Methods to assess potential reduced exposure products

Conceptual model for the evaluation of attractiveness, addictiveness and toxicity of tobacco and related products: The example of JUUL e-cigarettes

Many new tobacco and related products (nTRP) have emerged on the market, with unknown health risks. Here, we present a conceptual model containing the factors and relations between them that contribute to the nTRP's health effects. Factors that determine attractiveness, addictiveness and toxicity of nTRP were defined based on previous assessments, literature, and expert discussions. Our model will aid in identifying key risk factors contributing to increased risk of adverse health effects for a product in a qualitative manner. Additionally, it can gauge attractiveness for specific user groups, as a determinant for population prevalence of use. Our model can be used to identify aspects of nTRP that require attention for public information or product regulation. As an example, we applied this to JUUL, a popular e-cigarette in the US. Aspects of concern for JUUL are its attractive and discrete shape, user-friendly prefilled pods, flavors, high aerosol nicotine levels, and liquids containing nicotine salts instead of free-based nicotine. The addictiveness and especially attractiveness are sufficiently high to have a large potential impact on population health due to its contribution to use and hence exposure. Products and their use can change over time; therefore market research and monitoring are crucial.

Piloting a clinical laboratory method to evaluate the influence of potential modified risk tobacco products on smokers' quit-related motivation, choice, and behavior

Research methods are needed that can predict whether the availability of potential modified risk tobacco products (MRTPs) may influence smokers' quit-related motivation, choice, and behavior. This pilot study assessed the primary outcomes of feasibility and adherence to address this need using an electronic cigarette (ECIG) as a model MRTP. Cigarette smokers were randomly assigned to use only their own brand of cigarettes (OB-only) or a second-generation ECIG (18 ng/ml nicotine) plus their OB cigarettes (ECIG+OB) ad libitum for four weeks. Participants logged products using a mobile device, collected used cigarette filters, and provided saliva samples every day for analysis of cotinine. They returned to the lab once per week to provide a breath sample and accept or decline a choice to quit all tobacco products (i.e., cigarettes and/or ECIGs). They also returned for a one-month follow-up visit. Of those participants randomized (n = 60), 56.7% completed the 4-week intervention and 40.0% completed the follow-up visit. The primary reason for withdrawal was poor adherence with mobile device use. Comparable numbers of participants in each group chose to make a quit attempt, although more OB-only participants chose to quit during the first two weeks and more ECIG+OB participants during the last two weeks. With protocol modifications to reduce participation burden, the current method might ultimately be used by regulators to predict how smokers' quit-related motivation, choice, and behavior are influenced by current and future MRTPs.

Answering questions about electronic cigarettes using a multidisciplinary model

Electronic cigarettes (ECIGs) are a relatively new class of tobacco products and a subject of much debate for scientists and policymakers worldwide. Objective data that address the ECIG risk-benefit ratio for individual and public health are needed, and addressing this need requires a multidisciplinary approach that spans several areas of psychology as well as chemistry, toxicant inhalation, and physiology. This multidisciplinary approach would benefit from methods that are reliable, valid, and swift. For this reason, we formed a multidisciplinary team to develop methods that could answer questions about ECIGs and other potential modified risk tobacco products. Our team includes scientists with expertise in psychology (clinical, community, and experimental) and other disciplines, including aerosol research, analytical chemistry, biostatistics, engineering, internal medicine, and public health. The psychologists on our team keep other members focused on factors that influence individual behavior, and other team members keep the psychologists aware of other issues, such as product design. Critically, all team members are willing to extend their interests beyond the boundaries of their discipline to collaborate effectively with the shared goal of producing the rigorous science needed to inform empirically based tobacco policy. In addition, our trainees gain valuable knowledge from these collaborations and learn that other disciplines are accessible, exciting, and can enhance their own research. Multidisciplinary work presents challenges: learning other scientists' languages and staying focused on our core mission. Overall, our multidisciplinary team has led to several major findings that inform the scientific, regulatory, and public health communities about ECIGs and their effects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Smoking and Lung Cancer: Future Research Directions

The aim of future research in this area is to provide the mechanistic understanding and the tools for effective prevention, early diagnosis, and therapy of lung cancer. With the established causal link between cigarette smoking and the risk of developing lung cancer, the most effective prevention is certainly not to smoke. A much better mechanistic understanding of lung cancer and its variability will support the development and evaluation of potentially reduced risk products for those who maintain smoking as well as for the development of early diagnostic tools and targeted therapies. Because of the complexity of lung cancer and the long duration for its development, nonclinical and clinical research efforts need to complement each other. Recent promising advances in this research area are the understanding of the interaction between genotoxic and epigenetic effects of smoking, the development of laboratory animal models for lung tumorigenesis by smoke inhalation, the unraveling of molecular pathways and signatures in clinical lung cancer research useful for developing diagnostic tools and therapeutic approaches, and the first successful therapy for lung cancer—although less suitable for smokers. The above—in combination with emerging data sets from explorative non-clinical and clinical studies as well as improved modeling approaches—are setting the stage for accelerated progress towards developing successful early diagnostic tools and therapies as well as for the assessment of new consumer products with potentially reduced risk.

Interventions to reduce harm from continued tobacco use

BACKGROUND

Although smoking cessation is currently the only guaranteed way to reduce the harm caused by tobacco smoking, a reasonable secondary tobacco control approach may be to try and reduce the harm from continued tobacco use amongst smokers unable or unwilling to quit. Possible approaches to reduce the exposure to toxins from smoking include reducing the amount of tobacco used, and using less toxic products, such as pharmaceutical, nicotine and potential reduced-exposure tobacco products (PREPs), as an alternative to cigarettes.

OBJECTIVES

To assess the effects of interventions intended to reduce the harm to health of continued tobacco use, we considered the following specific questions: do interventions intended to reduce harm have an effect on long-term health status?; do they lead to a reduction in the number of cigarettes smoked?; do they have an effect on smoking abstinence?; do they have an effect on biomarkers of tobacco exposure?; and do they have an effect on biomarkers of damage caused by tobacco?

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Trials Register (CRS) on the 21st October 2015, using free-text and MeSH terms for harm reduction, smoking reduction and cigarette reduction.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials of interventions to reduce the amount smoked, or to reduce harm from smoking by means other than cessation. We include studies carried out in smokers with no immediate desire to quit all tobacco use. Primary outcomes were change in cigarette consumption, smoking cessation and any markers of damage or benefit to health, measured at least six months from the start of the intervention.

DATA COLLECTION AND ANALYSIS

We assessed study eligibility for inclusion using standard Cochrane methods. We pooled trials with similar interventions and outcomes (> 50% reduction in cigarettes a day (CPD) and long-term smoking abstinence), using fixed-effect models. Where it was not possible to meta-analyse data, we summarized findings narratively.

