Vamorolone

Comparable long-term effectiveness to classic corticosteroids, both prednisone (p=0.8587) and deflazacort (p=0.6544), based on time to loss of ambulation 80% fewer patients with vertebral fractures (8.1% vs 41.9% on deflazacort, p=0.0082) Maintenance of normal height with 12.17 cm mean height advantage vs classic corticosteroids where significant stunting was observed (p<0.0001) Cataracts in 5.3% vs 37.8% patients, significantly lower than deflazacort (p=0.015); no glaucoma observed Pratteln, Switzerland, March 9, 2026 – Santhera Pharmaceuticals (SIX: SANN) today announced that full results from long-term real-world comparative analyses, including baseline data from the ongoing GUARDIAN study of AGAMREE® (vamorolone), were presented at the Muscular Dystrophy Association (MDA) Clinical & Scientific Conference 2026 in Orlando, Florida. The dataset includes up to eight years of AGAMREE exposure (median approximately five years) in boys with Duchenne muscular dystrophy (DMD). The analyses incorporate data from participants in clinical studies who continued treatment through various access programs as well as the Phase 4 GUARDIAN study (NCT06713135). Long-term data including baseline results from GUARDIAN were compared to a propensity-matched historical control cohort treated with deflazacort or prednisone. Together, the data demonstrate that vamorolone maintains long-term effectiveness comparable to traditional corticosteroids, while improving tolerability and meaningfully reducing key steroid-associated side effects that often lead to dose reductions or discontinuations that impact long-term patient outcomes. These data were presented during the MDA poster session on Sunday, March 8, 2026 (6:00–8:00 pm ET). In addition, Catalyst Pharmaceuticals, in conjunction with Santhera, will host an MDA Industry Forum titled “Vamorolone in DMD: Real-World Experience, Emerging Questions and the Path to Long-Term Evidence” on Tuesday, March 10, 2026, from 12:00–1:30 pm ET in the Key Largo Room, The Hilton Orlando, Orlando, FL. The forum will be presented by Craig McDonald, MD, Professor of Physical Medicine & Rehabilitation and Pediatrics, UC Davis Health. Comparable Long-Term Effectiveness There was no statistically significant difference in time to loss of ambulation (LoA) between pooled vamorolone doses (2–6 mg/kg/day) and classic corticosteroids (p=0.9041), or vs deflazacort (p=0.6544) and prednisone (p=0.8587) individually. The mean real-world vamorolone dose was 4.5 ± 1.8 mg/kg/day, with median exposure of approximately 5 years. These findings suggest that improved long-term safety outcomes can be achieved without compromising efficacy and that real-world dosing indicates patients may tolerate higher doses of vamorolone over the long term compared with experience using classic corticosteroids. Maintained Growth Without Compromising Motor Function Height trajectories were maintained on vamorolone, while growth decline and stunting were observed in classic corticosteroid cohorts as expected. Growth stunting was defined as a height z-score < –2.0, which is approximately two standard deviations below age-matched healthy boys, a commonly used threshold for clinically meaningful short stature. After 5 years, the mean height difference was +12.17 cm in favor of vamorolone. Importantly, vamorolone is the first dissociative corticosteroid to demonstrate patients with DMD can achieve normal growth without compromising efficacy. BMI z-scores increased in both treatment groups, consistent with corticosteroid class effects. Substantially Lower Vertebral Fracture Risk After a median treatment duration of approximately five years, there was an 80% reduction in the proportion of patients with vertebral fractures (8.1% of vamorolone-treated boys vs 41.9% in boys treated with deflazacort, p=0.0082). Non-vertebral fractures occurred in 27.5% of patients, including long bone fractures in 12.5%, which are at the lower end of rates reported in the literature for traditional corticosteroids, indicating a favourable pro chronic use. Bone age remained within normal limits relative to chronological age on vamorolone, whereas delays are commonly reported with classic corticosteroids. Favorable Long-Term Ocular and Metabolic Profile Cataracts were observed in significantly fewer patients compared with deflazacort (5.3% vs 37.8%, p=0.015) and numerically lower vs prednisone (5.3% vs 12.1%, p=0.05). No cases of glaucoma were observed. Glucose and lipid parameters were within normal ranges in the majority of patients. Morning cortisol levels were consistent with expected adrenal suppression for corticosteroid therapy, and no new safety signals were identified. Ongoing Data Collection The prospective GUARDIAN study will continue to assess long-term outcomes over the coming years, including anthropometrics, muscle function, bone health, cardiac and respiratory function, eye