Cartesian Therapeutics, Inc.

Previous wording

Selecta, Sakura Merger Sub I, Inc., a wholly owned subsidiary of Selecta, or First Merger Sub, Sakura Merger Sub II, LLC, a wholly owned subsidiary of Selecta, or Second Merger Sub, and Old Cartesian. Pursuant to the Merger Agreement, First Merger Sub merged with and into Old Cartesian, pursuant to which Old Cartesian was the surviving corporation and became a wholly owned subsidiary of Selecta, or the First Merger. Immediately following the First Merger, Old Cartesian merged with and into Second Merger Sub, pursuant to which Second Merger Sub was the surviving entity, or the Second Merger and, together with the First Merger, the Merger. In connection with the Second Merger, Old Cartesian changed its name to Cartesian Bio, LLC. In connection with the Merger and pursuant to the Merger Agreement, the Company changed its corporate name to Cartesian Therapeutics, Inc. See Note 4 of the notes to the consolidated financial statements inour Annual Report on Form 10-K for the year ended December 31, 2024 foradditional information regarding the Merger.

Current wording

Selecta, Sakura Merger Sub I, Inc., a wholly owned subsidiary of Selecta, or First Merger Sub, Sakura Merger Sub II, LLC, a wholly owned subsidiary of Selecta, or Second Merger Sub, and Old Cartesian. Pursuant to the Merger Agreement, First Merger Sub merged with and into Old Cartesian, pursuant to which Old Cartesian was the surviving corporation and became a wholly owned subsidiary of Selecta, or the First Merger. Immediately following the First Merger, Old Cartesian merged with and into Second Merger Sub, pursuant to which Second Merger Sub was the surviving entity, or the Second Merger and, together with the First Merger, the Merger. In connection with the Second Merger, Old Cartesian changed its name to Cartesian Bio, LLC. In connection with the Merger and pursuant to the Merger Agreement, the Company changed its corporate name to Cartesian Therapeutics, Inc. See Note 4, “Merger” of the notes to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2024 for additional information regarding the Merger.

Previous wording

We have incurred significant operating losses since our inception. We incurred a net loss of $1.8 million and $43.0 million for the six months ended June 30, 2025 and 2024, respectively. As of June 30, 2025, we had an accumulated deficit of $693.9 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future as we:

Current wording

We have incurred significant operating losses since our inception. We incurred a net loss of $37.7 million and $67.2 million for the nine months ended September 30, 2025 and 2024, respectively. As of September 30, 2025, we had an accumulated deficit of $729.8 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future as we:

Previous wording

We believe that our existing cash, cash equivalents, and restricted cash as of June 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements into mid-2027. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect.

Current wording

We believe that our existing cash, cash equivalents, and restricted cash as of September 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements for at least the next 12 months from the date of issuance of these financial statements. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect.

Previous wording

To date, we have not generated any revenue from product sales. Our revenue consists primarily of collaboration and license revenue, which includes amounts recognized related to upfront and milestone payments for research and development funding under collaboration and license agreements. We expect that any revenue we generate will fluctuate from quarter to quarter because of the timing and amounts of fees, research and development reimbursements and other payments from collaborators. We do not expect to generate revenue from product sales for at least the next several years. If we or our collaborators fail to complete the development of our product candidates in a timely manner or fail to obtain regulatory approval as needed, our ability to generate future revenue will be harmed, and will affect the results of our operations and financial position. For further descriptions of the agreements underlying our collaboration and license revenue, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

To date, we have not generated any revenue from product sales. Our revenue consists primarily of collaboration and license revenue, which includes amounts recognized related to upfront and milestone payments for research and development funding under collaboration and license agreements. We expect that any revenue we generate will fluctuate from quarter to quarter because of the timing and amounts of fees, research and development reimbursements and other payments from collaborators. We do not expect to generate revenue from product sales for at least the next several years. If we or our collaborators fail to complete the development of our product candidates in a timely manner or fail to obtain regulatory approval as needed, our ability to generate future revenue will be harmed, and will affect the results of our operations and financial position. For further descriptions of the agreements underlying our collaboration and license revenue, see Note 13, “Revenue Arrangements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Previous wording

During the three months ended June 30, 2025, we recognized $0.3 million of grant revenue, compared to $0.2 million for the three months ended June 30, 2024, an increase of $0.1 million. The increase was primarily due to increased expenses reimbursable under the grant from the National Institute of Neurological Disorders and Stroke of the National Institutes of Health, or NINDS, incurred during the three months ended June 30, 2025, for which we received funding approval during the three months ended June 30, 2024.