MAIN RESULTS

Twenty-four trials evaluated interventions to help those who smoke to cut down the amount smoked or to replace their regular cigarettes with PREPs, compared to placebo, brief intervention, or a comparison intervention. None of these trials directly tested whether harm reduction strategies reduced the harms to health caused by smoking. Most trials (14/24) tested nicotine replacement therapy (NRT) as an intervention to assist reduction. In a pooled analysis of eight trials, NRT significantly increased the likelihood of reducing CPD by at least 50% for people using nicotine gum or inhaler or a choice of product compared to placebo (risk ratio (RR) 1.75, 95% confidence interval (CI) 1.44 to 2.13; 3081 participants). Where average changes from baseline were compared for different measures, carbon monoxide (CO) and cotinine generally showed smaller reductions than CPD. Use of NRT versus placebo also significantly increased the likelihood of ultimately quitting smoking (RR 1.87, 95% CI 1.43 to 2.44; 8 trials, 3081 participants; quality of the evidence: low). Two trials comparing NRT and behavioural support to brief advice found a significant effect on reduction, but no significant effect on cessation. We found one trial investigating each of the following harm reduction intervention aids: bupropion, varenicline, electronic cigarettes, snus, plus another of nicotine patches to facilitate temporary abstinence. The evidence for all five intervention types was therefore imprecise, and it is unclear whether or not these aids increase the likelihood of smoking reduction or cessation. Two trials investigating two different types of behavioural advice and instructions on reducing CPD also provided imprecise evidence. Therefore, the evidence base for this comparison is inadequate to support the use of these types of behavioural advice to reduce smoking. Four studies of PREPs (cigarettes with reduced levels of tar, carbon and nicotine, and in one case delivered using an electronically-heated cigarette smoking system) showed some reduction in exposure to some toxicants, but it is unclear whether this would substantially alter the risk of harm. We judged the included studies to be generally at a low or unclear risk of bias; however, there were some ratings of high risk, due to a lack of blinding and the potential for detection bias. Using the GRADE system, we rated the overall quality of the evidence for our cessation outcomes as 'low' or 'very low', due to imprecision and indirectness. A 'low' grade means that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. A 'very low' grade means we are very uncertain about the estimate.

AUTHORS' CONCLUSIONS

People who do not wish to quit can be helped to cut down the number of cigarettes they smoke and to quit smoking in the long term, using NRT, despite original intentions not to do so. However, we rated the evidence contributing to the cessation outcome for NRT as 'low' by GRADE standards. There is a lack of evidence to support the use of other harm reduction aids to reduce the harm caused by continued tobacco smoking. This could simply be due to the lack of high-quality studies (our confidence in cessation outcomes for these aids is rated 'low' or 'very low' due to imprecision by GRADE standards), meaning that we may have missed a worthwhile effect, or due to a lack of effect on reduction or quit rates. It is therefore important that more high-quality RCTs are conducted, and that these also measure the long-term health effects of treatments.

Behavioral Economic Laboratory Research in Tobacco Regulatory Science

OBJECTIVES

Research that can provide a scientific foundation for the United States Food and Drug Administration (FDA) tobacco policy decisions is needed to inform tobacco regulatory policy. One factor that affects the impact of a tobacco product on public health is its intensity of use, which is determined, in part, by its abuse liability or reinforcing efficacy. Behavioral economic tasks have considerable utility for assessing the reinforcing efficacy of current and emerging tobacco products.

METHODS

This paper provides a narrative review of several behavioral economic laboratory tasks and identifies important applications to tobacco regulatory science.

RESULTS

Behavioral economic laboratory assessments, including operant self-administration, choice tasks and purchase tasks, can be used generate behavioral economic data on the effect of price and other constraints on tobacco product consumption. These tasks could provide an expedited simulation of the effects of various tobacco control policies across populations of interest to the FDA.

CONCLUSIONS

Tobacco regulatory research questions that can be addressed with behavioral economic tasks include assessments of the impact of product characteristics on product demand, assessments of the abuse liability of novel and potential modified risk tobacco products (MRTPs), and assessments of the impact of conventional and novel products in vulnerable populations.

Biomarkers of tobacco smoke exposure

Diseases and death caused by exposure to tobacco smoke have become the single most serious preventable public health concern. Thus, biomarkers that can monitor tobacco exposure and health effects can play a critical role in tobacco product regulation and public health policy. Biomarkers of exposure to tobacco toxicants are well established and have been used in population studies to establish public policy regarding exposure to second-hand smoke, an example being the nicotine metabolite cotinine, which can be measured in urine. Biomarkers of biological response to tobacco smoking range from those indicative of inflammation to mRNA and microRNA patterns related to tobacco use and/or disease state. Biomarkers identifying individuals with an increased risk for a pathological response to tobacco have also been described. The challenge for any novel technology or biomarker is its translation to clinical and/or regulatory application, a process that requires first technical validation of the assay and then careful consideration of the context the biomarker assay may be used in the regulatory setting. Nonetheless, the current efforts to investigate new biomarker of tobacco smoke exposure promise to offer powerful new tools in addressing the health hazards of tobacco product use. This review will examine such biomarkers, albeit with a focus on those related to cigarette smoking.

Longitudinal study of long-term smoking behaviour by biomarker-supported determination of exposure to smoke

BACKGROUND

Long-term studies of smokers who switch to lower nicotine yield cigarettes have been identified by the World Health Organization Study Group TobReg and the US Food and Drug Administration as one key area where new knowledge is required to guide science based regulation. The limited number of long-term switching studies have concluded that smokers who switch to lower nicotine yield cigarettes show evidence of partial compensation. Since the European Union tobacco product directive of 2001 introduced tar and nicotine yield ceilings, there has been no long-term observational switching study. To address the limitations of previous studies where smokers were forced switched for relatively short durations, we plan to undertake a long-term study of spontaneous switching which is appropriately powered and includes non-switchers as a control group.

METHODS/DESIGN

Healthy adult smokers aged 21-64 years will be enrolled into this 5-year non-residential, multicentre study across 10 cities in Germany. They will be assessed at 10 timepoints with 6 month intervals during which inclusion criteria will be reassessed and spent cigarette filter tips, saliva and 24 h urine samples will be collected. These samples will be used to determine average daily cigarette consumption, estimate mouth-level exposure to tar and nicotine and measure selected biomarkers of exposure, respectively. Spontaneous changes in subjects' preferred cigarette products and any consequent change in tar or nicotine yield will be monitored. Subjects will be required to complete questionnaires on quality of life, smoking behaviours, smoking-related sensory attributes and recent life changes.

DISCUSSION

The planned study is anticipated to contribute to understanding smokers' behaviours and their consequent exposure to smoke constituents. It will also allow assessment of compensatory changes in their behaviour following spontaneous switching of cigarette product smoked. Data from this study are expected to provide insights into study design and conduct for non-clinical assessment of smokers' exposure as part of post marketing surveillance programmes.

TRIAL REGISTRATION

Current Controlled Trials Database reference ISRCTN95019245.

Research priorities for FCTC Articles 20, 21, and 22: surveillance/evaluation and information exchange

INTRODUCTION

Framework Convention on Tobacco Control (FCTC) Articles 20, 21, and 22 call for strong monitoring and reporting of tobacco use and factors influencing use and disease (Articles 20 and 21) and for collaboration among the Parties and relevant organizations to share resources, knowledge, and expertise on all relevant tobacco control strategies (Article 22).

