Pratteln, Switzerland, July 1, 2026
Santhera Pharmaceuticals announced positive topline findings from a Phase 1 clinical study of AGAMREE® (vamorolone) conducted by its North American licensing partner, Catalyst Pharmaceuticals, demonstrating that the dissociative corticosteroid delivered strong glucocorticoid and anti-inflammatory activity while avoiding significant immunosuppressive effects at clinically relevant doses. The results strengthen AGAMREE’s potential beyond its approved use in Duchenne muscular dystrophy (DMD) and support future development across a broad range of chronic inflammatory rare diseases. The two-part study was conducted in healthy adult volunteers to evaluate pharmacological activity, dose equivalence with deflazacort, and the immunosuppressive profile of AGAMREE. Under their 2023 licensing agreement, Catalyst holds commercialization rights for North America across DMD and future indications, while Santhera remains eligible for milestone payments and royalties from future commercial sales.
Phase 1 Results Demonstrate Anti-Inflammatory Activity with Reduced Immunosuppression
The clinical study evaluated AGAMREE’s glucocorticoid receptor activity and compared its biological effects with deflazacort, one of the standard corticosteroid therapies used in DMD. In Part A, both therapies demonstrated expected glucocorticoid activity and comparable cortisol suppression at approved clinical doses, confirming therapeutic potency. However, AGAMREE showed less pronounced immunosuppressive biomarker effects, suggesting that it can maintain anti-inflammatory benefits while reducing suppression of the immune system. In Part B, investigators evaluated ascending dose levels and observed clinically relevant immunosuppressive effects only at the highest dose, which exceeded currently approved AGAMREE dosing. Importantly, no meaningful immunosuppressive activity was detected at clinically relevant dose levels, reinforcing the differentiated safety profile of the therapy.
Unique Dissociative Corticosteroid Design Supports Broader Therapeutic Potential
AGAMREE is a dissociative corticosteroid engineered to selectively activate the glucocorticoid receptor while minimizing activation of biological pathways responsible for many long-term corticosteroid side effects. Unlike conventional corticosteroids, AGAMREE is not metabolized by 11β-hydroxysteroid dehydrogenase enzymes, which are associated with tissue-specific amplification of glucocorticoid activity and corticosteroid toxicity. This unique mechanism is designed to preserve potent anti-inflammatory efficacy while reducing complications commonly associated with chronic steroid treatment. The new Phase 1 findings further support this differentiated pharmacological profile and provide a scientific rationale for evaluating AGAMREE across multiple rare inflammatory diseases, where long-term corticosteroid therapy often remains the standard of care despite substantial safety concerns.
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Long-Term Clinical Evidence Reinforces AGAMREE’s Safety and Commercial Potential
The encouraging Phase 1 data complement previously reported long-term clinical evidence from the VISION-DMD program and follow-up analyses presented at the Muscular Dystrophy Association Clinical & Scientific Conference 2026. In those studies, AGAMREE demonstrated durable clinical efficacy comparable to conventional corticosteroids while delivering a differentiated safety profile, including a significantly lower incidence of vertebral fractures, preservation of normal growth, fewer cataracts, and no reported glaucoma cases after extended treatment. AGAMREE has already secured regulatory approvals for DMD in the United States, European Union, United Kingdom, Switzerland, Canada, China, and Hong Kong, positioning the therapy as a globally approved treatment. The latest Phase 1 results now expand the potential commercial opportunity by supporting development into additional chronic inflammatory rare diseases, providing Santhera and Catalyst with a stronger foundation for future clinical programs and lifecycle expansion.
Source: Santhera Pharmaceuticals press release
