New Study Shows Patients Treated With CroFab® Have Improved Recovery From Copperhead Envenomation

A study sponsored by BTG plc (LSE: BTG), the global specialist healthcare company, has been recently published in the Annals of Emergency Medicine (AEM) that shows administering CroFab® to patients en

A study sponsored by BTG plc (LSE: BTG), the global specialist healthcare company, has been recently published in the Annals of Emergency Medicine (AEM) that shows administering CroFab® to patients envenomated by copperhead snakes can aid the recovery of a patient’s affected limb function as compared with placebo.

The randomised, double-blind, placebo-controlled study compared CroFab® Crotalidae Polyvalent Immune Fab (Ovine) – the only antivenom currently marketed for the treatment of crotaline snake envenomation – against placebo for the treatment of copperhead snake envenomation for the first time.

Copperhead envenomation is generally considered less severe than other North American Pit Viper snakebites, but more than 95% of copperhead victims still develop significant pain and swelling of the injured limb, and other soft tissue injury. Most patients resume activities within 2-4 weeks but residual symptoms can last for a year.

Dr Charles Gerardo, Chief of Emergency Medicine at Duke University and expert in Copperhead snake envenomation, said: “For the first time, this data demonstrates that CroFab® improves recovery of limb function from Copperhead envenomation. Additionally, antivenom treatment was associated with less opioids use throughout the patient’s recovery. These results can be used to help physicians and patients make a more informed choice about their care.”

In total, 74 patients participated in the study; 45 were treated with CroFab® and the rest received a placebo. All participating trial staff (apart from the study pharmacist) and patients were unaware of the treatment given in each case. Within the patient cohort was a mix of upper and lower extremity conditions depending on where the copperhead had bitten the patient.

The Patient Specific Functional Scale (PSFS) was used to measure study outcomes by assessing each patient’s ability to do daily activities that they were unable to do or had difficulty with post copperhead inflicted injury. The tasks varied from driving a car, climbing the stairs, brushing teeth, or using a cell phone and took in to account the score at envenomation + 14 days using a 0-10 scale. In addition to the positive primary outcome of the study, it was also discovered that opioid analgesic use was less in CroFab® treated patients.

Dan Schneider, SVP and General Manager, Specialty Pharmaceuticals, Commercial Operations at BTG, said: “We are pleased with the clinical study findings that show that patients treated with CroFab® recover faster from Copperhead bites. Even though we haven’t reached summer months yet, we are seeing multiple reports stating that the frequency of bites in the U.S. are on the rise this year. As snake sightings start to pick up, don’t forget to download our free, educational SnakeBite911™ App Suite. It has useful information about the dos and don’ts if envenomation occurs and helps raise awareness about North American Pit Vipers.”

To review the published article in full, please refer to the following link:



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

The most common adverse reactions reported in the clinical studies were urticaria, rash and nausea. 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. Anaphylaxis and hypersensitivity reactions can occur, and patients should be monitored closely during treatment. CroFab® should not be administered to patients with a known history of hypersensitivity to papaya or papain unless the benefits outweigh the risks and appropriate management for anaphylactic reactions is readily available.

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 rehospitalization 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.

About BTG

BTG is a global specialist healthcare company bringing to market innovative products in specialist areas of medicine to better serve doctors and their patients. We have a portfolio of Interventional Medicine products to advance the treatment of cancer, severe emphysema, severe blood clots and varicose veins, and Specialty Pharmaceuticals that help patients overexposed to certain medications or toxins. Inspired by patient and physician needs, BTG is investing to expand its portfolio to address some of today’s most complex healthcare challenges. To learn more about BTG, please visit:

For further information contact:


Andy Burrows, VP Corporate & Investor Relations

+44 (0)20 7575 1741; Mobile: +44 (0)7990 530 605

Chris Sampson, Corporate Communications Director

+44 20 7575 1595; Mobile: +44 7773 251 178

FTI Consulting

Ben Atwell/Simon Conway

+44 (0)20 3727 1000

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