health, pubertal development, and additional safety endpoints. Shabir Hasham, Chief Medical Officer of Santhera, said: “These longer-term analyses contribute to a growing body of evidence characterising the clinical pro vamorolone as patients remain on therapy over extended periods of time. The data presented at MDA continue to indicate that vamorolone maintains effectiveness comparable to traditional corticosteroids, while showing improvements in steroid-associated safety and tolerability outcomes. As the treatment landscape for Duchenne muscular dystrophy continues to evolve, with increasing use of combination treatment strategies, understanding the long-term benefit–risk pro corticosteroid therapy is particularly important. A treatment that preserves efficacy while reducing treatment-limiting adverse effects would be better suited to support long-term disease management, including in combination with emerging therapies. The ongoing GUARDIAN study will continue to expand our understanding of vamorolone across a broader range of real-world outcomes as patients age and remain on treatment.” About AGAMREE® (vamorolone) AGAMREE is a novel drug with a mode of action based on binding to the same receptor as glucocorticoids but modifying its downstream activity. Moreover, it is not a substrate for the 11-β-hydroxysteroid dehydrogenase (11β-HSD) enzymes that may be responsible for local drug amplification and corticosteroid-associated toxicity in local tissues [2-5]. This mechanism has shown the potential to ‘dissociate’ efficacy from steroid safety concerns and therefore AGAMREE is positioned as a dissociative anti-inflammatory drug and an alternative to classic corticosteroids, the current standard of care in children and adolescent patients with DMD [2-5]. In the pivotal VISION-DMD study, AGAMREE 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 [2, 5]. The most commonly reported side effects were cushingoid features, vomiting, weight increase and irritability. Side effects were generally of mild to moderate severity. Currently available data show that AGAMREE, unlike classic corticosteroids, has no restriction of growth [6] and no negative effects on bone metabolism as demonstrated by normal bone formation and bone resorption serum markers [7]. ▼ This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions. References: [1] Dang UJ et al. (2024) Neurology 2024;102:e208112. doi.org/10.1212/WNL.0000000000208112. Link . [2] Guglieri M et al (2022). JAMA Neurol. 2022;79(10):1005-1014. doi:10.1001/jamaneurol.2022.2480. Link . [3] Liu X et al (2020). Proc Natl Acad Sci USA 117:24285-24293 [4] Heier CR et al (2019). Life Science Alliance DOI: 10.26508 [5] Ward et al., WMS 2022, FP.27 - Poster 71. Link . [6] Hasham et al., MDA 2022 Poster presentation. Link . About Santhera Santhera Pharmaceuticals (SIX: SANN) is a Swiss specialty pharmaceutical company focused on the development and commercialization of innovative medicines for rare neuromuscular 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 in the U.S. by the Food and Drug Administration (FDA), in the EU by the European Commission (EC), in the UK by the Medicines and Healthcare products Regulatory Agency (MHRA), in Switzerland by Swissmedic, in China by the National Medical Products Administration (NMPA), in Hong Kong by the Department of Health (DoH) and in Canada by Health Canada. Santhera has out-licensed the rights to AGAMREE as follows: to Catalyst Pharmaceuticals for North America; to Sperogenix Therapeutics for China and certain countries in Southeast Asia; and to Nxera Pharma for Japan, South Korea, Australia, and New Zealand. For further information, please visit . AGAMREE® is a trademark of Santhera Pharmaceuticals. For further information, please contact : Santhera Catherine Isted, Chief Financial Officer: IR@santhera.com ICR Healthcare: Santhera@icrhealthcare.com Stifel Brough Ransom, Charles Hoare, Fred Walsh +44 (0)20 7710 7600 Octavian Serge Monnerat, Marius Zuberbuehler +41 (0)44 520 1588 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 260309 Santhera Guardian data at MDA Final_English (1)

CORAL GABLES, Fla., March 06, 2026 (GLOBE NEWSWIRE) -- Catalyst Pharmaceuticals, Inc. ("Catalyst") (Nasdaq: CPRX), a commercial-stage biopharmaceutical company focused on in-licensing, developing, and commercializing novel medicines for patients living with rare and difficult-to-treat diseases, today announced that the Company will showcase real‑world findings in Duchenne muscular dystrophy (DMD) through multiple poster presentations at the 2026 MDA Clinical & Scientific Conference in Orlando, Florida. Catalyst will also sponsor a vamorolone-focused MDA Industry Forum with Santhera Pharmaceuticals. “The MDA meeting is a key opportunity to highlight the expanding real‑world evidence shaping care for the Duchenne community,” said Will Andrews, MD, Chief Medical Officer of