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. reported that director Nessan Bermingham received a stock option grant covering 14,677 shares of common stock. The option has an exercise price of $10.59 per share and expires on June 9, 2036. The option vests in full on the earlier of the one-year anniversary of the grant date or the next annual meeting of stockholders, subject to his continued service as a non-employee director.
Korro Bio director Katharine Knobil received a grant of stock options covering 14,677 shares of common stock at an exercise price of $10.59 per share. These options vest in full on the earlier of one year from the grant date or the next annual stockholder meeting, subject to her continued service as a non-employee director, and will expire on June 9, 2036.
Korro Bio director Jean Francois Formela received a stock option grant as equity compensation. The award covers 14,677 shares of common stock at an exercise price of $10.59 per share and expires on June 9, 2036. The option vests in full on the earlier of the one-year anniversary of the grant date or the next annual meeting of stockholders, provided he continues serving as a non-employee director through that vesting date.
Korro Bio director Timothy R. Pearson reported receiving a grant of stock options under the company’s equity plan. The award covers 14,677 options for Common Stock at an exercise price of $10.59 per share, with no cash paid for the grant itself.
The options vest in full on the earlier of the one-year anniversary of the grant date or the next annual meeting of stockholders, provided he continues serving as a non-employee director through that date. Following this grant, Pearson holds 14,677 stock options directly, which expire on June 9, 2036.
Korro Bio, Inc. reported the results of its 2026 annual stockholder meeting held on June 10, 2026. Stockholders elected Nessan Bermingham and Rachel Meyers as Class I directors for three-year terms ending at the 2029 annual meeting.
Both directors received several million votes in favor, with additional votes withheld and broker non-votes recorded. Stockholders also approved, in a non-binding advisory vote, the compensation of Korro’s named executive officers by a wide margin.
In addition, stockholders ratified the selection of Ernst & Young LLP as Korro’s independent registered public accounting firm for the fiscal year ending December 31, 2026. These items collectively confirm continued support for the company’s board, executive pay program, and auditor.
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.