Development and validation of a novel semi-homogenous clinical assay for quantitation of Ranibizumab in human serum

Population Pharmacokinetics of Ranibizumab Delivered via the Port Delivery System Implanted in the Eye in Patients with Neovascular Age-Related Macular Degeneration

The port delivery system with ranibizumab (PDS) is designed to continuously deliver ranibizumab to maintain therapeutic drug concentrations in the vitreous of the eye for an extended duration. The PDS has been evaluated for the treatment of neovascular age-related macular degeneration in the Ladder (PDS 10, 40, and 100 mg/mL, with refill exchanges as needed, versus monthly intravitreal ranibizumab 0.5 mg), Archway (PDS 100 mg/mL with 24-week refill exchanges, versus monthly intravitreal ranibizumab 0.5 mg), and ongoing Portal (PDS 100 mg/mL with 24-week refill exchanges) clinical trials. Data from Ladder, Archway, and Portal were used to develop a population pharmacokinetics (PK) model to estimate the ranibizumab release rate from the PDS implant, describe ranibizumab PK in serum and aqueous humor, and predict the concentration in vitreous humor. A model was developed to adequately describe the serum and aqueous humor PK data, as suggested by goodness-of-fit plots as well as visual predictive checks. In the final model, the first-order implant release rate was estimated to be 0.00654 (1/day), corresponding to a half-life of 106 days, consistent with the implant release rate determined in vitro. The model-predicted vitreous concentrations achieved with PDS 100 mg/mL given every 24 weeks were below the intravitreal peak concentration and above the intravitreal trough concentration of ranibizumab over the entire 24-week refill interval. The results demonstrate a durable release of ranibizumab from the PDS with a half-life of 106 days, providing vitreous exposure to ranibizumab for at least 24 weeks that is within the range of exposure for monthly intravitreal treatment.

Pharmacokinetics of the Port Delivery System with Ranibizumab in the Ladder Phase 2 Trial for Neovascular Age-Related Macular Degeneration

INTRODUCTION

Ladder was a phase 2 trial that evaluated the Port Delivery System with ranibizumab (PDS) for neovascular age-related macular degeneration. Serum and aqueous humor samples were collected to characterize the pharmacokinetics (PK) of ranibizumab delivered through the PDS.

METHODS

Ladder was a multicenter, randomized, active treatment-controlled, phase 2 clinical trial. Patients with neovascular age-related macular degeneration (n = 220) were randomized (3:3:3:2) to PDS 10 mg/ml, PDS 40 mg/ml, PDS 100 mg/ml, or monthly intravitreal ranibizumab 0.5 mg. Serum PK samples were collected in all arms and analyzed for ranibizumab concentration using an enzyme-linked immunosorbent assay. The main PK analyses were conducted in the PK-evaluable population (n = 68), which excluded patients who received fellow eye intravitreal treatment, supplemental ranibizumab treatment, or had previous treatment with bevacizumab in either eye within 9 months of randomization.

RESULTS

In the PDS 10 mg/ml arm, median serum ranibizumab concentrations were below the serum trough concentration (C_trough; 130 pg/ml) expected with monthly intravitreal ranibizumab 0.5 mg at all time points. In the PDS 40 mg/ml and 100 mg/ml arms, median serum ranibizumab concentrations were above the C_trough expected with monthly intravitreal ranibizumab 0.5 mg (130 pg/ml) through month 3 and month 12 after implantation, respectively, and remained above the lower limit of quantification through month 15 and month 16 after implantation, respectively.

CONCLUSIONS

These PK data indicate that the implant in the PDS 100 mg/ml arm maintained ranibizumab concentrations within the range of monthly intravitreal ranibizumab 0.5 mg injections (130-2220 pg/ml) through month 12 after implantation.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02510794.

