Korro Bio (NASDAQ: KRRO) Plunge 80.18% on Failed Trial as Collaboration Halted, Workforce Cut 34%

The share price dropped to a record low today, with an intraday decline of 80.78% so far this month. Korro Bio (NASDAQ: KRRO) has fallen 80.18% over two trading days, marking its worst performance in recent history. The stock closed at $6.61, erasing nearly all gains from its November 13 peak.

The collapse follows the failure of Korro Bio’s lead candidate, KRRO-110, to meet therapeutic thresholds in a Phase 1/2a trial for alpha-1 antitrypsin deficiency (AATD). The drug only increased functional mutant alpha-1 antitrypsin protein by 2 µM, far below the target of 11 µM. This result triggered a 78% after-hours drop and raised doubts about the viability of its RNA-editing platform. Analysts cited potential issues with lipid nanoparticle formulation or manufacturing, further eroding confidence.

Compounding the setbacks, Korro Bio suspended its Novo Nordisk collaboration for 12 months, halting joint R&D on cardiometabolic therapies. The firm also announced a 34% workforce reduction and a $2.4 million restructuring charge. Key executives, including the Chief Medical Officer and CFO, have exited or transitioned roles. Multiple analysts downgraded the stock, with Clear Street slashing its price target from $93 to $7, reflecting a 92.5% valuation cut. The company now faces pressure to prove its GalNAc-based delivery system can revive its pipeline and extend its cash runway into mid-2027.