7. SAFE Liability

The Company issued Simple Agreements for Future Equity (“SAFEs”) for aggregate principal proceeds of $45.7 million that entitled holders to receive shares of Legacy Ionetix redeemable convertible preferred stock upon the occurrence of a qualifying equity financing event at a 15% discount to the price per share paid by other investors in such financing.

The SAFEs were freestanding financial instruments and were classified as liabilities, as the SAFEs represented an obligation to issue a variable number of shares for a fixed monetary amount. The SAFEs were initially recorded at fair value upon issuance and subsequently remeasured to fair value at each reporting date, with changes in fair value recognized in the condensed consolidated statements of operations.

No SAFEs were issued or outstanding during the three months ended June 30, 2026. During the six months ended June 30, 2026, the Company issued SAFEs with aggregate proceeds of $2.4 million, all of which converted into shares of Legacy Ionetix Series F redeemable convertible preferred stock on March 31, 2026. During the three and six months ended June 30, 2025, the Company issued SAFEs with aggregate proceeds of $3.8 million and $3.9 million, respectively.

All SAFEs issued during the six months ended June 30, 2026 included common stock warrant coverage. The warrants were equity classified. The SAFE liability and the warrants were recorded at their respective fair values on the issuance date, with $2.4 million and $2.2 million allocated to the SAFE liability and the warrants, respectively. Any excess of the aggregate fair value of the instruments issued over the proceeds received was recognized as an upfront loss of $2.2 million during the six months ended June 30, 2026, and included in other income (expense), net in the condensed consolidated statements of operations. No common stock warrants were issued in connection with the SAFEs issued during the three and six months ended June 30, 2025. The Company recognized a loss on change in fair value of the SAFE liability of $134 during the six months ended June 30, 2026. No change in fair value of the SAFE liability was recognized during the three months ended June 30, 2026, as all outstanding SAFEs converted into Legacy Ionetix Series F redeemable convertible preferred stock on March 31, 2026 and no SAFE liability remained outstanding thereafter. The Company recognized a loss on change in fair value of the SAFE liability of $3.2 million and $1.1 million during the three and six months ended June 30, 2025, respectively.

Election to Convert SAFEs

On October 31, 2025, holders of SAFEs with an aggregate carrying value of $50.7 million elected to settle their SAFEs into shares of Legacy Ionetix Series F redeemable convertible preferred stock at a conversion price of $1.40 per share. The Company accounted for the transaction as an extinguishment of the SAFE liability and, in connection with the conversion, recognized a freestanding make-whole derivative liability as described below.

On March 31, 2026, holders of all remaining outstanding SAFEs converted into shares of Legacy Ionetix Series F redeemable convertible preferred stock at $1.40 per share. The SAFE liability was remeasured to fair value immediately prior to conversion, and the Legacy Ionetix Series F redeemable convertible preferred stock was recorded at an amount equal to that fair value. No additional gain or loss was recognized upon conversion.

Make-Whole Provision

In connection with the October 31, 2025 SAFE conversion, the Company recognized a freestanding derivative liability. The make-whole derivative liability was $71 as of December 31, 2025 and was derecognized upon termination of the make-whole right in connection with the Merger in April 2026, with no liability outstanding as of June 30, 2026. The Company recognized a change in fair value of $13 during the six months ended June 30, 2026, substantially all of which was recognized during the three months ended March 31, 2026. No change in fair value during the three and six months ended June 30, 2025, as the make-whole provision did not exist prior to October 31, 2025.

Contingent Equity Arrangement Associated with a SAFE

In connection with a SAFE issued in 2023, the Company entered into an arrangement that provided the investor with the right to receive a warrant upon the occurrence of certain future events, for which, no amount had been recognized in the Company’s historical financial statements prior to the Merger.

In connection with the Merger, the Company settled the arrangement by terminating the contingent right and related arrangements and issuing a new ten-year warrant to purchase 6,443,076 shares of Legacy Ionetix common stock at an exercise price of $0.01 per share. In connection with the Merger, such warrant was assumed by the Company and converted into a warrant to purchase 3,230,558 shares of the Company’s common stock at an exercise price of $0.02 per share, based on the Conversion Ratio. The new warrant is classified within stockholders’ equity. The Company determined the fair value of the new warrant at issuance to be $9.7 million, which was recognized as expense in other income (expense), net, with a corresponding increase to additional paid-in capital during the six months ended June 30, 2026.