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Prescribing Information
Important Safety Information
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Efficacy of CroFab

CroFab Is Clinically Proven to Arrest Local Injury, Resolve Systemic Effects, and Reduce Hematologic Effects of Envenomation 

 

Clinically Proven to Achieve Initial and Clinically Relevant Control of North American Pit Viper Envenomation 

Initial Control Chart

Based on 2 open-label trials with 42 patients with mild or moderate envenomation. Exclusion criteria for both trials included envenomation by copperhead snakes. In study 1, patients were given up to 2 doses of 4 vials each to gain initial control. In study 2, patients were given up to 2 doses of 6 vials each to gain initial control. 

Level 1 Evidence Specifically for Copperhead Envenomation 

    Improved Functioning

    CroFab Administration Resulted in Improved Limb Function Following Copperhead Envenomation 

    Improved Limb Function Graph


    Source: Gerardo CJ et al. Ann Emerg Med. 2017;70(2):233-244.e3.

    Clinically meaningful and statistically significant improvements in limb function at 7, 10, and 14 days following envenomation compared with placebo (P<0.05) for all 3 time points). 

    PSFS, Patient-Specific Functional Scale.
    Based on a double-blind, placebo-controlled trial with 74 patients with mild or moderate envenomation.
    Patients with severe envenomation were excluded. Patients were given up to 2 doses of 6 vials each to gain initial control. 

    Shortened Time to Complete Recovery

    Early Administration of CroFab Resulted in Shorter Time to Complete Recovery 

    Post Envenomation Graph


    Early administration of CroFab resulted in significantly shorter median time to full recovery compared with later treatment (17 vs 28 days respectively, P=0.025).

    Based on a secondary analysis of a double-blind, placebo-controlled trial with 45 patients with mild or moderate envenomation. Patients with severe envenomation were excluded. Patients were given up to 6 vials each to gain initial control. Early treatment was defined as treatment within 5.47 hours post envenomation, and later treatment was defined as treatment that occurred 5.47 or more hours post envenomation.

    Reduced Use of Opiods

    CroFab Administration Resulted in Less Opioid Use ,*

    Reduced Opioid Use Graph

     

    • Treatment with CroFab was associated with less opioid use at all time points (up to 28 days post treatment) 
    • Patients treated with CroFab discontinued opioid use by 3 weeks compared with 3 months for untreated patients 

    Patients who received placebo were over 5 times more likely to require opioids than those who received CroFab ,‡

    *Based on a double-blind, placebo-controlled trial with 74 patients with mild or moderate envenomation. Patients with severe envenomation were excluded. Patients were given up to 2 doses of 6 vials each to gain initial control.
    †On Day 28 post envenomation, 1 patient receiving CroFab continued to take a daily opioid prescribed for anxiety prior to study initiation. 
    ‡Based on a secondary analysis of opioid use post discharge. Two patients were excluded from the secondary analysis. 

    Watch Dr. Rutherfoord Rose discuss using CroFab to treat copperhead envenomation.

    CroFab Clinical Studies

    Review publications evaluating efficacy and safety for CroFab

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    CroFab safety is backed by more than 20 years of clinical experience 

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    Appropriate dosing achieves initial and sustained control of envenomation 

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    Real-world use supports improved outcomes with CroFab 

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    References

    1. CroFab®. Prescribing information. BTG International Inc.; August 2018.

    2. WHO Expert Committee on Biological Standardization. WHO Technical Report Series, No. 1004, Annex 5; 2017. Accessed September 13, 2023. https://cdn.who.int/media/docs/default-source/biologicals/blood-products/document-migration/antivenomglrevwho_trs_1004_web_annex_5.pdf?sfvrsn=ef4b2aa5_3&download=true.

    3. Data on file. BTG International Inc.

    4. Tasoulis T, Isbister GK. Toxins (Basel). 2017;9(9):290

    5. Gutiérrez JM et al. [Erratum in: Nat Rev Dis Primers. 2017;3:17079]. Nat Rev Dis Primers. 2017;3:17063.

    6. Strickland JL et al. Sci Rep. 2018;8(1):17622.

    7. Riley BD et al. In: Nelson LS et al, eds. Goldfrank’s Toxicologic Emergencies. 9th ed. McGraw-Hill Professional; 2010.

    8. Borja M et al. Toxins (Basel). 2018;10(1):35.

    Indication and Important Safety Information
    Indication

    CroFab® Crotalidae Polyvalent Immune Fab (Ovine) is a sheep-derived antivenin indicated for the management of adult and pediatric patients with North American crotalid envenomation. The term crotalid is used to describe the Crotalinae subfamily (formerly known as Crotalidae) of venomous snakes which includes rattlesnakes, copperheads and cottonmouths/water moccasins.

    Important Safety Information
    Contraindications

    Do not administer CroFab® to patients with a known history of hypersensitivity to any of its components, or to papaya or papain unless the benefits outweigh the risks and appropriate management for anaphylactic reactions is readily available.

    Warnings and Precautions

    Coagulopathy: In clinical trials, recurrent coagulopathy (the return of a coagulation abnormality after it has been successfully treated with antivenin), characterized by decreased fibrinogen, decreased platelets, and elevated prothrombin time, occurred in approximately half of the patients studied; one patient required re-hospitalization and additional antivenin administration. Recurrent coagulopathy may persist for 1 to 2 weeks or more. Patients who experience coagulopathy due to snakebite should be monitored for recurrent coagulopathy for up to 1 week or longer. During this period, the physician should carefully assess the need for re-treatment with CroFab® and use of any type of anticoagulant or anti-platelet drug.

    Hypersensitivity Reactions: Severe hypersensitivity reactions may occur with CroFab®. In case of acute hypersensitivity reactions, including anaphylaxis and anaphylactoid reactions, discontinue infusion and institute appropriate emergency treatment. Patients allergic to papain, chymopapain, other papaya extracts, or the pineapple enzyme bromelain may also have an allergic reaction to CroFab®. Follow-up all patients for signs and symptoms of delayed allergic reactions or serum sickness (e.g., rash, fever, myalgia, arthralgia).

    Adverse Reactions

    The most common adverse reactions (incidence ≥ 5% of subjects) reported in the clinical studies were urticaria, rash, nausea, pruritus and back pain. Adverse reactions involving the skin and appendages (primarily rash, urticaria, and pruritus) were reported in 12 of the 42 patients. Two patients had a severe allergic reaction (severe hives and a severe rash and pruritus) following treatment and one patient discontinued CroFab® due to an allergic reaction. Recurrent coagulopathy due to envenomation and requiring additional treatment may occur.

    Please see full Prescribing Information.