Smoking cigarettes is a major risk factor in the development and progression of cardiovascular disease (CVD) and pulmonary diseases (e.g., COPD). That is why modified risk tobacco products (MRTPs) – products with the potential to reduce individual risk and population harm in comparison to smoking cigarettes – are developed.

Philip Morris International (PMI)'s potential MRTPs are in various stages of development and commercialization.

In order to assess whether switching to these novel products can indeed reduce the risk of developing diseases most strongly associated with smoking, PMI has conducted extensive and rigorous scientific studies, including non-clinical in vitro and in vivo studies as well as clinical assessment studies in adult smokers. Before making any risk reduction claim, the full set of data from the relevant scientific studies will be rigorously evaluated and reviewed to determine whether they substantiate reduced exposure or risk claims. Any such claims may also be subject to government review and authorization, as is the case in the United States today. Some of these studies are accessible below for review.

Studies on THS2.2


In Vitro study

THS2.2 aerosol characterization: chemical composition, genotoxicity, cytotoxicity and physical properties (vs. 3R4F)

Evaluation of the Tobacco Heating System 2.2 (THS2.2) - Chemical composition, genotoxicity, cytotoxicity, and physical properties of the aerosol compared with smoke from the reference cigarette 3R4F

In Vivo study

8-month systems toxicology inhalation / cessation study with THS2.2 in Apoe‑/‑ mice

Cardiovascular and Respiratory Exposure Effects in an 8-month Inhalation Study in Apoe‑/‑ Mice of a Candidate Modified Risk Tobacco Product, THS 2.2, Compared with Conventional Cigarettes

In Vitro study

Atherogenesis study in vitro - Adhesion assay (of monocytic cells to endothelial cells) with THS2.2

In vitro adhesion assay coupled with innovative computational systems biology approaches to analyze omics data, our study aimed at investigating CS-induced mechanisms by which monocyte–endothelial cell adhesion is promoted.

In Vitro study

Atherogenesis study in vitro - Transendothelial migration assay with THS2.2

Aerosol from a candidate modified risk tobacco product has reduced effects on chemotaxis and transendothelial migration compared to combustion of conventional cigarettes

In Vitro study

Assessment of acute THS2.2 aerosol exposure in in vitro Human nasal epithelial cultures

This study reports the applicability of an in vitro human 3D organotypic nasal epithelial culture model to assess the biological impact of aerosol generated from a candidate MRTP - THS2.2 - compared with smoke from 3R4F reference cigarette

In Vitro study

Assessment of acute THS2.2 aerosol exposure in in vitro Human buccal epithelial cultures

This study reports the applicability of an in vitro human 3D organotypic buccal epithelial culture model to assess the biological impact of aerosol generated from a candidate MRTP - THS2.2 - compared with smoke from 3R4F reference cigarette

In Vitro study

Assessment of acute THS2.2 aerosol exposure in in vitro Human bronchial epithelial cultures

This study reports the use of an in vitro human 3D organotypic bronchial epithelial culture model to assess the biological impact of aerosol generated from a candidate MRTP - THS2.2 - compared with smoke from 3R4F reference cigarette

In Vitro study

Assessment of repeated THS2.2 aerosol exposure in in vitro Human gingival epithelial cultures

This study reports the applicability of an in vitro human 3D organotypic gingival epithelial culture model to assess the biological impact of aerosol generated from a cMRTP - THS2.2 - compared with smoke from 3R4F reference cigarette

Studies on pMRTP


In Vitro study

Aerosol chemistry of pMRTP vs. 3R4F

Determination of the concentration of 58 HPHCs in the aerosol of a pMRTP and smoke from the 3R4F reference cigarette generated using the Health Canada Intense machine-smoking regimen.

In Vivo study

7-month systems toxicology inhalation / cessation study with pMRTP in C57BL6 mice

Emphysema progression in C57Bl/6 mice in response to chronic exposure to conventional cigarette smoke, and the impact of cessation or switching to aerosol from a prototypic MRTP (pMRTP) - A 7-month inhalation study

Studies on: