Korro Bio Q2 rev. up 21% YoY, EMA grants Orphan Drug Designation to KRRO-110.

• Korro Bio reports interim Phase 1/2a REWRITE clinical trial data on track for 2H 2025 • No treatment emergent SAEs or dose limiting toxicities observed in REWRITE healthy volunteers • EMA grants Orphan Drug Designation to KRRO-110 for AATD treatment • Rare metabolic disorder program development candidate to be announced by end of 2025 • Korro Bio ends Q2 2025 with $119.6 million in cash, cash equivalents and marketable securities.

Cambridge, Mass., July 2, 2025 — Korro Bio, Inc. (Korro) has reported significant progress in its Phase 1/2a REWRITE clinical trial for Alpha-1 Antitrypsin Deficiency (AATD), with interim data expected in the second half of 2025. The company also secured Orphan Drug Designation from the European Medicines Agency (EMA) for its KRRO-110 product candidate, which is designed to treat AATD. Additionally, Korro announced that a development candidate for its rare metabolic disorder program will be announced by the end of 2025. The company ended the second quarter of 2025 with $119.6 million in cash, cash equivalents, and marketable securities [1].

The REWRITE clinical trial, which is evaluating the safety and tolerability of KRRO-110 in up to 64 participants, has completed dosing of over 80% of planned healthy volunteers across multiple single ascending dose (SAD) cohorts. No treatment emergent serious adverse events (SAEs) or dose limiting toxicities were observed, indicating the drug's safety and well-tolerated profile [1].

The EMA granted orphan drug designation to KRRO-110, recognizing its potential to treat AATD, a genetic disorder affecting fewer than five in 10,000 people in the European Union. Orphan drug designation provides Korro with various development incentives, including protocol assistance, reduced regulatory fees, and market exclusivity once the medicine is approved [1].

Korro's 3-2-1 strategy, which aims to establish three clinical-stage development programs targeting two tissue types by the end of 2027, continues to generate momentum. The company is also progressing with its collaboration with Novo Nordisk to advance programs in cardiometabolic diseases [1].

Financial Highlights:
Korro ended the second quarter of 2025 with $119.6 million in cash, cash equivalents, and marketable securities, compared to $163.1 million as of December 31, 2024. The company expects this cash position to fund operating expenses and capital expenditure requirements into 2027 [1].

Collaboration revenue for the three months ended June 30, 2025, was $1.5 million, up from no revenue in the same period last year. Research and Development (R&D) expenses were $21.0 million, up from $17.1 million in the same period last year. General and Administration (G&A) expenses were $7.6 million, up from $7.0 million in the same period last year. Korro reported a net loss of $25.8 million for the three months ended June 30, 2025, compared to $21.8 million in the same period last year [1].

References:
[1] https://www.globenewswire.com/news-release/2025/08/12/3131541/0/en/Korro-Reports-Second-Quarter-2025-Financial-Results-and-Provides-Business-Updates.html