This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Black Widow Spider Antivenin for Patients With Systemic Latrodectism (BWSP3)

This study has been completed.
Rare Disease Therapeutics Inc.
Information provided by (Responsible Party):
Instituto Bioclon S.A. de C.V. Identifier:
First received: April 9, 2008
Last updated: December 15, 2015
Last verified: December 2015
The purpose of this study is to test the effectiveness and safety of a new antivenom called Analatro® for treating black widow spider bites in patients who present to a hospital emergency room within 24 hours of symptom onset. This study will be a phase III, multi-center, double-blind, randomized controlled study that takes place in emergency departments. The primary aim of this study is to determine the proportion of patients in which pain control was not achieved by 48 hours post treatment. Secondary aims are as follows: 1) a reduction in pain intensity at the end of the treatment phase compared to baseline; 2) the proportion of patients with a clinically significant decrease in pain intensity at 30 minutes post-treatment; 3) the proportion of patients in which drug-related adverse events occurred; and 4) to determine if serious, drug-related adverse events in Analatro-treated patients occurred at a rate greater than one in 10 (10%).

Condition Intervention Phase
Latrodectism Drug: Analatro Drug: Saline Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase III Multicenter Clinical Trial of Analatro® [Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2] in Patients With Systemic Latrodectism

Resource links provided by NLM:

Further study details as provided by Instituto Bioclon S.A. de C.V.:

Primary Outcome Measures:
  • Pain Control [ Time Frame: 48 hours post treatment ]

Secondary Outcome Measures:
  • Serious, drug-related adverse events [ Time Frame: 17 days post treatment ]
  • Reduction in pain intensity [ Time Frame: End of treatment phase ]
  • Reduction in pain intensity [ Time Frame: 30 minutes post treatment ]
  • Drug-related adverse events [ Time Frame: 17 days post treatment ]

Enrollment: 60
Study Start Date: August 2009
Study Completion Date: October 2014
Primary Completion Date: October 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2
Drug: Analatro
30 mL of lyophilized antivenom, reconstituted in 50 mL saline infused over 10 minutes, up to 2 doses
Placebo Comparator: 2
Normal Saline
Drug: Saline
50 mL of saline infused over 10 minutes
Other Name: Placebo

  Show Detailed Description


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

Inclusion Criteria:

  • Moderate to severe pain intensity measured using the visual analog scale (VAS score ≥ 40mm) at the start of screening phase (VAS 0)
  • Diagnosis of latrodectism by the Investigator, with concurrence of diagnosis by a physician not directly involved with the study
  • Moderate to severe pain intensity measured using the visual analog scale (VAS score ≥ 40mm) at Baseline (VAS 1)

Exclusion Criteria:

  • Less than 10 years of age
  • Presents to the emergency department of any healthcare facility greater than 24 hours after onset of symptoms
  • Has a known (self-reported) hypersensitivity to fentanyl, morphine, diazepam, or equine serum
  • History of significant cardiac, respiratory, hepatic or renal disease, psychiatric disorder or chronic pain syndrome that in the investigator's assessment would confound efficacy or safety endpoint assessment (e.g., a bite to the leg of a patient with reflex sympathetic dystrophy)
  • History or suspected history or substance abuse
  • Pregnant or breast-feeding
  • Has a distracting injury with acute pain, or is unable to make a reliable self-report of pain intensity to pain relief based solely on the condition of interest
  • Was already treated with Merck Antivenin Latrodectus Mactans for signs/symptoms related to the current widow spider bite
  • Unable to provide a telephone number to be contacted for follow-up interviews on Days 2, 10, and 17 after discharge from the emergency department
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00657540

United States, Arizona
Banner Good Samaritan Medical Center
Phoenix, Arizona, United States, 85006
Maricopa Medical Center
Phoenix, Arizona, United States, 85008
United States, California
University of California Davis
Davis, California, United States, 95616
University California San Francisco - Fresno
Fresno, California, United States, 93701
University of California Irvine
Irvine, California, United States, 92697
Loma Linda University
Loma Linda, California, United States, 92354
University of California San Diego
San Diego, California, United States, 92103
San Diego Children's Hospital
San Diego, California, United States, 92123
United States, Colorado
University of Colorado Hospital
Aurora, Colorado, United States, 80010
Denver Health and Hospital Authority
Denver, Colorado, United States, 80204
United States, Florida
Cape Coral Hospital
Cape Coral, Florida, United States, 33990
University of Florida, Department of Emergency Medicine
Gainesville, Florida, United States, 32610
United States, Louisiana
LSU Health Sciences
Shreveport, Louisiana, United States, 71106
United States, New Mexico
University of New Mexico
Albuquerque, New Mexico, United States, 87131
United States, Texas
Texas Tech - West Texas Regional Poison Center
El Paso, Texas, United States, 79905
United States, Virginia
University of Virginia Health System
Charlottesville, Virginia, United States, 22908
Sponsors and Collaborators
Instituto Bioclon S.A. de C.V.
Rare Disease Therapeutics Inc.
Principal Investigator: Richard C Dart, MD, PhD Rocky Mountain Poison & Drug Center - Denver Health
Study Director: Walter Garcia, MD Instituto Bioclon S.A. de C.V.
  More Information

Responsible Party: Instituto Bioclon S.A. de C.V. Identifier: NCT00657540     History of Changes
Other Study ID Numbers: XF-07/03
Study First Received: April 9, 2008
Last Updated: December 15, 2015

Keywords provided by Instituto Bioclon S.A. de C.V.:
black widow spider

Additional relevant MeSH terms:
Immunologic Factors
Physiological Effects of Drugs processed this record on August 18, 2017