A Phase 2 interventional study of Anavip and CroFab in Snake Bite and Blood Coagulation Disorders, sponsored by Instituto Bioclon S.A. de C.V.. Completed at 1 site in United States. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2016-04-18.
Sponsored by Instituto Bioclon S.A. de C.V. (part of Laboratorios Silanes S.A. de C.V.) · Phase 2, Interventional, and Treatment
This phase II study was a prospective, randomized, open-label, multi-center study in the United States, involving patients from 18 to 70 years of age, comparing Anavip (Antivenin Crotalinae [pit viper] equine immune F(ab)2; Instituto Bioclon, Mexico City, Mexico) against CroFab (Protherics Inc., Nashville, Tennessee), the only currently approved product for treatment of Crotalinae (pit viper) envenomation in the US.
The study was designed to evaluate the hypothesis that lasting correction of snakebite induced thrombocytopenia and hypofibrinogenemia are possible following correction with F(ab)2 antivenom, by analyzing in detail the relationships among platelet count, fibrinogen, venom levels, and antivenom levels in subjects presenting with thrombocytopenia following crotaline viper envenomation. In the study we expected to see a fall in platelet count following Fab treatment, commensurate with that reported in the past. We hypothesized that following F(ab)2 treatment there would be a slower drop in post-treatment platelet counts, with a relatively higher platelet count at any given point in the follow-up period. We further hypothesized that an initial rise and later fall in platelet count would correspond with rise and fall in antivenom levels, and would be mirrored by concurrent drop and rise in levels of unbound circulating venom.
The overall objective of this Phase 2 open-label comparative study was to demonstrate that the F(ab)2 antivenom Anavip has significantly longer plasma persistence than does Fab, and that this is associated with a slower rise in venom levels and slower decline in platelet count and fibrinogen following hospital discharge of envenomated subjects. The effectiveness of F(ab)2 in preventing the recurrence of coagulopathies after the subject's discharge from hospital will indicate that, inherently, F(ab)2 antivenom has an improved safety profile relative to the Fab antivenom CroFab in treating envenomation by crotaline vipers.
Each subject was assessed for quantitative serum venom levels. Relatively few historical data exist to support the use of venom levels as a surrogate endpoint in envenomation. However, changes in venom levels have been correlated with coagulopathic effects, during both the acute phase of venom toxicity and the post treatment period of recurrent venom effect. Validation of this surrogate endpoint via correlation of venom effect with platelet count and fibrinogen level in this phase II study is intended to support future studies.
The secondary endpoints were the determination of coagulation abnormalities during the follow up period.
38 studies on the registry are indexed under Snake Bites; 11 are open to participants now.
This study's enrollment of 12 is below the median of 70 across 18 interventional studies indexed under Snake Bites.
Browse Snake Bites studies →Instituto Bioclon S.A. de C.V. is the lead sponsor of 11 studies on the registry; none are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The initial dose of study drug was administered in a total volume of 500 mL (initial doses only) IV over 30 minutes for Anavip
Biological: Anavip
The initial dose of study drug was administered in a total volume of 500 mL (initial doses only) IV over 60 minutes for CroFab, or as permitted by IV access.
Biological: CroFab
Anavip, 10 vials Intravenous (IV) every 2 hours until initial control has been achieved; then 3 maintenance doses of 4 vials every 6 hrs
Also known as: Antivenin Crotalinae (pit viper) equine immune F(ab)2
CroFab, 5 vials Intravenous (IV) every 2 hours until initial control has been achieved; then 3 maintenance doses of 2 vials every 6 hrs
Detection of Plasma Venom Levels During the Post Acute Treatment Period.
Time frame: Follow up after Maintenance doses were completed. Two Weeks.
>50,000 Platelets/mm3
Thrombocytopenia during follow up period. Two weeks
Time frame: Follow up after maintenance dose
Subjects arriving at participating centers with a pit viper bite were evaluated with respect to the inclusion/exclusion criteria.
| Milestone | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom |
|---|---|---|
| Started | 6 | 6 |
| Completed | 6 | 6 |
| Not completed | 0 | 0 |
| participants | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom |
|---|---|---|
| Detectable venom | 0 | 4 |
| Undetectable venom | 6 | 2 |
Thrombocytopenia during follow up period. Two weeks
| participants | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom |
|---|---|---|
| Thrombocytopenia present | 0 | 3 |
| Thrombocytopenia absent | 6 | 3 |
Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | — | — | 6/6 (100%) |
| CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom | — | — | 6/6 (100%) |
| Event | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom |
|---|---|---|
| Rehospitalization for treatment of thrombocytopeniaBlood and lymphatic system disorders | 0/6 | 1/6 |
| Event | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom |
|---|---|---|
| pruritusSkin and subcutaneous tissue disorders | 2/6 | 5/6 |
| RashSkin and subcutaneous tissue disorders | 1/6 | 3/6 |
| insomniaPsychiatric disorders | 1/6 | 3/6 |
| NauseaGastrointestinal disorders | 0/6 | 2/6 |
| VomitingGastrointestinal disorders | 0/6 | 2/6 |
| pruritus generalisedSkin and subcutaneous tissue disorders | 0/6 | 2/6 |
| hyperhidrosisSkin and subcutaneous tissue disorders | 2/6 | 0/6 |
| petechiaeSkin and subcutaneous tissue disorders | 0/6 | 2/6 |
| erythemaSkin and subcutaneous tissue disorders | 0/6 | 2/6 |
| thrombocytopeniaBlood and lymphatic system disorders | 0/6 | 2/6 |
| Age, Categorical(Participants) | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 6 | 6 | 12 |
| >=65 years | 0 | 0 | 0 |
| Age, Continuous(years) | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom | Total |
|---|---|---|---|
| Mean | 50.2 ± 4.8 | 40.7 ± 16.5 | 45.3 ± 12.6 |
| Sex: Female, Male(Participants) | Anavip Crotalinae (Pit Viper) Equine Immune F(ab)2 Antivenom | CroFab Crotalidae Polyvalent Immune Fab, Ovine Antivenom | Total |
|---|---|---|---|
| Female | 5 | 1 | 6 |
| Male | 1 | 5 | 6 |
Plan to share: Undecided
No publications or documents are linked to this record.
The record gives a start of Jan 2005, a primary completion of Aug 2006 and a completion of Feb 2007. It does not say whether these dates are actual or estimated.
Results were first posted in Mar 2009, 2 years 7 months after primary completion.
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This study is completed, as verified in Mar 2016. You cannot join it, but the record below documents what was studied.
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