1. Nature of the Business and Basis of Presentation

Background and Basis of Presentation

Jade Biosciences, Inc. together with its subsidiaries (“Jade” or the “Company”), formerly known as Aerovate Therapeutics, Inc., is the resulting company of the Merger and Redomestication discussed below. Prior to the Merger and Redomestication, the private corporation Jade Biosciences, Inc. (“Pre-Merger Jade”) was established and incorporated under the laws of the state of Delaware on June 18, 2024 (referred to in these notes as the inception of the Company). Jade is focused on developing therapies to address critical unmet needs in autoimmune diseases. Its lead product candidate, JADE101, is a monoclonal antibody (“mAb”) targeting a cytokine called “A PRoliferation Inducing Ligand” (“APRIL”) that modulates plasma cell survival and immunoglobulin production, which the Company is initially developing for the treatment of IgA nephropathy (“IgAN”). Jade’s second product candidate is JADE201, a mAb targeting B cell activating factor receptor (“BAFF-R”) currently being evaluated in a Phase 1 clinical trial in patients with rheumatoid arthritis. Jade’s pipeline also includes JADE301, a mAb targeting Interferon beta (“IFN-β”) which is currently in pre-clinical development. Jade was launched based on assets licensed from Paragon Therapeutics Inc. (“Paragon”), an antibody discovery engine founded by healthcare investor Fairmount Funds Management LLC (“Fairmount”).

The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. In the opinion of the Company, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting of only normal recurring adjustments, necessary for a fair statement of its financial position as of June 30, 2026, its results of operations for the three and six months ended June 30, 2026 and June 30, 2025 and cash flows for the six months ended June 30, 2026 and June 30, 2025. The condensed consolidated balance sheet at December 31, 2025 was derived from the audited annual financial statements but does not contain all of the footnote disclosures from the annual financial statements for the period ended December 31, 2025 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 6, 2026 (the “Annual Report”). The accompanying condensed consolidated statements include accounts of the Company and its wholly owned subsidiaries, Jade Biosciences Canada ULC, Jade Biosciences MA Security Corporation, and Aerovate MA Securities Corporation (dissolved on December 29, 2025). All intercompany amounts are eliminated in consolidation.

Reverse Recapitalization and Pre-Closing Financing

On April 28, 2025 (the “Closing Date”), the Company consummated the previously announced transaction (the “Closing”) pursuant to that certain Agreement and Plan of Merger and Reorganization, dated as of October 30, 2024, (the “Merger Agreement”) by and among Pre-Merger Jade, Aerovate Therapeutics, Inc., a Delaware corporation (“Aerovate”), Caribbean Merger Sub I, Inc., a Delaware corporation and wholly-owned subsidiary of Aerovate (“First Merger Sub”), and Caribbean Merger Sub II, LLC, a Delaware limited liability company and wholly-owned subsidiary of Aerovate (“Second Merger Sub”). As part of the Closing, First Merger Sub merged with and into Pre-Merger Jade, with Pre-Merger Jade continuing as a wholly owned subsidiary of Aerovate and the surviving corporation of the merger (the “First Merger” and such time, the “First Effective Time”), and Pre-Merger Jade merged with and into Second Merger Sub, with Second Merger Sub being the surviving entity of the merger (the “Second Merger” and, together with the First Merger, the “Merger”). In connection with the Merger, Second Merger Sub changed its name to “Jade Biosciences, LLC” and Aerovate changed its name to “Jade Biosciences, Inc.” Subsequently, Jade Biosciences, LLC merged with and into Jade Biosciences, Inc. The combined company following the Merger is the “Company.” The Company is led by Pre-Merger Jade’s management team and focuses on developing differentiated biologic therapies for patients living with autoimmune diseases.

In accordance with an exchange ratio determined in accordance with the terms of the Merger Agreement (the “Exchange Ratio”), as a result of and upon the First Effective Time, (i) each then-outstanding share of common stock, par value $0.0001 per share, of Pre-Merger Jade (the “Pre-Merger Jade common stock”) (including shares of Pre-Merger Jade common stock issued in connection with the Pre-Closing Financing (as defined below)) immediately prior to the First Effective Time (excluding shares cancelled pursuant to the Merger Agreement and excluding dissenting shares) automatically converted into the right to receive a number of shares of common stock, par value $0.0001, of Aerovate (the “Company common stock” and prior to the effective time of the Merger, the “Aerovate common stock”) equal to the Exchange Ratio, (ii) each then-outstanding share of Series Seed Convertible Preferred Stock, par value $0.0001 per share, of Pre-Merger Jade (the “Pre-Merger Jade Series Seed Convertible Preferred Stock”) immediately prior to the First Effective Time (excluding shares cancelled pursuant to the Merger Agreement and excluding dissenting shares) automatically converted into the right to receive a number of shares of Series A Non-Voting Convertible Preferred Stock, par value $0.0001 per share, of Aerovate (the “Series A Preferred Stock”), which are each convertible into 1,000 shares of Company common stock, equal to the Exchange Ratio divided by 1,000, (iii) each then-outstanding option to purchase Pre-Merger Jade common

stock was assumed by Aerovate and was converted into an option to purchase shares of Company common stock, subject to adjustment as set forth in the Merger Agreement, and (iv) each then-outstanding pre-funded warrant to purchase shares of Pre-Merger Jade common stock (including any pre-funded warrants to purchase shares of Pre-Merger Jade common stock issued in the Jade Pre-Closing Financing) was converted into a pre-funded warrant to purchase shares of Company common stock (subject to adjustment as set forth in the Merger Agreement and the form of pre-funded warrant).

