Sivopixant

Shionogi is doubling down on its sleep disorder pipeline by buying out Apnimed’s half of their joint venture in the niche field. The Japanese pharma will pay $100 million upfront to buy the 50% equity interest held by its Boston-area partner, Shionogi said Tuesday. The pair teamed up in 2023 under a “ $150 million transaction ” to develop a jointly owned pipeline of sleep disorder medicines. The deal gives Shionogi full control of the pipeline under the joint venture named Shionogi-Apnimed Sleep Science, or SASS. That includes SASS-001 and SASS-002 (sulthiame). SASS-001 is a combo drug containing sivopixant, a P2X3 receptor antagonist, in Phase 2a for a type of sleep apnea. Meanwhile, the oral candidate SASS-002 was in-licensed from Germany-based company Desitin Arzneimittel last April. It is in Phase 2 for obstructive sleep apnea. Their venture also had “multiple new drug discovery projects” underway, Shionogi said, adding that the buy-out decision was the result of “extensive discussions with Apnimed.”  Shionogi “concluded that to effectively build on this momentum and accelerate the delivery of new treatment options for patients,” it was an “optimal time to transition SASS to a wholly owned subsidiary.” Beyond the $100 million payment, Apnimed could get a $50 million developmental milestone payment for SASS‑002 and tiered royalties of undisclosed size, Apnimed said in a press release. With the joint venture set to fully transition to Shionogi soon, Apnimed will now likely devote nearly all its efforts to becoming a commercial-stage biotech. The duo did not work together on AD109, the Apnimed sleep apnea pill that hit the bar in two Phase 3 trials last year and is on tap for an FDA approval filing this year . Apnimed is likely in need of money to support its commercialization plans. The biotech last disclosed an $80 million Series C extension three years ago. At the time of the second Phase 3 win in July, CEO Larry Miller told Endpoints News that Apnimed had runway to get through the new drug application but funding wouldn’t stretch “much beyond” that point. The company was exploring commercial partnerships, further private funding and other financing paths, he said. A few months later, a regulatory filing pointed to a $35 million debt financing. On Tuesday, Miller said the JV deal is a “strategic monetization of SASS assets to strengthen our balance sheet and enable us to further focus” on AD109. Apnimed plans to submit the approval application to the FDA in the second quarter, he said in a press release. The CEO previously projected submitting the NDA in January. Last year, Apnimed chief commercial officer Graham Goodrich told Endpoints the company would focus its initial commercialization of AD109 on the approximately 10 million people who are diagnosed with sleep apnea but not using CPAP machines. He came to Apnimed two years ago after steering the US migraine franchise for Pfizer. Editor’s note: This story has been updated to include details from an Apnimed press release.

Accelerating research and development toward establishing the sleep disorder field as one of Shionogi’s key QOL disease areas OSAKA, Japan, March 24, 2026 – Shionogi & Co., Ltd. (Head Office: Osaka, Japan; Chief Executive Officer: Isao Teshirogi, Ph.D.; hereafter “Shionogi”) announced that its Board of Directors, at a meeting held on March 23, 2026, resolved to consolidate Shionogi-Apnimed Sleep Science, LLC (Head Office: Massachusetts, U.S.; hereafter “SASS”), an equity-method affiliate of Shionogi, as a consolidated subsidiary, and entered into an equity transfer agreement with Apnimed, Inc. (Head Office: Massachusetts, U.S.; Chief Executive Officer: Lawrence G. Miller, MD; hereafter “Apnimed”) to acquire its equity interest in SASS. SASS was established in 2023 as a joint venture between Shionogi and Apnimed to provide promising solutions that address unmet needs in the field of sleep disorders1. By combining Shionogi’s strengths in small‑molecule drug discovery and first-in-class and best-in-class compound creation with Apnimed’s deep expertise and outstanding translational research capabilities, SASS has been working to advance novel solutions for sleep disorders. SASS has made steady progress since its formation including advancing the SASS-001 and SASS-002 (sulthiame) development programs and launching multiple new drug discovery projects. Following extensive discussions with Apnimed, Shionogi concluded that to effectively build on this momentum and accelerate the delivery of new treatment options for patients, this is an optimal time to transition SASS to a wholly owned subsidiary. Shionogi will continue to strengthen its research and development capabilities in sleep disorders to generate mid- to long-term growth in this area of substantial unmet medical need. SASS is currently jointly owned by Shionogi and Apnimed, each holding a 50% equity interest. Under the equity transfer agreement, Shionogi expects to acquire all of Apnimed’s equity interest in SASS at closing, resulting in SASS becoming a wholly owned consolidated subsidiary of Shionogi. Under the terms of the agreement, Shionogi will pay Apnimed an upfront cash payment of USD 100 million upon completion of the transaction. In addition, Shionogi will make a development milestone payment related to SASS‑002, as well as tiered royalties based on future sales of products derived from intellectual property contributed by Apnimed to the joint venture. Key Assets and Capabilities to Be Secured Through This Acquisition ・Full ownership and control of research, development, and commercialization framework of SASS-001, SASS-002, and drug discovery programs in the sleep disorder field ・Intellectual property, information and know-how related to SASS-001, SASS-002 and drug discovery programs 1. Overview of the Subsidiary Subject to the Change Company Name Shionogi‑Apnimed Sleep Science, LLC Head Office Massachusetts, United States Representative None Business Description Research and development of pharmaceuticals Capital Not disclosed Date of Establishment 2023 Major Ownership Ratio Apnimed: 50%, Shionogi & Co., Ltd.: 50% Consolidated Operating Results and Consolidated Financial Position of the Company As the company is a privately held entity, information regarding its consolidated operating results and consolidated financial position has not been disclosed. Relationship with Shionogi Capital Relationship: An equity-method affiliate of the Company. Personnel Relationship: Multiple directors have been appointed by the Company. Business Relationship: Research and development–related transactions with the Company. 