Current wording

During the three months ended September 30, 2025, we recognized $0.5 million of grant revenue, compared to $0.4 million for the three months ended September 30, 2024, an increase of $0.1 million. The increase was primarily due to increased expenses reimbursable under the grant from the National Institute of Neurological Disorders and Stroke of the National Institutes of Health, or NINDS, incurred during the three months ended September 30, 2025.

Previous wording

Astellas in 2024. The increase in expenses for Descartes-08 for MG was primarily related to the expenses for the ongoing Phase 3 AURORA trial. The increase in our expenses for early stage programs was primarily related to increased discovery expenses and manufacturing operations expenses. The increases in our research and development employee expenses and stock-based compensation expense were primarily a result of headcount growth.

Current wording

For the three months ended September 30, 2025, our research and development expenses were $13.8 million, compared to $11.4 million for the three months ended September 30, 2024, an increase of $2.4 million. The increase was primarily due to an increase in expenses for Descartes-08 for MG, primarily related to the expenses for the ongoing Phase 3 AURORA trial, coupled with an increase in our research and development employee expenses and stock-based compensation expense, primarily the result of headcount growth, and an increase in expenses for early stage programs, primarily related to increased discovery expenses and manufacturing operations expenses. This increase was partially offset by a decrease in expenses for legacy Selecta programs, which were primarily related to expenses for Xork as a result of the termination of the License and Development Agreement, or the Astellas Agreement, with Audentes Therapeutics, Inc., doing business as Astellas Gene Therapies, or Astellas in 2024.

Previous wording

For the three months ended June 30, 2025, ourgeneral and administrative expenses were$7.2 million, compared to$7.0 million for thethree months ended June 30, 2024, an increase of $0.2 million. The increase in cost was primarily the result of increased facilities expenses.

Current wording

For the three months ended September 30, 2025, our general and administrative expenses were $7.7 million, compared to $6.6 million for the three months ended September 30, 2024, an increase of $1.1 million. The increase in cost was primarily the result of increased facilities expenses and expenses incurred for stock-based compensation.

Previous wording

Interest income for the three months ended June 30, 2025 was $1.7 million, compared to $1.2 million for the three months ended June 30, 2024, an increase of $0.5 million. The increase in interest income was due to increased cash and cash equivalents balance.

Current wording

Interest income for the three months ended September 30, 2025 was $1.5 million, compared to $2.6 million for the three months ended September 30, 2024, a decrease of $1.1 million. The decrease in interest income was due to decreased cash and cash equivalents balance.

Previous wording

For the six months ended June 30, 2025, we recognized $2.5 million of income from the decrease in the fair value of warrant liabilities, compared to $2.9 million charge from the increase in the fair value of warrant liabilities for the six months ended June 30, 2024, an increase of $5.4 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock.

Current wording

For the three months ended September 30, 2025, we recognized $0.5 million of income from the decrease in the fair value of warrant liabilities, compared to $5.7 million of income from the decrease in the fair value of warrant liabilities for the three months ended September 30, 2024, a decrease of $5.2 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock and the expiration of the warrants we issued in 2019, or the 2019 Warrants, during the year ended December 31, 2024.

Previous wording

For the three months ended June 30, 2025, we recognized $35.3 million of income from the decrease in the fair value of the CVR liability, compared to $2.5 million of income from the decrease in the fair value of the CVR liability for the three months ended June 30, 2024, an increase of $32.8 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The decrease in the fair value of the CVR liability was primarily due to changes in the timing of anticipated payments.

Current wording

For the three months ended September 30, 2025, we recognized $16.9 million of expense associated with the increase in the fair value of the CVR liability, compared to $15.1 million of expense associated with the increase in the fair value of the CVR liability for the three months ended September 30, 2024, an increase of $1.8 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The increase in both periods in the fair value of the CVR liability was primarily due to a decrease in interest rates and the passage of time.