Intact quantitative bioanalytical method development and fit-for-purpose validation of a monoclonal antibody and its related fab fragment in human vitreous and aqueous humor using LC-HRMS

Ranibizumab is an FDA-approved drug used to treat wet age-related macular degeneration (AMD), diabetic retinopathy, macular edema, and myopic choroidal neovascularization. Bevacizumab is another drug often used off-label to treat wet AMD. In order to reduce unwanted angiogenesis, ranibizumab and bevacizumab target circulating VEGF-A in the eye. Concentration levels in human vitreous and aqueous humor can be used to provide valuable efficacy information. However, vitreous and aqueous humor's aqueous environment, and vitreous humor's viscosity, as well as the stickiness of the analytes can provide bioanalytical challenges. In this manuscript, we describe the development, optimization, and fit-for-purpose validation of an LC-HRMS method designed for intact quantitative bioanalysis of ranibizumab and bevacizumab in human vitreous and aqueous humor following intravitreal administration. In order to fully develop this method, evaluations were conducted to optimize the conditions, including the data processing model (extracted ion chromatograms (XICs) vs deconvolution), carryover mitigation, sample preparation scheme optimization for surrogate and primary matrices, use of internal standard/immunocapture/deglycosylation, and optimization of the extraction and dilution procedure, as well as optimization of the liquid chromatography and mass spectrometry conditions. Once the method was fully optimized, a fit-for-purpose validation was conducted, including matrix parallelism, with a linear calibration range of 10 to 200 µg/mL. The development of this intact quantitative method using LC-HRMS provides a proof-of-concept template for challenging, but valuable new and exciting bioanalytical techniques.

Optimization and method validation for the quantitative analysis of a monoclonal antibody and its related fab fragment in human plasma after intravitreal administration, using LC-MS/MS

As biologic based drugs become an increasingly important sector of the pharmaceutical industry, accurate and precision techniques for bioanalysis are required to support clinical trials and beyond. Ranibizumab, a fab therapeutic, is an FDA approved drug to treat wet age-related macular degeneration (AMD), as well as other eye related diseases. Ranibizumab's mAb counterpart, bevacizumab, is often also used off-label to treat wet AMD. Ranibizumab and bevacizumab target circulating VEGF-A in the eye, reducing unwanted angiogenesis. Since these drugs are designed for local intravitreal administration, concentration levels in human plasma are expected to be significantly lower compared to vitreous fluid concentrations, presenting bioanalytical challenges. However, this is important for assessment of drug toxicity. In this manuscript, we describe the development, optimization, and validation of an LC-MS/MS method designed for quantitative bioanalysis of ranibizumab and bevacizumab in human plasma following intravitreal administration. In order to fully develop this method, evaluations were conducted to optimize the conditions, including selection of the surrogate peptide by in-silico experiments, optimizations of the immunocapture, denaturation, reduction, alkylation, and digestion extraction steps, as well as optimization of the LC-MS/MS conditions, and evaluation of a dissociation step to determine if there was interference from VEGF or ADAs. Once the method was fully optimized, it was then validated, following the 2018 FDA guidance on bioanalytical method validations. This method is now available for use during clinical trials and precision medicine, for the quantitative evaluation of systemic exposure of ranibizumab or bevacizumab in human plasma after intravitreal administration, with a linear calibration range of 0.300-100 ng/mL.

Pharmacokinetics of Intravitreal Anti-VEGF Drugs in Age-Related Macular Degeneration

Intravitreal administration of anti-vascular endothelial growth factor (VEGF) antibodies has become the standard treatment for Age-Related Macular Degeneration; however, the knowledge of their pharmacokinetics is limited. A comprehensive review of the preclinical and clinical pharmacokinetic data that were obtained in different studies with intravitreal bevacizumab, ranibizumab, and aflibercept has been conducted. Moreover, the factors that can influence the vitreous pharmacokinetics of these drugs, as well as the methods that were used in the studies for analytical determination, have been exposed. These anti-VEGF drugs present different charge and molecular weights, which play an important role in vitreous distribution and elimination. The pharmacokinetic parameters that were collected differ depending on the species that were involved in the studies and on physiological and pathological conditions, such as vitrectomy and lensectomy. Knowledge of the intravitreal pharmacokinetics of the anti-VEGF drugs that were used in clinical practice is of vital importance.

