To evaluate the safety profile of intravitreal injection of Stivant (biosimilar of the bevacizumab) in rabbits using electrophysiological and histologic analysis.

Both eyes of the forty-one New Zealand albino rabbits were injected with 0.1 mL (2.5 mg) Stivant drug. The rabbits were scheduled to be sacrificed 1, 2, 7, 14 and 28 days after injection for histopathologic evaluations. Clinical examinations and Electro-retinograms (ERGs) were done at baseline and just before sacrificing the rabbits. Fourteen separate rabbits were received the reference drug (Avastin) and considered as a control group, also three other rabbits were received the same volume of saline. Both of the control groups were sacrificed 4 weeks after injection, although ERG was done at 1, 2, 7, 14 and 28 days after injections.

There were no significant differences in a- and b-wave amplitude and latency after intravitreal Stivant injection between baseline and different time points. Also, there was no statistically significant difference in the waves amplitude and latency between the Stivant and control groups. The histology of both Stivant and control eyes after intravitreal injections was not distinguishable.

The biosimilar Stivant up to 2.5 mg dosage did not appear to be toxic to the retina in albino rabbits. These results suggest that this drug could become a safe, cost-benefit therapy for intravitreal injections. Intravitreally injected Stivant should be evaluated for efficacy in the next studies.