Previous wording

During the three months ended June 30, 2025, we recognized less than $0.1 million other expense, net, compared to $0.3 million other income, net for the three months ended June 30, 2024. The decrease was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Current wording

During the three months ended September 30, 2025, we recognized no other income, net, compared to $0.3 million other income, net for the three months ended September 30, 2024. The decrease was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Previous wording

During the six months ended June 30, 2025, we recognized $0.4 million of collaboration and license revenue, compared to $39.1 million for the six months ended June 30, 2024, a decrease of $38.7 million. The decrease was primarily due to a decrease in revenue recognized under the Sobi License resulting from the $30.0 million unconstrained development milestone recognized during the six months ended June 30, 2024 and a decrease for revenue recognized under the Astellas Agreement upon notice of termination during the six months ended June 30, 2024.

Current wording

During the nine months ended September 30, 2025, we recognized $0.4 million of collaboration and license revenue, compared to $39.1 million for the nine months ended September 30, 2024, a decrease of $38.7 million. The decrease was primarily due to a decrease in revenue recognized under the Sobi License resulting from the $30.0 million unconstrained development milestone recognized during the nine months ended September 30, 2024 and a decrease for revenue recognized under the Astellas Agreement upon notice of termination during the nine months ended September 30, 2024.

Previous wording

During the six months ended June 30, 2025, we recognized $1.0 million of grant revenue, compared to $0.2 million for the six months ended June 30, 2024, an increase of $0.8 million. The increase was primarily due to increased expenses reimbursable under the grant from NINDS incurred during the six months ended June 30, 2025, for which we received funding approval during the six months ended June 30, 2024.

Current wording

During the nine months ended September 30, 2025, we recognized $1.5 million of grant revenue, compared to $0.6 million for the nine months ended September 30, 2024, an increase of $0.9 million. The increase was primarily due to increased expenses reimbursable under the grant from NINDS incurred during the nine months ended September 30, 2025, for which we received funding approval during the nine months ended September 30, 2024.

Previous wording

The following is a comparison of research and development expenses for the six months ended June 30, 2025 and 2024 (in thousands, except percentages):

Current wording

The following is a comparison of research and development expenses for the nine months ended September 30, 2025 and 2024 (in thousands, except percentages):

Previous wording

For the six months ended June 30, 2025, our research and development expenses were$29.5 million, compared to $22.4 million for the six months ended June 30, 2024, an increase of $7.1 million. The decrease in expenses for legacy Selecta programs was primarily related to decreased expenses for Xork as a result of the termination of the Astellas Agreement in 2024. The increase in expenses for Descartes-08 for MG was primarily related to the expenses for the ongoing Phase 3 AURORA trial. The increase in our expenses for early stage programs was primarily related to increased discovery expenses and manufacturing operations expenses. The increases in our research and development employee expenses and stock-based compensation expense were primarily a result of headcount growth.

Current wording

For the nine months ended September 30, 2025, our research and development expenses were $43.3 million, compared to $33.8 million for the nine months ended September 30, 2024, an increase of $9.5 million. The increase was primarily due to an increase in expenses for Descartes-08 for MG, primarily related to the expenses for the ongoing Phase 3 AURORA trial, coupled with an increase in our research and development employee expenses and stock-based compensation expense, primarily as the result of headcount growth, and an increase in expenses for early stage program, primarily related to increased discovery expenses and manufacturing operations expenses. These increases were partially offset by a decrease in expenses for legacy Selecta programs, primarily related to decreased expenses for Xork as a result of the termination of the Astellas Agreement in 2024.

Previous wording

For the six months ended June 30, 2025, ourgeneral and administrative expenses were$15.6 million compared to$16.5 million for thesix months ended June 30, 2024, a decrease of $0.9 million. The decrease in cost was primarily the result of expenses incurred for professional fees incurred in connection with the Merger.

Current wording

For the nine months ended September 30, 2025, our general and administrative expenses were $23.3 million compared to $23.0 million for the nine months ended September 30, 2024, an increase of $0.3 million. The increase in cost was primarily the result of increased facilities expenses and expenses incurred for stock-based compensation, partially offset by decreased expenses incurred for personnel expenses and professional fees incurred in connection with the Merger.

Previous wording

Interest income for the six months ended June 30, 2025 was $3.8 million, compared to $2.4 million for the six months ended June 30, 2024. The increase in interest income was due to increased cash and cash equivalents balance.

Current wording

Interest income for the nine months ended September 30, 2025 was $5.3 million, compared to $4.9 million for the nine months ended September 30, 2024. The increase in interest income was due to increased cash and cash equivalents balance.

