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Explore PMI Science, where innovation meets harm reduction. Learn about our scientists, smoke-free research, and commitment to transparency in research.
PMI offers smoke-free alternatives with the potential to reduce the risk of harm for adult smokers who do not quit. Learn about harm reduction, the role of nicotine, and the regulation of smoke-free products.
Discover PMI's rigorous scientific approach to smoke-free products and product assessment. Dive into our research results, peer-reviewed publications, independent research, and expert reports.
PMI believes that offering a range of smoke-free alternatives is essential to ensure individual smokers are able to find a smoke-free product that they can fully switch to.
Explore the latest insights and stay informed about upcoming events and conference presentations from PMI scientists.
Ask a question or send us feedback. We're happy to answer.
Pouly, S.; Talikka, M.; van der Plas, A.; Titz, B.; Iskandar, A.; de La Bourdonnaye, G.; Blanc, N.; Martin, F.; Haziza, C.; Ivanov, N. V.; Lüdicke, F.; Hoeng, J.; Peitsch, M. C.
Society of Toxicology (SOT) 2019
Cytochrome P450s (CYP) are prominent xenobiotic metabolism enzymes that detoxify or activate xenobiotic compounds. CYP1A2 is a key factor in the activation metabolism of various constituents found in cigarette smoke (CS), in particular of polycyclic aromatic hydrocarbons, and is indicative of CS exposure. The Tobacco Heating System (THS) 2.2 is designed to heat tobacco instead of burning it, thereby significantly reducing the levels of harmful chemicals in the aerosol compared with those found in cigarette smoke. As part of the pre-clinical THS 2.2 assessment, mRNA and protein abundance of CYP1A2 was measured in the livers of ApoE-/- mice exposed to CS from a 3R4F reference cigarette, aerosol from THS 2.2, or fresh air (sham). Elevated levels of CYP1A2 were observed in the livers of mice in the 3R4F group, but not in the THS 2.2 group, compared with the sham group. The combined enzymatic activity of CYP1A1 and CYP1B1 was further shown to be lower in human organotypic bronchial and nasal cultures exposed to THS 2.2 aerosol than in those exposed to 3R4F CS. Overall, gene expression levels of xenobiotic metabolizing enzymes and transporters were less impacted by exposure to THS 2.2 aerosol than exposure to 3R4F CS in all pre-clinical models tested. In addition, a causal biological network model that captures the xenobiotic metabolism response in the respiratory tract demonstrated weaker perturbation upon THS 2.2 aerosol compared with CS exposure at nicotine-matched exposure concentrations. Finally, in four clinical studies conducted with THS 2.2, CYP1A2 activity was found to be lower in the plasma of subjects who abstained from smoking or switched to THS 2.2 for five days compared with subjects who continued smoking. Taken together, these results demonstrate an overall reduced impact on xenobiotic metabolism for exposure to THS 2.2 compared with cigarette in non-clinical in vitro and in vivo models as well as clinical studies.
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Reduced Risk Products ("RRPs”) is the term we use to refer to products that present, are likely to present, or have the potential to present less risk of harm to smokers who switch to these products versus continuing smoking. PMI has a range of RRPs in various stages of development, scientific assessment and commercialization. All of our RRPs are smoke-free products that deliver nicotine with far lower quantities of harmful and potentially harmful constituents than found in cigarette smoke.