Data Demonstrate Vamorolone's Balanced Corticosteroid Profile with On-Target Glucocorticoid Activity and Without Evidence of Significant Immunosuppressive Activity at Clinical Doses
CORAL GABLES, Fla., June 30, 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 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.
Key Highlights and Readouts:
Overall study design
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
Part A: Vamorolone vs. deflazacort (equipotency assessment)
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
"By demonstrating similar cortisol suppression at label-based clinical doses of vamorolone and deflazacort, these data support the currently labeled dosing of vamorolone in the treatment of DMD and do not suggest the need for other dosing considerations when switching patients from deflazacort to vamorolone," said William Andrews, MD, Chief Medical Officer of Catalyst Pharmaceuticals. "Moreover, vamorolone achieved robust glucocorticoid and anti-inflammatory activity without evidence of significant immunosuppression at clinical doses."