Plasma Levels of Bevacizumab and Vascular Endothelial Growth Factor After Low-Dose Bevacizumab Treatment for Retinopathy of Prematurity in Infants

Importance

Intravitreal bevacizumab effectively treats severe retinopathy of prematurity (ROP), but it enters the bloodstream and may reduce serum vascular endothelial growth factor (VEGF), potentially causing detrimental effects on developing organs in the premature infant.

Objective

To evaluate the association of intravitreal bevacizumab with plasma bevacizumab and VEGF concentrations at 2 and 4 weeks after predefined, de-escalating doses of intravitreal bevacizumab were administered to infants with severe ROP.

Design, Setting, and Participants

This phase 1 dose de-escalation case series study was conducted at 10 US hospitals of ophthalmology institutions from May 21, 2015, to May 7, 2019. Blood samples were collected 2 and 4 weeks after intravitreal bevacizumab injection. Participants included 83 premature infants with type 1 ROP in 1 or both eyes and no previous ROP treatment. Data were analyzed from April 2017 to August 2021.

Interventions

Study eyes received a single bevacizumab injection of 0.250 mg, 0.125 mg, 0.063 mg, 0.031 mg, 0.016 mg, 0.008 mg, 0.004 mg, or 0.002 mg. When the fellow eye required treatment, one dose higher was administered. Total dose administered at baseline was defined as the sum of doses given to each eye within 3 days of initial study-eye injection.

Main Outcomes and Measures

Plasma bevacizumab concentration at 2 and 4 weeks after injection and the percentage change in plasma VEGF concentrations from pretreatment levels.

Results

A total of 83 infants (mean [SD] age, 25 [2] weeks; 48 boys [58%]) were included in this study. Higher doses of bevacizumab administered at baseline were associated with higher plasma bevacizumab concentrations at 2 weeks (ρ, 0.53; 95% CI, 0.31-0.70) and 4 weeks (ρ, 0.44; 95% CI, 0.18-0.64). Plasma VEGF concentrations decreased by 50% or more from pretreatment levels in 40 of 66 infants (61%) at 2 weeks and 31 of 61 infants (51%) at 4 weeks, but no association was observed between the total dose of bevacizumab administered at baseline and percentage change in plasma VEGF concentrations 2 weeks (ρ, -0.04; 95% CI, -0.28 to 0.20) or 4 weeks (ρ, -0.17; 95% CI, -0.41 to 0.08) after injection.

Conclusions and Relevance

Results of this phase 1 dose de-escalation case series study revealed that bevacizumab doses as low as 0.002 mg were associated with reduced plasma VEGF levels for most infants at 2 and 4 weeks after intravitreal administration; however, no association was observed between total bevacizumab dose administered and reductions in plasma VEGF levels from preinjection to 2 weeks or 4 weeks. Additional studies are needed to evaluate the long-term effects of low-dose bevacizumab on neurodevelopment and retinal structure.

Minoxidil overdose with ECG changes: case report and review

A 20-year-old female ingested an unknown quantity of minoxidil tablets as a suicide gesture. She presented to the emergency department about 90 minutes later with tachycardia, diffuse T wave inversion, and S-T segment depression on the ECG, labile hypotension, and a substantially elevated total serum minoxidil concentration of 3140 ng/mL. She responded to supportive therapy with intravenous fluids, and was discharged 32 hours later with stable blood pressure and mild residual tachycardia. The clinical toxicology, treatment, and previous case reports of minoxidil overdose are reviewed.