Efficacy and Safety Study of DX-88 to Treat Acute Attacks of Hereditary Angioedema (HAE)

This study has been completed.
Information provided by:
Dyax Corp.
ClinicalTrials.gov Identifier:
First received: December 5, 2005
Last updated: April 9, 2010
Last verified: April 2010
The purpose of this study is to determine if a subcutaneous dose of DX-88 (ecallantide; an investigational product) is safe and relieves symptoms of HAE in patients suffering from moderate to severe acute attacks of HAE.

Condition Intervention Phase
Hereditary Angioedema (HAE)
Drug: ecallantide
Drug: Phosphate Buffer Saline (PBS),
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Double-blind, Placebo-controlled Study (72 Patients, Randomized 1:1) Followed by a Repeat-dosing Phase to Assess the Efficacy and Safety of DX-88 (Ecallantide; Recombinant Plasma Kallikrein Inhibitor) for the Treatment of Acute Attacks of Hereditary Angioedema

Resource links provided by NLM:

Further study details as provided by Dyax Corp.:

Primary Outcome Measures:
  • Treatment Outcome Score at 4 Hours Post-Dose [ Time Frame: 4 hours post-dose (DOUBLE-BLIND PART) ] [ Designated as safety issue: No ]
    Treatment Outcome Score (TOS) is a validated, comprehensive measure of symptom response to treatment. At 4 hours , patient assessment of response characterized by their change from baseline in symptom severity and collected by anatomic site of attack involvement, was recorded on a categorical scale (significant improvement [100] to significant worsening [-100]). The response at each anatomic site was weighted by baseline severity and then the weighted scores across all involved sites were averaged to calculate the TOS. Clinically meaningful improvement was indicated by a TOS of 30 or higher.

Secondary Outcome Measures:
  • Change From Baseline in Mean Symptom Complex Severity (MSCS) Score at 4 Hours Post-dose [ Time Frame: baseline, 4 hours post-dose (DOUBLE-BLIND PART) ] [ Designated as safety issue: No ]
    Mean Symptom Complex Severity (MSCS) score is a validated, comprehensive point-in-time measure of symptom severity. At baseline and 4 hours, patients rated the severity on a categorical scale (0 = normal, 1 = mild, 2 = moderate, 3 = severe) for symptoms at each affected anatomical location. Ratings were averaged to obtain the MSCS score. A decrease in MSCS score reflected an improvement in symptoms; clinically meaningful improvement (minimally important difference) was indicated by a reduction in the score of 0.30 or more.

  • Time to Significant Improvement in Overall Response [ Time Frame: 4 hours post-dose (DOUBLE-BLIND PART) ] [ Designated as safety issue: No ]
    The overall response assessment is a patient-reported assessment of global response to therapy. Patients are asked to perform an overall response assessment at regular intervals, relative to baseline. Patients were asked "overall how are you feeling" compared to how they felt before study drug. Answer options were "a lot worse", "a litte worse", "same", "a little better" or "a lot better or resolved". Significant improvement was the first time that the patient responded to the assessment as "a little better or resolved". The results are by the number of patients reproting.

Enrollment: 91
Study Start Date: December 2005
Study Completion Date: February 2007
Primary Completion Date: December 2005 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: DX-88 (ecallantide)
DX-88 (ecallantide) 30 mg given as three 10 mg/mL subcutaneous injections.
Drug: ecallantide
dose of 30 mg (10 mg/ml) given as 3 subcutaneous injections.
Other Name: DX-88
Placebo Comparator: Placebo
Phosphate Buffer Saline (PBS), pH 7.0 given as 3 subcutaneous injections.
Drug: Phosphate Buffer Saline (PBS),
given as three 1mL subcutaneous injections.


Ages Eligible for Study:   10 Years and older   (Child, Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 10 and older
  • Documented diagnosis of HAE, Type I or II
  • Executed informed consent
  • Presentation for treatment within 8 hours of patient recognition of moderate to severe HAE attack

Exclusion Criteria:

  • Receipt of investigational drug or device, other than DX-88, within 30 days of treatment
  • Receipt of non-investigational C1-INH within 7 days of treatment
  • Diagnostic of acquired angioedema, estrogen-dependent angioedema or drug induced angioedema
  • Pregnancy or breastfeeding
  • Patients who have received DX-88 within 7 days of presentation for dosing in the Double-blind Phase
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00262080

United States, Maryland
Institute for Asthma and Allergy
Wheaton, Maryland, United States, 20902
Sponsors and Collaborators
Dyax Corp.
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Bill Pullman, MD, PhD, Executive Vice President, Chief Development Officer, Dyax Corp.
ClinicalTrials.gov Identifier: NCT00262080     History of Changes
Other Study ID Numbers: EDEMA3 (DX-88/14) 
Study First Received: December 5, 2005
Results First Received: December 30, 2009
Last Updated: April 9, 2010
Health Authority: United States: Food and Drug Administration

Additional relevant MeSH terms:
Angioedemas, Hereditary
Vascular Diseases
Cardiovascular Diseases
Skin Diseases, Vascular
Skin Diseases
Hypersensitivity, Immediate
Immune System Diseases
Genetic Diseases, Inborn

ClinicalTrials.gov processed this record on August 25, 2016