Bosentan

Ad hoc announcement pursuant to Art. 53 LR FDA confirms that prescribers and pharmacists are no longer expected to interact with the REMS Allschwil, Switzerland – March 17, 2025Idorsia Ltd (SIX: IDIA) today announced that – effective immediately – the US FDA has fully released TRYVIO™ (aprocitentan) from its REMS (Risk Evaluation and Mitigation Strategy) requirement. TRYVIO is Idorsia’s dual endothelin receptor antagonist (ERA) indicated for the treatment of systemic hypertension in combination with other antihypertensives to lower blood pressure in patients who are not adequately controlled on other drugs. The US FDA has determined that a REMS is no longer necessary to ensure the benefits of TRYVIO outweigh the risk of embryo-fetal toxicity and that labeling is sufficient for conveying the safety information. The FDA have therefore removed the requirement to minimize the burden on the healthcare delivery system of complying with the REMS. Consequently, Idorsia is also released from the post marketing requirement (PMR) to conduct a worldwide descriptive study that collects prospective and retrospective data in women exposed to TRYVIO during pregnancy and/or lactation as these data are no longer needed. Idorsia no longer has post marketing requirements for TRYVIO. Martine Clozel, Chief Scientific Officer of Idorsia, commented:“As a dual endothelin receptor antagonist (ERA), TRYVIO targets a previously unaddressed but important pathway in systemic hypertension, the endothelin pathway. The FDA decision that a REMS is no longer necessary for TRYVIO reflects the progressive understanding of the risk / benefit of TRYVIO. The decision of the FDA is based on an evaluation of human fetal outcomes after exposure to a drug in the ERA class. This change is very important considering that TRYVIO can be prescribed to a large patient population, who have a high cardiovascular risk and whose hypertension could not be brought under control with the previous classes of medication. This comes on top of the outstanding properties of TRYVIO, the result of over 25 years of optimization in our drug discovery team.” Michael Moye, President and General Manager of Idorsia US, commented:“TRYVIO is the first new antihypertensive working via a new pathway for over 40 years. It is a once-daily tablet, is easy to use for patients and easy to prescribe for physicians. In the absence of clinically relevant drug interactions, it can be safely combined with complex drug regimens and, importantly, can be used by chronic renal failure patients with hypertension without dose modification. On top of existing antihypertensives, aprocitentan has been shown to decrease systolic blood pressure by more than 15 mmHg from baseline at trough, and it is well tolerated over the long term. The release of the REMS is fantastic news as it makes TRYVIO even easier to prescribe. TRYVIO is available to prescribe today, and we are now looking for the best commercial solution to fully launch this important medication that fills a large unmet patient need.” Idorsia will submit revised labeling to the US FDA in accordance with the release of the REMS in the coming weeks. For current information on TRYVIO see the Full Prescribing Information including BOXED Warning (PI and Medication Guide). TRYVIO continues to be commercially available through Walgreens Specialty Pharmacy. For more information visit the following websites: US Healthcare Professionals: www.TRYVIOhcp.com US Patients: www.TRYVIO.com Notes to the editor About aprocitentanAprocitentan is Idorsia’s once-daily, orally active, dual endothelin receptor antagonist, which inhibits the binding of ET-1 to ETA and ETB receptors. Aprocitentan is approved as TRYVIO™ in the US for the treatment of systemic hypertension in combination with other antihypertensives and has been commercially available since October 2024. Aprocitentan is approved as JERAYGO™ for the treatment of resistant hypertension in combination with other antihypertensives in the European Union and the UK and marketing authorization applications are under review in Canada, and Switzerland. About IdorsiaIdorsia Ltd is reaching out for more – we have more passion for science, we see more opportunities, and we want to help more patients. The purpose of Idorsia is to challenge accepted medical paradigms, answering the questions that matter most. To achieve this, we will discover, develop, and commercialize transformative medicines – either with in-house capabilities or together with partners – and evolve Idorsia into a leading biopharmaceutical company, with a strong scientific core. Headquartered near Basel, Switzerland – a European biotech hub – Idorsia has a highly experienced team of dedicated professionals, covering all disciplines from bench to bedside; QUVIVIQ™ (daridorexant), a different kind of insomnia treatment with the potential to revolutionize this mounting public health concern; strong partners to maximize the value of our portfolio; a promising in-house development pipeline; and a specialized drug discovery engine focused on small-molecule drugs that can change the treatment paradigm for many patients. Idorsia is listed on the SIX Swiss Exchange (ticker symbol: IDIA). For further information, please contactInvestor & Media RelationsIdorsia Pharmaceuticals Ltd, Hegenheimermattweg 91, CH-4123 Allschwil+41 58 844 10 10investor.relations@idorsia.com – media.relations@idorsia.com – 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. Attachment Press Release PDF

Tiny doctors examining heart health flat vector illustration. Cartoon medical specialists doing checkup of blood pressure, pulse rate and cholesterol. Cardiovascular disease and cardiology concept BRO Vector/Getty Images Mineralys’ shares got a more than 50% boost Monday morning as new data showed its hypertension drug reduced blood pressure in a pair of clinical trials. Mineralys Therapeutics’ hypertension drug reduced blood pressure in a Phase III trial , sending the biotech’s shares up by more than 50%. But lorundrostat will face a tough market battle, with incumbent Idorsia settling in with a new medicine and several late-stage options coming down the pike. Lorundrostat is an inhibitor of aldosterone synthase, the enzyme responsible for making the steroid aldosterone. Increased amounts of aldosterone have been often linked to rates of hypertension. The pivotal Phase III Launch-HTN and Phase II Advance-HTN trials tested lorundrostat in 1,000 patients with uncontrolled high blood pressure who were already taking two to five antihypertensive drugs. The Phase III trial met its primary goal, assessing the change in systolic blood pressure from baseline compared to placebo after six weeks. Patients who received 50 mg of lorundrostat on top of their preexisting regimens saw a 9.1 mmHg placebo-adjusted drop in blood pressure. Zooming out, at 12 weeks, patients on the lower dose of lorundrostat had an 11.7 mmHg decrease in blood pressure, while patients in the higher dose group had an 8.4 mmHg drop at 12 weeks when adjusted for placebo. As for safety, 4 patients across the two dosing groups reported adverse events that were deemed related to the treatment. Twelve patients in the 50 mg dose group had events such as increased serum potassium, decreased kidney activity, urinary tract infection and hypertension. In the Phase II study, patients with uncontrolled or treatment-resistant hypertension on background therapy saw their blood pressure drop by 7.9 with 50 mg of lorundrostat, meeting the main goal of the study. The primary endpoint of blood pressure reduction was measured using a 24-hour average at week 12. Adverse events were fewer in this study, with two patients reporting AEs, with one report of hyponatremia, which is when sodium levels in the body drop below normal. Mineralys’ shares rose 52% to $16 per share Monday morning after the results were announced. “We believe the clinical pro for lorundrostat supports the potential regulatory approval of this novel agent and its significant commercial value,” Mineralys CEO Jon Congleton said in a statement. The company plans to announce more detailed findings later this month at the American College of Cardiology Scientific Sessions. These results continue a positive trend for Mineralys, which in September 2023 announced positive Phase II data from the Target-HTN trial of lorundrostat, also showing improvements in blood pressure. Monday’s data release also comes after a blizzard of activity in the hypertension space. In March 2024, Idorsia won FDA approval for its hypertension drug Tryvio, an endothelin receptor antagonist, claiming to be the first new mechanism in hypertension treatments in decades. Other companies, including Alnylam and George Medicines , have also announced late-stage anti-hypertension data in the last few months.