STOCK TITAN
  1. Home
  2. Sec-filings
  3. CPRX
  4. [8-K] CATALYST PHARMACEUTICALS, INC. Reports Material Event

Vamorolone Phase 1 results at Catalyst (NASDAQ: CPRX) show activity without key immunosuppression

Filing Impact
(Moderate)
Filing Sentiment
(Neutral)
Form Type
8-K

Rhea-AI Filing Summary

Catalyst Pharmaceuticals reported topline results from a two-part Phase 1 clinical study of AGAMREE (vamorolone) in healthy adult volunteers. The study showed balanced corticosteroid activity, with expected cortisol suppression and no evidence of significant immunosuppressive activity at clinical doses.

In Part A, vamorolone produced similar cortisol suppression to deflazacort at label-based clinical doses, supporting currently labeled dosing for Duchenne muscular dystrophy. In Part B, even at an ascending dose up to 40 mg/kg/day, which is above currently approved dosing, the data did not indicate clinically meaningful immunosuppression, reinforcing its potential use across a broad range of chronic inflammatory rare diseases.

Positive

  • None.

Negative

  • None.

Insights

Phase 1 data support vamorolone’s labeled dosing and differentiated safety profile at clinical doses.

Catalyst Pharmaceuticals released topline results from a two-part Phase 1 study of vamorolone in healthy adults. The trial found balanced corticosteroid effects, with expected cortisol suppression indicating on-target glucocorticoid and anti-inflammatory activity.

Importantly, the study reported no evidence of significant immunosuppressive activity at clinical doses, even though Part B escalated to a high 40 mg/kg/day dose above approved levels. The company notes these results support current dosing in Duchenne muscular dystrophy and suggest potential applicability across multiple chronic inflammatory rare diseases.

While early-stage, these data help position vamorolone as a corticosteroid alternative that may avoid clinically meaningful immunosuppression at relevant doses. Future updates in later-phase trials and new indication studies, as referenced in company disclosures, will be key to understanding how broadly this profile can translate into approved uses.

Item 8.01 Other Events Other
Voluntary disclosure of events the company deems important to shareholders but not covered by other items.
Item 9.01 Financial Statements and Exhibits Exhibits
Financial statements, pro forma financial information, and exhibit attachments filed with this report.
Clinical trial phase Phase 1 Two-part study in healthy adult volunteers
High vamorolone dose tested 40 mg/kg/day Part B ascending-dose evaluation above currently approved dosing
Announcement date June 30, 2026 Press release and Form 8-K disclosure date
topline results financial
"today announced topline results from a two-part Phase 1 clinical study of vamorolone"
Topline results are the initial, high-level summary of the most important outcomes from an event such as a clinical trial or a company reporting period — for a drug study this means whether the main goals were met and basic safety info, and for a company it often means headline revenue and profit figures. Investors care because these summaries act like a headline that quickly signals whether prospects have improved or worsened, often driving immediate market reactions before the full details are released.
Phase 1 clinical study medical
"today announced topline results from a two-part Phase 1 clinical study of vamorolone"
A phase 1 clinical study is the first stage of testing a new drug or therapy in people to check safety, how the body handles the treatment, and appropriate dosing. Think of it as a cautious test drive with a small group to confirm the product won’t cause serious harm and to gather early clues about whether it might work; for investors, positive phase 1 results reduce risk, guide development timelines and costs, and make later-stage value more tangible.
glucocorticoid activity medical
"Vamorolone Demonstrates On-Target Glucocorticoid Activity Without the Immunosuppression Characteristic of Traditional Corticosteroids"
immunosuppressive activity medical
"without evidence of significant immunosuppressive activity at clinical doses"
cortisol suppression medical
"demonstrating similar cortisol suppression at label-based clinical doses of vamorolone and deflazacort"
See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google
Add on Google
Understanding 8-K Material Events →
NASDAQ false 0001369568 0001369568 2026-06-30 2026-06-30
 
 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

 

FORM 8-K

 

 

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): June 30, 2026

 

 

CATALYST PHARMACEUTICALS, INC.