METHODS

This paper provides background information and discusses research strategies that would strengthen these efforts and better inform the parties. By necessity, Articles 20 and 21 are discussed separately from Article 22, although 1 example that relates to both 20/21 and 22 is discussed at the end.

RESULTS

Twelve important research opportunities on surveillance and evaluation are recognized, along with 4 on collaboration. The authors believe that the 6 most important areas for research would study (a) possible underreporting of tobacco use among certain demographic groups in some countries, (b) measures of industry activities, (c) optimal sampling strategies, (d) sentinel surveillance, (e) networks of tobacco companies and their partners as they promote tobacco use and interfere with implementation of the FCTC, and (f) network/relationship factors that impact diffusion of knowledge and decision making on the implementation of the FCTC. In addition, we call for a review process of existing surveillance and evaluation strategies to coordinate activities to make optimal use of existing resources. This activity would involve networking as prescribed in Article 22.

CONCLUSIONS

Studies and activities such as these would facilitate control of the tobacco epidemic.

Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 6: 6-Day randomized clinical trial of a menthol cigarette in Japan

A randomized, controlled, open-label, parallel-group, single-center study to determine biomarkers of exposure to 12 selected harmful and potentially harmful constituents (HPHC) in cigarette smoke, excretion of mutagenic material in urine, and serum Clara cell 16-kDa protein (CC16) in 102 male and female Japanese subjects who smoked Marlboro Ultra Lights Menthol cigarettes (M4J(M); 4 mg tar and 0.3mg nicotine) at baseline. Subjects were randomized to continue smoking M4J(M), or switch to smoking either the Electrically Heated Cigarette Smoking System menthol cigarette (EHCSS-K6(M); 5mg tar and 0.3mg nicotine) or the Lark One menthol cigarette (Lark1(M); 1mg tar and 0.1mg nicotine), or to no-smoking. The mean decreases from baseline to Day 5/6 were statistically significant (p ≤ 0.05) for exposure to 10 of 12 cigarette smoke HPHC including the primary endpoint (carbon monoxide) and urinary excretion of mutagenic material in the EHCSS-K6(M) group (-12.3% to -83.4%). Smaller, but statistically significant reductions (p ≤ 0.05) occurred in the Lark1(M) group (-3.3% to -35.2%), with the exception of urinary mutagens. The largest mean reductions (all p ≤ 0.05) in exposure to cigarette smoke HPHC and excretion of mutagenic material occurred in the no-smoking group (-1.4% to -93.6%). Serum CC16, an indicator of lung epithelial injury, was not significantly different between groups.

Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 1: Non-clinical and clinical insights

The following series of papers presents an extensive assessment of the Electrically Heated Cigarette Smoking System EHCSS series-K cigarette vs. conventional lit-end cigarettes (CC) as an example for an extended testing strategy for evaluation of reduced exposure. The EHCSS produces smoke through electrical heating of tobacco. The EHCSS series-K heater was designed for exclusive use with EHCSS cigarettes, and cannot be used to smoke (CC). Compared to the University of Kentucky Reference Research cigarette 2R4F and a series of commercial CC, mainstream cigarette smoke of both the non-menthol and menthol-flavored EHCSS cigarettes showed a reduced delivery of a series of selected harmful and potentially harmful constituents (HPHC), mutagenic activity determined using the Salmonella typhimurium Reverse Mutation (Ames) assay, and cytotoxicity in the Neutral Red Uptake Assay. Clinical evaluations confirmed reduced exposure to HPHC and excretion of mutagenic material under controlled clinical conditions. Reductions in HPHC exposure were confirmed in a real-world ambulatory clinical study. Potential biomarkers of cardiovascular risk were also reduced under real-world ambulatory conditions. A modeling approach, 'nicotine bridging', was developed based on the determination of nicotine exposure in clinical evaluations which indicated that exposure to HPHC for which biomarkers of exposure do not exist would also be reduced.

Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 5: 8-Day randomized clinical trial in Japan

A randomized, controlled, open-label, parallel-group, single-center study to determine biomarkers of exposure to twelve selected harmful and potentially harmful constituents (HPHCs) in cigarette smoke and urinary excretion of mutagenic material in 128 male and female Japanese subjects smoking Marlboro cigarettes (6 mg tar, 0.5mg nicotine, and 7.0mg CO) at baseline. Subjects were randomized to continue smoking Marlboro cigarettes, or switch to the Electrically Heated Cigarette Smoking System (EHCSS) and smoke either the EHCSS-K6 (5mg tar, 0.3mg nicotine, and 0.6 mg CO) or the EHCSS-K3 (3mg tar, 0.2mg nicotine, and 0.6 mg CO) cigarette, or switch to smoking Lark One cigarettes (1mg tar, 0.1mg nicotine, and 2.0mg CO), or to no-smoking. The mean decreases from baseline to Day 8 were statistically significant (p ≤ 0.05) for all cigarette smoke HPHC including CO (the primary objective) and excretion of mutagenic material in the EHCSS-K6 (range: -14.6% to -75.6%) and EHCSS-K3 (range: -9.8% to -73.0%) groups. Statistically significant reductions (all p ≤ 0.05) in exposure to ten cigarette smoke HPHC (range: -5.9% to -34.6%), but not urinary mutagenicity, were observed in the Lark One group. The largest mean reductions in exposure to HPHC (all p ≤ 0.01 level) occurred in the no-smoking group (range: -13.7% to -97.6%).

Delivery of nicotine in an extract of a smokeless tobacco product reduces its reinforcement-attenuating and discriminative stimulus effects in rats

RATIONALE

Animal models of tobacco addiction rely on administration of nicotine alone or nicotine combined with isolated constituents. Models using tobacco extracts derived from tobacco products and containing a range of tobacco constituents might more accurately simulate tobacco exposure in humans.

OBJECTIVE

To compare the effects of nicotine alone and an aqueous smokeless tobacco extract in several addiction-related animal behavioral models.

METHODS

Nicotine alone and nicotine dose-equivalent concentrations of extract were compared in terms of their acute effects on intracranial self-stimulation (ICSS) thresholds, discriminative stimulus effects, and effects on locomotor activity.

RESULTS

Similar levels of nicotine and minor alkaloids were achieved using either artificial saliva or saline for extraction, supporting the clinical relevance of the saline extracts used in these studies. Extract produced reinforcement-enhancing (ICSS threshold-decreasing) effects similar to those of nicotine alone at low to moderate nicotine doses, but reduced reinforcement-attenuating (ICSS threshold-increasing) effects at a high nicotine dose. In rats trained to discriminate nicotine alone from saline, intermediate extract doses did not substitute for the training dose as well as nicotine alone. Locomotor stimulant effects and nicotine distribution to brain were similar following administration of extract or nicotine alone.

CONCLUSIONS

The reinforcement-attenuating and discriminative stimulus effects of nicotine delivered in an extract of a commercial smokeless tobacco product differed from those of nicotine alone. Extracts of tobacco products may be useful for evaluating the abuse liability of those products and understanding the role of non-nicotine constituents in tobacco addiction.

