Nature of operations	9 Months Ended
Sep. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of operations	Nature of operations Yarrow Bioscience, Inc. (“Yarrow” or the “Company") is a clinical-stage biotechnology company focused on developing transformative therapies for autoimmune thyroid diseases. Yarrow’s lead product candidate, YB-101 (also known as GenSci098), is a humanized, monoclonal antibody targeting the thyroid-stimulating hormone receptor (“TSHR”), which the Company plans to develop for the treatment of Graves’ disease (“GD”) and thyroid eye disease (“TED”). Both GD and TED are serious and poorly treated autoimmune diseases in which autoantibodies against TSHR attack and overstimulate the receptor, leading to a wide spectrum of thyroidal and extra-thyroidal clinical sequelae. YB-101 was designed to selectively bind to TSHR and block autoantibody-induced receptor activation, thereby directly inhibiting the pathogenic activity of thyroid-stimulating autoantibodies that drive disease progression in GD and TED as well as the biological pathway responsible for hyperthyroidism and orbitopathy. Yarrow believes that this novel and targeted approach represents a potential breakthrough for patients with GD and TED and has the potential to address an important unmet need for therapies with differentiated risk-benefit profiles. In December 2025, Yarrow in-licensed from Changchun Genescience Pharmaceutical Company, Ltd. (“GenSci”) the exclusive rights to develop YB-101 for the treatment of GD and TED outside Greater China. Yarrow’s development strategy is to advance YB-101 in GD and explore a clinical development plan for TED with the goal of becoming the first company to commercialize an anti-TSHR antibody in the United States and other territories outside Greater China. YB-101 is currently being evaluated by GenSci in an ongoing Phase 1 single ascending dose (“SAD”) and multiple ascending dose (“MAD”) trial in patients with TED in China. Data from the MAD portion of the trial are expected in the second half of 2027. Yarrow submitted the GenSci SAD clinical data to the U.S. Food and Drug Administration (“FDA”) as part of a new investigational new drug application to support the initiation of a GD trial by Yarrow in the United States, which was cleared by the FDA in March 2026. Yarrow also submitted an application for Fast Track designation for YB-101 in GD to the FDA in March 2026 and received notice of Fast Track designation from the FDA on May 20, 2026. In addition, third-party clinical data from two SAD trials of another anti-TSHR antibody, K1-70, further support the therapeutic potential of targeting TSHR in patients with GD and TED. In June 2026, Yarrow initiated a combined Phase 2a/Phase 2b trial of YB-101 in patients with GD, with or without concurrent TED. Data from the Phase 2a portion of the trial are expected in the second half of 2027. Reverse recapitalization and pre-closing financing On July 27, 2026 (the “Closing Date”), Yarrow Bioscience, Inc., a private Delaware corporation (“Pre-Merger Yarrow”), consummated the previously announced transaction (the “Closing”) pursuant to an Agreement and Plan of Merger and Reorganization with VYNE Therapeutics Inc., a Delaware corporation (“VYNE”), which was amended on January 30, 2026 (as amended, the “Merger Agreement”), pursuant to which, among other matters, Yellow Merger Sub Corp., a direct, wholly owned subsidiary of VYNE, merged with and into Pre-Merger Yarrow, with Pre-Merger Yarrow surviving as a wholly owned subsidiary of VYNE and the surviving corporation of the merger (the “Merger”). In connection with the completion of the Merger, Pre-Merger Yarrow changed its name to “Yarrow Bioscience Operating Company Corp.,” VYNE changed its name to “Yarrow Bioscience, Inc.” and the business of Pre-Merger Yarrow became the primary business of the Combined Company. VYNE following the Merger is referred to herein as the “Combined Company.” Concurrently with the execution of the Merger Agreement, and in order to provide Pre-Merger Yarrow with additional capital for its development programs prior to the Closing of the Merger, existing investors entered into a securities purchase agreement (the "Securities Purchase Agreement") with Pre-Merger Yarrow, pursuant to which such investors purchased, immediately prior to the Merger, shares of Pre-Merger Yarrow’s common stock or, in lieu thereof, Pre-Merger Yarrow’s pre-funded warrants to purchase Pre-Merger Yarrow’s common stock, for gross proceeds of approximately $100.0 million (the “Yarrow Pre-Closing Financing”). On the Closing Date, VYNE issued an aggregate of 2,130,731 shares of its common stock to Pre-Merger Yarrow’s stockholders (after giving effect to the 1-for-50 reverse stock split of VYNE common stock in connection with the Merger), based on the exchange ratio of 0.7171 shares of VYNE common stock for each share of Pre-Merger Yarrow’s common stock, including those shares of Pre-Merger Yarrow’s common stock issued upon the conversion of Pre-Merger Yarrow’s preferred stock and those shares of Pre-Merger Yarrow’s common stock issued in the Yarrow Pre-Closing Financing. In addition, Pre-Merger Yarrow’s outstanding and unexercised pre-funded warrants to purchase shares of Pre-Merger Yarrow’s common stock and certain shares of Pre-Merger Yarrow’s common stock (including shares issued upon the conversion of Pre-Merger Yarrow’s preferred stock and shares issued in the Yarrow Pre-Closing Financing) were converted into 25,590,346 pre-funded warrants to purchase shares of VYNE common stock on the existing terms and conditions and outstanding options to purchase shares of Pre-Merger Yarrow’s common stock were converted into 2,002,285 options to purchase shares of VYNE common stock on the existing terms and conditions (including with respect to vesting and accelerated vesting). Also, in connection with the closing of the reverse recapitalization 672,305 shares of common stock were issued to former stockholders of VYNE. The Merger has been accounted for as a reverse recapitalization in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Under this method of accounting, Pre-Merger Yarrow is deemed to be the accounting acquirer for financial reporting purposes. This determination is primarily based on the fact that, immediately following the Merger: (i) Pre-Merger Yarrow’s stockholders owned a substantial majority of the voting rights in the Combined Company; (ii) Pre-Merger Yarrow’s largest stockholder retained the largest interest in the Combined Company; (iii) Pre-Merger Yarrow designated the initial members of the board of directors of the Combined Company; and (iv) Pre-Merger Yarrow’s executive management team and certain of VYNE’s 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 Yarrow issuing stock to acquire the net assets of VYNE, and (ii) the reported historical operating results of the Combined Company prior to the Merger are those of Pre-Merger Yarrow. Additional information regarding the Merger is included in "Note 3 - Reverse recapitalization." Liquidity and capital resources As of September 30, 2026, the Company had cash and cash equivalents of $268.9 million and an accumulated deficit of $90.0 million. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales from its product candidates currently in development. The Company had no outstanding debt as of September 30, 2026. For the nine months ended September 30, 2026, the Company incurred a net loss of $19.0 million and used $96.0 million of cash in operations. The Company believes its existing cash and cash equivalents of $268.9 million as of September 30, 2026 are sufficient to sustain planned operations through at least twelve months from the issuance date of these financial statements. Although management believes that existing liquidity is sufficient for the stated period, actual expenditures may differ from current estimates, and the Company may require additional capital to fund its longer-term development and commercialization activities. The Company’s primary uses of capital are research and development costs, compensation and related expenses, legal and other regulatory expenses and general overhead costs. The Company is subject to those risks associated with any specialty biotechnology company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants.

