The Company is a clinical-stage biopharmaceutical company advancing next generation medicines for patients with immune-mediated diseases.

The Company's lead program, SP001, is a third-generation, fully humanized, Fc-silent IgG1 monoclonal antibody targeting CD40 Ligand (“CD40L”). On July 8, 2026, the Company entered into a license agreement (the “Innovent Agreement”) with Innovent Biologics (Suzhou) Co., Ltd. and Fortvita Biologics (USA), Inc. (collectively, “Innovent”), pursuant to which Innovent granted the Company an exclusive (even as to Innovent and its affiliates, subject to Innovent’s right to directly or indirectly conduct certain research, non-clinical development and manufacturing activities), sublicensable right and license under certain patent rights and know-how (the “Licensed Intellectual Property”) to research, develop, manufacture, and commercialize SP001, and certain backup monoclonal antibodies and derivative monoclonal antibodies, in each case targeting CD40L (the “Licensed Compounds”) and products containing the Licensed Compounds (“Licensed Products”) worldwide, excluding the mainland of the People’s Republic of China, Taiwan, Hong Kong and Macau (collectively, the “Innovent Territory”) (see Note 12, Subsequent Events).

SP001 targets CD40L, an immune signal protein that sits upstream of multiple immune pathways and has the potential to be developed across a range of immune-mediated diseases. The Company is developing SP001 for the treatment of patients with Immunoglobulin G4 related disease, or IgG4-RD.

In September 2022, the Company entered into an exclusive licensing agreement with GSK for Utebzi (tebipenem pivoxil), which included transfer of the IND application and NDA ownership to GSK. The Company initially developed Utebzi as tebipenem HBr. In May 2025, the Company and GSK announced that the pivotal Phase 3 PIVOT-PO trial evaluating Utebzi met its primary endpoint and was stopped early for efficacy. GSK submitted the data from the trial as part of an NDA Class 2 resubmission to the FDA in December 2025. On June 17, 2026, the Company and GSK announced that the FDA approved Utebzi, an oral antibiotic for the treatment of complicated urinary tract infections (cUTIs) including pyelonephritis, caused by certain susceptible pathogens in adult patients who have limited or no alternative oral treatment options.

On July 8, 2026, the Company entered into a $105.0 million royalty financing transaction with affiliates of HCRx, pursuant to which Healthcare Royalty Management, LLC (“HCRx”) will receive a portion of the future GSK Proceeds (as defined below) (see Note 12, Subsequent Events).

The Company is subject to risks and uncertainties common to companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, risks of failure or unsatisfactory results of preclinical and clinical trials, the need to obtain marketing approval for its product candidates, the need to successfully commercialize and gain market acceptance of its product candidates, the ability to in-license or acquire other products or new technologies, and the ability to secure additional capital to fund operations. The Company’s product candidates will require additional preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

The accompanying consolidated financial statements of the Company have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its consolidated subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

To date, the Company has funded its operations with payments received under license and collaboration agreements and funding from government contracts, from the proceeds of multiple common stock offerings, and from proceeds received from a royalty financing transaction. Any of the Company has incurred recurring cash outflows from operating activities and losses in most periods since its inception. During the three months ended June 30, 2026 and 2025, the Company had net losses of $9.6 million and $1.7 million, respectively, and during the six months ended June 30, 2026 and 2025, the Company had net losses of $16.8 million and $15.6 million, respectively. In addition, as of June 30, 2026, the Company had an accumulated deficit of $467.8 million. The Company expects to continue to generate operating losses for the foreseeable future.

In accordance with Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date

that these consolidated financial statements are issued. As of the issuance date of these quarterly consolidated financial statements, based on its current operating plans, the Company expects that its existing cash and cash equivalents together with the proceeds received from the royalty financing transaction entered into in July 2026, and as more fully described below in Note 12 - Subsequent Events, will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance date of these quarterly consolidated financial statements. The Company currently expects that it will require additional funding to fund the development of any future product candidate(s) through regulatory approval and to support its continued operations. The Company may seek additional funding through public or private financings, debt financing, royalty finaning transactions, collaboration agreements, government grants or other sources. If the Company's access to capital is restricted or associated borrowing costs increase as a result of developments in financial markets, the Company's operations and financial condition could be adversely impacted. There is no assurance that the Company will be successful in obtaining sufficient funding on acceptable terms, if at all, and it could be forced to delay, reduce or eliminate some or all of its research and development programs, or product portfolio expansion efforts, which could materially affect its business prospects or its ability to continue operations.

Interim Financial Information

The consolidated balance sheet at December 31, 2025 was derived from audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited condensed consolidated financial statements as of June 30, 2026, and for the three and six months ended June 30, 2026, have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2025, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, on file with the SEC. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s financial position as of June 30, 2026, and results of operations for the three and six months ended June 30, 2026 and 2025, and cash flows for the six months ended June 30, 2026 and 2025 have been made. The results of operations for the three and six months ended June 30, 2026 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2026.