Tobacco and nicotine product testing

INTRODUCTION

Tobacco product testing is a critical component of the Family Smoking Prevention and Tobacco Control Act (FSPTCA), which grants the Food and Drug Administration the authority to regulate tobacco products. The availability of methods and measures that can provide accurate data on the relative health risks across types of tobacco products, brands, and subbrands of tobacco products on the validity of any health claims associated with a product, and on how consumers perceive information on products toxicity or risks is crucial for making decisions on the product's potential impact on public health. These tools are also necessary for making assessments of the impact of new indications for medicinal products (other than cessation) but more importantly of tobacco products that may in the future be marketed as cessation tools.

OBJECTIVE

To identify research opportunities to develop empirically based and comprehensive methods and measures for testing tobacco and other nicotine-containing products so that the best science is available when decisions are made about products or policies.

METHODS

Literature was reviewed to address sections of the FSPTCA relevant to tobacco product evaluation; research questions were generated and then reviewed by a committee of research experts.

RESULTS

A research agenda was developed for tobacco product evaluation in the general areas of toxicity and health risks, abuse liability, consumer perception, and population effects.

CONCLUSION

A cohesive, systematic, and comprehensive assessment of tobacco products is important and will require building consensus and addressing some crucial research questions.

Murine lung tumor response after exposure to cigarette mainstream smoke or its particulate and gas/vapor phase fractions

Knowledge on mechanisms of smoking-induced tumorigenesis and on active smoke constituents may improve the development and evaluation of chemopreventive and therapeutic interventions, early diagnostic markers, and new and potentially reduced-risk tobacco products. A suitable laboratory animal disease model of mainstream cigarette smoke inhalation is needed for this purpose. In order to develop such a model, A/J and Swiss SWR/J mouse strains, with a genetic susceptibility to developing lung adenocarcinoma, were whole-body exposed to diluted cigarette mainstream smoke at 0, 120, and 240 mg total particulate matter per m(3) for 6h per day, 5 days per week. Mainstream smoke is the smoke actively inhaled by the smoker. For etiological reasons, parallel exposures to whole smoke fractions (enriched for particulate or gas/vapor phase) were performed at the higher concentration level. After 5 months of smoke inhalation and an additional 4-month post-inhalation period, both mouse strains responded similarly: no increase in lung tumor multiplicity was seen at the end of the inhalation period; however, there was a concentration-dependent tumorigenic response at the end of the post-inhalation period (up to 2-fold beyond control) in mice exposed to the whole smoke or the particulate phase. Tumors were characterized mainly as pulmonary adenomas. At the end of the inhalation period, epithelial hyperplasia, atrophy, and metaplasia were found in the nasal passages and larynx, and cellular and molecular markers of inflammation were found in the bronchoalveolar lavage fluid. These inflammatory effects were mostly resolved by the end of the post-inhalation period. In summary, these mouse strains responded to mainstream smoke inhalation with enhanced pulmonary adenoma formation. The major tumorigenic potency resided in the particulate phase, which is contrary to the findings published for environmental tobacco smoke surrogate inhalation in these mouse models.

Further considerations on the evaluation of potential reduced-risk tobacco products. Part II: Re-assessment of a heuristic using the CPS-II database

In a previous analysis (see Part I) we proposed a heuristic for assessing the efficacy of potential reduced-risk tobacco products (PRRPs) on lung cancer (LC) rates, using smoking cessation data published in a report from the Iowa Women's Health Study (IWHS) as a basis for sample size estimates. In this study, an additional analysis was performed using cessation data from the much larger Cancer Prevention Study II (CPS-II), which also provides data on different durations of cessation. Statistical methods were used to assess whether smokers switching to a PRRP would reduce their risk of LC. Furthermore, non-inferiority tests compared the LC risk in switchers to that in smokers who had quit smoking. The present work shows that similar sample size estimates were obtained whether the analysis was based on the IWHS or the CPS-II data sets, suggesting that the heuristic may be generally applicable to prospective real-life studies to evaluate PRRPs. Non-inferiority testing of switchers compared with quitters required approximately 10-fold more subjects than did superiority testing of switchers compared with smokers. Altogether, these estimates indicate that it is feasible, in terms of study duration and sample size, to clinically assess the LC risk-reducing potential of a PRRP.

Hypotheses and fundamental study design characteristics for evaluating potential reduced-risk tobacco products. Part I: Heuristic

The risk-reducing effect of a potential reduced-risk tobacco product (PRRP) can be investigated conceptually in a long-term, prospective study of disease risks among cigarette smokers who switch to a PRRP and in appropriate comparison groups. Our objective was to provide guidance for establishing the fundamental design characteristics of a study intended to (1) determine if switching to a PRRP reduces the risk of lung cancer (LC) compared with continued cigarette smoking, and (2) compare, using a non-inferiority approach, the reduction in LC risk among smokers who switched to a PRRP to the reduction in risk among smokers who quit smoking entirely. Using standard statistical methods applied to published data on LC incidence after smoking cessation, we show that the sample size and duration required for a study designed to evaluate the potential for LC risk reduction for an already marketed PRRP, compared with continued smoking, varies depending on the LC risk-reducing effectiveness of the PRRP, from a 5-year study with 8000-30,000 subjects to a 15-year study with <5000 to 10,000 subjects. To assess non-inferiority to quitting, the required sample size tends to be about 10 times greater, again depending on the effectiveness of the PRRP.

Cigarette filter-based assays as proxies for toxicant exposure and smoking behavior--a literature review

BACKGROUND

Cigarettes are being marketed with filters that differ in composition and design. The filters have different toxicant trapping efficiencies, and smoking stains reflect variations in smoking behavior. Presented herein are the results of a structured literature review that was done to identify cigarette filter-based assays that may serve as proxies for mouth-level exposure and assessing smoking methods.

METHODS

A search of the published scientific literature and internal tobacco company documents from 1954 to 2009 was carried out.

RESULTS

The literature search identified diverse schemes for assessing cigarette filters, including visual inspection and digital imaging of smoked-stained spent filters, and quantitative determinations for total particulate matter (TPM), nicotine, and solanesol. The results also showed that: (a) there are sufficient data to link filter-based chemical measures to standardized smoking machine-measured yields of tar and nicotine; (b) TPM eluted from filters or in chemical digest of filters can be used to estimate the efficiency of the filter for trapping smoke solids; (c) visual and digital inspection of spent filters is useful in finding indicators of variations in smoking behaviors; and (d) there is a correlation between solanesol and nicotine measured in filters and exposure biomarkers in smokers.

CONCLUSIONS

The cigarette filter may prove useful in estimating smoking behaviors such as filter vent blocking and puffing intensity, and may have utility as proxy measures of mouth-level smoke exposure in clinical trials. Additional investigations are needed to compare the different proposed assay schemes and the assay results with measurements of human biomarker assays of smoke exposure.

Methods used in internal industry clinical trials to assess tobacco risk reduction

OBJECTIVE

Methods to assess reduced exposure products should include those that aid in determining likely patterns of human use and exposure. Tobacco industry clinical trial methods may provide insight into strategies to assess potential reduced exposure products (PREP) for public health purposes. Internal tobacco industry documents detailing human clinical research with PREPs were examined to document major research strategies used and identify potentially fruitful methods not currently used in the mainstream arena.

