british american tobacco p.l.c. sustainability report 2010 - Addressing the scientific challenges around the development of 'safer' cigarettes

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Sustainability Report 2010

PREP assessment framework

The development of ‘safer’ cigarettes is the ‘Holy Grail’ of tobacco research. But in order to be able to demonstrate reduced risk for one or more smoking-related diseases, scientists must have tools to objectively assess combustible candidate PREPs (potential reduced-exposure products) against conventional cigarettes. Currently, there is no agreement as to how these products should be assessed in practice. We are developing an assessment framework and are working to have it agreed by regulators and public health stakeholders. Our framework will include tests to assess tobacco smoke toxicant exposure in smokers, as well as tests to assess the biological effect and potential harm of this exposure.

Addressing the scientific challengesClinical studies

We have made good progress in validating biomarkers of exposure to tobacco smoke toxicants in our clinical studies. Biomarkers of exposure, which are metabolites of certain smoke toxicants, can be measured in biological fluids. They represent a measure of what smoke toxicants an individual has been exposed to. We are also making progress in identifying biomarkers of biological effect. These give an indication of the effect any exposure to smoke toxicants may have had on the body.

In 2010, we completed the analysis of two studies initiated in Italy in 2008 and 2009. The first study involved researching pairs of identical twins, where one twin in each pair was a smoker and one was not. This study revealed 10 biomarkers of biological effect that might be of assistance in predicting smoking-related risk. For many of these biomarkers, genetics are likely to play a role but, by studying identical twins, genetic variability has been excluded. The results should assist the interpretation of other population studies using these biomarkers.

The second study examined levels of biomarkers of biological effect in ex-smokers to determine whether any reduction in biomarkers is observed as a result of their quitting smoking. This will help us to identify which biomarkers may be responsive to a reduction in smoke toxicants. Results from both studies could help in the development of a database of biomarkers that could be used to assess any new products designed to be reduced risk.

In 2010, we also completed our analysis of a 2009 study of a range of prototype cigarettes, designed to have lower levels of several smoke toxicants compared to conventional cigarettes. This is a key piece of research for us, because it has enabled us to demonstrate in a clinical setting that reductions in levels of smoke toxicants measured in laboratory tests are reflected in reduced levels of exposure in smokers. We have seen significant reductions in exposure to a range of smoke toxicants. These include the toxicants acrolein, 1,3-butadiene and tobacco-specific nitrosamines.

Although a reduction in exposure is not sufficient to determine that the prototypes pose lower risk, this work is an important further step in our journey to develop and characterise a candidate PREP. We have submitted the results of this study for publication in a peer-reviewed journal and will also present the top-line results at a conference in 2011 of the Society for Research on Nicotine and Tobacco.

We are planning a longer clinical study of second generation prototypes to assess the sustainability of the reduction in exposure and to start to explore biomarkers of biological effect.

Biotechnology programme

We believe that biotechnology may offer unique ways to reduce some tobacco smoke toxicants in the future. In 2010, we reinvigorated our biotechnology programme, in which we employ both traditional plant breeding techniques and genetic modification with the aim of reducing tobacco smoke toxicant levels.

We have conducted field trials of plants genetically modified in a way that we anticipate will result in lower levels of tobacco-specific nitrosamines. We also want to reduce the uptake of heavy metals by the tobacco plant from the soil. Heavy metals like arsenic and cadmium can be toxic to humans. However, today we do not use genetically modified (GM) tobacco in any of our products.

Scientific challenges: what's next?

We plan to carry out further clinical studies, including developing a protocol for a longer clinical study of smokers who switch to reduced toxicant prototype cigarettes. This is being reviewed by our External Scientific Panel and we expect to have the results of the study in 2012. We will also continue to develop and validate laboratory models of diseases, such as cancer, chronic obstructive pulmonary disease and cardiovascular disease.