Regulatory respiratory data refinement with reduced animal usage

通過減少動物使用來完善法規呼吸數據

Author links open overlay panelLouiseSladen ^a,1, Rommel Matheson^b, Kevin Norton^b, Aileen Milne^c,1

a Safety and ADME Translational Sciences Department, Drug Safety and Metabolism, IMED Biotech Unit, AstraZeneca, Unit 310, Cambridge Science Park, Milton Road, Cambridge CB4 0FZ, UK
^bCharles River, Safety Pharmacology,Transcanadienne, Senneville, QC H9X 3R3, Canada
^cCharles River, Safety Pharmacology, Elphinstone Research Centre, Tranent, Edinburgh EH33 2NE, United Kingdom

Abstract Introduction
Assessment of effects of potential drug candidates on the respiratory system is part of the regulatory preclinical safety assessment conducted prior to first in human trials (FTIH). Commonly, this is carried out utilizing head out plethysmography (HOP) or whole body plethysmography (WBP) which record only ventilatory parameters. When dosing via the inhaled route a more thorough respiratory assessment, including a direct measure of airway mechanics, is desirable. The aim of the present work was to improve the strategy for respiratory safety testing by a) evaluating a emetered pleural pressure – HOP (PP-HOP) model and b) evaluating a crossover study design protocol in the WBP model to reduce variability and animal usage.

評估潛在候選藥物對呼吸系統的影響是在*人體試驗(FTIH)之前進行的臨床前安全性評估的一部分。一般情況下，這是利用頭顱容積描記術(HOP)或全身容積描記術(WBP)進行的，后者只記錄通氣參數。通過吸入途徑給藥時，需要進行更*的呼吸評估，包括直接測量氣道力學。本研究的目的是通過a)評估遙測胸膜壓-跳(PP-HOP)模型和b)評估WBP模型中的交叉研究設計方案來改善呼吸安全性測試策略，以減少變異性和動物使用。

Methods
For the PP- HOP model, rats were surgically implanted with a emetry device for measurement of pleural pressure. Animals were placed in HOP tubes and respiratory function assessed when exposed to methacholine at doses of 0 (saline only), 0.42, 1.6 and 3.8?mg/kg. WBP assessment was performed in rats in a crossover study design when treated with theophylline at doses of 0 (saline only), 3, 10 and 30?mg/kg.

在PP-HOP模型中，大鼠被外科植入遙測裝置以測量胸膜壓。將動物置于啤酒花管中，在0(僅生理鹽水)、0.42、1.6和3.8?mg/kg劑量下暴露于乙酰*時評估呼吸功能。在交叉研究設計中，當*劑量為0(僅生理鹽水)、3、10和30?mg/kg時，對大鼠進行WBP評估。

Results
Data from the PP-HOP study confirmed the expected changes in ventilatory parameters and airway mechanics in response to inhaled methacholine, including an increase in pulmonary resistance and decrease in tidal volume.

Data from the WBP crossover study demonstrated similar sensitivity and statistical power to detect changes in respiratory rate and tidal volume to a standard parallel group design.

PP-HOP研究的數據證實了吸入甲基*后通氣參數和氣道力學的預期變化，包括肺阻力增加和潮氣量減少。
來自WBP交叉研究的數據顯示，檢測呼吸頻率和潮氣量變化的敏感性和統計能力與標準平行組設計相似。

Conclusion
Measurement of PP-HOP in a stand-alone safety pharmacology study in conjunction with HOP assessment conducted as part of a toxicology study, represents an improved respiratory testing strategy for inhaled drugs. For compounds administered by other routes, we conclude that use of WBP using a crossover dosing design is a suitable alternative to parallel dosing groups, with a significant reduction in animal numbers and no loss of statistical power.

在一個獨立的安全藥理學研究中，PP-HOP的測量與作為毒理學研究的一部分的HOP評估相結合，代表了一種改進的吸入藥物呼吸測試策略。對于通過其他途徑給藥的化合物，我們得出結論，使用交叉給藥設計的WBP是平行給藥組的合適替代方案，動物數量顯著減少，且不喪失統計能力。

Abbreviations
FTIH first time in human
PP-HOP pleural pressure-head out plethysmography
WBP whole body plethysmography
i.t. intra tracheal
VT tidal volume
Bpm breaths per minute
MV minute volume
ICH The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use
GLP good laboratory practice