Previous wording

For the three months ended June 30, 2025, we recognized $0.7 million of income from the decrease in the fair value of warrant liabilities, compared to $3.9 million charge from the increase in the fair value of warrant liabilities for the three months ended June 30, 2024, an increase of $4.6 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock and the expiration of the warrants we issued in 2019 during the year ended December 31, 2024.

Current wording

For the nine months ended September 30, 2025, we recognized $3.0 million of income from the decrease in the fair value of warrant liabilities, compared to $2.8 million of income from the decrease in the fair value of warrant liabilities for the nine months ended September 30, 2024, an increase of $0.2 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock and the expiration of the 2019 Warrants during the year ended December 31, 2024.

Previous wording

For the six months ended June 30, 2025, we recognized $35.6 million of income from the decrease in the fair value of the CVR liability, compared to $36.8 million charge from the increase in the fair value of the CVR liability for the six months ended June 30, 2024, an increase of $72.4 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The increase in the fair value of CVR liability was primarily due to changes in the timing of anticipated payments during the six months ended June 30, 2025.

Current wording

For the nine months ended September 30, 2025, we recognized $18.7 million of income from the decrease in the fair value of the CVR liability, compared to $51.9 million of expense from the increase in the fair value of the CVR liability for the nine months ended September 30, 2024, a change of $70.6 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The decrease in the fair value of CVR liability in the current period was primarily due to changes in the timing of anticipated payments during the nine months ended September 30, 2025. The increase in the fair value of CVR liability in the prior period was primarily due to changes in the amount and timing of anticipated payments and the passage of time during the nine months ended September 30, 2024.

Previous wording

Change in fair value of forward contract liabilities

Current wording

Change in fair value of forward contract liability

Previous wording

The remaining Series A Preferred Stock forward contract liability was settled during the six months ended June 30, 2024. As such, no change in the fair value of the Series A Preferred Stock forward contract liability is reflected in our unaudited consolidated financial statements for the six months ended June 30, 2025.

Current wording

The remaining Series A Preferred Stock forward contract liability was settled during the nine months ended September 30, 2024. As such, no change in the fair value of the Series A Preferred Stock forward contract liability is reflected in our unaudited consolidated financial statements for the nine months ended September 30, 2025.

Previous wording

During the six months ended June 30, 2025, we recognized less than $0.1 million of other expense, net, compared to $0.8 million other income, net for the six months ended June 30, 2024, a decrease of $0.8 million, or 100%. The decrease was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Current wording

During the nine months ended September 30, 2025, we recognized less than $0.1 million of other expense, net, compared to $1.1 million other income, net for the nine months ended September 30, 2024, a change of $1.1 million. The change was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Previous wording

Net loss for the six months ended June 30, 2025 was $1.8 million as compared to net loss of $43.0 million for the six months ended June 30, 2024, a decrease of $41.2 million or 96%. The change was primarily due to income associated with the change in the fair value of the CVR liability and warrant liabilities during the six months ended June 30, 2025, partially offset by revenue recognized under the Sobi License during the six months ended June 30, 2025.

Current wording

Net loss for the nine months ended September 30, 2025 was $37.7 million as compared to net loss of $67.2 million for the nine months ended September 30, 2024, a decrease of $29.5 million. The decrease in net loss was primarily due to higher income associated with the change in the fair value of the CVR liability, partially offset by increased research and development expenses and revenue recognized under the Sobi License during the nine months September 30, 2024.

Previous wording

Our cash, cash equivalents, and restricted cash were $162.1 million as of June 30, 2025, of which $1.7 million was restricted cash related to lease commitments.

Current wording

Our cash, cash equivalents, and restricted cash were $145.1 million as of September 30, 2025, of which $1.7 million was restricted cash related to lease commitments.

