^Ad hoc announcement pursuant to Art. 53 LR * CEO, Jean-Paul Clozel, to update on how Idorsia is being adapted for sustainable value creation * The company is focused on extending the cash runway beyond the current estimate of early April 2024, through various avenues, including potential out-licensing deals * Postponement of the publication of Full-Year 2023 Financial Results and the subsequent Annual General Meeting of Shareholders Allschwil, Switzerland - January 10, 2024 Idorsia Ltd (SIX: IDIA) today announced that Jean-Paul Clozel, Chief Executive Officer of Idorsia, will present at the J.P. Morgan Healthcare Conference on January 10, 2024, at 10:30 PST / 19:30 CET. The conference will take place at the Westin St. Francis hotel in San Francisco, USA. Jean-Paul will describe how Idorsia is being adapted for sustainable value creation. The presentation will cover the progress of QUVIVIQ(TM) (daridorexant) in the US and Europe, and the clinical data included in the new drug application for aprocitentan with the US Food and Drug Administration (FDA) which is currently under review. He will also present other unencumbered assets that provide the company with strategic flexibility and several avenues to explore potential fundraising. Follow this link (https://jpmorgan.metameetings.net/events/healthcare24/sessions/49264-idorsia- pharmaceuticals-ltd/webcast?gpu_only=true&kiosk=true) to access the audio stream and find the presentation available here (https://www.idorsia.com/dam/jcr:3b9c11d2-a3af-4914-935a-239588d0b046/2024- idorsia-at-jpm-investor-webcast.pdf). Jean-Paul Clozel MD and Chief Executive Officer of Idorsia commented: "Creating a sustainable pharma company requires scientific innovation and substantial investment. We have demonstrated our ability to innovate and bring new drugs to the market and have a portfolio of innovative products, however, we have limited financing, so we need to prioritize activities that offer the maximum return in the near term. We estimate the current cash reserves to last to early April 2024, we therefore plan to extend the cash runway through various avenues, including potential out-license deals." Expected highlights in 2024 * Secure additional funding to extend the cash runway * Expand access and availability of QUVIVIQ (daridorexant) in the US, Canada and across Europe * Achieve FDA decision for the NDA for aprocitentan in resistant hypertension * Achieve EMA decision for the MAA for aprocitentan in resistant hypertension Jean-Paul commented on the portfolio: "More than 11 million QUVIVIQ tablets have been dispensed to help patients achieve better nights and days. We have made great progress with access and availability in our key markets, and I expect to see that translating into income in 2024. I also expect aprocitentan - the first antihypertensive working on a new pathway for 30 years - to become available for treated patients whose hypertension remains uncontrolled. Discussions with health authorities are going well and I'm confident that the label will reflect the outstanding results we've seen for these high-risk patients. We also intend to progress the two global Phase 3 programs with selatogrel and cenerimod which have the potential to transform treatment in their target indications." Idorsia's portfolio ------------------------------------------------------------------------------- Product / compound Mechanism of action Therapeutic area Status ------------------------------------------------------------------------------- Commercially available in the US Germany, Italy, Switzerland, Spain, the UK, and Canada; QUVIVIQ(TM) Dual orexin receptor Approved in the (daridorexant) antagonist Insomnia EU; Phase 2 in pediatric insomnia - recruiting Partners: Mochida & Sosei in Japan, Simcere in China and Hong Kong ------------------------------------------------------------------------------- NDA under review in the US, MAA under review Dual endothelin Resistant in the EU, other Aprocitentan receptor antagonist hypertension filings in preparation Partner: Unencumbered ------------------------------------------------------------------------------- Phase 3 primary endpoint not met; Glucosylceramide open-label Lucerastat synthase Fabry disease extension study inhibitor ongoing Partner: Unencumbered ------------------------------------------------------------------------------- Phase 3 Suspected acute recruiting Selatogrel P2Y(12) inhibitor myocardial infarction Partner: Unencumbered ------------------------------------------------------------------------------- Phase 3 S1P(1) receptor Systemic lupus recruiting Cenerimod modulator erythematosus Partner: Unencumbered ------------------------------------------------------------------------------- Multiple