Comparative Efficacy and Safety of Biosimilar Bevacizumab (Stivant®) versus Reference Product (Avastin®) in Prethreshold Type I Retinopathy of Prematurity.

Purpose: To compare the efficacy and safety of Stivant® (biosimilar bevacizumab, CinnaGen, Iran) to Avastin® (innovator bevacizumab, Genentech, South San Francisco, CA) in premature infants with prethreshold type I retinopathy of prematurity (ROP). Methods: Preterm infants with bilateral prethreshold type 1 ROP were enrolled in this nonrandomized contralateral clinical trial. Bilateral intravitreal bevacizumab (IVB) was administered, with Stivant® injected in one eye and Avastin® in the other. Patients were followed up weekly for 4 weeks, then biweekly until complete retinal vascularization. Efficacy was evaluated based on disease activity regression (plus disease regression) and complete retinal vascularization. Safety was assessed through the monitoring of adverse events such as uveitis and endophthalmitis. Results: Forty-four infants were included in the study. The mean age at IVB injection was 34.5 weeks. Complete retinal vascularization occurred at a mean age of 60.02 weeks for Stivant® and 59.93 weeks for Avastin® (P = 0.59). Five patients (11.3%) underwent bilateral laser photocoagulation as rescue treatment. Our results showed that Stivant® was noninferior to Avastin® in retinal vascularization progress. However, this study cannot make definitive noninferiority claims due to the sample size and its design as a pilot investigation. No cases of endophthalmitis or uveitis were reported. Conclusions: Stivant® exhibited noninferiority to Avastin® in efficacy and demonstrated a comparable safety profile in treating prethreshold type I ROP. A definite conclusion requires more extended studies with a larger sample size.