Date

2025-07-20

Protocol

Protocol changed

Item Changed

Intervention(s) planned

Previous Version

At first, about 20 patients with snakebite eligible to receive ASV will be randomized for a safety study of the candidate ASV. Having established the safety, the study will enroll a further 40 patients. Patients who attend the hospital emergency and are clinically eligible to receive ASV will be stabilized and then administered ASV intravenously. Investigations and management will be as per standard of care, till the discharge of the patient Intervention- Snake Venom Antiserum, I.P. is a sterile solution containing enzyme-refined anti-snake venom equine immunoglobulin F(ab’)2 fragments for parenteral administration. Snake Venom Antiserum is supplied in 10 ml glass vial with 10 ml sterile water for injection, as diluent. The diluent will be withdrawn in to a 10 ml sterile syringe and the needle inserted through the vial stopper and injected to the powder. The contents will be mixed gently by a swirling action. The serum will be used as soon as possible after reconstitution. Administration is by slow IV infusion over one hour. The dose (number of vials used and frequency) will depend on envenomation. Comparator- ANTI-SNAKE VENOM SERUM, I.P. (ASVS).

Next Version

The trial will be conducted as a phase II/III study. The sample size is 130 participants (100 of Big 4 snakebites and 30 of hump-nosed viper bites). Initially, 40 cases of Big 4 will be recruited, including the intervention arm-20 and the comparator arm 20. Then, an interim analysis after 40 cases will be done. After that, the remaining 60 will be recruited as the intervention arm-30 and the comparator arm-30. For the dose-finding study, 30 cases of HNV bites that will require AVS during this one year will be recruited. Patients who attend the hospital emergency and are clinically eligible to receive ASV will be stabilized and then administered ASV intravenously. Investigations and management will be as per standard of care, till the discharge of the patient. Intervention- Sri Lanka specific antivenom (SL-AVS) is a sterile solution containing enzyme-refined anti-snake venom equine immunoglobulin F(ab’)2 fragments for parenteral administration. SL-AVS is supplied in a 10 ml glass vial with 10 ml sterile water for injection as diluent. The diluent will be withdrawn into a 10 ml sterile syringe and the needle inserted through the vial stopper and injected into the powder. The contents will be mixed gently by a swirling action. Administration is by slow IV infusion with normal saline over one hour. The dose (number of vials used and frequency) will depend on envenomation. Comparator is the currently used Indian polyvalent antivenom