Welcome to our dedicated page for Korro Bio SEC filings (Ticker: KRRO), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Korro Bio, Inc. filings document the regulatory record of a biopharmaceutical company developing RNA-editing genetic medicines through its OPERA® platform. Its 8-K reports disclose operating and financial results, corporate presentations, clinical and regulatory program updates, capital-structure activity, and material events tied to its RNA-editing pipeline.
The company’s filings also cover proxy governance, executive compensation, equity incentive and inducement arrangements, employment agreements, and material collaboration and license agreements. Program-related disclosures focus on KRRO-121, hyperammonemia in urea cycle disorders and hepatic encephalopathy, GalNAc-conjugated oligonucleotide research, alpha-1 antitrypsin deficiency, risk factors, and the financing and governance framework supporting Korro Bio’s development-stage operations.
Korro Bio, Inc. director and President & CEO Ram Aiyar reported a disposition of common stock primarily tied to equity compensation. On the reported date, 15,152 shares of common stock were sold at a weighted-average price of $12.98 per share solely to satisfy tax withholding obligations arising from the vesting and settlement of a performance stock unit award. Following this tax-related sale, Aiyar directly held 74,848 shares of common stock, and an additional 4,613 shares were held indirectly through The Ram Aiyar Irrevocable Trust, for which he serves as trustee and disclaims beneficial ownership except for any pecuniary interest. The filing also notes that his holdings include 40,000 shares of common stock issuable upon settlement of a restricted stock unit granted under the company’s 2023 equity plan.
Korro Bio director-related funds report small planned share sale. Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund II, L.P., entities associated with director Jean Francois Formela, sold a total of 2,860 shares of Korro Bio common stock at $13.95 per share on May 28, 2026 in open-market transactions under a Rule 10b5-1 trading plan adopted on April 8, 2026.
Following these indirect transactions, Atlas Venture Fund XI, L.P. is shown holding 194,655 shares and Atlas Venture Opportunity Fund II, L.P. is shown holding 939,634 shares of common stock. Formela is a member of the general partner entities and disclaims Section 16 beneficial ownership of these shares except to the extent of any pecuniary interest.
Korro Bio, Inc. President and CEO Ram Aiyar reported an equity award that increased his beneficial holdings. On May 26, 2026, he acquired 50,000 shares of common stock at $12.33 per share, issued upon settlement and vesting of a performance stock unit granted under the company’s 2023 Stock Option and Incentive Plan.
Following this transaction, he beneficially owns 90,000 shares directly, which includes 40,000 shares issuable upon settlement of a previously reported restricted stock unit grant. An additional 4,613 shares are held indirectly by The Ram Aiyar Irrevocable Trust, for which he serves as trustee and disclaims beneficial ownership except to the extent of his pecuniary interest.
Korro Bio reported a new development candidate, KRRO-111, added to its pipeline for the potential treatment of Alpha-1 Antitrypsin Deficiency (AATD). Preclinical mouse data showed more than 90% editing of the SERPINA1 transcript and about 90% repaired functional AAT protein in plasma.
KRRO-111, a subcutaneously delivered GalNAc‑conjugated oligonucleotide, nearly eliminated active Z‑protein production and drove progressive clearance of pre‑existing liver aggregates in PiZZ mouse models. Korro also reaffirmed its OPERA RNA editing platform strategy and noted $157.1 million in cash, cash equivalents and marketable securities as of March 31, 2026, which it expects to support operations into the second half of 2028.
Korro Bio, Inc. ownership disclosure: Point72 reporting persons state beneficial ownership of 276,831 shares of Common Stock, representing 1.9% of the class as of March 31, 2026.
The amendment names Point72 Asset Management, Point72 Capital Advisors, Point72 Biotech Private Investments, Differentiated Ventures, 72 Investment Holdings, and Steven A. Cohen and describes shared voting and dispositive power for the listed shares.
KRRO files a prospectus supplement to update its resale prospectus registering up to 7,650,764 shares of common stock, consisting of 4,501,928 shares and 3,148,836 shares issuable upon exercise of pre-funded warrants. This supplement substitutes SILV Fund, Ltd. for Point72 Associates, LLC as a selling stockholder for 540,054 shares. The supplement makes no other changes and reiterates that these shares were issued in a private placement under a subscription agreement dated March 9, 2026. The Nasdaq closing price on May 12, 2026 was $11.22 per share.
Korro Bio, Inc. reported a net loss of $19.6 million for the quarter ended March 31, 2026, improving from a $23.4 million loss a year earlier, as research and development and general and administrative costs declined. Collaboration revenue from Novo Nordisk fell to zero after a 12‑month pause of that agreement. Cash, cash equivalents and marketable securities rose to $157.1 million, driven by a March 2026 private placement and at‑the‑market share sales. The company expects this liquidity to fund operations into the second half of 2028 while advancing its OPERA RNA‑editing platform and lead program KRRO‑121 toward first‑in‑human studies.
Korro Bio reported first quarter 2026 results and highlighted progress across its RNA editing pipeline. Cash, cash equivalents and marketable securities were $157.1 million as of March 31, 2026, up from $85.2 million at year-end, helped by an oversubscribed $85 million private placement that is expected to fund operations into the second half of 2028.
The company advanced lead candidate KRRO-121 toward a planned regulatory filing in the second half of 2026 and achieved greater than 90% in vivo RNA editing in its GalNAc-conjugated AATD program. R&D expenses fell to $12.9 million from $19.7 million, while net loss narrowed to $19.6 million from $23.4 million year over year.