Convertible Preferred Stock	12 Months Ended
Convertible Preferred Stock	Dec. 31, 2024
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock Series B Preferred Stock The Certificate of Designation of Preferences, Rights, and Limitations of the Series B Non-Voting Convertible Preferred Stock, or the Series B Certificate of Designation, was filed with the Secretary of State of the State of Delaware on July 2, 2024, and provided for the designation of shares of Series B Preferred Stock and authorized the issuance of 2,937,903 shares of Series B Preferred Stock. Additionally, on July 2, 2024, the Company entered into the 2024 Securities Purchase Agreement with certain institutional and accredited investors, or the Purchasers. The Purchasers included (i) Dr. Timothy A. Springer, a member of the Company’s Board of Directors; (ii) TAS Partners LLC, an affiliate of Dr. Springer, and (iii) Dr. Chafen Lu, Dr. Springer’s wife. Pursuant to the 2024 Securities Purchase Agreement, the Company agreed to issue and sell an aggregate of 3,563,247 shares of common stock and 2,937,903 shares of Series B Preferred Stock for an aggregate purchase price of $130.0 million in the 2024 Private Placement. Each share of Series B Preferred Stock is convertible into one share of the Company’s common stock subject to stockholder approval of a proposal to issue such shares of common stock upon conversion of such shares of Series B Preferred Stock in accordance with the Listing Rules of the Nasdaq Stock Market LLC, or the Series B Conversion Proposal. Under the 2024 Securities Purchase Agreement, the Company issued 3,563,247 shares of common stock and 578,403 shares of Series B Preferred Stock for an aggregate purchase price of $82.8 million to the Purchasers other than Dr. Springer, TAS Partners LLC, and Dr. Lu. The Company also issued (i) 1,636,832 shares of Series B Preferred Stock to Dr. Springer, (ii) 721,361 shares of Series B Preferred Stock to TAS Partners LLC, and (iii) 1,307 shares of Series B Preferred Stock to Dr. Lu for an aggregate purchase price of $47.2 million. Pursuant to the 2024 Securities Purchase Agreement, the Company agreed to submit to its stockholders the approval of the Series B Conversion Proposal, at a special meeting of stockholders, which was held on September 20, 2024. On September 20, 2024, at such special meeting, the Company’s stockholders approved the Series B Conversion Proposal, among other matters. On September 25, 2024, pursuant to the terms of the Series B Certificate of Designation, 2,499,976 shares of Series B Preferred Stock automatically converted into 2,499,976 shares of common stock; 437,927 shares of Series B Preferred Stock did not automatically convert at such time due to beneficial ownership limitations. The Series B Preferred Stock were classified in permanent equity as there were no conditions that could have required cash redemption of the shares. The Series B Preferred Stock has the following rights and preferences: Conversion Prior to the stockholder approval of the Series B Conversion Proposal the Series B Preferred Stock were not convertible into shares of common stock. Following the stockholder approval of the Series B Conversion Proposal, each share of Series B Preferred Stock automatically converted into one share of common stock, subject to certain limitations, including that a holder of Series B Preferred Stock is prohibited from converting shares of Series B Preferred Stock into shares of common stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than a specified percentage (to be established by the holder between 0.0% and 19.9%) of the total number of shares of common stock issued and outstanding immediately after giving effect to such conversion; provided, however, that such beneficial ownership limitation does not apply to Dr. Springer, TAS Partners LLC, or any of their respective affiliates. Each share of Series B Preferred Stock outstanding that was not automatically converted into common stock as a result of the stockholder approval of the Series B Conversion Proposal shall be convertible at any time at the option of the holder following stockholder approval of the Series B Conversion Proposal, only to the extent the beneficial ownership limitation does not apply to the shares of Series B Preferred Stock to be converted. Redemption The Series B Preferred Stock is not redeemable. Dividends Holders of Series B Preferred Stock are entitled to receive dividends on shares of Series B Preferred Stock on an as-converted basis (without regard to the beneficial ownership limitation) equal to the dividends paid on shares of the common stock. Voting Except as otherwise required by law, the Series B Preferred Stock does not have voting rights. However, as long as any shares of Series B Preferred Stock are outstanding, the Company will not, without the affirmative vote of the holders of a majority of the then-outstanding shares of the Series B Preferred Stock, (a) alter or change adversely the powers, preferences or rights given to the Series B Preferred Stock, (b) alter or amend the Series B Certificate of Designation, or (c) amend the Charter or other organizational documents in any manner that alters or changes the preferences, rights, privileges, or powers of, or restrictions provided for the benefit of the holders of Series B Preferred Stock. Liquidation The holders of Series B Preferred Stock shall rank on parity with the holders of common stock and the holders of Series A Preferred Stock as to distributions of assets upon liquidation, dissolution or winding up of the Company, whether voluntarily or involuntarily. Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, each holder of Series B Preferred Stock shall be entitled to receive out of the assets of the Company, whether capital or surplus, the same amount that a holder of common stock would receive if the Series B Preferred Stock were fully converted, which shall be paid pari passu with holders of common stock and holders of Series A Preferred Stock, plus an amount equal to any dividends declared but unpaid. If the assets available for distribution are not sufficient to pay the holders of the Series B Preferred Stock pursuant to the preceding sentence, all remaining assets will be distributed ratably to the holders of the Series A Preferred Stock, Series B Preferred Stock and common stock. Series A Preferred Stock The Certificate of Designation of Preferences, Rights, and Limitations of the Series A Non-Voting Convertible Preferred Stock, or the Series A Certificate of Designation, was filed on November 13, 2023, which provided for the designation of shares of the Series A Preferred Stock and authorized the issuance of 548,375 shares of Series A Preferred Stock. Additionally on November 13, 2023, the Company entered into the 2023 Securities Purchase Agreement with (i) Dr. Timothy A. Springer, a member of the Company’s Board of Directors; (ii) TAS Partners LLC, an affiliate of Dr. Springer, and (iii) Seven One Eight Three Four Irrevocable Trust, a trust associated with Dr. Murat Kalayoglu, a co-founder and the former chief executive officer of Old Cartesian, who joined the Company’s Board of Directors effective immediately after the effective time of the Merger, or the Investors. Pursuant to the 2023 Securities Purchase Agreement, the Company agreed to issue and sell an aggregate of 149,330.115 shares of Series A Preferred Stock for an aggregate purchase price of $60.25 million in the 2023 Private Placement. In the 2023 Private Placement, Dr. Timothy A. Springer agreed to settle his purchases in three tranches of shares of Series A Preferred Stock, the first for a purchase price of $10.0 million and each thereafter for a purchase price of approximately $20.0 million, with the three tranches settling 30, 60, and 90 days, respectively, following the Closing Date. TAS Partners LLC agreed to settle its purchase for approximately $10.0 million within 30 days following the Closing Date. The first, second and third tranches were settled on December 13, 2023, January 12, 2024 and February 11, 2024, respectively, under which (i) 24,785.081 shares of Series A Preferred Stock were issued to each of TAS Partners LLC and Dr. Timothy A. Springer in the first tranche, (ii) 49,570.163 shares of Series A Preferred Stock were issued to Dr. Timothy A. Springer in the second tranche, and (iii) 49,570.163 shares of Series A Preferred Stock were issued to Dr. Timothy A. Springer in the third tranche. On November 15, 2023, the Company issued 619.627 shares of Series A Preferred Stock to Seven One Eight Three Four Irrevocable Trust for $0.25 million. The Company determined the obligation to issue 148,710.488 shares of Series A Preferred Stock to Dr. Springer and TAS Partners LLC represented a forward contract and was accounted for as a liability with changes in fair value recorded in earnings. A portion of the liability was settled with the initial issuance of 49,570.162 shares of Series A Preferred Stock on December 13, 2023. The remaining portion of the forward contract liability was settled upon the issuance of 49,570.163 shares of Series A Preferred Stock each on January 12, 2024 and February 11, 2024, respectively (see Note 6). On December 5, 2023, the Company issued 384,930.724 shares of Series A Preferred Stock as part of its consideration transferred in connection with the Merger which settled the related forward contract liability (see Note 6). On March 26, 2024, the Company, with the consent of the requisite holders of Series A Preferred Stock, amended the Series A Certificate of Designation such that the automatic conversion of the Series A Preferred Stock into common stock, or the Automatic Conversion, would occur eight business days following stockholder approval of the Conversion Proposal. On March 27, 2024, the Company’s stockholders approved the Conversion Proposal, among other matters, at the Special Meeting. On April 8, 2024, pursuant to the terms of the Series A Certificate of Designation, as amended, 367,919.247 shares of Series A Preferred Stock automatically converted into 12,263,951 shares of common stock, including the non-cash reclassification of an amount equal to the increase in par value of common stock from additional paid-in capital; 166,341.592 shares of Series A Preferred Stock did not automatically convert at such time due to beneficial ownership limitations. On October 11, 2024, pursuant to a Notice of Optional Conversion delivered to the Company by a holder of Series A Preferred Stock pursuant to the Series A Certificate of Designation, 45,551.190 shares of Series A Preferred Stock held by such holder were converted into 1,518,373 newly issued shares of common stock. In accordance with the guidance in ASC Topic 480, Distinguishing Liabilities from Equity (ASC 480) the Series A Preferred Stock was classified outside of stockholders’ deficit upon issuance and as of December 31, 2023 because the shares of Series A Preferred Stock contained redemption features that were not solely within the control of the Company. The Series A Preferred Stock was not currently redeemable, nor was it probable that the instrument would become redeemable, as it was only redeemable upon the occurrence of a contingent event. Accordingly, no accretion was recognized for the Series A Preferred Stock. As a result of the approval of the Conversion Proposal, all conditions that could have required cash redemption of the Series A Preferred Stock were removed. Since the Series A Preferred Stock was no longer redeemable, the associated balances of the Series A Preferred Stock were reclassified to permanent equity during the first quarter of 2024. The Series A