Article | Open Science events | Jun 15, 2020

      Using smoking cessation as a benchmark to assess health impacts of switching to the tobacco heating system (THS)

      Quitting smoking is the best way for smokers to reduce the harms from smoking. This analysis compares changes in eight biomarkers resulting from switching to THS with the gold standard of smoking cessation.


      As part of our six-month Exposure Response Study, we measured eight coprimary biomarkers of potential harm that are associated with the development of smoking-related diseases. In that study, all eight biomarkers of potential harm improved in the group of smokers who switched to THS, with five of the eight showing statistical significance. This analysis compares those changes in these biomarkers against results observed in another study where smokers quit smoking cigarettes altogether over the six months – the Smoking Cessation Study.

      The data from the two studies was pooled so that a comparison could be made, accounting for differences in demographics, lifestyle characteristics, and baseline values of the measured biomarkers and nicotine levels. For each biomarker, we calculate the difference in effect between those who switched to THS and those who continued to smoke (THS – cigarette). We also take the difference between cessation and continuing to smoke (SC – cigarette). These two differences are then compared against one another to obtain a percentage: (THS - cigarette) / (SC – cigarette).

      This percentage shows how similar switching to THS is to smoking cessation for that specific biomarker. At 0%, THS’ effect would be the same as for cigarettes while 100% would mean it’s similar to cessation for a given biomarker of potential harm. For five of the eight biomarkers of potential harm, switching to THS for at least 70% of participants' tobacco use resulted in at least 40% of the effect of smoking cessation. Among those THS users whose urine tests showed they had likely quit smoking, seven of the eight biomarkers showed that switching to THS resulted in at least 66% of the effect of smoking cessation. The values ranged from 44.3% up to 100% across all 8 biomarkers among those who completely switched.

      This comparison provides additional supporting evidence that switching to THS has the potential to reduce the risk of developing smoking-related diseases in smokers who would otherwise continue smoking cigarettes.


      Watch Dr. Bosilkovska's presentation:


      Below is a transcript of the video:

      My name is Marija, I’m a clinical scientist working on the design and interpretation of clinical studies.

      Today, I will talk to you about the extent to which the favorable effects of smoking cessation are preserved six months after switching to one of our products, THS, commercially known under the name of IQOS.

      When comparing our product, to assess the potential to reduce the risk of harm related to smoking, we compare them on hand against cigarettes, and on the other hand against smoking cessation, which is the best benchmark and the best option for every smoker.

      For that reason, I will present to you today the results of two studies.

      The first one was an exposure response study conducted in the U.S. which included adult smokers, who were willing to quit and were subsequently randomized to continue smoking, or to switch to THS for six months.

      The exposure response study showed favorable changes in biomarkers of potential harm, which are representative of the major pathophysiological pathways underlying smoking related diseases, such as inflammation, oxidative stress, genotoxicity, et cetera.

      In order to evaluate the relevance of these favorable changes and assess how close they approach the effects observed following smoking cessation, the data from the exposure response study have been pooled with the data from our cessation study, which was a study conducted worldwide in smokers willing to quit smoking. To assess the effects of partial and full switching to analysis populations have been defined.

      The first one was the primary analysis population, where THS subjects, who were using at least 70% of the product based on self-reporting, have been included and compared against cigarette users and successful quitters from the smoking abstinence study.

      The second analysis population was the CEMA analysis population, where THS users have been identified as adherent based on biochemical verification of their CEMA levels, which is an indicator of smoking. They were again, compared against cigarette and smoke successful quitters.

      In both analysis populations, baseline comparability between the groups was assured by a propensity score approach. Demographics show that the study groups were very similar in terms of age, race, and smoking history with a slightly higher number of female subjects in the smoking cessation group.

      The preserved effect has been defined as the effect of THS versus cigarettes over the effect of smoking abstinence versus cigarettes. This means that the preserved effect, which is close to 100%, means that switching to THS will have the same effect as smoking cessation, while for a preserved effect, which is close to 0%, it will indicate that switching to THS has a similar effect as continuing to smoke cigarettes.

      In the results graph, we can see that for the primary analysis population, at least 40% of the effect was preserved for five out of the 8 biomarkers of potential harm, with the majority of the effect being preserved for FEV1, a lung function marker, and for HDL-C, which is indicative of improved lipid metabolism.

      For the CEMA analysis population, where concomitant cigarette use in the THS group was minimal, as biochemically verified, more than two-thirds of the cessation effect have been preserved for all but one of the biomarkers of potential harm.

      This study has shown that both quitting smoking and switching to THS resulted in favorable changes in all eight biomarkers of potential harm, with the effect still being higher in the smoking cessation arm. However, smokers switching to THS show a substantial preserved effect of cessation when evaluating with self-reported product use, which allows up to 30% of concomitant cigarette use.

      When looking into the adherent population based on CEMA, the majority of the cessation effect has been preserved.

      This analysis provides additional evidence that smokers who switch to THS have the potential to reduce the risk of smoking-related disease as compared to continuous cigarette smoking.