11. Related Party Transactions

As described in Note 3, Discontinued Operations and TSA, in September 2024, the Company sold the VOWST Business, including inventory and equipment, certain patents and patent applications, know-how, trade secrets, trademarks, domain names, marketing authorizations and related rights, documents, materials, business records and data and contracts that are used or held for use primarily in the development, commercialization and manufacturing of VOWST, to SPN, and SPN assumed certain liabilities from the Company. As consideration for the Transaction, the Company received an upfront cash payment of $139,788, which consisted of $100,000, less $17,857 owed by the Company to an affiliate of SPN under the prior license agreement between the Company and the SPN affiliate, less approximately $2,355 in satisfaction of fees due under the Bacthera Manufacturing Agreement; plus a prepayment of the $60,000 milestone payment tied to the achievement of worldwide annual net sales of VOWST of $150,000; plus an equity investment of $15,000 based on the Securities Purchase Agreement pursuant to which SPN purchased 714,285 shares of common stock at a purchase price of $21.00 per share.

As of June 30, 2026 and December 31, 2025, there was $3,278 included in Accrued Liabilities due to SPN - related party on the Company’s condensed consolidated balance sheet, which represents amounts due to SPN pursuant to the Purchase Agreement, which are further described in Note 3, Discontinued Operations and TSA. During the three and six months ended June 30, 2026 and 2025, the Company paid $0, $0, $0, and $1,309, to SPN related to the Purchase Agreement during the periods, respectively.

As described in Note 3, Discontinued Operations and TSA, the Company entered into the TSA with NESA, an affiliate of SPN, in connection with the Transaction, through which the Company provided certain manufacturing services until December 31, 2025, and other transition services, for the duration specified in the schedule to the TSA for each service. For the three and six months ended June 30, 2026 and 2025, the Company recognized $0, $0, $3,490, and $9,799, respectively, of TSA reimbursement income in other income in the Company’s condensed consolidated statements of operations and comprehensive (loss) income. For the three and

six months ended June 30, 2026 and 2025, the Company incurred $0, $0, $1,689, and $5,216, respectively, of expenses related to manufacturing services and $0, $0, $1,261, and $3,509, respectively, of TSA labor and passthrough expenses to support the transition services, including finance and accounting, information technology, human resources, operations, and other services.

During the three and six months ended June 30, 2026 and 2025, $0, $0, $4,585, and $11,987, respectively, was billed to NESA related to transition services performed by the Company, and the Company received payments of $0, $360, $6,464, and $63,173, respectively, related to transition services performed. The payments received in the first quarter of 2025 included the installment payment of $50,000 received in January 2025 which was conditioned on the Company’s material compliance with obligations under the TSA. As of June 30, 2026 and December 31, 2025, the Company had $25,000 and $360 in accounts receivable due from SPN - related party, respectively, and $0 and $169 included in prepaid expenses and other current assets, respectively, relating to the sale of certain manufacturing and laboratory equipment, in the Company’s condensed consolidated balance sheets.

As described in Note 3, Discontinued Operations and TSA, the Company entered into the APA Amendment with SPN pursuant to which the parties agreed to terminate SPN’s obligations with respect to the Second Sales Milestone Payment, the Third Sales Milestone Payment and eliminate the Milestone Interest Payments that would have been due from the Company to SPN. In consideration for the foregoing, SPN agreed to a one-time payment to the Company of $25,000 (the “Milestone Termination Payment”), which amount is payable in two equal installments of $12,500, with the first installment paid on July 1, 2026 and the second installment payable on October 1, 2026. The Company recorded a Gain on Sale of VOWST Business within continuing operations and the corresponding receivable due from SPN of $25,000 during the three months ended June 30, 2026 because the amount is fixed consideration and is no longer contingent on a future event.