Why is Nurix Therapeutics stock collapsing 28% today?

Nurix Therapeutics stock plunged 28.4% in pre-open trading after its pharmaceutical collaboration partner Sanofi notified the company of its decision to discontinue the Phase 1 first-in-human clinical trial of SAR448272, an oral STAT6 degrader, and terminate the program in its entirety. The announcement, made after the close of regular trading on Tuesday, eliminated Nurix’s eligibility for all future development, regulatory, and commercial milestone payments and royalties associated with that specific asset under the collaboration agreement.

Adding to the pressure, Jefferies moved swiftly on November 4 to cut its 12-month price target on Nurix from $45 to $36, while keeping a Buy rating in place. The firm noted that Sanofi’s decision came as a surprise, that Nurix management had not seen any clinical or preclinical data underpinning the move, and that the rationale for the discontinuation remained unclear — though Sanofi indicated no immediate patient safety concern was involved.

On the positive side, Nurix confirmed that its cash runway guidance remains intact, with approximately $1.1 billion in cash, cash equivalents, and marketable securities as of late August 2026, sufficient to fund operations into the second half of 2029. The broader Sanofi collaboration also continues, with Nurix remaining eligible for milestone payments and royalties from other licensed programs. Meanwhile, the macro backdrop offered little relief, as U.S. equity futures faced broad selling pressure in pre-market trading amid uncertainty surrounding U.S. midterm election results, with early vote counts pointing toward a potential shift in congressional control.

Taken together, the sudden loss of a key partnered program, the absence of a clear scientific explanation from Sanofi, and a high-profile analyst price target reduction converged to drive one of the sharpest single-session declines in Nurix’s recent history, overshadowing the company’s otherwise solid balance sheet and its remaining clinical pipeline anchored by bexobrutinib and NX-1607.