CORESTA Congress, Kunming, 2018, Smoke Science/Product Technology Groups, ST 17

A clinical study investigating changes in exposure to cigarette smoke chemicals in U.K. smokers who switch to using a tobacco heating product for a five-day period

(1) British American Tobacco (Investments) Limited, R&D, Southampton, U.K.; (2) Celerion Inc., Lincoln, NE, U.S.A.

Smoking is a leading cause of numerous diseases, particularly lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases. Consequently, there is a recognized need to provide smokers with alternative nicotine-delivery devices that have less chemical toxicants compared to conventional cigarette smoke. Tobacco heating products (THPs) hold great potential for reducing the harms associated with tobacco use. Therefore, a comprehensive scientific assessment is important to fully characterise the reduced exposure and/or reduced risk THPs offer to cigarette smokers.

A clinical study was carried out to test the hypothesis that biomarkers of cigarette smoke exposure are reduced when smokers switch from smoking commercial cigarettes to using THPs.

This clinical study, conducted in Belfast, U.K. (ISRCTN80651909), was approved by a local Research Ethics Committee and run in accordance with ICH-GCP. 150 healthy smokers smoked combustible cigarettes during a two-day baseline period, after which they were randomized to either continue smoking cigarettes, switch to using a THP or completely quit any nicotine or tobacco product use, for five days. Both baseline and post-randomisation 24-h urine samples were collected for biomarker of exposure (BoE) analysis and exhaled carbon monoxide was also measured daily.

Interim results from the urinary BoE and exhaled CO showed reductions in levels in subjects who switched to the glo™ device for five days, as well as reductions in the levels in subjects who abstained from any tobacco use for five days.

This study demonstrated that when smokers switched from smoking combustible cigarettes to using a THP, their exposure to smoke toxicants decreased, in many cases, to similar levels as cessation. These results suggest that THPs have the potential to be reduced exposure and/or reduced risk tobacco products. Further clinical studies are required to confirm the sustainability of these exposure reductions and the translation to reductions in smoking-related health risks.