(Exact Name Of Registrant As Specified In Its Charter)

 

 

 

Delaware   001-33057   76-0837053
(State or other jurisdiction
of incorporation)		   (Commission
File Number)		   (I.R.S. Employer
Identification No.)

 

355 Alhambra Circle

Suite 801

  
Coral Gables, Florida   33134
(Address of principal executive offices)   (Zip Code)

Registrant’s telephone number, including area code: (305) 420-3200

Not Applicable

Former Name or Former address, if changed since last report

 

 

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

 

☐

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

 

☐

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

 

☐

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR240.14d-2(b))

 

☐

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

 

Title of Each Class

  

Name of Exchange
on Which Registered

  

Ticker
Symbol

Common Stock, par value $0.001 per share   NASDAQ Capital Market   CPRX

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this Chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging Growth Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

 

 
 

Item 8.01

Other Events

On June 30, 2026, the Company issued a press release announcing topline results from a two-part Phase 1 clinical study of AGAMREE (vamorolone). A copy of the press release is attached hereto as Exhibit 99.1.

 

Item 9.01

Financial Statements and Exhibits.

 

  (d)

Exhibits

 

99.1   Press release issued by the Company on June 30, 2026.
104   Cover Page Interactive Data File (embedded within the Inline XBRL document)

 

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

 

Catalyst Pharmaceuticals, Inc.
By:  

/s/ Michael Kalb

 

Michael Kalb

 

Executive Vice President and CFO

Dated: June 30, 2026

 

3

Exhibit 99.1

Vamorolone Demonstrates On-Target Glucocorticoid Activity Without the Immunosuppression Characteristic of Traditional Corticosteroids at Clinical Doses

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 — 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.”

Part B: Ascending dose evaluation of immunosuppressive potential

 

  •  

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,” Dr. Andrews added. “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.”

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 Companies 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 www.catalystpharma.com.

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, including (i) whether vamorolone can be developed and successfully commercialized in the future for the treatment of other chronic inflammatory rare diseases, and (ii) those 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

Source: View Original Filing on SEC EDGAR

FAQ

What did Catalyst Pharmaceuticals (CPRX) announce about vamorolone in this 8-K?

Catalyst Pharmaceuticals announced topline results from a two-part Phase 1 study of vamorolone in healthy adults. The data showed balanced glucocorticoid activity with expected cortisol suppression and no evidence of significant immunosuppressive activity at clinical doses, supporting its current clinical dosing strategy.

How did vamorolone perform versus deflazacort in Catalyst (CPRX)’s Phase 1 study?

Vamorolone demonstrated similar cortisol suppression to deflazacort at label-based clinical doses. Catalyst stated this supports the currently labeled dosing of vamorolone in Duchenne muscular dystrophy and does not suggest additional dosing adjustments when switching patients from deflazacort to vamorolone in that setting.

What is the significance of the 40 mg/kg/day vamorolone dose reported by Catalyst (CPRX)?

Part B of the study tested vamorolone at doses up to 40 mg/kg/day, above approved levels. Catalyst reported that, even at this high dose, findings suggest clinically meaningful immunosuppression is unlikely at clinically relevant doses, reinforcing the drug’s profile compared with traditional corticosteroids.

Does Catalyst Pharmaceuticals see vamorolone as useful beyond Duchenne muscular dystrophy?

Catalyst believes the data support vamorolone’s potential use across a broad range of chronic inflammatory rare diseases. The company highlighted the combination of glucocorticoid and anti-inflammatory activity without clinically meaningful immunosuppression at relevant doses as a rationale for exploring additional indications.

Why does Catalyst (CPRX) describe vamorolone’s profile as potentially differentiating from conventional corticosteroids?

The company emphasizes that vamorolone showed on-target glucocorticoid and anti-inflammatory activity without significant immunosuppression at clinical doses. Catalyst suggests this favorable profile could distinguish vamorolone from traditional corticosteroids and may support its broader use in chronic inflammatory rare diseases.

Filing Exhibits & Attachments

4 documents

Press Releases

Other Documents