Response to the article entitled:
"Possible hepatotoxicity of IQOS"
by Chun et al., 20181.
 Department of Medicine, University of California, San Francisco, San Francisco, California, USA
by Gizelle Baker, Patrick Picavet, Maurice Smith, Patrick Vanscheeuwijck and Manuel C. Peitsch2.
Philip Morris International R&D
 Philip Morris Products S.A., PMI Research and Development, Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland. Authors are listed in alphabetical order.
The Department of Medicine, University of California, and San Francisco, California, USA has recently published a letter in Tobacco Control claiming that “The preclinical and clinical data PMI submitted to FDA indicate that IQOS exposure may be associated with unexpected liver toxicity. We reviewed preclinical studies conducted by PMI scientists and clinical studies of 5 and 90 days of exposure to IQOS and IQOS menthol included in PMI’s Modified Risk Tobacco Product application submitted to the US FDA.”
In summary, we have assessed these claims based on a careful review of our scientific data submitted to FDA. The scientific data is in the FDA submission and requires knowledge of the design and conduct of toxicology and clinical studies, together with a careful and detailed review of the resulting data to reach accurate, science-based conclusions. Such an analysis was not performed by the authors of the letter and therefore the conclusions they have drawn are incorrect and misleading.
In conclusion, based on an analysis of our toxicological studies and clinical studies performed according to international standards of good practice, there is no evidence that IQOS use leads to hepatotoxicity.