Systemic exposure to aflibercept after intravitreal injection in premature neonates with retinopathy of prematurity: results from the FIREFLEYE randomized phase 3 study

Abstract

Background: There are no data on pharmacokinetics, pharmacodynamics, and immunogenicity of intravitreal aflibercept in preterm infants with retinopathy of prematurity (ROP). FIREFLEYE compared aflibercept 0.4 mg/eye and laser photocoagulation in infants with acute-phase ROP requiring treatment.

Methods: Infants (gestational age ≤32 weeks or birthweight ≤1500 g) with treatment-requiring ROP in ≥1 eye were randomized 2:1 to receive aflibercept 0.4 mg or laser photocoagulation at baseline in this 24-week, randomized, open-label, noninferiority, phase 3 study. Endpoints include concentrations of free and adjusted bound aflibercept in plasma, pharmacokinetic/pharmacodynamic exploration of systemic anti-vascular endothelial growth factor effects, and immunogenicity.

Results: Of 113 treated infants, 75 received aflibercept 0.4 mg per eye at baseline (mean chronological age: 10.4 weeks), mostly bilaterally (71 infants), and with 1 injection/eye (120/146 eyes). Concentrations of free aflibercept were highly variable, with maximum concentration at day 1, declining thereafter. Plasma concentrations of adjusted bound (pharmacologically inactive) aflibercept increased from day 1 to week 4, decreasing up to week 24. Six infants experienced treatment-emergent serious adverse events within 30 days of treatment; aflibercept concentrations were within the range observed in other infants. There was no pattern between free and adjusted bound aflibercept concentrations and blood pressure changes up to week 4. A low-titer (1:30), non-neutralizing, treatment-emergent anti-drug antibody response was reported in 1 infant, though was not clinically relevant.

Conclusions: 24-week data suggest intravitreal aflibercept for treatment of acute-phase ROP is not associated with clinically relevant effects on blood pressure, further systemic adverse events, or immunogenicity.

Gov identifier: NCT04004208.

Fig. 1. Screening, randomization, and follow-up in the FIREFLEYE trial.

^aSee eMethods for additional details of inclusion and exclusion criteria. ^bOne infant with retinopathy of prematurity only in zone III was screened but not randomized. ^cRandomization was stratified by retinopathy of prematurity category (zones) and country of enrollment. Randomization and evaluation were by infant, with each infant demonstrating retinopathy in 1 eye or both eyes. ^dOne infant was discontinued from the trial after an adverse event of sinus tachycardia. ^eOne infant was discontinued from the trial after an adverse event of retinal detachment.

Fig. 2. Arithmetic mean ± SD concentrations of free and adjusted bound aflibercept (ng/mL) in plasma (in bilaterally and unilaterally treated infants combined).

D day, LLOQ lower limit of quantitation, VEGF vascular endothelial growth factor, W week. ^aA detectable concentration of free aflibercept was measured at week 12 (194 ng/mL) in 1 infant who received aflibercept retreatment in both eyes at week 11. Values below the LLOQ were substituted by 0 for the calculation of statistics. LLOQ was 15.6 ng/mL for free aflibercept and 31.3 ng/mL for bound aflibercept. The concentration of the bound aflibercept complex was adjusted by multiplying by 0.717 to account for the VEGF present in the bound complex (adjusted bound aflibercept).

Fig. 3. Systolic blood pressure.

