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

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00657540
First Posted: April 14, 2008
Last Update Posted: September 18, 2017
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.
Collaborator:
Rare Disease Therapeutics Inc.
Information provided by (Responsible Party):
Instituto Bioclon S.A. de C.V.
Results First Submitted: August 16, 2017  
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
  Hide Participant Flow

Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Due to the nature of the treatment emergent condition of interest, no patients were actively recruited. Potential subjects presenting with moderate to severe pain associated with diagnosed latrodectism were evaluated at 16 sites across the United States. The first subject was enrolled on 10/08/09. The last subject completed the study on 10/27/14.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
No text entered.

Reporting Groups
  Description
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


Participant Flow:   Overall Study
    Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline
STARTED   29   31 
COMPLETED   28 [1]   27 [1] 
NOT COMPLETED   1   4 
Lost to Follow-up                1                4 
[1] All subjects had know treatment failure disposition at time of loss to follow-up.



  Baseline Characteristics
  Hide 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
  Description
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 
Age 
[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]
     
United States   29   31   60 
Baseline VAS Pain Score (mm) 
[Units: Mm]
Mean (Standard Deviation)
 79.7  (13.16)   73.8  (16.14)   76.7  (14.96) 


  Outcome Measures
  Hide All Outcome Measures

1.  Primary:   Proportion of Treatment Failures   [ Time Frame: From start of Dose 1 infusion to 48 hours post treatment ]

Measure Type Primary
Measure Title Proportion of Treatment Failures
Measure Description

The primary efficacy endpoint for this study was the proportion of subjects in which pain control was not achieved 48 hours post-study drug infusion as identified by treatment failure. A treatment failure was defined as a subject who did not achieve pain control during the treatment phase, up to 48 hours after Dose 1 infusion start time. Subjects were deemed treatment failures if they met one or more of the following criteria:

  • Subject did not complete the treatment phase due to absence of clinically significant improvement in pain intensity relative to baseline at 60, 90, 120, or 150 minutes post start of Dose 1.
  • Subject required treatment with commercially available antivenin or prescription pain medication for signs and symptoms associated with latrodectism at any time during the treatment phase up to 48 hours after Dose 1 infusion start time.
Time Frame From start of Dose 1 infusion to 48 hours post treatment  

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 subjects that were randomized and received any study drug (modified intent to treat population).

Reporting Groups
  Description
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


Measured Values
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline 
Participants Analyzed 
[Units: Participants]
 29   31 
Proportion of Treatment Failures 
[Units: Participants]
Count of Participants
 15   24 


Statistical Analysis 1 for Proportion of Treatment Failures
Groups [1] All groups
Statistical Test Type [2] Superiority or Other
Statistical Method [3] Chi-squared
P Value [4] 0.0185
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  No text entered.
[2] Details of power calculation, definition of non-inferiority margin, and other key parameters:
  No text entered.
[3] Other relevant method information, such as adjustments or degrees of freedom:
  The proportion of treatment failures was compared between groups using a one-sided test at the 0.025 level of significance.
[4] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.



2.  Secondary:   Reduction in Pain Intensity   [ Time Frame: 30 minutes post treatment ]

Measure Type Secondary
Measure Title Reduction in Pain Intensity
Measure Description The proportion of patients with a clinically significant decrease in pain intensity at 30 minutes post-treatment (after Dose 1 and Dose 2, as applicable) will be measured by the patient's self-assessment of pain intensity using the visual analog scale (VAS). A clinically significant reduction in pain is defined as a decrease in VAS scores of greater than or equal to 13 mm.
Time Frame 30 minutes post treatment  

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.
No text entered.

Reporting Groups
  Description
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


Measured Values
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline 
Participants Analyzed 
[Units: Participants]
 29   31 
Reduction in Pain Intensity 
[Units: Participants]
Count of Participants
 13   11 


Statistical Analysis 1 for Reduction in Pain Intensity
Groups [1] All groups
Statistical Test Type [2] Superiority or Other
Statistical Method [3] Chi-squared
P Value [4] 0.2302
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  No text entered.
[2] Details of power calculation, definition of non-inferiority margin, and other key parameters:
  No text entered.
[3] Other relevant method information, such as adjustments or degrees of freedom:
  Chi-squared tests at the 0.025 level of significance were used to test for a difference in proportions between the treatment groups.
[4] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.



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

Measure Type Secondary
Measure Title Drug-related Adverse Events
Measure Description To evaluate safety of Analatro, the proportion of subjects experiencing at least one adverse event (AE) that was determined to be related to study drug was computed for each treatment group. All AEs classified as definitely or possibly related to study drug were considered drug-related.
Time Frame Start of Dose 1 through 17 days post treatment  

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.
No text entered.

Reporting Groups
  Description
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


Measured Values
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline 
Participants Analyzed 
[Units: Participants]
 29   31 
Drug-related Adverse Events 
[Units: Participants]
Count of Participants
 16   18 


Statistical Analysis 1 for Drug-related Adverse Events
Groups [1] All groups
Statistical Test Type [2] Superiority or Other
Statistical Method [3] Chi-squared
P Value [4] 0.8213
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  No text entered.
[2] Details of power calculation, definition of non-inferiority margin, and other key parameters:
  No text entered.
[3] Other relevant method information, such as adjustments or degrees of freedom:
  The proportion of subjects with at least one drug-related adverse event by treatment groups using a two-sided test at the 0.05 level of significance.
[4] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.



4.  Secondary:   Reduction in Pain Intensity   [ Time Frame: Start of Dose 1 to any post-infusion time point ]

Measure Type Secondary
Measure Title Reduction in Pain Intensity
Measure Description The proportion of patients with a clinically significant decrease in pain intensity relative to baseline at any time point during the treatment phase was measured by the patient's self-assessment of pain intensity using the visual analog scale (VAS). A clinically significant reduction in pain was defined as a decrease in VAS scores of greater than or equal to 13 mm.
Time Frame Start of Dose 1 to any post-infusion time point  

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.
No text entered.

Reporting Groups
  Description
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


Measured Values
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline 
Participants Analyzed 
[Units: Participants]
 29   31 
Reduction in Pain Intensity 
[Units: Participants]
Count of Participants
 19   18 


Statistical Analysis 1 for Reduction in Pain Intensity
Groups [1] All groups
Statistical Test Type [2] Superiority or Other
Statistical Method [3] Chi-squared
P Value [4] 0.2765
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  No text entered.
[2] Details of power calculation, definition of non-inferiority margin, and other key parameters:
  No text entered.
[3] Other relevant method information, such as adjustments or degrees of freedom:
  The proportion of subjects with decreased pain at any time point between treatment groups using a one-sided test at the 0.025 level of significance.
[4] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.



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

Measure Type Secondary
Measure Title Drug-related Serious Adverse Events
Measure Description The proportion of subjects with drug-related serious adverse events.
Time Frame Start of Dose 1 through 17 days post treatment  

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.
No text entered.

Reporting Groups
  Description
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


Measured Values
   Antivenin Latrodectus (Black Widow) Equine Immune F(ab)2   Normal Saline 
Participants Analyzed 
[Units: Participants]
 29   31 
Drug-related Serious Adverse Events 
[Units: Participants]
Count of Participants
 0   0 

No statistical analysis provided for Drug-related Serious Adverse Events




  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats
  Hide 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
  Hide 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
e-mail: victoria.anderson@rmpdc.org



Responsible Party: Instituto Bioclon S.A. de C.V.
ClinicalTrials.gov 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: September 18, 2017