The SnaFab versus the Razi antivenom for treatment of snakebite envenomation: A randomized, double-blind (investigator and victims), active controlled, non-inferiority clinical trial

Snakebite envenomation is a significant public health issue in Iran, and it is crucial to have effective and easily accessible antivenom treatments. This study aimed to evaluate the non-inferiority of the SnaFab and the Razi antivenoms for treating snakebite envenomation. The study was a randomized, double-blind, multicenter, active-controlled, non-inferiority trial involving 98 snakebite victims. The patients received either the SnaFab or the Razi antivenoms, with the primary endpoint being the recovery rate within 48 hours after antivenom infusion. The secondary endpoints included adverse events over a 14-day monitoring period and total antivenom consumption. The non-inferiority margin (NIM) was set at 20 percent. The study was commenced on April 17th, 2020, and concluded on May 15th, 2021. The recovery rate was 100 percent in the SnaFab group, which was non-inferior to the Razi antivenom group (98%). The mean number of antivenom units administered was 8.95 ± 4.40 units in the SnaFab group, compared to 9.04 ± 4.49 units in the Razi group (P value: 0.92). Adverse events were reported by 10.2% of individuals in the SnaFab group and 20.4% in the Razi group (p value = 0.27). Muscle weakness was the most commonly reported adverse event in the Razi group (8%), while vertigo was most frequent in the SnaFab group (4%). Moreover, there were no reports of anaphylactic shock or serum sickness. In summary, this study found that SnaFab antivenom is non-inferior to Razi antivenom for treating snakebite envenomation in Iran. Overall, the incidence of adverse events was comparable between groups, with no statistically significant differences observed.