METHODS

Primary data were obtained from records of research conducted internally by tobacco companies and affiliated researchers, and included manuscript drafts, presentations, protocols, and instruments relating to internal clinical trials of human tobacco use and exposure.

RESULTS

Tobacco industry clinical research has focused on reduced exposure products, most notably Premier, Accord, and Eclipse. The most widely used strategy observed is switching studies, and details of study designs and protocols favored by the industry are described. Key measures include biomarkers of exposure (e.g., cotinine, CO, and specific carcinogens) and acute health effects such as physical health and fitness.

CONCLUSIONS

Tobacco industry clinical research has used relatively standard switching study methods, but with a broad set of measures. Clinical switching studies have been conducted by the industry primarily to support existing claims or to develop new claims. Knowledge of prior industry activity can guide and inform future public health research efforts. Although industry clinical trial methods are comparable with current mainstream methods, limited information about the validity of outcome measures used limits their viability for immediate adoption in mainstream science.

Evaluating oral noncombustible potential-reduced exposure products for smokers

INTRODUCTION

Potential-reduced exposure products (PREPs) are marketed as a way for smokers to continue using tobacco while possibly lessening their tobacco toxicant intake. Some tobacco-based PREPs are combustible and intended to be smoked, while others are noncombustible and intended to be administered orally (e.g., Camel Snus [CS] tobacco sachets and Ariva tobacco tablets). The ability of these noncombustible PREPs to reduce smokers' exposure to cigarette-delivered toxicants and suppress tobacco abstinence symptoms effectively is unclear. Clinical laboratory methods have been used to measure combustible PREP-associated toxicant exposure and abstinence symptom suppression and could be applied to evaluating the effects of orally administered noncombustible PREPs.

METHODS

In this study, 21 smokers (6 women) participated in four 5-day conditions that differed by product used: CS, Ariva, own brand cigarettes, or no tobacco. Measures included expired-air carbon monoxide (CO), the urinary metabolite of nicotine (cotinine), the urinary metabolite of the carcinogen NNK (NNAL-T), and subjective effect ratings.

RESULTS

Relative to own brand, all other conditions were associated with CO and cotinine levels that were lower and abstinence symptom ratings that were greater. Only no-tobacco use was associated with significantly lower NNAL levels. Acceptability ratings were also lower in all conditions relative to own brand.

DISCUSSION

Although these oral products reduce exposure to CO, their ineffective abstinence symptom suppression and low acceptability may limit their viability as PREPs. As with combustible PREPs, clinical laboratory study of orally administered noncombustible PREPs will be a valuable part of any comprehensive PREP evaluation strategy.

Assessing consumer responses to potential reduced-exposure tobacco products: a review of tobacco industry and independent research methods

BACKGROUND

Internal tobacco industry documents and the mainstream literature are reviewed to identify methods and measures for evaluating tobacco consumer response. The review aims to outline areas in which established methods exist, identify gaps in current methods for assessing consumer response, and consider how these methods might be applied to evaluate potentially reduced exposure tobacco products and new products.

METHODS

Internal industry research reviewed included published articles, manuscript drafts, presentations, protocols, and instruments relating to consumer response measures were identified and analyzed. Peer-reviewed research was identified using PubMed and Scopus.

RESULTS

Industry research on consumer response focuses on product development and marketing. To develop and refine new products, the tobacco industry has developed notable strategies for assessing consumers' sensory and subjective responses to product design characteristics. Independent research is often conducted to gauge the likelihood of future product adoption by measuring consumers' risk perceptions, responses to product, and product acceptability.

CONCLUSIONS

A model that conceptualizes consumer response as comprising the separate, but interacting, domains of product perceptions and response to product is outlined. Industry and independent research supports the dual domain model and provides a wide range of methods for assessment of the construct components of consumer response. Further research is needed to validate consumer response constructs, determine the relationship between consumer response and tobacco user behavior, and improve reliability of consumer response measures. Scientifically rigorous consumer response assessment methods will provide a needed empirical basis for future regulation of potentially reduced-exposure tobacco products and new products, to counteract tobacco industry influence on consumers, and enhance the public health.

Abuse liability assessment of tobacco products including potential reduced exposure products

The harm produced by tobacco products is a result of frequent use of a highly toxic product. Reducing the adverse public health impact of tobacco products might be most effectively achieved by reducing the likelihood of their use and the toxicity of the products. Products that retain some characteristics of cigarettes but have been altered with the intention of reducing toxicity have been referred to as modified risk tobacco products or potential reduced exposure products (MRTP/PREP). Evaluation of their content, emission, and toxicity is discussed in other articles in this special issue. Here, we discuss the methodology that has been used to examine the likelihood of abuse or addiction. Abuse liability assessment (ALA) methodology has been used by the Food and Drug Administration (FDA) and other drug regulatory agencies world-wide for decades to assess the risks posed by a wide variety of pharmacologically active substances. ALA is routinely required among other evaluations of safety during the pre-market assessment of new drugs, and is continually adapted to meet the challenges posed by new drug classes and drug formulations. In the 2009 law giving FDA regulation over tobacco products, FDA is now required to evaluate new tobacco products including MRTP/PREPs to determine their risk for abuse and toxicity at the population level. This article describes the traditional tools and methods of ALA that can be used to evaluate new tobacco and nicotine products including MRTP/PREPs. Such ALA data could contribute to the scientific foundation on which future public policy decisions are based.

Clinical trials methods for evaluation of potential reduced exposure products

Potential reduced exposure products (PREPs) to tobacco toxicants may have promise in reducing tobacco-related morbidity or mortality or may promote greater harm to individuals or the population. Critical to determining the risks or benefits from these products are valid human clinical trial PREP assessment methods. Such an assessment involves determining the effects of these products on biomarkers of exposure and effect, which serve as proxies for harm, and assessing the potential for consumer uptake and abuse of the product. This article identifies critical methodologic issues associated with PREP assessments, reviews the methods that have been used to assess PREPs, and describes the strengths and limitations of these methods. Additionally, recommendations are provided for clinical trial PREP assessment methods and future research directions in this area based on this review and on the deliberations from a National Cancer Institute sponsored Clinical Trials PREP Methods Workshop.

Surveillance methods for identifying, characterizing, and monitoring tobacco products: potential reduced exposure products as an example

Tobacco products are widely sold and marketed, yet integrated data systems for identifying, tracking, and characterizing products are lacking. Tobacco manufacturers recently have developed potential reduced exposure products (PREP) with implied or explicit health claims. Currently, a systematic approach for identifying, defining, and evaluating PREPs sold at the local, state, or national levels in the United States has not been developed. Identifying, characterizing, and monitoring new tobacco products could be greatly enhanced with a responsive surveillance system. This article critically reviews available surveillance data sources for identifying and tracking tobacco products, including PREPs, evaluating strengths and weaknesses of potential data sources in light of their reliability and validity. With the absence of regulations mandating disclosure of product-specific information, it is likely that public health officials will need to rely on a variety of imperfect data sources to help identify, characterize, and monitor tobacco products, including PREPs.