Previous wording

In September 2023, we entered into a non-exclusive, sublicensable, worldwide, perpetual patent license agreement, or the Biogen Agreement, with Biogen MA, Inc., or Biogen, to research, develop, make, use, offer, sell and import products or processes containing or using an engineering T-cell modified with an mRNA comprising, or encoding a protein comprising, certain sequences licensed under the Biogen Agreement for the prevention, treatment, palliation and management of autoimmune diseases and disorders, excluding cancers, neoplastic disorders, and paraneoplastic disorders. We are not obligated to pay Biogen any expenses, fees, or royalties. For further description of the Biogen Agreement, see Note 15 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

In September 2023, we entered into a non-exclusive, sublicensable, worldwide, perpetual patent license agreement, or the Biogen Agreement, with Biogen MA, Inc., or Biogen, to research, develop, make, use, offer, sell and import products or processes containing or using an engineering T-cell modified with an mRNA comprising, or encoding a protein comprising, certain sequences licensed under the Biogen Agreement for the prevention, treatment, palliation and management of autoimmune diseases and disorders, excluding cancers, neoplastic disorders, and paraneoplastic disorders. We are not obligated to pay Biogen any expenses, fees, or royalties. For further description of the Biogen Agreement, see Note 15, “Collaboration and License Agreements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Previous wording

Effective September 2019, we entered into a non-exclusive, worldwide license agreement, or the NCI Agreement, with the U.S. Department of Health and Human Services, represented by the National Cancer Institute of the National Institutes of Health, or NCI. Under the NCI Agreement, we were granted a license under certain NCI patents and patent applications designated in the agreement, to make, use, sell, offer and import products and processes within the scope of the patents and applications licensed under the NCI Agreement when developing and manufacturing anti-BCMA CAR-T cell products for the treatment of MG, pemphigus vulgaris, and immune thrombocytopenic purpura according to methods designated in the NCI Agreement. In connection with our entry into the NCI Agreement, we paid to NCI a one-time $0.1 million license royalty payment. Under the NCI Agreement, we are further required to pay NCI a low five-digit annual royalty. We must also pay earned royalties on net sales in a low single-digit percentage and pay up to $0.8 million in benchmark royalties upon our achievement of designated benchmarks that are based on the commercial development plan agreed between the parties. For further description of the NCI Agreement, see Note 15 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

Effective September 2019, we entered into a non-exclusive, worldwide license agreement, or the NCI Agreement, with the U.S. Department of Health and Human Services, represented by the National Cancer Institute of the National Institutes of Health, or NCI. Under the NCI Agreement, we were granted a license under certain NCI patents and patent applications designated in the agreement, to make, use, sell, offer and import products and processes within the scope of the patents and applications licensed under the NCI Agreement when developing and manufacturing anti-BCMA CAR-T cell products for the treatment of MG, pemphigus vulgaris, and immune thrombocytopenic purpura according to methods designated in the NCI Agreement. In connection with our entry into the NCI Agreement, we paid to NCI a one-time $0.1 million license royalty payment. Under the NCI Agreement, we are further required to pay NCI a low five-digit annual royalty. We must also pay earned royalties on net sales in a low single-digit percentage and pay up to $0.8 million in benchmark royalties upon our achievement of designated benchmarks that are based on the commercial development plan agreed between the parties. For further description of the NCI Agreement, see Note 15, “Collaboration and License Agreements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Previous wording

In January 2023, we entered into the Astellas Agreement with Astellas. Under this agreement, Astellas obtained the sole and exclusive right to commercialize Xork for use in Pompe disease in combination with an Astellas gene therapy investigational or authorized product, with a current focus on AT845. In connection with entry into this agreement, we received a $10.0 million upfront payment and were eligible to receive $340.0 million for certain additional development and commercial milestones plus royalties on any potential commercial sales where Xork is used as a pre-treatment for AT845. As a result of the sublicense of Xork to Astellas, we made a $4.0 million payment to Genovis in February 2023. The Astellas Agreement was terminated effective June 6, 2024. For further description of the Astellas Agreement, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report. Amounts paid and remaining obligations with regard to the Xork product candidate not reimbursed by Astellas through the Astellas Agreement were subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

Current wording

In January 2023, we entered into the Astellas Agreement with Astellas. Under this agreement, Astellas obtained the sole and exclusive right to commercialize Xork for use in Pompe disease in combination with an Astellas gene therapy investigational or authorized product, with a current focus on AT845. In connection with entry into this agreement, we received a $10.0 million upfront payment and were eligible to receive $340.0 million for certain additional development and commercial milestones plus royalties on any potential commercial sales where Xork is used as a pre-treatment for AT845. As a result of the sublicense of Xork to Astellas, we made a $4.0 million payment to Genovis in February 2023. The Astellas Agreement was terminated effective June 6, 2024. For further description of the Astellas Agreement, see Note 13, “Revenue Arrangements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report. Amounts paid and remaining obligations with regard to the Xork product candidate not reimbursed by Astellas through the Astellas Agreement were subject to potential reimbursement through deductions to CVR distributions as described in Note 7, “Fair Value Measurements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