2. Equity Interest to Be Acquired, Acquisition Price, and Changes in Ownership Before and After the Acquisition Ownership Interest Before the Transaction 50.0% Equity Interest to Be Acquired 50.0% (equity interest held by Apnimed) Acquisition Price USD 100 million (equivalent to JPY 15,952 million*) *Converted at an exchange rate of USD 1 = JPY 159.52 Ownership Interest After the Transaction 100% 3. Overview of the Counterparty to the Transaction Company Name Apnimed, Inc. Head Office Massachusetts, United States Representative Chief Executive Officer: Lawrence G. Miller, MD Business Description Research and development of pharmaceuticals Capital Not disclosed Date of Establishment 2017 Consolidated Net Assets Not disclosed Consolidated Total Assets Not disclosed Major Shareholders and Ownership Ratio Not disclosed Relationship with Shionogi Capital Relationship: The Company holds a portion of the shares of Apnimed Personnel Relationship: None Business Relationship: None Status as a Related Party: Not applicable 4. Schedule Date of Board Resolution March 23, 2026 Date of Agreement Execution March 23, 2026 Date of Acquisition of Equity Interest 　　　　Expected on April 6, 2026 5. Future Outlook The impact of this transaction on Shionogi’s consolidated financial results for the fiscal year ending March 2026 is expected to be immaterial. About SASS‑001 SASS‑001 is a therapeutic candidate for patients with sleep apnea with a central component. It is a novel oral drug that combines S‑600918 (generic name: sivopixant), a P2X3 receptor antagonist discovered by Shionogi, with another compound that has a different mechanism of action. Currently, a randomized, double‑blind, placebo‑controlled Phase 2a clinical trial (the RESTEADY study) is underway in adult patients with sleep apnea with a central component. About SASS‑002 (sulthiame) SASS‑002 (sulthiame)² is a therapeutic candidate for patients with obstructive sleep apnea (OSA). It is a carbonic anhydrase inhibitor that has been approved primarily as an antiepileptic drug in Japan and other countries, and favorable results have been demonstrated in a Phase 2 clinical trial involving approximately 300 patients with OSA³. As an oral medication administered once daily at bedtime, SASS‑002 is expected to become a new treatment option for OSA. About Shionogi & Co., Ltd. Shionogi & Co., Ltd. is a 148-year-old global, research-driven pharmaceutical company headquartered in Osaka, Japan, that is dedicated to bringing benefits to patients based on its corporate philosophy of “supplying the best possible medicine to protect the health and wellbeing of the patients we serve.” The company currently markets products in several therapeutic areas including anti-infectives, pain, CNS disorders and cardiovascular diseases. Shionogi’s research and development currently targets two therapeutic areas: infectious diseases and diseases with unmet medical needs in pain/CNS, including Alzheimer’s disease, oncology, rare diseases, and sleep apnea. For more information on Shionogi & Co., Ltd., please visit https://www.shionogi.com/global/en. References: 1. Press Release dated November 1, 2023 Establishment of a Joint Venture Company with U.S.-based Apnimed to Address Challenges in Sleep Disorders 2. Press Release dated April 25, 2025 Shionogi Announces Further Agreement with Apnimed for Sleep Disorder Treatments - Introduction of New Assets to Joint Venture Shionogi-Apnimed Sleep Science – (SASS) 3. Sulthiame once per day in obstructive sleep apnoea (FLOW): a multicentre, randomised, double-blind, placebo-controlled, dose-finding, phase 2 trial - The Lancet Forward-Looking Statements This announcement contains forward-looking statements. These statements are based on expectations in light of the information currently available, assumptions that are subject to risks and uncertainties which could cause actual results to differ materially from these statements. Risks and uncertainties include general domestic and international economic conditions such as general industry and market conditions, and changes of interest rate and currency exchange rate. These risks and uncertainties particularly apply with respect to product-related forward-looking statements. Product risks and uncertainties include, but are not limited to, completion and discontinuation of clinical trials; obtaining regulatory approvals; claims and concerns about product safety and efficacy; technological advances; adverse outcome of important litigation; domestic and foreign healthcare reforms and changes of laws and regulations. Also for existing products, there are manufacturing and marketing risks, which include, but are not limited to, inability to build production capacity to meet demand, lack of availability of raw materials and entry of competitive products. The company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise. For Further Information, Contact: SHIONOGI Website Inquiry Form: https://www.shionogi.com/global/en/contact.html Shionogi Inc.: ShionogiCommunications@shionogi.com Shionogi Europe Press Office: pressoffice@shionogi.eu