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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00657540
Recruitment Status : Completed
First Posted : April 14, 2008
Results First Posted : September 18, 2017
Last Update Posted : April 3, 2018
Rare Disease Therapeutics Inc.
Information provided by (Responsible Party):
Instituto Bioclon S.A. de C.V.

Study Type: Interventional
Study Design: Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor);   Primary Purpose: Treatment
Condition: Latrodectism
Interventions: Drug: Analatro
Drug: Saline

  Participant Flow

  Baseline Characteristics

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
The analysis population consists of all patients that were randomized and received any study drug (modified intent-to-treat population).

Reporting Groups
Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2

Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2

Analatro: 30 mL of lyophilized antivenom, reconstituted in 50 mL saline infused over 10 minutes, up to 2 doses

Normal Saline

Normal Saline

Saline: 50 mL of saline infused over 10 minutes

Total Total of all reporting groups

Baseline Measures
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline   Total 
Overall Participants Analyzed 
[Units: Participants]
 29   31   60 
[Units: Years]
Mean (Standard Deviation)
 37.3  (15.18)   41.0  (17.84)   39.2  (16.57) 
Sex: Female, Male 
[Units: Participants]
Count of Participants
Female      11  37.9%      8  25.8%      19  31.7% 
Male      18  62.1%      23  74.2%      41  68.3% 
Ethnicity (NIH/OMB) 
[Units: Participants]
Count of Participants
Hispanic or Latino      13  44.8%      17  54.8%      30  50.0% 
Not Hispanic or Latino      16  55.2%      14  45.2%      30  50.0% 
Unknown or Not Reported      0   0.0%      0   0.0%      0   0.0% 
Race (NIH/OMB) 
[Units: Participants]
Count of Participants
American Indian or Alaska Native      3  10.3%      0   0.0%      3   5.0% 
Asian      0   0.0%      0   0.0%      0   0.0% 
Native Hawaiian or Other Pacific Islander      0   0.0%      0   0.0%      0   0.0% 
Black or African American      2   6.9%      0   0.0%      2   3.3% 
White      14  48.3%      20  64.5%      34  56.7% 
More than one race      0   0.0%      0   0.0%      0   0.0% 
Unknown or Not Reported      10  34.5%      11  35.5%      21  35.0% 
Region of Enrollment 
[Units: Participants]
Count of Participants
United States   29   31   60 
Baseline VAS Pain Score (mm) [1] 
[Units: Mm]
Mean (Standard Deviation)
 79.7  (13.16)   73.8  (16.14)   76.7  (14.96) 
[1] The Visual Analog Scale (VAS) ranged from 0 (no pain) to 100 mm (worst possible pain).

  Outcome Measures

1.  Primary:   Number of Participants With Treatment Failure   [ Time Frame: From start of Dose 1 infusion to 48 hours post treatment ]

2.  Secondary:   Number of Participants With at Least 13 mm Reduction in Pain Score at 30 Minutes Post-Treatment   [ Time Frame: 30 minutes post treatment ]

3.  Secondary:   Drug-related Adverse Events   [ Time Frame: Start of Dose 1 through 17 days post treatment ]

4.  Secondary:   Number of Participants With at Least 13 mm Reduction in Pain Score at Any Time Point   [ Time Frame: Start of Dose 1 to any post-infusion time point ]

5.  Secondary:   Drug-related Serious Adverse Events   [ Time Frame: Start of Dose 1 through 17 days post treatment ]

  Serious Adverse Events

  Other Adverse Events

  Limitations and Caveats

Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
The study is limited by the small sample size; however this trial was powered appropriately for an orphan indication. The study is also limited by the difficulty in confirming latrodectism without a spider or clear history of seeing a spider.

  More Information

Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact:  
Name/Title: Victoria Anderson - Research Projects Manager
Organization: Rocky Mountain Poison and Drug Center
phone: 303-389-1236

Responsible Party: Instituto Bioclon S.A. de C.V. Identifier: NCT00657540     History of Changes
Other Study ID Numbers: XF-07/03
First Submitted: April 9, 2008
First Posted: April 14, 2008
Results First Submitted: August 16, 2017
Results First Posted: September 18, 2017
Last Update Posted: April 3, 2018