’ blockbuster anti-inflammatory drug whose U.S. patent protection is set to expire in 2031.
Once considered undruggable, STAT6 is emerging as a hot target in immunology, where Sanofi is a key player.
The STAT6 protein is crucial for IL-4–mediated biological responses. It is believed to play a role in several dermatologic and respiratory diseases, according to Recludix Pharma, with whom Sanofi is developing a STAT6 inhibitor in a Phase 1 trial.
With the fate of Nurix’s STAT6 program “unclear,” Oppenheimer said the biotech’s story now rests primarily on the fate of a separate collaboration with Roche. The Swiss pharma in June paid Nurix $700 million upfront—with milestones totaling a potential $2.3 billion—to co-develop and co-commercialize bexobrutideg, a Bruton’s tyrosine kinase (BTK) degrader, for B cell malignancies as well as immunological and neurological conditions.
The drug is currently in Phase 1/2 studies in chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL).
Nurix “remains well-positioned in CLL” with bexobrutideg, Oppenheimer said.
