Announcement • Jul 01
Santhera Pharmaceuticals Notes Topline Results from Catalyst Pharmaceuticals Phase 1 Clinical Study of AGAMREE Santhera Pharmaceuticals noted topline results from a two-part Phase 1 clinical study of AGAMREE conducted by its North American licensing partner, Catalyst Pharmaceuticals, Inc. The study suggests that AGAMREE delivers glucocorticoid and anti-inflammatory activity, while avoiding significant immunosuppressive effects, supporting its potential use as a treatment across a broad range of chronic inflammatory rare diseases. The study, conducted in healthy adult volunteers, evaluated equipotency between deflazacort and AGAMREE and assessed the clinical immunosuppressive potential of AGAMREE across ascending doses. In part A, both AGAMREE and deflazacort demonstrated expected on-target glucocorticoid receptor activity and comparable cortisol suppression at clinical doses, with AGAMREE showing less pronounced immunosuppressive biomarker effects, consistent with the currently labelled dosing of AGAMREE in the treatment of Duchenne muscular dystrophy (DMD). Part B demonstrated that clinically relevant immunosuppressive effects were observed only at the highest dose level, above currently approved AGAMREE dosing. No relevant immunosuppressive effects were observed at lower dose levels. Under an exclusive license agreement entered into in 2023, Catalyst holds commercialization rights to AGAMREE in North America for DMD and all potential future indications, while Santhera retains a right of first negotiation for any rights outside North America relating to new indications. Under the terms of the license agreement, Santhera is eligible to receive sales-based milestone payments as well as royalties on net sales across all commercialized indications. AGAMREE is a dissociative corticosteroid approved for the treatment of Duchenne muscular dystrophy (DMD). It binds selectively to the glucocorticoid receptor and triggers anti-inflammatory activity through inhibition of NF-?B-mediated gene transcription, while inducing reduced transactivation of other genes. AGAMREE is not a substrate for 11-ß-hydroxysteroid dehydrogenase (11ß-HSD) enzymes, which are involved in the local amplification of glucocorticoid activity in tissues and have been implicated in corticosteroid-associated toxicity. This pharmacological profile is the basis for its classification as a dissociative corticosteroid, designed to preserve anti-inflammatory efficacy while reducing the systemic effects associated with long-term conventional corticosteroid therapy. In the pivotal Phase 2b VISION-DMD study, AGAMREE met its primary endpoint, demonstrating a statistically significant improvement in Time to Stand (TTSTAND) velocity versus placebo at 24 weeks (p = 0.002). The most commonly reported adverse reactions were cushingoid features, vomiting, weight increase, increased appetite, and irritability; most were mild to moderate in severity. Long-term data from up to eight years of AGAMREE treatment were presented at the Muscular Dystrophy Association Clinical & Scientific Conference in March 2026. In propensity-matched analyses, AGAMREE demonstrated durable efficacy comparable to standard-of-care corticosteroids and a differentiated safety profile: a lower incidence of vertebral fractures versus deflazacort-treated cohorts (8.1% vs 41.9%; p = 0.0082); maintained a normal growth trajectory with a mean height advantage of 12.17 cm versus conventional corticosteroids (p < 0.0001), and a lower incidence of cataracts versus deflazacort (p = 0.015), with no observed cases of glaucoma. This medicinal product is subject to additional monitoring. Healthcare professionals are asked to report any suspected adverse reactions. Announcement • Jun 30
Catalyst Pharmaceuticals Announces Topline Results From Two-Part Phase 1 Clinical Study Of Vamorolone In Healthy Adult Volunteers Catalyst Pharmaceuticals, Inc. announced topline results from a two-part Phase 1 clinical study of vamorolone in healthy adult volunteers. The study demonstrated balanced corticosteroid activity with expected cortisol suppression and no evidence of significant immunosuppressive activity at clinical doses. These findings suggest that vamorolone delivers glucocorticoid and anti-inflammatory activity, while avoiding significant immunosuppressant effects, supporting its potential use as a treatment across a broad range of chronic inflammatory rare diseases. A two-part (referred to as Parts A and B) Phase 1 study was conducted in healthy adult volunteers. The primary purpose of Part A was to assess equipotency between deflazacort and vamorolone to help address the clinical case in which a patient might experience differential cortisol effects when switching from deflazacort to vamorolone. The primary purpose of Part B was to evaluate ascending doses of vamorolone to assess vamorolone’s clinical immunosuppressive potential in consideration of potential life cycle management indications. The study evaluated cortisol suppression, anti-inflammatory activity, and immunosuppressive effects across clinical and supratherapeutic doses. 24 healthy adults were enrolled in a randomized, single-center, crossover study. Single doses of vamorolone (300 mg) and deflazacort (0.9 mg/kg) were evaluated. Both agents demonstrated expected on-target glucocorticoid receptor activity, including cortisol suppression, leukocyte redistribution, and effects on functional immune biomarkers. Similar time to onset was observed for both treatments (approximately 2–4 hours post-dose). Comparable cortisol suppression was observed at clinical doses. Vamorolone demonstrated less pronounced immunosuppressive biomarker effects compared with deflazacort. 36 healthy volunteers received vamorolone at doses of 9, 27, or 40 mg/kg once daily for seven days. Immune biomarkers and cellular markers were evaluated through Day 21. Clinically relevant immunosuppressive effects were observed only at the highest dose level (40 mg/kg/day). No relevant immunosuppressive effects observed at lower dose levels (9 or 27 mg/kg/day). Immunosuppressive effects increased with repeated dosing at 40 mg/kg/day and persisted after treatment cessation. As the 40 mg/kg/day dose is above currently approved vamorolone dosing and higher than doses previously studied in clinical trials, these findings suggest that clinically meaningful immunosuppression with vamorolone is unlikely at clinically relevant doses. The prospect of this favorable profile—glucocorticoid and anti-inflammatory activity without clinically meaningful immunosuppression at clinically relevant doses—has the potential to distinguish vamorolone from conventional corticosteroids. Additionally, this profile may support vamorolone’s potential utility across a broad range of chronically inflammatory rare diseases. CPRX
Live News • Jun 24
Catalyst Pharmaceuticals Merger with Angelini Pharma Advances with FTC Clearance Targeting Q3 2026 Completion Catalyst Pharmaceuticals said the U.S. Federal Trade Commission granted early termination of the Hart-Scott-Rodino antitrust waiting period for its planned merger with Angelini Pharma, clearing a key regulatory step toward closing in Q3 2026, subject to remaining conditions and majority shareholder approval.
The transaction would result in Catalyst becoming a wholly owned subsidiary of Angelini Pharma, marking a change in control that could reshape how the business is funded, governed and prioritized once the deal closes.
Catalyst Pharmaceuticals shares trade at about $31.40, with the stock up 35.6% year to date, indicating investors have already reacted to recent company developments and the pending merger process.
This clearance reduces regulatory uncertainty around the Angelini deal, but timing and outcome still depend on shareholder approval and execution of remaining closing conditions, which keeps some event risk in play for Catalyst holders. 