The Port Delivery System with Ranibizumab for Neovascular Age-Related Macular Degeneration: Results from the Randomized Phase 2 Ladder Clinical Trial

PURPOSE

To evaluate the safety and efficacy of the Port Delivery System with ranibizumab (PDS) for neovascular age-related macular degeneration (nAMD) treatment.

DESIGN

Phase 2, multicenter, randomized, active treatment-controlled clinical trial.

PARTICIPANTS

Patients diagnosed with nAMD within 9 months who had received 2 or more prior anti-vascular endothelial growth factor intravitreal injections and were responsive to treatment.

METHODS

Patients were randomized 3:3:3:2 to receive the PDS filled with ranibizumab 10 mg/ml, 40 mg/ml, 100 mg/ml, or monthly intravitreal ranibizumab 0.5-mg injections.

MAIN OUTCOME MEASURES

Time to first implant refill assessed when the last enrolled patient completed the month 9 visit (primary efficacy end point), improvement in best-corrected visual acuity (BCVA) and central foveal thickness (CFT), and safety.

RESULTS

The primary analysis population was 220 patients, with 58, 62, 59, and 41 patients in the PDS 10-mg/ml, PDS 40-mg/ml, PDS 100-mg/ml, and monthly intravitreal ranibizumab 0.5-mg arms, respectively. Median time to first implant refill was 8.7, 13.0, and 15.0 months in the PDS 10-mg/ml, PDS 40-mg/ml, and PDS 100-mg/ml arms, respectively. At month 9, the adjusted mean BCVA change from baseline was ‒3.2 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, ‒0.5 ETDRS letters, +5.0 ETDRS letters, and +3.9 ETDRS letters in the PDS 10-mg/ml, PDS 40-mg/ml, PDS 100-mg/ml, and monthly intravitreal ranibizumab 0.5-mg arms, respectively. At month 9, the adjusted mean CFT change from baseline was similar in the PDS 100-mg/ml and monthly intravitreal ranibizumab 0.5-mg arms. The optimized PDS implant insertion and refill procedures were generally well tolerated. After surgical procedure optimization, postoperative vitreous hemorrhage rate was 4.5% (7/157; 1 event classified as serious). There was no evidence of implant clogging.

CONCLUSIONS

In the phase 2 Ladder trial, the PDS was generally well tolerated and demonstrated a dose response across multiple end points in patients with nAMD. The PDS 100-mg/ml arm showed visual and anatomic outcomes comparable with monthly intravitreal ranibizumab 0.5-mg injections but with a reduced total number of ranibizumab treatments. The PDS has the potential to reduce treatment burden in nAMD while maintaining vision.

Generation by phage display and characterization of drug-target complex-specific antibodies for pharmacokinetic analysis of biotherapeutics

Anti-idiotypic antibodies play an important role in pre-clinical and clinical development of therapeutic antibodies, where they are used for pharmacokinetic studies and for the development of immunogenicity assays. By using an antibody phage display library in combination with guided in vitro selection against various marketed drugs, we generated antibodies that recognize the drug only when bound to its target. We have named such specificities Type 3, to distinguish them from the anti-idiotypic antibodies that specifically detect free antibody drug or total drug. We describe the generation and characterization of such reagents for the development of ligand binding assays for drug quantification. We also show how these Type 3 antibodies can be used to develop very specific and sensitive assays that avoid the bridging format.

Abbreviations: BAP: bacterial alkaline phosphatase; CDR: complementarity-determining regions in VH or VL; Fab: antigen-binding fragment of an antibody; HRP: horseradish peroxidase; HuCAL®: Human Combinatorial Antibody Libraries; IgG: immunoglobulin G; LBA: ligand binding assay; LOQ: limit of quantitation; NHS: normal human serum; PK: pharmacokinetics; VH: variable region of the heavy chain of an antibody; VL: variable region of the light chain of an antibody.