A clinical pharmacokinetic study comparing two azelastine hydrochloride nasal formulations in a single-dose design

Pharmacometric Modeling of the Impact of Azelastine Nasal Spray on SARS-CoV-2 Viral Load and Related Symptoms in COVID-19 Patients

The histamine-1 receptor antagonist azelastine was recently found to impact SARS-CoV-2 viral kinetics in a Phase 2 clinical trial (CARVIN). Thus, we investigated the relationship between intranasal azelastine administrations and viral load, as well as symptom severity in COVID-19 patients and analyzed the impact of covariates using non-linear mixed-effects modeling. For this, we developed a pharmacokinetic (PK) model for the oral and intranasal administration of azelastine. A one-compartment model with parallel absorption after intranasal administration described the PK best, covering both the intranasal and the gastro-intestinal absorption pathways. For virus kinetic and symptoms modeling, viral load and symptom records were gathered from the CARVIN study that included data of 82 COVID-19 patients receiving placebo or intranasal azelastine. The effect of azelastine on viral load was described by a dose–effect model targeting the virus elimination rate. An extension of the model revealed a relationship between COVID-19 symptoms severity and the number of infected cells. The analysis revealed that the intranasal administration of azelastine led to a faster decline in viral load and symptoms severity compared to placebo. Moreover, older patients showed a slower decline in viral load compared to younger patients and male patients experienced higher peak viral loads than females.

Pharmacokinetics and Bioequivalence of a Generic and a Branded Budesonide Nasal Spray in Healthy Chinese Subjects

The aim of this study was to evaluate the pharmacokinetic bioequivalence of a generic budesonide nasal spray and a branded product in healthy Chinese subjects under fasting condition. A single-center, single-dose, randomized, open-label, crossover study was conducted in 32 healthy Chinese subjects under fasting condition. The subjects were administered 256 μg of generic budesonide nasal spray (test drug) or branded budesonide nasal spray (RHINOCORT AQUA, reference drug), respectively. For each period, the subjects were administered with 64 μg of budesonide per spray and 2 sprays for each nostril followed by a washout period of 7 days. Plasma concentration of budesonide was determined by a validated high-performance liquid chromatography-tandem mass spectrometry method. The pharmacokinetic (PK) parameters were calculated, and the bioequivalence was compared using the noncompartment model with the Phoenix WinNonlin 7.0 program. Results show that the 90% confidence intervals of the test/reference ratios of maximum concentration, area under the plasma concentration-time curve from time 0 to the last measurable concentration, and area under the plasma concentration-time curve from time 0 to infinity for the budesonide concentration were 84.8% to 102.7%, 84.6% to 94.4%, and 85.4% to 95.2%, respectively, all fall within the bioequivalent range of 80% to 125%. The test and reference budesonide nasal sprays were PK bioequivalents in healthy Chinese subjects with comparable PK parameters. No serious adverse events were reported, and the 2 products have a good and similar safety profile.

10th Anniversary of a Two-Stage Design in Bioequivalence. Why Has it Still Not Been Implemented?

PURPOSE

In 2010 the European Medicines Agency allowed a two-stage design in bioequivalence studies. However, in the public domain there are mainly articles describing the theoretical and statistical base for the application of the two-stage design. One of the reasons seems to be the lack of practical guidance for the Sponsors on when and how the two-stage design can be beneficial in bioequivalence studies.

METHODS

Different variants with positive and negative outcomes have been evaluated, including a pivotal study, pilot + pivotal study and two-stage study. The scientific perspective on the two-stage bioequivalence study has been confronted with the industrial one.

RESULTS

Key information needed to conduct a bioequivalence study - such as in vitro data and pharmacokinetics - have been listed and organized into a decision scheme. Advantages and disadvantages of the two-stage design have been summarized.

CONCLUSION

The use of the two-stage design in bioequivalence studies seems to be a beneficial alternative to the 2 × 2 crossover study. Basic information on the properties of the active substance and the characteristics of the drug form are needed to make an initial decision to carry out the two-stage study.

Two-stage designs in bioequivalence trials

PURPOSE

The aim of this study is to assess the current status of non-fixed sample size designs in bioequivalence trials with a focus on two-stage adaptive approaches.

METHODS

We searched PubMed and Google Scholar from inception to October 2014. Regulatory guidelines were obtained from the public domain. Different methods were compared by Monte Carlo simulations for their impact on the patient's and producer's risks.

RESULTS

Add-on designs, group sequential designs and adaptive two-stage sequential designs are currently accepted to demonstrate bioequivalence in various regulations. All three approaches may inflate the patient's risk if applied inconsiderately. Direct transfer of methods developed for superiority testing to bioequivalence is not warranted. Published two-stage frameworks maintain the type I error and generally the desired power. Adaptation based on the observed T/R ratio observed in the first stage should be applied with caution. Monte Carlo simulations are an efficient tool to explore the operating characteristics of methods.

CONCLUSIONS

Validated two-stage frameworks can be applied without requiring the sponsor to perform own simulations-which could further improve power based on additional assumptions. Two-stage designs are both ethical and economical alternatives to fixed sample designs.