The Strategic Dialogue on Tobacco Harm Reduction: a vision and blueprint for action in the US

The issues related to tobacco harm reduction continue to challenge the tobacco control research and policy communities. The potential for combusting tobacco products to reduce exposure and risk remains largely unknown, but this has not stopped manufacturers from offering such products making these claims. The role of oral tobacco products in a harm reduction regimen has also been a source of dialogue and debate. Within the last few years, major cigarette manufacturing companies have begun selling smokeless products for the first time, claiming to target current cigarette smokers. Other cigarette manufacturers are also offering smokeless products in markets around the world. The harm reduction debate has at times been divisive. There has been no unifying set of principles or goals articulated to guide tobacco control efforts. In particular, the research needs are extraordinarily high in order to drive evidence-based policy in this area and avoid the mistakes made with "light" cigarettes. This paper discusses recommendations from a strategic dialogue held with key, mostly US-based tobacco control researchers and policy makers to develop a strategic vision and blueprint for research, policy and communications to reduce the harm from tobacco for the US. Short-term and long-term objectives are described.

Potential reduced exposure products (PREPs) for smokeless tobacco users: clinical evaluation methodology

Several potential reduced exposure products (PREPs) for smokeless tobacco (SLT) users are marketed in the United States, though their effects are largely unknown. These products include some that are low in tobacco-specific nitrosamines (TSNs), like Stonewall, a pressed tobacco tablet, and General snus, a moist snuff product produced in Sweden. Methodology assessing the toxicant exposure and effects of cigarette-like PREPs for smokers has been developed, and might be modified for use in evaluating PREPs for SLT users. This report describes two studies examining the toxicant exposure and effects of two PREPs for SLT users. Study 1 (n = 13) consisted of four 4.5-hr laboratory sessions where SLT products (own brand, Stonewall, General snus, and tobacco-free placebo) were used for four 30-min episodes and nicotine exposure and tobacco/nicotine abstinence symptoms were measured. Study 2 (n = 19) consisted of four 5-day ad libitum use periods when participants used own brand, Stonewall, General snus, or no SLT and urinary levels of metabolites of nicotine (cotinine) and the TSN 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNAL) and abstinence symptoms were measured. Compared with own brand, Stonewall was associated with lower levels of cotinine and NNAL, while General snus was associated with similar levels of cotinine and lower levels of NNAL. Abstinence symptoms generally did not differ across tobacco conditions. These results show that clinical laboratory methods can be used to evaluate the toxicant exposure and abstinence symptom suppression associated with PREPs for SLT users.

Monitoring the tobacco use epidemic II: The agent: Current and emerging tobacco products

OBJECTIVE

This Agent paper (II of V on monitoring the tobacco use epidemic) summarizes the findings and recommendations of the Agent (product) Working Group of the November, 2002, National Tobacco Monitoring, Research and Evaluation Workshop.

METHODS

The Agent Working Group evaluated the need to develop new surveillance systems for quantifying ingredients and emissions of tobacco and tobacco smoke and to improve methods to assess uptake and metabolism of these constituents taking into account variability in human smoking behavior.

RESULTS

The toxic properties of numerous tobacco and tobacco smoke constituents are well known, yet systematic monitoring of tobacco products has historically been limited to tar, nicotine, and CO in mainstream cigarette smoke using a machine-smoking protocol that does not reflect human smoking behavior. Toxicity of smokeless tobacco products has not been regularly monitored. Tobacco products are constantly changing and untested products are introduced into the marketplace with great frequency, including potential reduced-exposure products (PREPs). The public health impact of new or modified tobacco products is unknown.

CONCLUSIONS

Systematic surveillance is recommended for mainstream smoke constituents such as polycyclic aromatic hydrocarbons (PAH), tobacco-specific nitrosamines (TSNA), total and free-base nicotine, volatile organic compounds, aromatic amines, and metals; and design attributes including tobacco blend, additives, and filter ventilation. Research on smoking topography is recommended to help define machine-smoking protocols for monitoring emissions reflective of human smoking behavior. Recommendations are made for marketplace product sampling and for population monitoring of smoking topography, emissions of toxic constituents, biomarkers of exposure and, eventually, risk of tobacco-related diseases.

Monitoring the tobacco use epidemic I. Overview: Optimizing measurement to facilitate change

OBJECTIVE

This Overview paper (I of V) summarizes research work to date on monitoring the tobacco use epidemic, discusses the recommendations made at the November, 2002 National Tobacco Monitoring, Research and Evaluation Workshop sponsored by the U.S. National Cancer Institute (NCI), Centers for Disease Control and Prevention (CDC), the American Legacy Foundation, and the Robert Wood Johnson Foundation on the topic of tobacco surveillance and evaluation, and discusses the current state of affairs.

METHODS

A conceptual model based on the classical infectious diseases framework/paradigm focusing on the Agent, Host, Vector and Environment is used to integrate the work presented in the four other papers that appear in this supplemental issue of Preventive Medicine.

RESULTS

The Agent paper (II) describes surveillance on tobacco products and biomarkers; the Host paper (III) describes surveillance on the smoker/user, or potential smoker/user; the Vector paper (IV) describes monitoring of industry activity; and the Environment paper (V) describes several key strategies for monitoring influential environmental factors. Overall, some improvements to the nation's surveillance system have been made in recent years. However, additional steps are needed to optimize measurement of tobacco use and factors influencing use in the United States.

CONCLUSIONS

Tobacco monitoring efforts play a vital role in combating the epidemic of addiction and disease produced by various tobacco products. The knowledge and experience gained by the tobacco use prevention and control community through this commitment to linkages of data collected in the domains of Vector and Environment, in addition to Agent and Host, could inform monitoring of a wide range of other public health issues as well, including diet and nutrition, physical activity, overweight and obesity, and substance abuse.

Nicotine content and delivery across tobacco products

Nicotine is the principal alkaloid in both commercial and homemade products (e.g., cigarettes, smokeless tobacco, bidis, waterpipes) followed by nornicotine, anabasine, anatabine, and many other basic substances that contain a cyclic nitrogenous nucleus. Tobacco types, leaf position on the plant, agricultural practices, fertilizer treatment, and degree of ripening are among some prominent factors that determine the levels of alkaloids in tobacco leaf. From a random examination of 152 cultivated varieties of Nicotiana tabacum, a range of alkaloid variation between 0.17 and 4.93% was determined. In fact, every step in tobacco production that affects plant metabolism will influence the level of alkaloid content to a certain degree. Depending on blending recipe, type and amount of additives, and product design, all types of tobacco products contain a very wide range of nicotine concentration. However, the ultimate emission of nicotine to the user, exposure, and psychophar-macological effects depend not only on the content and emission, but also on the relationship between the product and the user.

Puffing style and human exposure minimally altered by switching to a carbon-filtered cigarette

OBJECTIVE

Potential Reduced Exposure tobacco Products (PREP) are intended to lower human exposure to toxic constituents of tobacco smoke, but rigorous clinical evaluations are required to assess such claims. The present study assessed human smoking behavior and short-term exposure to a new carbon-filtered PREP, Marlboro UltraSmooth (MUS). Two MUS prototypes with filter carbon loads of 120 and 180 mg were compared with low and ultralow-yield conventional cigarettes.

