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Sanofi has scrapped an experimental eczema drug it licensed from Nurix Therapeutics — just two months after paying a $10 million milestone to start its first human trial. Nurix shares plunged about 38% in extended trading on the news, in one of the sharpest biotech sell-offs of the week.
What was axed, and why
The drug, known as SAR448272 (also called NX-3911), was an oral medicine designed to eliminate STAT6, a protein involved in many inflammatory conditions, including atopic dermatitis (eczema) and asthma. It was a "degrader" — a newer kind of drug that does not merely block a protein, but marks it for destruction by the cell's own disposal machinery.
Nurix disclosed on Tuesday 3 November that Sanofi had decided to stop the early-stage first-in-human trial and terminate the programme entirely. Sanofi told Reuters the decision was based on its assessment of "emerging non-clinical data, which did not meet our criteria for continued development," and told analyst firm Leerink Partners that the findings "did not warrant continued development" in atopic dermatitis, according to BioPharma Dive. Sanofi stressed that the move should not be viewed as a broader judgment on STAT6 as a drug target.
What Nurix loses — and what it keeps
The termination ends any future development, regulatory or commercial milestone payments and royalties for this programme specifically. Nurix had been eligible for roughly $455 million in additional milestones on this programme alone, plus potential royalties, on top of about $139 million already received from Sanofi under their 2019 collaboration, including the $10 million August milestone. Reuters reported the share plunge at 38% in extended trading; other market reports put the afternoon-session fall at about 39.8%, to around $15.84–$15.95.
Analysts, however, were divided on how much this matters. Truist called the drop an overreaction, noting STAT6 was not in its valuation of Nurix, while Needham's analyst said the stock looked oversold. Nurix noted it remains eligible for milestones and royalties on other previously licensed programmes under the same Sanofi collaboration, and that its $1.1 billion in cash and marketable securities as of 31 August should fund operations into the second half of 2029. It has no approved drugs; all its medicines are still in development.
Why the wider STAT6 race still matters
The timing made the news sting more. Rival Kymera Therapeutics had recently shown positive proof-of-concept results for its own STAT6 degrader, KT-621, and is expected to report eczema test results before the end of the year. Sanofi itself is said to have another STAT6 degrader in development with privately held Recludix Pharma. In other words, the target survives; this particular molecule does not.
That distinction is the real lesson for patients and investors alike. Early-stage drug development fails often, and a single molecule's failure is not the same as a failed idea. But for Nurix, which had just collected a milestone for starting the trial, the whiplash — from "trial begins" in August to "programme terminated" in November — is a reminder of how quickly a promising pipeline asset can disappear. This article is general information only and is not medical advice.