Xu Diyong 4/A

What Happened
Xu Diyong, reported as a 10% owner of Q32 Bio, received a derivative award on June 12, 2026: 10,826 shares underlying an option were granted and reported at a $0.00 price (transaction value $0). This Form 4 is an amendment filed July 21, 2026 to correct the number of options reported in the original filing.

Key Details

• Transaction date: June 12, 2026 (amended Form 4 filed July 21, 2026).
• Transaction type/code: Award (derivative option) — reported as “A.”
• Quantity and price: 10,826 underlying shares; reported price $0.00; transaction value $0.
• Vesting: Options vest and become exercisable in full upon the earlier of (i) June 12, 2027 or (ii) the issuer’s next annual meeting of stockholders, subject to continued service.
• Post-transaction ownership: Not specified in the provided excerpt.
• Footnote on transfer: Per an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VII LLC, the Reporting Person is obligated to transfer any securities issued under these options (or their economic benefit) to those OrbiMed entities so they can provide them to OrbiMed Private Investments VII, LP.
• Amendment note: The filing was amended solely to correct the number of options awarded on June 12, 2026 (no new transaction reported).

Context
This is a derivative award (options) rather than an open-market purchase or sale. For a 10% owner, such awards can reflect institutional or fund-level arrangements; here a contractual transfer to OrbiMed entities is explicitly stated, suggesting the economic benefit is intended for OrbiMed’s investment vehicle. The amendment corrects reporting detail and does not by itself indicate an additional trade or change in economic exposure beyond what’s disclosed.