Abstract
Purpose :
Reference product (RP) aflibercept (Eylea®) is a soluble decoy VEGF-A receptor which reduces angiogenesis and vascular permeability, lessening vascular inflammation and leukocyte infiltration and downstream vision loss in several macular related diseases. AVT06, a proposed biosimilar medicine to RP aflibercept, is formulated with different excipients than RP. Alvotech performed an in vitro proliferation and cytotoxicity cell-based assay to compare RP vehicle, RP aflibercept, AVT06 vehicle, and AVT06 to assess any effect of the different excipients.
Methods :
Human retinal microvascular endothelial cells (HRMEC) were incubated with physiologically relevant concentrations of AVT06 vehicle, AVT06 drug substance or drug product, RP vehicle, or RP drug product (2 batches), for 72 hours. Different volumes of compound represented different ratios between compound and cell growth medium. The effect on cell proliferation was determined using an ATPlite Luminescence Assay (Perkin Elmer; Figure 1). Results are expressed as total luminescence signal. Mean values, standard deviation, and coefficient of variation of test and control samples were calculated by GraphPad Prism and Microsoft Excel.
Results :
No increased toxicity was observed between AVT06 vehicle exposure and RP vehicle exposure (Figure 2). Similar results were observed after exposure to the respective drug product/ substance (Figure 2). AVT06 vehicle demonstrated comparable toxicity at a three times higher volume compared to RP vehicle. AVT06 vehicle and AVT06 drug product showed similar toxicity when compared, as did RP vehicle and RP drug product.
Conclusions :
Based on a typical volume of around 3 mL, treatment in the vitreous humor with 50µl RP leads to a final dilution of a 1:60. The highest non-toxic dilution of AVT06 vehicle in this in vitro proliferation and cytotoxicity assay is 1:21, a three times lower dilution then the anticipated in vivo situation. A similar pattern of lower toxicity can be observed after AVT06 and RP drug product exposure. Based on these data it is expected that treatment of the eye with 50µl of AVT06 will have no increased toxic effect due to the different excipients in AVT06 compared with RP, with or without drug product/ substance, at the relevant physiological concentration and volume-to-cell ratio.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.