Yarrow Bioscience, Inc. (“Yarrow” or the “Company") is a clinical-stage biotechnology company focused on developing transformative therapies for autoimmune thyroid diseases. Yarrow’s lead product candidate, YB-101 (also known as GenSci098), is a humanized, monoclonal antibody targeting the thyroid-stimulating hormone receptor (“TSHR”), which the Company plans to develop for the treatment of Graves’ disease (“GD”) and thyroid eye disease (“TED”). Both GD and TED are serious and poorly treated autoimmune diseases in which autoantibodies against TSHR attack and overstimulate the receptor, leading to a wide spectrum of thyroidal and extra-thyroidal clinical sequelae.

YB-101 was designed to selectively bind to TSHR and block autoantibody-induced receptor activation, thereby directly inhibiting the pathogenic activity of thyroid-stimulating autoantibodies that drive disease progression in GD and TED as well as the biological pathway responsible for hyperthyroidism and orbitopathy. Yarrow believes that this novel and targeted approach represents a potential breakthrough for patients with GD and TED and has the potential to address an important unmet need for therapies with differentiated risk-benefit profiles.

In December 2025, Yarrow in-licensed from Changchun Genescience Pharmaceutical Company, Ltd. (“GenSci”) the exclusive rights to develop YB-101 for the treatment of GD and TED outside Greater China. Yarrow’s development strategy is to advance YB-101 in GD and explore a clinical development plan for TED with the goal of becoming the first company to commercialize an anti-TSHR antibody in the United States and other territories outside Greater China. YB-101 is currently being evaluated by GenSci in an ongoing Phase 1 single ascending dose (“SAD”) and multiple ascending dose (“MAD”) trial in patients with TED in China. Data from the MAD portion of the trial are expected in the second half of 2027. Yarrow submitted the GenSci SAD clinical data to the U.S. Food and Drug Administration (“FDA”) as part of a new investigational new drug application to support the initiation of a GD trial by Yarrow in the United States, which was cleared by the FDA in March 2026. Yarrow also submitted an application for Fast Track designation for YB-101 in GD to the FDA in March 2026 and received notice of Fast Track designation from the FDA on May 20, 2026. In addition, third-party clinical data from two SAD trials of another anti-TSHR antibody, K1-70, further support the therapeutic potential of targeting TSHR in patients with GD and TED. In June 2026, Yarrow initiated a combined Phase 2a/Phase 2b trial of YB-101 in patients with GD, with or without concurrent TED. Data from the Phase 2a portion of the trial are expected in the second half of 2027.

