Santhera Pharmaceuticals (USA), Inc.

Ad hoc announcement pursuant to Art. 53 LR Food and Drug Administration (FDA) approved AGAMREE® (vamorolone) for the treatment of Duchenne muscular dystrophy (DMD) in children and adults aged 2 years and older U.S. license holder Catalyst Pharmaceuticals plans for commercial launch in Q1-2024 FDA approval triggers USD 36 million payment obligation from Catalyst to Santhera, of which USD 26 million will be used to cover Santhera’s third-party milestone obligations Following the recent positive CHMP opinion on AGAMREE in DMD, approval in the European Union by the European Commission (EC) is expected in late 2023 AGAMREE would then become the first drug fully approved in both the U.S. and Europe for the treatment of patients with DMD Santhera Pharmaceuticals (SIX: SANN) announces that the U.S. Food and Drug Administration (FDA) has approved AGAMREE® (vamorolone) oral suspension 40 mg/ml for the treatment of Duchenne muscular dystrophy (DMD) in patients 2 years of age and older. “We are delighted to secure FDA approval which comes just weeks after the positive opinion from the CHMP of the European Medicines Agency. This is a hugely important moment for DMD patients who need an efficacious and well-tolerated therapy for this debilitating condition,” said Dario Eklund, CEO of Santhera. “Today is a very satisfying day for the Santhera team and we are grateful to the patients, their families and physicians who participated in the vamorolone program. We look forward to working closely with our partner Catalyst Pharmaceuticals as it prepares for U.S. commercialization of the product.” “This new drug approval gives Duchenne patients and their families one more reason for hope,” said Pat Furlong, Founding President & CEO Parent Project Muscular Dystrophy (PPMD). “Steroids are considered standard of care for Duchenne, due to their valuable role in slowing disease progression. However, they often come with considerable side effects. Vamorolone has the potential to be an alternative steroid with a better tolerability profile addressing an important unmet medical need for patients.” “I am excited for the Duchenne community who have been waiting a long time for an alternative to the current standard of care. Today’s news represents the culmination of many years of research to bring vamorolone to patients,” said Eric Hoffman, PhD, President and CEO of ReveraGen BioPharma. “We are pleased to have worked alongside Santhera, the DMD patient community, researchers and healthcare practitioners to reach this important milestone.” The FDA approval of AGAMREE® was based on the data from the pivotal Phase 2b VISION-DMD study as supplemented with safety information collected from three open-label studies, including extension studies. In these trials, AGAMREE was administered at doses ranging from 2 to 6 mg/kg/day, extending for a period of up to 48 months. Compared with current standard of care corticosteroids, this novel corticosteroid treatment exhibited comparable efficacy, with data suggesting a reduction in adverse events, notably related to bone health, growth trajectory and behavior. The studies in the development program were carried out by Santhera’s partner ReveraGen and 32 academic clinical trial centers in 11 countries. With the FDA approval of AGAMREE for DMD, Catalyst will pay USD 36 million to Santhera, consisting of a USD 10 million approval milestone to the Company and an additional USD 26 million to cover contracted third-party milestone obligations. Furthermore, under the terms of the agreement, Catalyst will pay Santhera sales-based milestones of up to USD 105 million as well as up to low-teen percentage royalties, and will assume Santhera's corresponding third-party royalty obligations on vamorolone sales in all indications in North America. Santhera will now transfer the U.S. marketing authorization (NDA) for AGAMREE to its partner Catalyst Pharmaceuticals who holds an exclusive license for AGAMREE in North America and plans to launch the product in the U.S. in Q1-2024. In Europe, following the positive opinion from the CHMP received on October 12, 2023, approval of AGAMREE (vamorolone) for the treatment of DMD by the European Commission is expected in late 2023. Subject to approval, AGAMREE will be the only medicinal product fully approved in both territories, the EU and the U.S., for the treatment of DMD. Vamorolone is a novel drug candidate with a mode of action based on binding to the same receptor as glucocorticoids but modifying its downstream activity and is not a substrate for the 11-β-hydroxysteroid dehydrogenase (11β-HSD) enzymes that may be responsible for local tissue amplification and corticosteroid-associated toxicity in local tissues [1-3]. This mechanism has shown the potential to ‘dissociate’ efficacy from steroid safety concerns and therefore vamorolone is positioned as an alternative to existing corticosteroids, the current standard of care in children and adolescent patients with DMD [1-3]. In the pivotal VISION-DMD study, vamorolone met the primary endpoint Time to Stand (TTSTAND) velocity versus placebo (p=0.002) at 24 weeks of treatment and showed a good safety and tolerability profile [1]. The most commonly reported adverse events versus placebo from the VISION-DMD study were cushingoid features, vomiting and vitamin D deficiency. Adverse events were generally of mild to moderate severity. Currently available data show that vamorolone, unlike corticosteroids, has no restriction of growth [4] and no negative effects on bone metabolism as demonstrated by normal bone formation and bone resorption serum markers [5]. AGAMREE (vamorolone) has Orphan Drug status for DMD in the U.S. and in Europe and has received Fast Track and Rare Pediatric Disease designations by the U.S. FDA and Promising Innovative Medicine (PIM) status from the UK MHRA for DMD. Vamorolone is not approved for use outside the United States. References: [1] Guglieri M et al (2022). JAMA Neurol. 