Previous wording

In June 2020, we entered into the Sobi License. Sobi paid us a one-time, upfront payment of $75 million, and upon the closing of a private placement of our common stock to Sobi at a price of $138.468 per share, we received an additional $25 million from Sobi. We are eligible to receive $630.0 million in milestone payments upon the achievement of various development and regulatory milestones and sales thresholds for annual net sales of SEL-212, and tiered royalty payments ranging from the low double digits on the lowest sales tier to the high teens on the highest sales tier. Sobi has agreed to fund the Phase 3 clinical program of SEL-212, which commenced in September 2020. In July 2022, we received $10.0 million for the completion of the enrollment of the DISSOLVE II trial. In July 2024, we received $30.0 million for the milestone associated with the initiation of a rolling biologics license application to the FDA for SEL-212 for the potential treatment of chronic refractory gout by Sobi. Proceeds from milestone payments and royalties on sales of SEL-212, if any, are required to be distributed, net of certain agreed deductions, to holders of the CVRs. For further description of the Sobi License, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

In June 2020, we entered into the Sobi License. Sobi paid us a one-time, upfront payment of $75 million, and upon the closing of a private placement of our common stock to Sobi at a price of $138.468 per share, we received an additional $25 million from Sobi. We are eligible to receive $630.0 million in milestone payments upon the achievement of various development and regulatory milestones and sales thresholds for annual net sales of SEL-212, and tiered royalty payments ranging from the low double digits on the lowest sales tier to the high teens on the highest sales tier. Sobi has agreed to fund the Phase 3 clinical program of SEL-212, which commenced in September 2020. In July 2022, we received $10.0 million for the completion of the enrollment of the DISSOLVE II trial. In July 2024, we received $30.0 million for the milestone associated with the initiation of a rolling biologics license application to the FDA for SEL-212 for the potential treatment of chronic refractory gout by Sobi. Proceeds from milestone payments and royalties on sales of SEL-212, if any, are required to be distributed, net of certain agreed deductions, to holders of the CVRs. For further description of the Sobi License, see Note 13, “Revenue Arrangements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Previous wording

On December 13, 2024, we and Leerink Partners LLC entered into a Sales Agreement, or the Sales Agreement. Under the Sales Agreement, we may issue and sell shares of our common stock, from time to time, through Leerink Partners LLC or aggregate gross sales proceeds of up to $100.0 million. During the six months ended June 30, 2025, we sold no shares of our common stock pursuant to the Sales Agreement.

Current wording

On December 13, 2024, we and Leerink Partners LLC entered into a Sales Agreement, or the Sales Agreement. Under the Sales Agreement, we may issue and sell shares of our common stock, from time to time, through Leerink Partners LLC or aggregate gross sales proceeds of up to $100.0 million. During the nine months ended September 30, 2025, we sold no shares of our common stock pursuant to the Sales Agreement.

Previous wording

Cartesian, who joined our Board of Directors effective immediately after the effective time of the Merger, providing for the 2023 Private Placement. In the 2023 Private Placement, we issued and sold an aggregate of 149,330.115 shares of Series A Preferred Stock for an aggregate purchase price of $60.25 million, of which 50,189.789 shares of Series A Preferred Stock were issued and sold in the year ended December 31, 2023 for gross proceeds of $20.25 million, and 99,140.326 shares of Series A Preferred Stock were issued and sold during the three months ended March 31, 2024 for gross proceeds of $40.0 million.

Current wording

On November 13, 2023, we entered into the 2023 Securities Purchase Agreement with (i) Dr. Timothy A. Springer, a member of our 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 our Board of Directors effective immediately after the effective time of the Merger, providing for the 2023 Private Placement. In the 2023 Private Placement, we issued and sold an aggregate of 149,330.115 shares of Series A Preferred Stock for an aggregate purchase price of $60.25 million, of which 50,189.789 shares of Series A Preferred Stock were issued and sold in the year ended December 31, 2023 for gross proceeds of $20.25 million, and 99,140.326 shares of Series A Preferred Stock were issued and sold during the three months ended March 31, 2024 for gross proceeds of $40.0 million.

