Kalayoglu Murat

SEC source: 0002064832-26-000148 · form4.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 33,662.224

Underlying: Common Stock · 758,001 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On April 2, 2026, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F3 · price: On November 13, 2023, the issuer acquired the private Delaware corporation which was then known as Cartesian Therapeutics, Inc. in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023 (the "Merger"). These securities represent merger consideration payable as a result of the closing of the Merger and securities purchased in a private placement in November 2023.

F1 · derivative.exercise_date: On April 2, 2026, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F1 · derivative.expiration_date: On April 2, 2026, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F2 · ownership.nature: Shares are held by the Trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0002064832-26-000148 · form4.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 5,313,261

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On April 2, 2026, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F2 · ownership.nature: Shares are held by the Trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0001453687-26-000028 · wk-form4_1767734285.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,800

Underlying: Common Stock · 7,800 shares

Expires 2036-01-01

SEC source: 0001453687-26-000028 · wk-form4_1767734285.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 511,577

F1 · acquired: Each Restricted Stock Unit represents a contingent right to receive one share of common stock, which will vest in full on January 2, 2027.

SEC source: 0001453687-25-000022 · wk-form4_1736198413.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,800

Underlying: Common Stock · 7,800 shares

Expires 2035-01-01

SEC source: 0001453687-25-000022 · wk-form4_1736198413.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 508,977

F1 · acquired: Each Restricted Stock Unit represents a contingent right to receive one share of common stock, which will vest in full on January 2, 2026.

SEC source: 0001453687-24-000117 · wk-form4_1729025606.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 56,402.254

Underlying: Common Stock · 1,518,373 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On October 11, 2024, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F3 · price: On November 13, 2023, the issuer acquired the private Delaware corporation which was then known as Cartesian Therapeutics, Inc. in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023 (the "Merger"). These securities represent merger consideration payable as a result of the closing of the Merger and securities purchased in a private placement in November 2023.

F1 · derivative.exercise_date: On October 11, 2024, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F1 · derivative.expiration_date: On October 11, 2024, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F2 · ownership.nature: Shares are held by the Trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0001453687-24-000117 · wk-form4_1729025606.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 4,555,260

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On October 11, 2024, a trust (the "Trust") for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.

F2 · ownership.nature: Shares are held by the Trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0001453687-24-000065 · wk-form4_1712799774.xml · derivative · entry 4

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 101,953.444

Underlying: Common Stock · 2,926,764 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F5 · price: These securities represent merger consideration payable as a result of the closing of the Merger and securities purchased in a private placement in November 2023.

F1 · derivative.exercise_date: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F1 · derivative.expiration_date: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F2 · derivative.underlying_shares: On April 4, 2024, the issuer effected a 1-for-30 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.

F3 · ownership.nature: Shares are held in a trust (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0001453687-24-000065 · wk-form4_1712799774.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 491,853 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F4 · price: On November 13, 2023, the issuer acquired the private Delaware corporation which was then known as Cartesian Therapeutics, Inc. in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023 (the "Merger"). These securities represent merger consideration payable as a result of the closing of the Merger.

F1 · derivative.exercise_date: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F1 · derivative.expiration_date: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F2 · derivative.underlying_shares: On April 4, 2024, the issuer effected a 1-for-30 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.

SEC source: 0001453687-24-000065 · wk-form4_1712799774.xml · nonDerivative · entry 2

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 3,036,887

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F2 · balance_after: On April 4, 2024, the issuer effected a 1-for-30 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.

F3 · ownership.nature: Shares are held in a trust (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.

SEC source: 0001453687-24-000065 · wk-form4_1712799774.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 506,377

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On March 27, 2024, issuer held a special meeting of stockholders (the "Special Meeting"). At the Special Meeting, the issuer's stockholders approved the Reverse Stock Split and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock ("Series A Preferred Stock") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the "Automatic Conversion"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, the reporting person's shares of Series A Preferred Stock were limited to the extent that doing so would result in the reporting person beneficially owning greater than 19.9% of the issuer's outstanding Common Stock after giving effect to such conversion.

F2 · balance_after: On April 4, 2024, the issuer effected a 1-for-30 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.

SEC source: 0001453687-24-000017 · wk-form4_1704405827.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 228,000

Underlying: Common Stock · 228,000 shares

Expires 2034-01-01

F3 · derivative.exercise_date: This award will vest in 36 equal monthly installments, so that it shall be fully vested on January 2, 2027.

SEC source: 0001453687-24-000017 · wk-form4_1704405827.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 435,739

F1 · kind: Each Restricted Stock Unit represents a contingent right to receive one share of common stock, which will vest in three equal annual installments so that the underlying shares will be fully vested on January 2, 2027.

SEC source: 0001062993-23-020921 · form4.xml · derivative · entry 5

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 619.627

Underlying: Common Stock · 619,627 shares

Expires not disclosed

F3 · derivative.exercise_price: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F4 · price: On November 13, 2023, the Trust entered into a Securities Purchase Agreement with the Company and other investors, pursuant to which the Trust agreed to acquire 619.627 shares of Series A Preferred Stock.

F3 · derivative.exercise_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F3 · derivative.expiration_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F2 · ownership.nature: Shares are held in a trust (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.

SEC source: 0001062993-23-020921 · form4.xml · derivative · entry 4

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 189,136.767

Underlying: Common Stock · 189,136,767 shares

Expires not disclosed

F3 · derivative.exercise_price: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F1 · price: On November 13, 2023, Selecta Biosciences, Inc. (the "Company") acquired Cartesian Therapeutics, Inc. ("Cartesian") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger.

F3 · derivative.exercise_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F3 · derivative.expiration_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F2 · ownership.nature: Shares are held in a trust (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.

SEC source: 0001062993-23-020921 · form4.xml · derivative · entry 3

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,755.609

Underlying: Common Stock · 14,755,609 shares

Expires not disclosed

F3 · derivative.exercise_price: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F1 · price: On November 13, 2023, Selecta Biosciences, Inc. (the "Company") acquired Cartesian Therapeutics, Inc. ("Cartesian") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger.

F3 · derivative.exercise_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

F3 · derivative.expiration_date: Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company ("Series A Preferred Stock") into shares of common stock of the Company ("Common Stock"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series 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 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion.

SEC source: 0001062993-23-020921 · form4.xml · nonDerivative · entry 2

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · by trust

Disclosed balance after: 3,303,699

F1 · price: On November 13, 2023, Selecta Biosciences, Inc. (the "Company") acquired Cartesian Therapeutics, Inc. ("Cartesian") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger.

F2 · ownership.nature: Shares are held in a trust (the "Trust") for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the trust.

SEC source: 0001062993-23-020921 · form4.xml · nonDerivative · entry 1

Kalayoglu Murat · CIK 0002000002 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 257,739

F1 · price: On November 13, 2023, Selecta Biosciences, Inc. (the "Company") acquired Cartesian Therapeutics, Inc. ("Cartesian") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger.