Abstract
Purpose :
The PDS is an investigational drug delivery system that includes a pars plana implant for continuous delivery of ranibizumab into the vitreous. Ranibizumab release from the implant is mediated by passive diffusion. In the ongoing phase 3 Archway trial (NCT03677934) in patients with neovascular age-related macular degeneration (N=415), serum and aqueous humor samples were collected to characterize the PK of ranibizumab administered via the PDS refilled Q24W.
Methods :
In the PDS with ranibizumab 100 mg/mL Q24W and monthly intravitreal ranibizumab 0.5 mg injection arms, serum PK samples were scheduled to be collected at randomization and at weeks 4, 24, 36, and 96 from all patients. At selected sites, samples were taken at days 2 and 7 and at weeks 12, 48, and 72 in the PDS arm, and 1–5 days after an injection in the monthly ranibizumab arm. Optional aqueous humor samples were collected from patients in either arm at weeks 24, 28, 48, 52, 72, 76, and 96; serum samples were also collected at this time. The PK-evaluable population consisted of patients who did not receive ranibizumab injections in the study eye or fellow eye after implant insertion or prior intravitreal bevacizumab treatment. Ranibizumab concentrations were measured using a validated enzyme-linked immunosorbent assay with lower limits of quantification of 15 pg/mL for serum and 20,000 pg/mL for aqueous humor.
Results :
Based on Archway primary analysis data, in the PDS arm (n=94), geometric mean (coefficient of variation) serum concentrations ranged from 419 (54%) pg/mL at week 4 to 340 (94%) pg/mL at week 24. In the monthly ranibizumab arm (n=79), geometric mean serum ranibizumab concentrations ranged from 1880 (57%) pg/mL near maximum concentration (1-5 days after injection) to 58.1 (171%) pg/mL at Week 4 (Ctrough). The aqueous humor PK profile reflected the same trends seen in serum, with PDS 100 mg/mL Q24W (n=42) maintaining concentrations above monthly intravitreal ranibizumab Ctrough (n=46).
Conclusions :
The PDS continuously releases ranibizumab over the Q24W refill interval at steady concentrations. Ranibizumab concentrations with PDS 100 mg/mL Q24W are within the range experienced with monthly intravitreal ranibizumab 0.5 mg injections. Aqueous humor PK were consistent with serum PK.
This is a 2021 ARVO Annual Meeting abstract.