A Baseline Score to Predict Response to Ranibizumab Treatment in Neovascular Age-Related Macular Degeneration.

Purpose: What are the patient characteristics predictive of response to ranibizumab treatment? Methods: Model-based characterization of best-corrected visual acuity (BCVA) time profiles of patients with neovascular age-related macular degeneration under ranibizumab or sham treatment based on 24-month observations of BCVA in 2419 patients from randomized multicenter phase 3 trials of ranibizumab: ANCHOR, MARINA, PIER, and HARBOR. Goodness-of-fit plots and precision of parameter estimates were used for measure of accuracy. Results: The model incorporates a long-term effect on disease progression and an additive and more potent short-term effect of ranibizumab. Response to ranibizumab treatment and progression of the disease were found to be a function of seven baseline characteristics (visual acuity, age, leakage size, central retinal lesion thickness, presence or absence of cyst, type of choroidal neovascularization (CNV), and size of pigment epithelium detachment). A composite score of these seven baseline characteristics was derived and used to categorize response to ranibizumab treatment. The ranibizumab treatment arms of two proof-of-concept studies held out from the model development were used to validate the methodology. Conclusions: A composite score based on seven patient characteristics prior to treatment could be used to discriminate patients with predicted insufficient response to anti-vascular endothelial growth factor treatment. Translational Relevance: The method could be used to create a virtual ranibizumab treatment arm in clinical trials or to reduce the size of a ranibizumab active control arm.

Safety and Efficacy of Different Doses and Regimens of Faricimab vs Ranibizumab in Neovascular Age-Related Macular Degeneration: The AVENUE Phase 2 Randomized Clinical Trial.

Importance: Faricimab, the first bispecific antibody designed for intraocular use, simultaneously and independently binds and neutralizes angiopoietin 2 (Ang-2) and vascular endothelial growth factor A (VEGF-A). Objective: To assess the efficacy and safety of different doses and regimens of faricimab vs ranibizumab in patients with neovascular age-related macular degeneration (nAMD). Design, Setting, and Participants: AVENUE was a 36-week, multiple-dose-regimen, active comparator-controlled, double-masked, phase 2 randomized clinical study performed at 58 sites in the United States. Eligible participants were anti-VEGF treatment naive with choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score of 73 (Snellen equivalent, 20/40) to 24 (Snellen equivalent, 20/320). Data were collected from August 11, 2015, to January 12, 2017, with the final patient visit completed September 26, 2017. Data were analyzed from August 11, 2015, to October 4, 2019. Interventions: Patients were randomized 3:2:2:2:3 to receive ranibizumab, 0.5 mg every 4 weeks (arm A [n = 68]); faricimab, 1.5 mg every 4 weeks (arm B [n = 47]); faricimab, 6.0 mg every 4 weeks (arm C [n = 42]); faricimab, 6.0 mg every 4 weeks until week 12, then faricimab, 6.0 mg every 8 weeks (arm D [n = 47]); and ranibizumab, 0.5 mg every 4 weeks until week 8, then faricimab, 6.0 mg every 4 weeks (arm E [n = 69]). Main Outcomes and Measures: Mean change in BCVA from baseline to week 36, proportion of participants gaining at least 15 letters, BCVA of 20/40 or better or 20/200 or worse, and ocular coherence tomographic outcomes in anti-VEGF treatment-naive participants (arms A, B, C, D) and from weeks 12 to 36 in those with incomplete response (participants in arms A and E with week 12 BCVA ETDRS letter score of ≤68 [Snellen equivalent, 20/50 or worse]). Results: A total of 263 participants were included in the analysis (172 [65.4%] female; 258 [98.1%] white; mean [SD] age, 78.3 [8.7] years). At week 36, adjusted mean change in BCVA vs ranibizumab was 1.6 (80% CI, -1.6 to 4.7) letters for arm B (P = .52), -1.6 (80% CI, -4.9 to 1.7) letters for arm C (P = .53), and -1.5 (80% CI, -4.6 to 1.6) letters for arm D (P = .53). For arm E, adjusted mean change from week 12 was -1.7 (80% CI, -3.8 to 0.4) letters (P = .30). Conclusions and Relevance: AVENUE did not meet its primary end point of superiority of faricimab over ranibizumab in BCVA at week 36. Although not superior to monthly ranibizumab as given in this trial, overall visual and anatomical gains noted with faricimab support pursuing phase 3 trials for a potential alternative to monthly anti-VEGF therapy. Faricimab showed no new or unexpected safety signals. Trial Registration: ClinicalTrials.gov Identifier: NCT02484690.

Simultaneous Inhibition of Angiopoietin-2 and Vascular Endothelial Growth Factor-A with Faricimab in Diabetic Macular Edema: BOULEVARD Phase 2 Randomized Trial.

