4. Sale of Asset

On November 28, 2025, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Q32 Bio Operations Inc., a wholly-owned subsidiary of the Company (“Q32 Bio Operations” and, together with the Company, the “Seller”), and Akebia Therapeutics, Inc. (“Akebia”) pursuant to which the Seller sold to Akebia substantially all of the Seller’s assets related to the research, development, manufacture and commercialization of ADX-097 (the “ADX-097 Asset Sale”). As consideration for the ADX-097 Asset Sale, the Company received an upfront payment of $7.0 million on November 28, 2025, and a payment of $3.0 million on the six-month anniversary of the closing, or May 28, 2026. The Company will also receive a near-term milestone payment of $2.0 million upon the earlier of achievement of the first milestone under the Asset Purchase Agreement or December 31, 2026. In addition to these payments, the Company is eligible to receive up to $580.0 million upon the achievement of additional specified milestones, including up to $92.5 million related to development and regulatory milestones and up to $487.5 million related to commercial milestones. The Company is also eligible to receive tiered royalties on potential future sales of ADX-097 ranging from low single-digit to mid-teen percentages of annual net sales. The royalties will expire on a country-by-country basis on the later to occur of (a) the date of expiration of the last-to-expire valid claim of any transferred patent right that covers such product in such country, and (b) the tenth anniversary of the first commercial sale of such product.

The Company accounted for the transaction as an asset sale and recognized $11.7 million, comprised of $12.0 million in guaranteed upfront and near-term milestones less certain contractual offsets, as a gain on sale of asset included in other income (expense) in the consolidated statements of operations for the year ended December 31, 2025. The guaranteed near-term milestone payments less certain contractual offsets of $4.8 million were recorded as a short-term receivable included in prepaid expenses and other current assets on the Company’s condensed consolidated balance sheets, and as of June 30, 2026, the balance was $1.8 million. Any future milestones and royalties will be recognized when achieved.

On November 28, 2025, in connection with the ADX-097 Asset Sale, the Colorado License Agreement (defined in Note 10) was

amended and restated and all of the Company’s rights and obligations thereunder were transferred to Akebia.