Sionna (SION) CEO Michael Cloonan Receives RSUs, Option Repricing

What Happened

• Michael Cloonan, President, CEO and director of Sionna Therapeutics (SION), received two restricted stock unit (RSU) awards totaling 218,050 RSUs (109,025 + 109,025) on September 17, 2026 (acquired at $0). On the same date there are derivative entries for 436,100 shares recorded as an acquisition and an immediate disposition to the issuer (both $0). The RSU awards have vesting conditions (time- and performance-based); the derivative entries relate to an option repricing approved by the board.

Key Details

• Transaction date: September 17, 2026; Form filed September 18, 2026 (timely).
• RSUs: 109,025 + 109,025 granted at $0 (total 218,050). One grant vests June 17, 2027 subject to continued service; the other vests upon a performance milestone, subject to continued service (see footnotes).
• Derivative entries: 436,100 shares shown as acquired and immediately disposed to the issuer at $0. Footnotes state the board approved an option repricing, resetting the exercise price to $7.18 on the repricing date and imposing a retention period (ends no later than March 17, 2028, or upon specific events). Transactions were reported as exempt under Rules 16b-6(d) and 16b-3.
• Shares owned after the transaction: not specified in the provided excerpt — see the full Form 4 for post-transaction beneficial ownership.
• No indication in this filing of a 10b5-1 plan, tax withholding sale, or late filing.

Context

• RSUs are awards that convert to shares only if vesting conditions are met; they are not immediate open‑market purchases or sales. The derivative line items reflect an option repricing action (exercise price changed to $7.18) and related reporting mechanics rather than a cash sale. These entries are administrative and compensation-related rather than a straightforward buy or sell; review the full Form 4 and company disclosures for complete context.