Preferred Stock has the following rights and preferences: Conversion Prior to the stockholder approval of the Conversion Proposal, the Series A Preferred Shares were not convertible. Following the stockholder approval of the Conversion Proposal, each share of Series A Preferred Stock automatically converted into 33.333 shares of common stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series A Preferred Stock into shares of common stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than a specified percentage (to be established by the holder between 0% and 19.9%) of the total number of shares of common stock issued and outstanding immediately after giving effect to such conversion; provided, however, that such beneficial ownership limitation does not apply to Dr. Springer, TAS Partners LLC, or any of their respective affiliates. Each share of Series A Preferred Stock outstanding that was not otherwise automatically converted into common stock as a result of the beneficial ownership limitation shall be convertible at any time at the option of the holder following stockholder approval of the Conversion Proposal, only to the extent the beneficial ownership limitation does not apply to the shares of Series A Preferred Stock to be converted. Redemption Prior to the stockholder approval of the Conversion Proposal, each share of Series A Preferred Stock was redeemable at the option of the holder at any time following the date that was 18 months after the initial issuance date of the Series A Preferred Stock, other than any shares of Series A Preferred Stock that would not have been convertible into shares of common stock as a result of the beneficial ownership limitation referred to above. The amount payable upon redemption would have been equal to the average closing sale price of the common stock listed over the ten consecutive trading days ending on, and including, the day immediately prior to the redemption date multiplied by the number of shares of common stock the Series A Preferred Stock would have been convertible into. Following the Conversion Proposal, the Series A Preferred Stock is not redeemable. Dividends Holders of Series A Preferred Stock are entitled to receive dividends on shares of Series A Preferred Stock on an as-converted basis equal to the dividends paid on shares of the common stock; provided, however, that holders of Series A Preferred Stock (or any shares of common stock into which the Series A Preferred Stock are convertible) are not entitled to any CVRs or any amounts paid under the CVR Agreement. Voting Except as otherwise required by law, the Series A Preferred Stock does not have voting rights. However, as long as any shares of Series A Preferred Stock are outstanding, the Company will not, without the affirmative vote of the holders of a majority of the then-outstanding shares of the Series A Preferred Stock, (a) alter or change adversely the powers, preferences or rights given to the Series A Preferred Stock, (b) alter or amend the Series A Certificate of Designation, (c) amend the Charter or other organizational documents in any manner that adversely affects any rights of the holders of Series A Preferred Stock, (d) issue further shares of Series A Preferred Stock (other than in connection with the exercise of the stock options to purchase Series A Preferred Stock) or increase or decrease (other than by conversion) the number of authorized shares of Series A Preferred Stock, (e) prior to the stockholder approval of the Conversion Proposal or at any time while at least 30% of the originally issued Series A Preferred Stock remains issued and outstanding, consummate either (A) a Fundamental Transaction (as defined in the Series A Certificate of Designation) or (B) any merger or consolidation of the Company or other business combination in which the stockholders of the Company immediately before such transaction do not hold at least a majority of the capital stock of the Company immediately after such transaction, (f) amend or fail to comply with, in any manner that would be reasonably likely to prevent, impede or materially delay the conversion (or the stockholder approval thereof), or terminate, any of the stockholder support agreements entered into in connection with the Merger, or the Support Agreements, or agree to any transfer, sale or disposition of such shares subject to the Support Agreements (except for such transfers, sales or dispositions with respect to which the approval of the Company is not required pursuant to the applicable Support Agreement) or (g) enter into any agreement with respect to any of the foregoing. Liquidation The holders of Series A Preferred Stock shall rank on parity with the common stockholders and the holders of Series B Preferred Stock as to distributions of assets upon liquidation, dissolution or winding up of the Company, whether voluntarily or involuntarily. Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary each holder of Series A Preferred Stock shall be entitled to receive out the assets of the Company equal to of the same amount that a holder of common stock would receive if the Series A Preferred Stock were fully converted, which shall be paid pari passu with holders of common stock and holders of Series B Preferred Stock, plus an amount equal to any dividends declared but unpaid. If the assets available for distribution are not sufficient to pay the holders of the Series A Preferred Stock pursuant to the preceding sentence, the assets will be distributed ratably to the holders of the Series A Preferred Stock, Series B Preferred Stock and common stock. As of December 31, 2024, the Company had 120,790.402 shares of Series A Preferred Stock and 437,927 shares of Series B Preferred Stock issued and outstanding, respectively, which are convertible into a total of 4,464,273 shares of common stock.