Streamlined downstream process for efficient and sustainable (Fab')2 antivenom preparation

• Published in: Journal of Venomous Animals and Toxins including Tropical Diseases
• Main Authors: Tihana Kurtović, Marija Brgles, Maja Lang Balija, Stephanie Steinberger, Dora Sviben, Martina Marchetti-Deschmann, Beata Halassy
• Format: Article in Journal/Newspaper
• Language: English
• Published: SciELO 2020
• Subjects: Antivenom downstream processing; F(ab')2 immunotherapy; Hyperimmune plasma; Ion-exchange chromatography; Mass spectrometry; Arctic medicine. Tropical medicine; RC955-962; Toxicology. Poisons; RA1190-1270; Zoology; QL1-991; Arctic
• Online Access: https://doi.org/10.1590/1678-9199-jvatitd-2020-0025; https://doaj.org/article/99c1ce2a234c4c67ae62bada9f56bf83

Abstract Background: Antivenoms are the only validated treatment against snakebite envenoming. Numerous drawbacks pertaining to their availability, safety and efficacy are becoming increasingly evident due to low sustainability of current productions. Technological innovation of procedures generating therapeutics of higher purity and better physicochemical characteristics at acceptable cost is necessary. The objective was to develop at laboratory scale a compact, feasible and economically viable platform for preparation of equine F(ab')2 antivenom against Vipera ammodytes ammodytes venom and to support it with efficiency data, to enable estimation of the process cost-effectiveness. Methods: The principle of simultaneous caprylic acid precipitation and pepsin digestion has been implemented into plasma downstream processing. Balance between incomplete IgG breakdown, F(ab')2 over-digestion and loss of the active drug's protective efficacy was achieved by adjusting pepsin to a 1:30 substrate ratio (w/w) and setting pH at 3.2. Precipitation and digestion co-performance required 2 h-long incubation at 21 °C. Final polishing was accomplished by a combination of diafiltration and flow-through chromatography. In vivo neutralization potency of the F(ab')2 product against the venom's lethal toxicity was determined. Results: Only three consecutive steps, performed under finely tuned conditions, were sufficient for preservation of the highest process recovery with the overall yield of 74%, comparing favorably to others. At the same time, regulatory requirements were met. Final product was aggregate- and pepsin-free. Its composition profile was analyzed by mass spectrometry as a quality control check. Impurities, present in minor traces, were identified mostly as IgG/IgM fragments, contributing to active drug. Specific activity of the F(ab')2 preparation with respect to the plasma was increased 3.9-fold. Conclusion: A highly streamlined mode for production of equine F(ab')2 antivenom was engineered. In addition to ...