ADX-324 for Hereditary Angioedema

(STOP-HAE Trial)

Overseen By Lisa Melia, MA

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: ADARx Pharmaceuticals, Inc.

Must not be taking: ACE inhibitors, Androgens

Disqualifiers: Other angioedema, Cardiovascular disease, Diabetes, others

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 25 weeks

90 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called ADX-324 for hereditary angioedema (HAE), a condition that causes sudden and severe swelling. Researchers aim to evaluate the effectiveness, safety, and impact on quality of life of ADX-324 for individuals with Type I and Type II HAE. Participants will be randomly assigned to one of three groups: two receiving different doses of ADX-324 and one receiving a placebo. Suitable candidates for this trial are adults with a history of HAE attacks, a diagnosis of Type I or II HAE, and current management of their condition with on-demand treatment. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants a chance to contribute to a potentially groundbreaking treatment.

Will I have to stop taking my current medications?

The trial requires stopping certain medications before joining. You must stop taking ACE inhibitors 4 weeks before, and certain HAE treatments like C1-INH, berotralstat, lanadelumab, and androgens weeks before screening. If you're on estrogen-containing medications, you need to be on a stable dose for at least 3 months before screening.

Is there any evidence suggesting that ADX-324 is likely to be safe for humans?

Research has shown that ADX-324 is generally safe and well-tolerated in people. In previous studies, no serious side effects were reported. Most side effects were mild, with only one moderate case. These findings suggest the treatment is relatively safe. Prospective participants might find this information reassuring. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for hereditary angioedema?

Researchers are excited about ADX-324 for hereditary angioedema (HAE) because it offers a new approach that could enhance treatment effectiveness. Unlike current treatments, which often focus on managing symptoms with C1 inhibitors or bradykinin receptor antagonists, ADX-324 may work by targeting different pathways involved in HAE attacks. This could potentially offer better control over the frequency and severity of attacks. Additionally, the different dose levels being tested could provide more personalized treatment options, which is a promising development for individuals with varying attack rates.

What evidence suggests that ADX-324 might be an effective treatment for hereditary angioedema?

Research has shown that ADX-324 might help reduce attacks in people with hereditary angioedema (HAE). Early results indicate that ADX-324 lowers the amount of a protein called prekallikrein (PKK), which contributes to HAE attacks, for at least three months. This reduction could prevent attacks more reliably and with less frequent doses than current treatments. While this is encouraging, researchers are still collecting more information about its effectiveness specifically for HAE in humans. However, these early signs suggest that ADX-324 could improve attack prevention for those with HAE. Participants in this trial will receive either ADX-324 at one of two dose levels or a placebo, allowing researchers to further evaluate its effectiveness and safety. ^{3 4 5 6 7}

Who Is on the Research Team?

Masako Murai, MD

Principal Investigator

ADARx Pharmaceuticals, Inc.

Are You a Good Fit for This Trial?

This trial is for people with Hereditary Angioedema (HAE), specifically those who have a certain level of C1-INH function and antigen, a pathogenic mutation in the SERPING1 gene, complement factor C4 below normal levels, onset of HAE by age 30, and family history of HAE. It's not open to individuals outside these specific criteria.

Inclusion Criteria

Provided written informed consent and any authorizations required by local law and be willing to comply with all study requirements for the duration of the study

Experienced ≥1 Investigator-confirmed HAE attack in the first 4 weeks of Screening or ≥2 Investigator-confirmed HAE attacks in 8 weeks of Screening

I am 18 years old or older.

Exclusion Criteria

Received treatment with another investigational product or device within specified timeframes

History of alcohol or drug abuse within the previous year prior to Screening, or current evidence of substance dependence or abuse and/or self-reported alcoholic intake averaging >3 drinks/day

I have significant kidney disease or a history of nephrotic syndrome.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive ADX-324 or placebo to evaluate efficacy in preventing HAE attacks

25 weeks

Monthly visits

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• ADX-324

Trial Overview The STOP-HAE study is testing ADX-324 against a placebo to see if it's effective and safe for treating Type I and II HAE. The trial will also look at how the body processes the drug, its effects on the body over time, and how it impacts patients' quality of life.

How Is the Trial Designed?

Group I: ADX-324 Dose Level 2 Experimental Treatment 2 Interventions

Participants who meet screening eligibility criteria will be randomized to 1 of 3 treatment groups in a 1:1:1 ratio. Randomization will be stratified by baseline HAE attack rate.

Group II: ADX-324 Dose Level 1 Experimental Treatment 1 Intervention

Participants who meet screening eligibility criteria will be randomized to 1 of 3 treatment groups in a 1:1:1 ratio. Randomization will be stratified by baseline HAE attack rate.

Group III: Placebo Placebo Group 1 Intervention

Participants who meet screening eligibility criteria will be randomized to 1 of 3 treatment groups in a 1:1:1 ratio. Randomization will be stratified by baseline HAE attack rate.

Who Is Running the Clinical Trial?

ADARx Pharmaceuticals, Inc.

Lead Sponsor

Trials

3

Recruited

220+

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06960213

NCT06960213 | STOP-HAE: A Phase 3 Study of ADX-324 ... This Phase 3 study will evaluate the efficacy of 2 dose levels and regimens of ADX-324 in preventing HAE attacks compared with placebo in participants with ...

2. clinicaltrialsarena.com clinicaltrialsarena.com/news/adarx-first-subject-phaseiii-adx324/

ADARx doses first subject in Phase III trial of ADX-324 for ... The Phase III placebo-controlled, randomised, double-blind study is evaluating ADX-324's efficacy in adults with HAE. October 23, 2025. Share.

3. clinicaltrials.gov clinicaltrials.gov/study/NCT05691361

Safety, Tolerability, PK, PD of ADX-324 in Healthy ... The first-in-human Phase 1 study will evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of ADX-324 in healthy volunteers (HV) ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1081120623007020

HAE PROPHYLAXIS BY TARGETING PREKALLIKREIN ... The interim outcomes provide preliminary evidence that ADX-324 is safe and significantly decreases PKK levels for at least 3 months. This should translate to ...

5. rarediseaseadvisor.com rarediseaseadvisor.com/news/first-patient-dosed-phase-3-stop-hae-trial-adx-324/

First Patient Dosed in Phase 3 STOP-HAE Trial of ADX-324 If successful, ADX-324 could offer less frequent dosing and more consistent control of HAE attacks compared with current prophylactic therapies.

6. clinicaltrials.gov clinicaltrials.gov/study/NCT05691361

NCT05691361 | Safety, Tolerability, PK, PD of ADX-324 in ... The clinical study described in this protocol is a Phase 1, single-center study evaluating safety, tolerability, PK, and PD of ADX-324.

7. adarx.com adarx.com/safety-tolerability-pk-pd-of-adx-324-in-healthy-volunteers-and-hereditary-angioedema-patients/

Safety, Tolerability, PK, PD of ADX-324 in Healthy ... A Phase 1, Randomized, Placebo-Controlled, Double-Blind Study in Healthy Volunteers and a Phase 2a, Open-Label Study in Patients with Hereditary Angioedema