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. (KRRO) has a notice of proposed resale of restricted common stock under Rule 144 by Atlas-affiliated funds. Atlas Venture Fund XI, L.P. plans to sell 23,584 shares, while disclosures list prior open-market sales by Atlas Venture Fund XI and Atlas Venture Opportunity Fund II over the past three months.
Korro Bio, Inc. (KRRO) is the issuer of common stock for which Atlas Venture Opportunity Fund II, L.P. has filed a notice of proposed resale under Rule 144. The fund indicates an intention to sell 4,884 shares of Korro Bio common stock through Merrill Lynch on Nasdaq.
The shares to be sold were originally acquired on April 22, 2024 in a private placement for cash. The notice also lists multiple Korro Bio share sales during the past three months by Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund II, L.P., with individual transactions ranging from hundreds to over one hundred thousand shares.
Korro Bio, Inc. (KRRO) reports that on August 19, 2026 it submitted materials to the Australian Alfred Health Human Ethics Committee to initiate a first-in-human Phase 1/2 clinical trial for KRRO-121. KRRO-121 is a GalNAc-conjugated RNA editing oligonucleotide being developed for the potential treatment of hyperammonemia in patients with Urea Cycle Disorders.
The planned Phase 1/2 study is designed to evaluate safety and tolerability of escalating doses, characterize pharmacokinetics, and assess effects in both healthy volunteers and participants with Urea Cycle Disorders. Additional trial details are available at ClinicalTrials.gov under identifier NCT 07773246.
Korro Bio, Inc. has a significant shareholder group led by Balyasny Asset Management L.P. and related entities, which report beneficial ownership of 951,783 shares of Korro Bio common stock. This position represents approximately 6.60% of the outstanding common shares, based on 14,422,571 shares outstanding as of May 4, 2026.
The shares are held through two Cayman Islands investment vehicles: Atlas Diversified Master Fund, Ltd. with 411,729 shares and Atlas Private Holdings (Cayman) Ltd with 540,054 shares. Each reporting person, including Balyasny Asset Management L.P., BAM GP LLC, Balyasny Asset Management Holdings LP, Dames GP LLC, and Dmitry Balyasny, is deemed to have sole voting and dispositive power over the full 951,783 shares and no shared power.
Korro Bio, Inc. director Jean Francois Formela reported indirect sales of Korro Bio common stock on August 11, 2026. A total of 2,143 shares were sold at a weighted average price of $13.96 per share, in transactions executed under a Rule 10b5-1 trading plan adopted on April 8, 2026. The sold shares were held by Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund II, L.P., and Formela disclaims Section 16 beneficial ownership except to the extent of any pecuniary interest.
Korro Bio, Inc. reported insider purchases of common stock by entities associated with Lynx1 Capital Management LP and Weston Nichols. On August 6, 2026, Lynx1 Master Fund LP purchased 5,222 shares at a weighted average price of $11.3998 per share, and on August 10, 2026 it purchased 1,462 shares at a weighted average price of $13.1869, for a total of 6,684 shares, all held indirectly. The investment manager and Mr. Nichols disclaim beneficial ownership except to the extent of any pecuniary interest.
KRRO common shareholders have filed a notice to sell shares under Rule 144. The filing covers 368 shares of common stock, with an aggregate market value of $4,964.32, and notes 14,725,646 shares outstanding as of 08/11/2026 on Nasdaq. The notice also lists recent market sales by affiliated funds between May and July 2026 as background disclosure.
KRRO common stock holders filed to sell shares under a resale notice. The planned transaction lists 1,775 shares of common stock to be sold through Merrill Lynch on Nasdaq. Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund II, L.P. also report multiple prior common stock sales over the past three months with varying sizes and proceeds.
Korro Bio, an RNA‑editing biopharma, reported no collaboration revenue for the three or six months ended June 30, 2026, versus $1,460 thousand and $4,010 thousand a year earlier, reflecting a 12‑month pause of its Novo Nordisk partnership. Net loss narrowed to $18,916 thousand for the quarter and $38,541 thousand for the first half, driven mainly by lower research and development spending.
Research and development expense fell to $26,539 thousand for the first half of 2026 from $39,874 thousand, and general and administrative expense declined to $14,007 thousand. The company strengthened liquidity through a March 2026 private placement (approximately $85.0 million gross) and January 2026 at‑the‑market sales ($5.1 million gross). Cash, cash equivalents and marketable securities totaled $137.9 million at June 30, 2026, which management expects to fund operations for at least 12 months.
Korro advanced lead programs KRRO‑121 for hyperammonemia, expected to enter first‑in‑human trials in the second half of 2026, and KRRO‑111 for alpha‑1 antitrypsin deficiency, after terminating the Phase 1/2a REWRITE trial for prior candidate KRRO‑110 in early 2026.
Korro Bio, Inc. entered into an exchange agreement with entities affiliated with Venrock Healthcare Capital Partners. Venrock will surrender 1,000,000 common shares to Korro for no consideration, and Korro will issue pre-funded warrants for 1,000,000 common shares with a $0.001 exercise price and no expiration. The warrants are immediately exercisable but include a 9.99% beneficial ownership cap. After the exchange, Korro will have 13,725,646 common shares outstanding and pre-funded warrants for 4,148,836 shares.
For the quarter ended June 30, 2026, Korro reported cash, cash equivalents and marketable securities of $137.9 million, supporting a projected cash runway into the second half of 2028. Research and development expenses were $13.6 million and general and administrative expenses were $6.5 million, contributing to a net loss of $18.9 million compared with $25.8 million a year earlier. Collaboration revenue was $0 versus $1.5 million in the prior-year quarter following a 12‑month pause of the Novo Nordisk collaboration.