PURPOSE: The phase 2 BOULEVARD trial compared safety and efficacy of faricimab, a novel bispecific antibody targeting angiopoietin-2 and vascular endothelial growth factor-A (VEGF-A), with ranibizumab in patients with diabetic macular edema (DME). DESIGN: The BOULEVARD trial (ClinicalTrials.gov identifier, NCT02699450) was a prospective, randomized, active comparator-controlled, double-masked, multicenter, phase 2 study conducted at 59 sites in the United States. PARTICIPANTS: The trial enrolled patients 18 years of age or older with center-involving DME, best-corrected visual acuity (BCVA) of 73 to 24 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, and central subfield thickness (CST) of 325 µm or more. METHODS: Anti-VEGF treatment-naïve patients were randomized 1:1:1 to intravitreal 6.0 mg faricimab, 1.5 mg faricimab, or 0.3 mg ranibizumab, and patients previously treated with anti-VEGF were randomized 1:1 to 6.0 mg faricimab or 0.3 mg ranibizumab. Patients were dosed monthly for 20 weeks, followed by an observation period up to week 36 to assess durability. MAIN OUTCOME MEASURES: The prespecified primary outcome measure was mean change in BCVA from baseline at week 24 for faricimab versus ranibizumab in treatment-naïve patients. Key secondary and exploratory outcome measures included CST, Diabetic Retinopathy Severity Scale (DRSS) score, and durability as assessed by time to re-treatment. RESULTS: The trial enrolled 229 patients (168 treatment-naïve and 61 previously treated with anti-VEGF). In treatment-naïve patients, 6.0 mg faricimab, 1.5 mg faricimab, and 0.3 mg ranibizumab resulted in mean improvements of 13.9, 11.7, and 10.3 ETDRS letters from baseline, respectively. The 6.0-mg faricimab dose demonstrated a statistically significant gain of 3.6 letters over ranibizumab (P = 0.03). In both patient populations, faricimab resulted in dose-dependent reductions in CST, improvements in DRSS score, and longer time to re-treatment during the observation period compared with ranibizumab. Faricimab showed no new or unexpected safety signals. CONCLUSIONS: The BOULEVARD trial met its primary end point; faricimab demonstrated statistically superior visual acuity gains versus ranibizumab at week 24 in treatment-naïve patients. Central subfield thickness reduction, DRSS score improvement, and extended durability outcomes support the primary outcome. These findings suggest the benefit of simultaneous inhibition of angiopoietin-2 and VEGF-A with faricimab for patients with DME.

A Mechanistic Model of the Intravitreal Pharmacokinetics of Large Molecules and the Pharmacodynamic Suppression of Ocular Vascular Endothelial Growth Factor Levels by Ranibizumab in Patients with Neovascular Age-Related Macular Degeneration.

Intravitreal injection of anti-VEGF (vascular endothelial growth factor) antibodies or antibody fragments has been shown to be a highly effective treatment for neovascular age-related macular degeneration (wet AMD). The ocular half-life (t1/2) of these large molecules, determined in ocular fluids or derived from serum levels, varies with molecular size and is larger in humans than in preclinical animal species. The high affinity binding of VEGF to these molecules lowers the free concentration of VEGF and reduces its occupancy on VEGF receptors in ocular tissues. To understand the biophysical determinants of t1/2 for anti-VEGF antibodies and the time-course of VEGF in ocular fluids, we developed a mechanistic model of intravitreal pharmacokinetics (IVT PK) for anti-VEGF antibodies and combined it with a mechanistic model of the pharmacodynamics (RVR PD) of VEGF suppression by ranibizumab, an anti-VEGF recombinant, humanized monoclonal antibody fragment (Fab). Our IVT PK model predicts that the ocular t1/2 of a large molecule will be approximately four-times the calculated value of its vitreous diffusion time (Tdiff), defined as rvit(2)/6D, where rvit is the radius of the vitreous chamber in that species (modeled as a sphere), and D is the diffusion coefficient of the molecule in physiological saline at 37 °C obtained from the Stokes-Einstein relation. This prediction is verified from a compilation of data and calculations on various large molecules in the human, monkey, rabbit, and rat and is consistent with the reported t1/2 values of ranibizumab in humans (mean value 7.9 days) and the calculated Tdiff of 1.59 days. Our RVR PD model is based on the publication of Saunders et al. (Br. J. Ophthalmol. 2015, 99, 1554-1559) who reported data on the time-course of VEGF levels in aqueous humor samples obtained from 31 patients receiving ranibizumab treatment for wet AMD and developed a compartmental mathematical model to describe the VEGF suppression profiles. We modified Saunders' model with the known 2:1 stoichiometry of ranibizumab-VEGF binding and included the association and dissociation kinetics of the binding reactions. Using the RVR PD model, we reanalyzed Saunders' data to estimate the in vivo dissociation constant (KD) between ranibizumab and VEGF. Our analysis demonstrates the delicate interrelationship between the in vivo KD value and the intravitreal half-life and yields an in vivo KD estimate that is appreciably larger than the in vitro KD estimates reported in the literature. Potential explanations for the difference between the in vivo and in vitro KD values, which appear to reflect the different methodologies and experimental conditions, are discussed. We conclude that the combined mechanistic model of IVT PK and RVR PD provides a useful framework for simulating the effects of dose, KD, and the molecular weight of VEGF-binding molecules on the duration of VEGF suppression.

Comparison of in vitro P-glycoprotein screening assays: recommendations for their use in drug discovery.

The ATP-dependent drug efflux pump P-glycoprotein (P-gp) affects the absorption and disposition of many compounds. P-gp may also play role in clinically significant drug-drug interactions. Therefore, it is important to find potential substrates or inhibitors of P-gp early in the drug discovery process. To identify compounds that interact with this transporter, several P-gp assays were validated and compared by testing a set of 28 reference compounds, including inhibitors of cytochrome P450 3A4 (CYP3A4). The assays included in silico predictions, inhibition assays (based on cellular uptake of rhodamine-123 or calcein AM), and functional assays (ATPase activity assay and transcellular transport assay, the latter for a subset of compounds). In addition, species differences were studied in an indirect fluorescence indicator screening assay and test systems expressing porcine, mouse, or human P-gp. Our results suggest that several P-gp assays should be used in combination to classify compounds as substrates or inhibitors of P-gp. Recommendations are given on screening strategies which can be applied to different phases of the drug discovery and development process.