sclerosis Phase 2 in ACKR3 / CXCR7 and other preparation ACT-1004-1239 antagonist demyelinating diseases Partner: Unencumbered ------------------------------------------------------------------------------- Rare lysosomal Phase 1 complete Sinbaglustat GBA2/GCS inhibitor storage disorders Partner: Unencumbered ------------------------------------------------------------------------------- Phase 1 ACT-1014-6470 C5aR1 antagonist Immune-mediated disorders Partner: Unencumbered ------------------------------------------------------------------------------- Phase 1 ACT-777991 CXCR3 antagonist Recent-onset Type 1 diabetes Partner: Unencumbered ------------------------------------------------------------------------------- Phase 1 IDOR-1117-2520 Undisclosed Immune-mediated disorders Partner: Unencumbered ------------------------------------------------------------------------------- Phase 1 in Synthetic glycan Clostridium preparation IDO-090 vaccine difficile infection Partner: Unencumbered ------------------------------------------------------------------------------- Neurocrine Biosciences has a global license to develop and commercialize ACT- 709478 (NBI-827104), Idorsia's novel T-type calcium channel blocker. On July 20, 2023, Idorsia sold its operating businesses in the Asia Pacific (ex- China) region to Sosei Heptares, including the assignment of the license for PIVLAZ (clazosentan) for the Asia Pacific (ex-China) region. Idorsia retains the rights to clazosentan in the rest of the world. Further details including the current status of each project in our portfolio can be found in our innovation fact sheet (https://www.idorsia.com/dam/jcr:ed5ae81e-28cc-4040-b984-f7b1be039bd1/fs- innovation-portfolio.pdf). Upcoming Financial Updates The company has decided to postpone the publication of Full-Year 2023 Financial Results and the subsequent Annual General Meeting of Shareholders. * Full-Year 2023 and First Quarter 2024 Financial Results reporting on April 25, 2024 * Annual General Meeting of Shareholders on June 13, 2024 * Half-Year 2024 Financial Results reporting on July 25, 2024 Notes to the editor About Idorsia Idorsia Ltd is reaching out for more - We have more ideas, we see more opportunities and we want to help more patients. In order to achieve this, we will develop Idorsia into a leading biopharmaceutical company, with a strong scientific core. Headquartered near Basel, Switzerland - a European biotech-hub - Idorsia is specialized in the discovery, development and commercialization of small molecules to transform the horizon of therapeutic options. Idorsia has a 20-year heritage of drug discovery, a broad portfolio of innovative drugs in the pipeline, an experienced team of professionals covering all disciplines from bench to bedside, and commercial operations in Europe and North America - the ideal constellation for bringing innovative medicines to patients. Idorsia was listed on the SIX Swiss Exchange (ticker symbol: IDIA) in June 2017 and has over 800 highly qualified specialists dedicated to realizing our ambitious targets. For further information, please contact Andrew C. Weiss Senior Vice President, Head of Investor Relations & Corporate Communications Idorsia Pharmaceuticals Ltd, Hegenheimermattweg 91, CH-4123 Allschwil +41 58 844 10 10 investor.relations@idorsia.com (mailto:investor.relations@idorsia.com) media.relations@idorsia.com (mailto:media.relations@idorsia.com) www.idorsia.com (http://www.idorsia.com) The above information contains certain "forward-looking statements", relating to the company's business, which can be identified by the use of forward-looking terminology such as "estimates", "believes", "expects", "may", "are expected to", "will", "will continue", "should", "would be", "seeks", "pending" or "anticipates" or similar expressions, or by discussions of strategy, plans or intentions. Such statements include descriptions of the company's investment and research and development programs and anticipated expenditures in connection therewith, descriptions of new products expected to be introduced by the company and anticipated customer demand for such products and products in the company's existing portfolio. Such statements reflect the current views of the company with respect to future events and are subject to certain risks, uncertainties and assumptions. Many factors could cause the actual results, performance or achievements of the company to be materially different from any future results, performances or achievements that may be expressed or implied by such forward- looking statements. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described herein as anticipated, believed, estimated or expected. °

Quelle: dpa-Afx