2022;79(10):1005-1014. doi:10.1001/jamaneurol.2022.2480. Link. [2] Liu X et al (2020). Proc Natl Acad Sci USA 117:24285-24293 [3] Heier CR et al (2019). Life Science Alliance DOI: 10.26508 [4] Ward et al., WMS 2022, FP.27 - Poster 71. Link. [5] Hasham et al., MDA 2022 Poster presentation. Link. Duchenne muscular dystrophy (DMD) is a rare inherited X-chromosome-linked disease, which almost exclusively affects males. DMD is characterized by inflammation which is present at birth or shortly thereafter. Inflammation leads to fibrosis of muscle and is clinically manifested by progressive muscle degeneration and weakness. Major milestones in the disease are the loss of ambulation, the loss of self-feeding, the start of assisted ventilation, and the development of cardiomyopathy. DMD reduces life expectancy to before the fourth decade due to respiratory and/or cardiac failure. Corticosteroids are the current standard of care for the treatment of DMD. Santhera Pharmaceuticals (SIX: SANN) is a Swiss specialty pharmaceutical company focused on the development and commercialization of innovative medicines for rare neuromuscular and pulmonary diseases with high unmet medical need. The Company has an exclusive license from ReveraGen for all indications worldwide to AGAMREE® (vamorolone), a dissociative steroid with novel mode of action, which was investigated in a pivotal study in patients with Duchenne muscular dystrophy (DMD) as an alternative to standard corticosteroids. AGAMREE for the treatment of DMD is approved by the U.S. Food and Drug Administration (FDA); in Europe, the marketing authorization application (MAA) has received a positive opinion from the European Medicines Agency’s CHMP in October 2023, and is under review by the UK Medicines and Healthcare products Regulatory Agency (MHRA). Santhera has out-licensed rights to vamorolone for North America to Catalyst Pharmaceuticals and for China to Sperogenix Therapeutics. The clinical stage pipeline also includes lonodelestat to treat cystic fibrosis (CF) and other neutrophilic pulmonary diseases. For further information, please visit www.santhera.com. The content above comes from the network. if any infringement, please contact us to modify.

Ad hoc announcement pursuant to Art. 53 LR Chiesi Group acquires entire idebenone business including Raxone in Leber's hereditary optic neuropathy (LHON)Chiesi Group assumes French reimbursement liability of EUR 25.3 million from SantheraSanthera retains contingent value for LHON in U.S. and/or other indications worldwideSanthera ceases all Raxone-related activities and intensifies commercial preparation for Duchenne muscular dystrophy candidate vamorolone in Europe Pratteln, Switzerland, July 31, 2023 – Santhera Pharmaceuticals (SIX: SANN) announces the full divestment of its Raxone®/idebenone business worldwide and for all indications to Chiesi Farmaceutici S.p.A., an international research focused healthcare group (Chiesi Group). The transaction replaces the existing license agreement between the two companies entered into in 2019. Under the terms of the agreement, Chiesi Group acquired all assets and certain liabilities related to idebenone in all indications worldwide, including Raxone in LHON, for which Chiesi already held exclusive license rights globally since 2019, except for North America and France. The agreement simplifies the Raxone business significantly for both companies with Chiesi becoming the global brand owner while enabling Santhera to focus on the launch of vamorolone in Europe, subject to approval. The transaction closed on July 28, 2023. Under the terms of the agreement, Chiesi Group will assume the responsibility for the settlement agreed between Santhera and the French reimbursement authorities relating to Raxone in LHON amounting to EUR 25.3 million, significantly reducing near-term financial obligations and strengthening Santhera’s balance sheet. Furthermore, the cessation of Raxone-related activities allows Santhera to streamline business processes, thereby reducing operating costs and freeing up resources to be deployed for the European vamorolone launch and strategic projects. In addition, Santhera is eligible to participate in a potential marketing approval of Raxone in LHON in the U.S. through single-digit variable payments on net sales or milestone payments of up to USD 10 million. In the event that Chiesi chooses to pursue idebenone in non-ophthalmological indications, Santhera would be eligible for additional milestone payments in a similar order of magnitude and high single-digit variable payments on net sales. Dario Eklund, CEO of Santhera, commented: “Securing this agreement is an important step for the business, as we sharpen our focus on the commercialization of vamorolone in Europe, subject to approval. We look forward to seeing Chiesi’s progress over the coming months and years for the benefit of patients worldwide.” Giacomo Chiesi, Head of Chiesi Global Rare Diseases, said: “We are very pleased to have reached this agreement with Santhera, securing the North American and other rights to an exciting therapy for LHON. This agreement allows Chiesi to accelerate the regulatory and clinical development of Raxone at a global level. We look forward to working with the patient and medical communities, the FDA and other agencies around the world to continue the development of this experimental opportunity for the benefit of the patients.” Under the 2019 agreement, Chiesi Group in-licensed Raxone for the treatment of LHON and obtained rights to all other