Pharmacokinetics of bevacizumab and its effects on serum VEGF and IGF-1 in infants with retinopathy of prematurity.

PURPOSE: To measure serum levels of bevacizumab and to compare serum levels of free vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) in infants who were treated with either intravitreal injection of bevacizumab (IVB) or laser for type 1 retinopathy of prematurity (ROP). METHODS: Twenty-four infants with type 1 ROP were randomized into three treatment groups: IVB at 0.625 mg per eye per dose, IVB at 0.25 mg per eye per dose, and laser. Blood samples were collected prior to treatment and on posttreatment days 2, 14, 42, and 60. Weekly body weights were documented from birth until 60 days post treatment. Serum levels of bevacizumab, free VEGF, and IGF-1 were measured with enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum bevacizumab was detected 2 days after the injection, peaked at 14 days, and persisted for up to 60 days with half-life of 21 days. Area under the curve (AUC) analysis showed that systemic exposure to bevacizumab was variable among the subjects and was dose dependent. Serum free VEGF levels decreased in all three subgroups 2 days post treatment, with more significant reductions found in both IVB-treated groups, P = 0.0001. Serum IGF-1 levels were lower in both IVB-treated groups. CONCLUSIONS: Clearance of bevacizumab from the bloodstream in premature infants takes at least 2 months. Although serum free VEGF levels decreased following either laser or bevacizumab treatment, the reductions were more significant in the IVB-treated groups. Potential long-term effects of systemic exposure to bevacizumab in infants need to be studied further.

Outcome of 121 patients with congenitally corrected transposition of the great arteries.

Congenitally corrected transposition of the great arteries (ccTGA) is a rare disorder with reduced survival that is influenced by the presence of associated anomalies, tricuspid regurgitation (TR), and right ventricular (RV) function. The double switch procedure has been proposed as an aggressive surgical approach in selected patients. We sought to review our experience with conventional repair to determine if a change in surgical strategy was warranted. Clinical records of 121 patients with ccTGA and two adequate-sized ventricles were retrospectively reviewed. Median length of follow-up was 9.3 years; 5-, 10-, and 20-year survival rates were 92%, 91%, and 75%, respectively. Surgery was performed in 86 patients, including conventional biventricular repair in 47 patients. Risk factors for mortality by univariate analysis included age at biventricular repair (p = 0.04), complete atrioventricular (AV) canal defect (p = 0.02), dextrocardia (p = 0.05), moderate or severe TR (p = 0.05), and poor RV function (p = 0.001). By multivariate analysis, complete AV canal defect (p = 0.006) and poor RV function (p = 0.002) remained significant as risk factors for mortality. Risk factors for the development of significant TR included conventional biventricular repair (p = 0.03) and complete AV block (p = 0.04). Risk factors for progressive RV dysfunction included conventional biventricular repair (p = 0.02), complete AV block (p = 0.001), and moderate or severe TR (p < 0.001). This is the largest nonselected cohort of patients with ccTGA followed at a single center. Our results confirm that significant TR and poor RV function are risk factors for poor outcome and provide convincing evidence that patients undergoing conventional biventricular repair are at higher risk for deterioration of tricuspid valve and right ventricular function compared to palliated or unoperated patients. We support a move toward an alternative surgical approach (double switch procedure) in carefully selected patients.