Convertible Notes |
9 Months Ended |
|---|---|
Sep. 30, 2026 | |
| Convertible Notes [Abstract] | |
| Convertible Notes | 6. Convertible Notes
2023 Notes and 2024 Note
During 2023 and 2024, the Company issued unsecured convertible promissory notes with aggregate principal amounts of $10.0 million each (the “2023 Notes” and “2024 Note,” respectively). The 2024 Note included an embedded conversion feature that was bifurcated and accounted for as a derivative liability, remeasured to fair value at each reporting date, with changes in fair value recognized in other income (expense), net in the condensed consolidated statements of operations.
On October 31, 2025, all outstanding principal and accrued interest under the 2023 Notes and 2024 Note were converted into shares of Legacy Ionetix Series F redeemable convertible preferred stock at $1.40 per share pursuant to a conversion agreement (the “Conversion Agreement”) and the transaction was accounted for as a debt extinguishment. interest expense or change in fair value of the embedded conversion feature was recognized during the three and nine months ended September 30, 2026. For the three and nine months ended September 30, 2025, the Company recognized aggregate interest expense of $409 and $1,202 on these instruments, respectively, and a gain from the change in fair value of the embedded conversion feature of $27 and $19, respectively.
Make-Whole Provision
The Conversion Agreement included a one-time make-whole provision that could have required the Company to issue additional shares of Legacy Ionetix Series F redeemable convertible preferred stock if the price per share in the Company’s next equity financing was below a stated threshold. The Company determined that the make-whole provision represented a derivative liability. The derivative liability was initially recorded at its estimated fair value of $1.0 million on October 31, 2025 and was remeasured at fair value at each reporting date, with changes in fair value recognized in other income (expense), net in the condensed consolidated statements of operations. The derivative liability was $40 as of December 31, 2025, and the Company recognized a change in fair value of $8 during the nine months ended September 30, 2026, substantially all of which was recognized during the three months ended March 31, 2026.
In April 2026, the make-whole right and certain other investor rights were terminated pursuant to a termination agreement (the “Termination Agreement”) in exchange for 277,696 shares of common stock with a fair value of $833, based on the $3.00 per share price of the contemporaneous private placement. The difference between the fair value of the shares issued and the carrying amount of the derivative liability derecognized was recognized in other income (expense), net. See Note 11. |