A Arithmetic mean ± SD systolic blood pressure through week 24 in infants with retinopathy of prematurity in both treatment groups (aflibercept vs. laser photocoagulation) and B mean change from baseline in systolic blood pressure at week 4 after baseline treatment according to gestational age at birth. BL baseline, D day, N number of observations, SBP systolic blood pressure, W week. In panel A, n = 73 (baseline), n = 74 (day 1), n = 72 (week 1), n = 72 (week 2), n = 71 (week 3), n = 71 (week 4), n = 71 (week 6), n = 66 (week 8), n = 66 (week 10), n = 70 (week 12), n = 69 (week 16), n = 63 (week 20), n = 67 (week 24) for aflibercept and n = 38 (baseline), n = 37 (day 1), n = 37 (week 1), n = 37 (week 2), n = 37 (week 3), n = 36 (week 4), n = 34 (week 6), n = 30 (week 8), n = 30 (week 10), n = 30 (week 12), n = 34 (week 16), n = 30 (week 20), n = 36 (week 24) for laser. Data are not shown for infants whose BP was taken outside scheduled study visits. Week 1, day 1: n = 2 (aflibercept) and n = 2 (laser); week 2, day 1: n = 1 (aflibercept); week 3, day 1: n = 1 (laser); week 4, day 1: n = 2 (aflibercept); week 5, n = 4 (aflibercept) and n = 2 (laser); week 5, day 1: n = 1 (aflibercept) and n = 2 (laser); week 6, day 1: n = 1 (aflibercept) and n = 2 (laser); week 7: n = 2 (aflibercept) and n = 1 (laser); week 8, day 1, n = 1 (aflibercept); week 9: n = 1 (aflibercept) and n = 1 (laser); week 10, day 1: n = 3 (aflibercept) and n = 1 (laser); week 11: n = 5 (aflibercept); week 11, day 1: n = 3 (aflibercept); week 12, day 1: n = 3 (aflibercept); week 13: n = 2 (aflibercept); week 14: n = 3 (aflibercept); week 14, day 1: n = 1 (aflibercept); week 15: n = 2 (aflibercept); week 15, day 1: n = 1 (aflibercept); week 16, day 1: n = 4 (aflibercept); week 17: n = 4 (aflibercept); week 18: n = 1 (aflibercept). All data are shown in Supplementary eFig. 5. In panel B, individual observations in the aflibercept and laser groups are shown by black and gray circles, respectively. The dotted line depicts the regression line for laser; the solid line, the regression line for aflibercept.

Fig. 4. Diastolic blood pressure.

A Arithmetic mean ± SD diastolic blood pressure through week 24 in infants with retinopathy of prematurity in both treatment groups (aflibercept vs. laser photocoagulation) and B mean change from baseline in diastolic blood pressure at week 4 after baseline treatment according to gestational age at birth. BL baseline, D day, N number of observations, SBP systolic blood pressure, SD standard deviation, W week. In panel A, n = 73 (baseline), n = 74 (day 1), n = 72 (week 1), n = 72 (week 2), n = 71 (week 3), n = 71 (week 4), n = 71 (week 6), n = 66 (week 8), n = 66 (week 10), n = 70 (week 12), n = 69 (week 16), n = 63 (week 20), n = 67 (week 24) for aflibercept and n = 38 (baseline), n = 37 (day 1), n = 37 (week 1), n = 37 (week 2), n = 37 (week 3), n = 36 (week 4), n = 34 (week 6), n = 30 (week 8), n = 30 (week 10), n = 30 (week 12), n = 34 (week 16), n = 30 (week 20), n = 36 (week 24) for laser. Data are not shown for infants whose BP was taken outside scheduled study visits. Week 1, day 1: n = 2 (aflibercept) and n = 2 (laser); week 2, day 1: n = 1 (aflibercept); week 3, day 1: n = 1 (laser); week 4, day 1: n = 2 (aflibercept); week 5, n = 4 (aflibercept) and n = 2 (laser); week 5, day 1: n = 1 (aflibercept) and n = 2 (laser); week 6, day 1: n = 1 (aflibercept) and n = 2 (laser); week 7: n = 2 (aflibercept) and n = 1 (laser); week 8, day 1: n = 1 (aflibercept); week 9: n = 1 (aflibercept) and n = 1 (laser); week 10, day 1: n = 3 (aflibercept) and n = 1 (laser); week 11: n = 5 (aflibercept); week 11, day 1: n = 3 (aflibercept); week 12, day 1: n = 3 (aflibercept); week 13: n = 2 (aflibercept); week 14: n = 3 (aflibercept); week 14, day 1: n = 1 (aflibercept); week 15: n = 2 (aflibercept); week 15, day 1: n = 1 (aflibercept); week 16, day 1: n = 4 (aflibercept); week 17: n = 4 (aflibercept); week 18: n = 1 (aflibercept). All data are shown in Supplementary eFig. 5. In panel B, individual observations in the aflibercept and laser groups are shown by black and gray circles, respectively. The dotted line depicts the regression line for laser and the solid line, the regression line for aflibercept.

Fig. 5. Blood pressure versus concentrations of free aflibercept in plasma.

Change from baseline to day 1 in A systolic blood pressure and B diastolic blood pressure versus concentrations of free aflibercept in plasma at day 1 for individual infants. BP blood pressure, LLOQ lower limit of quantitation, TESAE treatment-emergent serious adverse event. Infants with TESAEs during the first 30 days following the start of treatment who had missing values for either aflibercept plasma concentrations and/or BP values at single time points are not included in the figure. Values below LLOQ were substituted by 0. LLOQ was 15.6 ng/mL for free aflibercept.