Previous wording

As of June 30, 2025, we had an accumulated deficit of $693.9 million. We anticipate operating losses to continue for the foreseeable future due to, among other things, costs related to research, development of our product candidates, conducting preclinical studies and clinical trials, and our administrative organization. We will require substantial additional financing to fund our operations and to continue to execute our strategy, and we will pursue a range of options to secure additional capital.

Current wording

As of September 30, 2025, we had an accumulated deficit of $729.8 million. We anticipate operating losses to continue for the foreseeable future due to, among other things, costs related to research, development of our product candidates, conducting preclinical studies and clinical trials, and our administrative organization. We will require substantial additional financing to fund our operations and to continue to execute our strategy, and we will pursue a range of options to secure additional capital.

Previous wording

We believe that our existing cash, cash equivalents, and restricted cash as of June 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements into mid-2027. We may pursue additional cash resources through public or private equity or debt financings, by establishing collaborations with other companies or through the monetization of potential royalty and/or milestone payments pursuant to our existing collaboration and license arrangements. Management’s expectations with respect to our ability to fund current and long-term planned operations are based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, we may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. However, there is no guarantee that any of these strategic or financing opportunities will be executed on favorable terms, and some could be dilutive to existing stockholders. If we are unable to obtain additional funding on a timely basis, we may be forced to significantly curtail, delay, or discontinue one or more of our planned research or development programs or be unable to expand our operations, meet long-term obligations or otherwise capitalize on our commercialization of our product candidates.

Current wording

We believe that our existing cash, cash equivalents, and restricted cash as of September 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements for at least the next 12 months from the date of issuance of these financial statements. We may pursue additional cash resources through public or private equity or debt financings, by establishing collaborations with other companies or through the monetization of potential royalty and/or milestone payments pursuant to our existing collaboration and license arrangements. Management’s expectations with respect to our ability to fund current and long-term planned operations are based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, we may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. However, there is no guarantee that any of these strategic or financing opportunities will be executed on favorable terms, and some could be dilutive to existing stockholders. If we are unable to obtain additional funding on a timely basis, we may be forced to significantly curtail, delay, or discontinue one or more of our planned research or development programs or be unable to expand our operations, meet long-term obligations or otherwise capitalize on our commercialization of our product candidates.

Previous wording

We are under agreement to lease approximately 32,294 square feet of laboratory and office space in Watertown, Massachusetts through May 2028. Remaining lease payments from June 30, 2025 through the end of the lease term total approximately $8.3 million. Payments made and remaining obligations on this lease liability were subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

Current wording

We are under agreement to lease approximately 32,294 square feet of laboratory and office space in Watertown, Massachusetts through May 2028. Remaining lease payments from September 30, 2025 through the end of the lease term total approximately $7.6 million. Payments made and remaining obligations on this lease liability were subject to potential reimbursement through deductions to CVR distributions as described in Note 7, “Fair Value Measurements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

Previous wording

In November 2023, in connection with the Merger, we acquired two leases for office and laboratory space in Gaithersburg, Maryland, which expire in January 2027. Annualized rent is approximately $0.3 million and remaining lease payments from June 30, 2025 through the end of the lease term total approximately $0.5 million.

Current wording

In November 2023, in connection with the Merger, we acquired two leases for office and laboratory space in Gaithersburg, Maryland, which expire in January 2027. Annualized rent is approximately $0.3 million and remaining lease payments from September 30, 2025 through the end of the lease term total approximately $0.4 million.

Previous wording

In February 2024, we entered into an agreement to lease approximately 19,199 square feet of integrated manufacturing and office space in Frederick, Maryland. In May 2024, we entered into an amendment to lease an additional approximately 7,842 square feet at the same site. In August 2024, we entered into a second amendment to lease an additional approximately 2,009 square feet at the same site. In March 2025, we entered into a third amendment to lease an additional approximately 6,439 square feet at the same site. The leases expire coterminously in June 2031. Annualized base rent under the leases is approximately $1.2 million and is subject to annual increases in accordance with the terms of the lease agreement. The leases provide for a tenant improvement allowance of $0.8 million. Remaining lease payments total $9.4 million through the end of the lease term.