The Exchange Ratio was calculated as 0.6311 shares of Aerovate common stock for each share of Pre-Merger Jade common stock (and 0.0006311 shares of Series A Preferred Stock for each share of Pre-Merger Jade Series Seed Convertible Preferred Stock) on the Closing Date, which gives effect to a 1-for-35 reverse stock split of shares of Aerovate common stock immediately prior to the Merger. The par value per share and the number of authorized shares were not adjusted as a result of the Exchange Ratio. The shares of Company common stock underlying outstanding stock options, restricted stock awards, and other equity instruments were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities. All references to common stock, options to purchase common stock, common stock share data, per share data, and related information contained in the condensed consolidated financial statements have been retrospectively adjusted to reflect the effect of the Exchange Ratio for all periods presented, unless otherwise specifically indicated or the context otherwise requires.

Immediately prior to the completion of the Merger, and in order to provide Jade with additional capital for its development programs, Pre-Merger Jade entered into a subscription agreement with certain investors (the “Subscription Agreement”), pursuant to which Pre-Merger Jade issued and sold, and certain new and existing investors purchased, 43,947,116 shares of Pre-Merger Jade common stock and 12,305,898 pre-funded warrants, exercisable for 12,305,898 shares of pre-exchange Pre-Merger Jade common stock (before giving effect to the Exchange Ratio), at a purchase price of $5.9407 per share or $5.9406 per Pre-Merger Jade pre-funded warrant, for an aggregate amount of $334.2 million, which included $95.0 million of proceeds previously received from the issuance of Convertible Notes (as defined herein) and accrued interest of $8.3 million on such Convertible Notes and the related conversion of the Convertible Notes into shares of Pre-Merger Jade common stock and Pre-Merger Jade pre-funded warrants (the “Pre-Closing Financing”). At the Closing, based on the Exchange Ratio, the Pre-Merger Jade common stock and Pre-Merger Jade pre-funded warrants subscribed for were converted into the right to receive 27,734,940 shares of Aerovate common stock and 7,766,247 Aerovate pre-funded warrants.

The Merger was accounted for as a reverse recapitalization in accordance with U.S. GAAP. Under this method of accounting, Pre-Merger Jade was deemed to be the accounting acquirer for financial reporting purposes. This determination was primarily based on the fact that, immediately following the Merger: (i) Pre-Merger Jade stockholders owned a substantial majority of the voting rights in the combined company; (ii) Pre-Merger Jade’s largest stockholders retained the largest interest in the combined company; (iii) Pre-Merger Jade designated a majority of the initial members of the board of directors of the combined company; and (iv) Pre-Merger Jade’s executive management team became the management team of the combined company. Accordingly, for accounting purposes: (i) the Merger was treated as the equivalent of Pre-Merger Jade issuing stock to acquire the net assets of Aerovate, and (ii) the reported historical operating results of the combined company prior to the Merger are those of Pre-Merger Jade. No goodwill or intangible assets were recognized as a result of the Merger.

Redomestication

On April 28, 2025, Jade changed its jurisdiction of incorporation from the State of Delaware to the State of Nevada (the “Redomestication”) pursuant to a plan of conversion. The Redomestication became effective on April 28, 2025.

The common stock of the Nevada corporation resulting from the conversion continues to be traded on The Nasdaq Capital Market (“Nasdaq”) under the symbol “JBIO.” The Redomestication did not cause any interruption in the trading of such common stock.

Liquidity

Since its inception, the Company has devoted substantially all of its resources to advancing the development of its portfolio of programs, organizing and staffing the Company, business planning, raising capital, and providing general and administrative support for these operations. Current and future programs will require significant research and development efforts, including preclinical and clinical trials, and, if the Company is successful in obtaining regulatory approval for one or more product candidates, significant commercialization efforts. Until such time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operating activities principally through equity offerings.

The Company has not generated any revenue from product sales or other sources and has incurred significant operating losses and

negative cash flows from operations since inception. The Company has incurred a net loss of $55.8 million and $96.1 million for the three and six months ended June 30, 2026, respectively. For the six months ended June 30, 2026, the Company used cash of $67.7 million for its operating activities. As of June 30, 2026, the Company had cash and cash equivalents of $107.2 million, and investments of $354.0 million.

The Company expects that its research and development and general and administrative costs will continue to increase significantly, including in connection with conducting future pre-clinical activities and clinical trials and manufacturing for its product candidates and providing general and administrative support for its operations, including the costs associated with operating as a public company. The Company expects that its existing cash and cash equivalents, and investments of $461.2 million as of June 30, 2026, are sufficient to fund its planned operating expenses and capital expenditure requirements for at least twelve months from the date these unaudited condensed consolidated financial statements were issued.