Arpeggio Biosciences is disbanding after leadership concluded its Nrf2 small-molecule degrader program for non-small cell lung cancer could not separate efficacy from off-target liability. In an update attributed to CEO Joey Azofeifa, the company says its Nrf2 efforts “began to unravel” over recent months and that the biotech made a decision to wind down operations. The company raised $17 million in a 2022 Series A from Builders VC, Khosla Ventures, and TechU Ventures. Arpeggio’s reported work included a library of more than 150,000 compounds, 50 million experiments across multiple reporter lines, and transcriptome-scale sequencing efforts, according to the CEO’s post. For the sector, the shutdown is a reminder that transcription-factor biology and degrader selectivity remain hard to de-risk, particularly when multi-pathway safety liabilities complicate target engagement.