Current wording

In February 2024, we entered into an agreement to lease approximately 19,199 square feet of integrated manufacturing and office space in Frederick, Maryland. In May 2024, we entered into an amendment to lease an additional approximately 7,842 square feet at the same site. In August 2024, we entered into a second amendment to lease an additional approximately 2,009 square feet at the same site. In March 2025, we entered into a third amendment to lease an additional approximately 6,439 square feet at the same site. The leases expire coterminously in June 2031. Annualized base rent under the leases is approximately $1.2 million and is subject to annual increases in accordance with the terms of the lease agreement. The leases provide for a tenant improvement allowance of $0.8 million. Remaining lease payments total $9.1 million through the end of the lease term.

Previous wording

We are also party to certain license and collaboration agreements with Biogen, NCI, and Shenyang Sunshine Pharmaceutical Co., Ltd., or 3SBio. We may be obligated to make certain future payments which are contingent upon future events such as our achievement of specified regulatory and commercial milestones, or royalties on net product sales under these agreements. As of June 30, 2025, we were unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. Payments made and remaining obligations on the license agreement with 3SBio are subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

We are also party to certain license and collaboration agreements with Biogen, NCI, and Shenyang Sunshine Pharmaceutical Co., Ltd., or 3SBio. We may be obligated to make certain future payments which are contingent upon future events such as our achievement of specified regulatory and commercial milestones, or royalties on net product sales under these agreements. As of September 30, 2025, we were unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. Payments made and remaining obligations on the license agreement with 3SBio are subject to potential reimbursement through deductions to CVR distributions as described in Note 7, “Fair Value Measurements” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Previous wording

Net cash used in operating activities for the six months ended June 30, 2025 was $40.6 million compared to $30.4 million for the six months ended June 30, 2024. The increase in cash used in operating activities of $10.2 million was primarily due to $32.0 million of net loss, adjusted for non-cash items, and $8.6 million of cash used in changes in operating assets and liabilities, in each case during the six months ended June 30, 2025 compared to $8.1 million of net loss, adjusted for non-cash items, and $38.5 million of cash used in changes in operating assets and liabilities during the six months ended June 30, 2024.

Current wording

Net cash used in operating activities for the nine months ended September 30, 2025 was $56.2 million compared to $16.7 million for the nine months ended September 30, 2024. The increase in cash used in operating activities of $39.5 million was primarily due to $48.2 million of net loss, adjusted for non-cash items, and $8.0 million of cash used in changes in operating assets and liabilities, in each case during the nine months ended September 30, 2025 compared to $4.0 million of net loss, adjusted for non-cash items, and $12.7 million of cash used in changes in operating assets and liabilities during the nine months ended September 30, 2024.

Previous wording

Net cash used in investing activities for the six months ended June 30, 2025 was $3.7 million compared to $2.2 million in the same period in 2024, a decrease of $1.5 million. The net cash used in investing activities for the six months ended June 30, 2025 and 2024 consisted primarily of purchases of property and equipment.

Current wording

Net cash used in investing activities for the nine months ended September 30, 2025 was $5.0 million compared to $8.4 million in the same period in 2024, a decrease of $3.4 million. The net cash used in investing activities for the nine months ended September 30, 2025 and 2024 consisted of purchases of property and equipment.

Previous wording

Net cash used in financing activities for the six months ended June 30, 2025 was $8.0 million compared to net cash provided by financing activities of $43.2 million for the six months ended June 30, 2024, a decrease of $51.2 million. The net cash used in financing activities in the six months ended June 30, 2025 was primarily the result of payments for the CVR distribution. The net cash provided by financing activities in the six months ended June 30, 2024 was primarily the result of proceeds of the 2023 Private Placement.

Current wording

Net cash used in financing activities for the nine months ended September 30, 2025 was $8.0 million compared to net cash provided by financing activities of $167.6 million for the nine months ended September 30, 2024, a decrease of $175.6 million. The net cash used in financing activities in the nine months ended September 30, 2025 was primarily the result of payments for the CVR distribution. The net cash provided by financing activities in the nine months ended September 30, 2024 was primarily the result of proceeds of the 2023 Private Placement and the 2024 Private Placement.

Previous wording

For a discussion of recently adopted or issued accounting pronouncements refer to Note 3 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Current wording

For a discussion of recently adopted or issued accounting pronouncements refer to Note 3, “Summary of Significant Accounting Policies” to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.