On July 27, 2026 (the “Closing Date”), Yarrow Bioscience, Inc., a private Delaware corporation (“Pre-Merger Yarrow”), consummated the previously announced transaction (the “Closing”) pursuant to an Agreement and Plan of Merger and Reorganization with VYNE Therapeutics Inc., a Delaware corporation (“VYNE”), which was amended on January 30, 2026 (as amended, the “Merger Agreement”), pursuant to which, among other matters, Yellow Merger Sub Corp., a direct, wholly owned subsidiary of VYNE, merged with and into Pre-Merger Yarrow, with Pre-Merger Yarrow surviving as a wholly owned subsidiary of VYNE and the surviving corporation of the merger (the “Merger”). In connection with the completion of the Merger, Pre-Merger Yarrow changed its name to “Yarrow Bioscience Operating Company Corp.,” VYNE changed its name to “Yarrow Bioscience, Inc.” and the business of Pre-Merger Yarrow became the primary business of the Combined Company. VYNE following the Merger is referred to herein as the “Combined Company.”

Concurrently with the execution of the Merger Agreement, and in order to provide Pre-Merger Yarrow with additional capital for its development programs prior to the Closing of the Merger, existing investors entered into a securities purchase agreement (the "Securities Purchase Agreement") with Pre-Merger Yarrow, pursuant to which such investors purchased, immediately prior to the Merger, shares of Pre-Merger Yarrow’s common stock or, in lieu thereof, Pre-Merger Yarrow’s pre-funded warrants to purchase Pre-Merger Yarrow’s common stock, for gross proceeds of approximately $100.0 million (the “Yarrow Pre-Closing Financing”).

On the Closing Date, VYNE issued an aggregate of 2,130,731 shares of its common stock to Pre-Merger Yarrow’s stockholders (after giving effect to the 1-for-50 reverse stock split of VYNE common stock in connection with the Merger), based on the exchange ratio of 0.7171 shares of VYNE common stock for each share of Pre-Merger Yarrow’s common stock, including those shares of Pre-Merger Yarrow’s common stock issued upon the conversion of Pre-Merger Yarrow’s preferred stock and those shares of Pre-Merger Yarrow’s common stock issued in the Yarrow Pre-Closing Financing. In addition, Pre-Merger Yarrow’s outstanding and unexercised pre-funded warrants to purchase shares of Pre-Merger Yarrow’s common stock and

certain shares of Pre-Merger Yarrow’s common stock (including shares issued upon the conversion of Pre-Merger Yarrow’s preferred stock and shares issued in the Yarrow Pre-Closing Financing) were converted into 25,590,346 pre-funded warrants to purchase shares of VYNE common stock on the existing terms and conditions and outstanding options to purchase shares of Pre-Merger Yarrow’s common stock were converted into 2,002,285 options to purchase shares of VYNE common stock on the existing terms and conditions (including with respect to vesting and accelerated vesting).

The Merger has been accounted for as a reverse recapitalization in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Under this method of accounting, Pre-Merger Yarrow is deemed to be the accounting acquirer for financial reporting purposes. This determination is primarily based on the fact that, immediately following the Merger: (i) Pre-Merger Yarrow’s stockholders owned a substantial majority of the voting rights in the Combined Company; (ii) Pre-Merger Yarrow’s largest stockholder retained the largest interest in the Combined Company; (iii) Pre-Merger Yarrow designated the initial members of the board of directors of the Combined Company; and (iv) Pre-Merger Yarrow’s executive management team and certain of VYNE’s 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 Yarrow issuing stock to acquire the net assets of VYNE, and (ii) the reported historical operating results of the Combined Company prior to the Merger are those of Pre-Merger Yarrow. Additional information regarding the Merger is included in "Note 3 - Reverse recapitalization."

As of September 30, 2026, the Company had cash and cash equivalents of $268.9 million and an accumulated deficit of $90.0 million. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales from its product candidates currently in development. The Company had no outstanding debt as of September 30, 2026. For the nine months ended September 30, 2026, the Company incurred a net loss of $19.0 million and used $96.0 million of cash in operations. The Company believes its existing cash and cash equivalents of $268.9 million as of September 30, 2026 are sufficient to sustain planned operations through at least twelve months from the issuance date of these financial statements. Although management believes that existing liquidity is sufficient for the stated period, actual expenditures may differ from current estimates, and the Company may require additional capital to fund its longer-term development and commercialization activities.

The Company’s primary uses of capital are research and development costs, compensation and related expenses, legal and other regulatory expenses and general overhead costs. The Company is subject to those risks associated with any specialty biotechnology company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants.