Analysis of reasons for screening failure of healthy subjects in clinical trials of orally inhaled drug products / 中国临床药理学与治疗学

AIM: To explore the reasons for screening failure of healthy subjects in clinical trials of orally inhaled drug products (OIDPs). METHODS: Screening data of 1 432 healthy subjects who participated in clinical trials of OIDPs were collected. The main reasons for the screening failure, gender differences in screening failure rate and the correlation between age and screening failure rate were summarized and analyzed. RESULTS: The screening failure rate was 72.4 % and increased with age. The failure rate was slightly higher in females than in males. Besides abnormal vital signs (17.3%), abnormal laboratory test results (16.5%) and withdrawal of consent (7.6%), poor venous condition (13.9%), positive for cigarette test results (12.6%) and failure in inhalation training (7.1%) were also the other three main reasons affecting the screening success rate. Abnormal vital signs and poor venous conditions were the primary screening failure reasons for males and females, respectively. CONCLUSION: The screening success rate could be improved by informing fully and communicating effectively, selecting young subjects with strong understanding abilities, and enhancing the training skills of investigators.

Safety analysis on bioequivalence studies of orally inhaled drug products in healthy Chinese subjects / 中国临床药理学与治疗学

AIM: To investigate the safety of bioequivalence (BE) studies of orally inhaled drug products (OIDPs) conducted by Phase I clinical Research Center of our hospital. METHODS: The safety data were collected from 482 healthy subjects enrolled in 20 OIDPs BE studies in Wuxi People's hospital from 2017 to 2022. The difference of adverse events (AEs) between test preparation and reference preparation were compared, as well as the influence of gender, age, mechanism of drug action and device type on AE were analyzed. RESULTS: A total of 102 cases of AEs were occurred in 77 subjects (16.0%, 77/482), 87 cases of AEs were related to experimental drugs, all AEs were mild or moderate, and no serious adverse events occurred. There was no difference in the incidence of AE between test preparation and reference preparation. In addition, gender, age, mechanism of drug action and device type had no significant effects on AEs. CONCLUSION: In 20 bioequivalence studies of OIDPs, OIDPs were safe and well tolerated in healthy subjects after dosing, and safety features of generic OIDPs and original drug were basically similar.

Application and progress of pharmacodynamics study in bioequivalence evaluation of orally inhaled drug products / 中国临床药理学与治疗学

Orally inhaled drug products (OIDPs) play a great role in the pharmacological treatment of chronic obstructive pulmonary disease (COPD) and asthma. There is an unmet clinical need for OIDPs. Pharmacodynamics-Bioequivalence studies (PD-BE) are recommended by several national guidelines as important research methods for bioequivalence study of OIDPs. It can effectively bridge the gap between in vitro studies and PK-BE studies in evaluating the efficacy and safety consistency of generic drugs with the original drugs. There are two research methods for PD-BE, using a diastolic model or an excitation model. The different methods use different metrics to evaluate efficacy. The more commonly used metrics include Forced Expiratory Volume in the First Second (FEV1), Specific Airway Conductance (sGaw), Peripheral Airway Resistance (R5-20), and stimulant concentration/dose (PC20/PD20). PD-BE studies using FEV1 as an efficacy metric is also recommended by the FDA (Food and Drug Administration), EMA (European Medicines Agency) and NMPA (National Medical Products Administration) guidelines and is widely accepted by investigators. In such PD-BE studies, the trial protocols for different OIDPs drugs are relatively consistent in terms of trial design, trial data processing, and equivalence evaluation criteria, while there are detailed differences in terms of target population, single/multiple dosing, dose administration, and collection site design. This paper reviews the progress of PD-BE studies in the bioequivalence evaluation of OIDPs by combining national guidelines and PD-BE-related studies of OIDPs published in the last five years, with a view to providing important theoretical information for PD-BE studies of OIDPs.

Application and progress of pharmacokinetics study in bioequivalence evaluation of orally inhaled drug products / 中国临床药理学与治疗学

Orally inhaled drug products (OIDPs) have a pivotal position and great clinical demand in the treatment of asthma and chronic obstructive pulmonary disease. The development of local generic drugs which are bioequivalent to branded drugs in efficacy and safety while with less price will not only help to solve the problem of drug accessibility, but also greatly reduce the public health burden.OIDPs are complex combinations of formulation and device, and have special drug delivery route and characteristic of local release. Thus, generic drugs of OIDPs are difficult to develop and get registration. Until now, Food and Drug Administration (FDA), European Medicines Association (EMA), Health Canada (HC) and National Medical Products Administration (NMPA) all consider that pharmacokinetics (PK) method can be used to evaluate systemic exposure (safety) in human bioequivalence (BE) study of OIDPs, but there is no consensus on its role in the evaluation of pulmonary deposition (efficacy). The possible reason lies in that the efficacy of OIDPs is determined by both the amount and the region of drug pulmonary deposition. Nevertheless, PK study is still more sensitive and economical in assessing potential differences among products, when compared with pharmacodynamics or clinical endpoint study. Here we mainly compared the domestic and international guidelines and evaluation methods of OIDPs BE study, and introduced the experimental design of PK study and its application and progress in lung deposition study.

Bioequivalence of Orally Inhaled Drug Products : Focus on Current Regulatory Perspectives.

Asthma/chronic obstructive pulmonary disease (COPD) medication market is a fast growing market, especially in the emerging markets where drugs have not been launched due to high costs. Use of generic medicines has been increasing in recent years, primarily as a cost saving measure in healthcare provision. Orally inhaled products (OIPs) should continue to remain an attractive clinical proposition. At the same time, establishing bioequivalence of an inhaled therapeutic can be a challenging proposition. The purpose of establishing bioequivalence is to demonstrate equivalence between the generic medicine and the originator medicine in order to allow bridging of the pre-clinical and clinical testing performed on the originator drug. Methodologies to determine bioequivalence are well established for oral, systemically acting formulations. However, for inhaled drugs, there is currently no universally adopted methodology, and regulatory guidance in this area has been subject to debate. There is no one-size-fits-all programme. This review article mainly focused on current regulatory perspectives on bioequivalence of topically acting, orally inhaled drug products.