ophthalmological indications worldwide, except France and North America, where Santhera retained rights. Chiesi Group also had the option to fully acquire said business outside North America. About SantheraSanthera Pharmaceuticals (SIX: SANN) is a Swiss specialty pharmaceutical company focused on the development and commercialization of innovative medicines for rare neuromuscular and pulmonary diseases with high unmet medical need. The Company has an exclusive license for all indications worldwide to vamorolone, a dissociative steroid with novel mode of action, which was investigated in a pivotal study in patients with Duchenne muscular dystrophy (DMD) as an alternative to standard corticosteroids. For vamorolone in the treatment of DMD, Santhera has a new drug application (NDA) under review by the U.S. FDA, a marketing authorization application (MAA) under review by the European Medicines Agency (EMA) and an MAA submitted to the UK Medicines and Healthcare products Regulatory Agency (MHRA). Santhera has out-licensed rights to vamorolone for North America to Catalyst Pharmaceuticals and for China to Sperogenix Therapeutics. The clinical stage pipeline also includes lonodelestat to treat cystic fibrosis (CF) and other neutrophilic pulmonary diseases. For further information, please visit www.santhera.com. About Chiesi GroupChiesi is an international, research-focused biopharmaceuticals group that develops and markets innovative therapeutic solutions in respiratory health, rare diseases, and specialty care. The company’s mission is to improve people’s quality of life and act responsibly towards both the community and the environment. By changing its legal status to a Benefit Corporation in Italy, the US, and France, Chiesi’s commitment to create shared value for society as a whole is legally binding and central to company-wide decision-making. As a certified B Corp since 2019, we’re part of a global community of businesses that meet high standards of social and environmental impact. The company aims to reach Net-Zero greenhouse gases (GHG) emissions by 2035. With over 85 years of experience, Chiesi is headquartered in Parma (Italy), operates in 31 countries, and counts more than 6,500 employees. The Group’s research and development centre in Parma works alongside 6 other important R&D hubs in France, the US, Canada, China, the UK, and Sweden. For further information please contact: public-relations@santhera.com orEva Kalias, Head Investor Relations & CommunicationsPhone: +41 79 875 27 80eva.kalias@santhera.com Disclaimer / Forward-looking statements This communication does not constitute an offer or invitation to subscribe for or purchase any securities of Santhera Pharmaceuticals Holding AG. This publication may contain certain forward-looking statements concerning the Company and its business. Such statements involve certain risks, uncertainties and other factors which could cause the actual results, financial condition, performance or achievements of the Company to be materially different from those expressed or implied by such statements. Readers should therefore not place undue reliance on these statements, particularly not in connection with any contract or investment decision. The Company disclaims any obligation to update these forward-looking statements. # # # Attachment 2023 07 31_ChiesiRax_e_FINAL

Phalguni Deswal Santhera expects to maximise the reduced financial burden of the Raxone development programme to focus on vamorolone’s European launch. Credit: MIRCO EMMY / Shutterstock. Santhera Pharmaceuticals announced the complete worldwide divestment of Raxone (idebenone) to Chiesi Farmaceutici while still being eligible for milestone-based payments from the drug sales. In 2019, Santhera and Chiesi signed a global licensing agreement, except in North America and France, for Raxone to treat Leber’s hereditary optic neuropathy (LHON) and any other ophthalmological conditions. Chiesi will also inherit the financial responsibility of the €25.3m ($27.9m) reimbursement agreement of Raxone in LHON with French reimbursement authorities, as per the press release . Since August 2021, and prior to finalising a reimbursement agreement with the French Government in February 2023, Santhera was providing Raxone for free to treat LHON. Drug sales resumed in April 2023, as per unaudited annual results released the same month. Following the latest news, Santhera would be eligible for US sales milestone payments for Raxone for up to $10m, and other milestone payments if Chiesi expands the use of Raxone in non-ophthalmological indications. Santhera expects to maximise the reduced financial burden of the Raxone development programme to focus on the vamorolone’s European launch. In September 2020, Santhera obtained the global rights of vamorolone in Duchenne muscular dystrophy (DMD) from ReveraGen BioPharma. Following this, Santhera signed a licensing agreement with Catalyst Pharmaceuticals and Sperogenix Therapeutics. This involved giving Catalyst licensing rights in the US, Canada, and Mexico for a $90m upfront payment, along with future milestone-based payments, and licensing rights in China to Sperogenix for $124m, including upfront and milestone-based payments. Vamorolone has a US FDA’s Prescription Drug User Fee Act (PDUFA) date for approval in DMD on 26 October 2023. Marketing authorisations for vamorolone are also under review with European Medicines Agency (EMA) and the UK’s Medicines and Healthcare products Regulatory Agency (MHRA). Another drug in Santhera’s pipeline is lonodelestat, a selective peptide inhibitor of human neutrophil elastase, which has orphan drug designations in the EU and US for treating cystic fibrosis, alpha-1 antitrypsin deficiency (AATD), and Primary ciliary dyskinesia (PCD).