Catalyst. “Through our poster presentations and our sponsored symposium on long‑term evidence generation, we’re contributing clinical insights that help clarify AGAMREE ® ’s pro its role in patient care. Our commitment is to advance rigorous, meaningful research that moves the field forward for patients and their families.” The poster presentations will focus on real-world analysis of vamorolone in patients living with DMD: Poster Presentations: Abstract Title: Real-world analysis of concomitant cardiac medication use with the novel corticosteroid vamorolone in patients with Duchenne muscular dystrophy (DMD) Authors: Linda Cripe, MD, Nationwide Children's Hospital, Steven Woods, PharmD, Catalyst, Katherine Habkouk, PharmD, AnovoRx Specialty Pharmacy, Regina Grebla, PhD, Northeast Epi, LLC Session Name: Poster Session Topic: Clinical Management Poster Number: 74 S Date of Presentation: Sunday, March 8, 2026, 6:00 PM–8:00 PM ET Abstract Title: Association Between Glucocorticoid Treatment Duration and Health Care Resource Utilization in Duchenne Muscular Dystrophy: A Real-World Analysis. Authors: Steven Woods, PharmD, Catalyst Pharmaceuticals, Bridget McGowan, MD, Ann and Robert H. Lurie Children's Hospital of Chicago, Ashley Martin, PhD, BluePath Solutions, Alexa Gordon, MS, BluePath Solutions, Sana Mirza, MPH, BluePath Solutions, Paula Alvarez, MBA, MS, Rph, Critical Intelligence Consulting Session Name: Poster Session Topic: Other Poster Number: 75 S Date of Presentation: Sunday, March 8, 2026, 6:00 PM–8:00 PM ET Abstract Title: Glucocorticoid Use and Delayed Respiratory Decline in Duchenne Muscular Dystrophy Patients: A Real-World Analysis Authors: Steven Woods, PharmD, Catalyst Pharmaceuticals, Bridget McGowan, MD, Ann and Robert H. Lurie Children's Hospital of Chicago, Ashley Martin, PhD, BluePath Solutions, Alexa Gordon, MS, BluePath Solutions, Sana Mirza, MPH, BluePath Solutions, Paula Alvarez, MBA, MS, Rph, Critical Intelligence Consulting, Oscar Mayer, MD, The Children's Hospital of Philadelphia Session Name: Poster Session Topic: Other Poster Number: 76S Date of Presentation: Sunday, March 8, 2026, 6:00 PM–8:00 PM ET MDA Industry Forum will highlight the latest insights from clinical leaders advancing our understanding of DMD: Symposium : Title: MDA Industry Forum Sponsored by Catalyst Pharmaceuticals in Conjunction With Santhera Pharmaceuticals Speakers: Dr. Craig McDonald, MD, Chair, Department of Physical Medicine & Rehabilitation Professor, Departments of Pediatrics and Physical Medicine & Rehabilitation UC Davis Health, Sacramento, CA Dr. Leanne Ward, MD, Professor of Pediatrics, University of Ottawa, Ottawa, ON Date of Presentation: Tuesday, March 10, 2026, 12:00 PM-1:30 PM ET Location: Key Largo Room, The Hilton Orlando About Catalyst Pharmaceuticals, Inc. Catalyst Pharmaceuticals, Inc. (Nasdaq: CPRX) is a biopharmaceutical company committed to improving the lives of patients with rare diseases. With a proven track record of bringing life-changing treatments to the market, we focus on in-licensing, commercializing, and developing innovative therapies. Guided by our deep commitment to patient care, we prioritize accessibility, ensuring patients receive the care they need through a comprehensive suite of support services designed to provide seamless access and ongoing assistance. Catalyst maintains a well-established U.S. presence, which remains the cornerstone of our commercial strategy, while continuously evaluating strategic opportunities to expand our global footprint. Catalyst, headquartered in Coral Gables, Fla., has been recognized by Forbes as one of America’s Most Successful Company in 2023, 2024, and 2025, and on the 2025 Deloitte Technology Fast 500™ list as one of North America’s Fastest-Growing Companies. For more information, please visit Catalyst's website at . Forward-Looking Statements This press release contains forward-looking statements, as that term is defined in the Private Securities Litigation Reform Act of 1995. Forward-looking statements involve known and unknown risks and uncertainties, which may cause Catalyst's actual results in future periods to differ materially from forecasted results. A number of factors described in Catalyst's Annual Report on Form 10-K for the 2025 fiscal year and its subsequent filings with the U.S. Securities and Exchange Commission (“SEC”), could adversely affect Catalyst. Copies of Catalyst's filings with the SEC are available from the SEC, may be found on Catalyst's website, or may be obtained upon request from Catalyst. Catalyst does not undertake any obligation to update the information contained herein, which speaks only as of this date. Contact Information: Investor Contact Melissa Kendis, Catalyst Pharmaceuticals, Inc. (305) 420-3200 IR@catalystpharma.com Media Contact Ignacio Guerrero-Ros, Ph.D., Russo Partners, LLC (646) 249-6817 Ignacio.Guerrero-Ros@russopartnersllc.com