METHODS

After a 48-hour baseline period, 32 adult Marlboro Lights smokers were switched in a counterbalanced order, to MUS and Marlboro Ultra Lights for 48 hours each. Measures of smoking topography, subjective response, change in cardiac response, and carbon monoxide boost were obtained under supervised test conditions on separate days. After each test, topography measures were obtained via a 48-hour free smoking phase for each brand. Salivary cotinine was measured at the end of each 48-hour period.

RESULTS

Although MUS was generally smoked in a style similar to conventional cigarettes, compensatory smoking was observed with 1 MUS prototype (P = 0.003). Carbon monoxide boost was lower for MUS compared with Marlboro Lights, but salivary cotinine and cardiac function measures after smoking of MUS did not vary from conventional brands.

CONCLUSIONS

Smoking MUS produced few differences in smoking topography and exposure compared with conventional low and ultralow-yield cigarettes. Results suggest that the manner in which MUS is smoked by humans is unlikely in the short term to reduce exposure among smokers who switch from a conventional brand.

Nicotine delivery, cardiovascular profile, and subjective effects of an oral tobacco product for smokers

The tobacco industry markets potential reduced exposure products (PREPs) to smokers, including oral products that are intended to be used in situations where cigarettes cannot. For example, Ariva, marketed by Star Scientific, is a tablet made from compressed tobacco powder and is intended for "adult smokers in situations where they cannot or choose not to smoke." No objective data are available regarding Ariva's effects in smokers, including its nicotine delivery, cardiovascular profile, or subjective effects. In this single-session, clinical laboratory study, 10 overnight-abstinent cigarette smokers were administered one Ariva tablet, followed 90 min later by two Ariva tablets, followed 90 min later by three Ariva tablets. Participants allowed each dose to dissolve in their mouths according to package instructions. Blood was sampled, heart rate monitored, and subjective effects assessed regularly. Ariva delivered nicotine in a dose-dependent manner; mean (SD) nicotine levels increased from 2.4 ng/ml (0.9) at baseline, to 3.4 ng/ml (1.4) 45 min post-1 tablet, 7.3 ng/ml (4.0) 45 min post-2 tablets, and 9.7 ng/ml (4.4) 45 min post-3 tablets. Heart rate increased after tablet administration, independent of dose. The tablets also significantly decreased subjective ratings of craving and urge, and increased ratings of nausea. Based on this short-term laboratory evaluation, Ariva exposes users to nicotine and may suppress some symptoms of tobacco abstinence, though its nausea-inducing characteristics may limit initial acceptability.

Impact of corrective health information on consumers' perceptions of "reduced exposure" tobacco products

OBJECTIVE

To determine whether providing corrective health information can reduce the tendency of consumers to believe that the implied marketing message that two "potentially reduced exposure products" (PREPs) are safer than regular cigarettes.

DESIGN

Face-to-face interviews with smokers assigned to one of four conditions, which varied in terms of the presence or absence of health information that qualified claims made in advertising for two PREPs.

SUBJECTS

A convenience sample of 177 smokers in Boston area.

INTERVENTIONS

Health information detailed the extent to which exposure to toxins and health risks of the brands were unknown.

MAIN OUTCOME MEASURES

Respondents' assessments of the health risks and toxicity of the two combustible PREPs, Advance and Eclipse.

RESULTS

The health information had a modest but significant effect on ratings of health risk, and reduced perceptions that switching to the new brands would lower a smoker's risk of cancer (OR 0.75; p<0.05). The health information had no effect on perceptions of toxicity.

CONCLUSIONS

A small dose of corrective information was effective in tempering smokers' perceptions. A higher dose of public health campaigns would be needed to affect misperceptions likely to follow a full-scale tobacco marketing effort.

Changing smokeless tobacco products new tobacco-delivery systems

Smokeless or noncombusted oral tobacco use as a substitute for cigarette smoking has been gaining greater interest and attention by the public health community and the tobacco industry. In order for the product to appeal to smokers, tobacco companies have been manufacturing new noncombusted oral tobacco (i.e., moist snuff) that is lower in moisture content and nitrosamine levels, packaged in small sachets and "spitless." While the primary motives of the major tobacco companies are to maintain or increase tobacco use, some members of the public health community perceive the use of noncombusted oral tobacco products as a harm reduction tool. Because cigarette smoking is associated with greater toxicant exposure compared to noncombusted oral tobacco, reduced mortality and morbidity are hypothesized to ensue, if cigarette smokers switched completely to these products. However, variability exists in levels of nicotine and toxicants and potential health consequences from use within and across countries. Therefore, promulgating noncombusted oral tobacco products as a safer alternative to smoking or as a substitute for smoking may engender more rather than less harm. To date, limited research is available on the effects of marketing noncombusted oral tobacco products to smokers, to support the use of these products as a harm reduction tool, and to determine the effects of varying levels of tobacco toxicants including nicotine on health. The need exists for manufacturing standards to lower toxicant levels of all noncombusted oral tobacco products, for the formulation of appropriate tobacco-product regulations and for the development of a strategic plan by the public health community to address this controversial topic.

The tobacco epidemic in the United States

Tobacco use, primarily in the form of cigarettes and exposure to tobacco smoke pollution, has caused the premature deaths of more than 14 million Americans since 1964. The major diseases caused by tobacco and tobacco smoke include lung cancer, other cancers, coronary heart disease, other cardiovascular diseases, chronic respiratory diseases, pregnancy complications, and respiratory diseases in children. Per capita consumption of various tobacco products has declined substantially since 1950, with current consumption at approximately 3.7 pounds per capita. Whereas approximately two in five adults smoked cigarettes in 1965, approximately one in five did so in 2005. Several factors can influence initiation and cessation, including product factors (e.g., ventilation holes, additives, and flavorings); host factors (intention to use, level of dependence); tobacco company activities (e.g., marketing strategies, efforts to undermine public health activities); and environmental factors (e.g., peer and parental smoking, smoke-free air laws and policies). Efforts to prevent initiation, promote quitting, and protect nonsmokers should reduce exposure to pro-tobacco marketing and increase (1) the price of tobacco products, (2) protection from tobacco smoke pollution, (3) effective mass media strategies, (4) provision of effective cessation support, (5) effective regulation, and (6) litigation that holds the industry responsible for its misdeeds. Adequate implementation of effective tobacco-control strategies and useful scientific advances will help to ensure that per capita consumption decreases to the lowest level possible. The economic benefits of tobacco in our society are replaceable and they pale in comparison to the extent of human life lost.

Developing the science base for reducing tobacco harm

The University of Minnesota Transdisciplinary Tobacco Use Research Center has been examining the multiple dimensions and the scientific evidence required to determine the feasibility of tobacco harm reduction as a means to reduce tobacco-related mortality and morbidity. Because of the complexity associated with exploring this area, an interdisciplinary approach is necessary. The research components that have been of particular focus at our center include (a) developing and validating biomarkers of tobacco-related exposure and toxicity, (b) developing animal models and designing studies with humans to assess a variety of smoking reduction approaches and potential reduced exposure products, and (c) determining individual differences in response to these interventions and products. A description of the ongoing activities and challenges in these areas is provided, along with projected directions for the future.

Nicotine pharmacokinetics and subjective effects of three potential reduced exposure products, moist snuff and nicotine lozenge

OBJECTIVE

To compare nicotine pharmacokinetics and subjective effects of three new smokeless tobacco potential reduced exposure products (PREPs; Ariva, Revel and Stonewall) with moist snuff (Copenhagen) and medicinal nicotine (Commit lozenge).

METHODS

10 subjects completed a randomised, within-subject, crossover study. Subjects used one product for 30 min at each of the five laboratory sessions. Maximal nicotine concentration (Cmax) was determined and area under the concentration time curve (AUC) was calculated for a 90-min period (during use and 60 min after use). Nicotine craving, withdrawal symptoms and ratings of product effects and liking were measured during product use.

RESULTS

Nicotine AUC and Cmax were higher for Copenhagen than for any other product (p<0.002) and higher for Commit than for either Ariva or Revel (p<0.001). Cmax for Commit was also higher than for Stonewall (p = 0.03). Craving was lowest during use of Copenhagen (p<0.03). Craving during use of Stonewall, Ariva and Commit was lower than during use of Revel (p<0.05). Withdrawal symptom score during use of Copenhagen was lower than during use of Revel (p = 0.009). Copenhagen scores were higher (p<0.005) than all other products in several measures of drug effects and liking (feel good effects, satisfaction, liking and desire for product, and strength of product).

CONCLUSION

The new smokeless tobacco PREPs result in lower nicotine concentrations and equivalent or lower reductions in subjective measures compared with medicinal nicotine. Since health effects of PREPs are largely unknown, medicinal nicotine should be preferentially encouraged for smokers or smokeless tobacco users wishing to switch to lower-risk products.

Clinical laboratory evaluation of potential reduced exposure products for smokers

Smoking-related cancer and other disease account for more than 400,000 U.S. deaths annually. Smoking cessation reduces smoking-related disease rates, but relapse rates are high. Thus, interest in reducing the harm of continued smoking is growing. Potential reduced exposure products (PREPs) are marketed to reduce smokers' exposure to smoke toxicants such as carbon monoxide (CO) and carcinogens and may be harm reduction tools. New PREPs are proliferating, but past experience with "low-yield" cigarettes that failed to reduce smokers' toxicant exposure suggests that comprehensive evaluation is necessary to predict if these new products are likely to alter the harm caused by smoking. The purpose of the study was to develop clinical laboratory methods for PREP evaluation. Smokers (N = 35) completed four, 5-day conditions that differed by product used: Advance, Eclipse, own brand cigarettes, or no cigarettes. Carcinogen (as assessed by one nitrosamine and one polycyclic aromatic hydrocarbon biomarker) and nicotine exposure were assessed via thrice-weekly urine sampling. Withdrawal symptoms were measured daily, and smoking behavior was assessed on the first and last day of each condition. Relative to own brand, Advance reduced exposure to the nitrosamine NNK and CO, and Eclipse reduced exposure to nicotine and the nitrosamine NNK, increased exposure to CO, and resulted in larger, longer, and more frequent puffs. No smoking reduced exposure to the nitrosamine NNK, CO, and nicotine, whereas withdrawal was elevated (all p values <.05). Clinical laboratory evaluation of PREPs for smokers is valuable for measuring users' smoke toxicant exposure, withdrawal, and smoking behavior and should be incorporated into a comprehensive PREP evaluation strategy.

Carboxyhemoglobin and thiocyanate as biomarkers of exposure to carbon monoxide and hydrogen cyanide in tobacco smoke

The determination of biomarkers in human body fluids is a useful tool, which allows the quantitative assessment of the exposure to chemicals or complex mixtures of chemicals and of early biological effects as a result of the exposure. Biomarkers require validation before their successful application in human studies. This review describes some general purposes of human biomonitoring and biomarkers including the requirements for validation. Risk assessment and harm reduction of smoking and tobacco products, respectively, is a very suitable field for the application of biomarkers. A brief historical review shows that the application of biomarkers of exposure and effect in human smoking goes back more than 150 years. Two 'classical' biomarkers of exposure to tobacco, namely carboxyhemoglobin (COHb and its equivalent carbon monoxide in exhalate, COex) and thiocyanate (SCN) in body fluids are discussed in terms of sources of exposure, metabolism, disposition kinetics and influencing host factors. Data on COHb/COex and SCN in nonsmokers and smokers as well as the power to discriminate between smokers and nonsmokers are presented. Both biomarkers are significantly correlated with the daily cigarette consumption. Smoking machine-derived yields of the precursors carbon monoxide and hydrogen cyanide were not correlated with COHb/COex and SCN, respectively. It is concluded that, while COHb/COex is a useful biomarker for assessing the smoke inhalation, preferably in controlled studies, the application of SCN in body fluids as a biomarker for smoking is limited, mainly due to the abundance of other sources for SCN.

Cotinine Concentration in Smokers from Different Countries: Relationship with Amount Smoked and Cigarette Type

This four-country study examined salivary cotinine as a marker for nicotine intake and addiction among smokers in relation to numbers and types of cigarettes smoked. Smoking characteristics of cigarette smokers in Brazil, China, Mexico, and Poland were identified using a standard questionnaire. Cotinine concentration was measured using a saliva sample from each participant; its relationship with numbers and types of cigarettes smoked was quantified by applying regression techniques. The main outcome measure was salivary cotinine level measured by gas chromatography. In all four countries, cotinine concentration increased linearly with cigarettes smoked up to 20 per day [11.3 ng/mL (95% confidence interval, 10.5-12.2)] and then stabilized as the number of cigarettes exceeded 20 [6.8 ng/mL per cigarette (95% confidence interval, 6.3-7.4) for up to 40 cigarettes]. On average, smokers of regular cigarettes consumed more cigarettes and had higher cotinine levels than light cigarette smokers. Cotinine concentration per cigarette smoked did not differ between regular and light cigarette smokers. Results suggest a saturation point for daily nicotine intake and minimal or no reduction in nicotine intake by smoking light cigarettes.

Biomarkers to assess the utility of potential reduced exposure tobacco products

To date, we have no valid biomarkers that serve as proxies for tobacco-related disease to test potential reduced exposure products. This paper represents the deliberations of four workgroups that focused on four tobacco-related heath outcomes: Cancer, nonmalignant pulmonary disease, cardiovascular disease, and fetal toxicity. The goal of these workgroups was to identify biomarkers that offer some promise as measures of exposure or toxicity and ultimately may serve as indicators for future disease risk. Recommendations were based on the relationship of the biomarker to what is known about mechanisms of tobacco-related pathogenesis, the extent to which the biomarker differs among smokers and nonsmokers, and the sensitivity of the biomarker to changes in smoking status. Other promising biomarkers were discussed. No existing biomarkers have been demonstrated to be predictive of tobacco-related disease, which highlights the importance and urgency of conducting research in this area.

Biomarkers to assess the utility of potential reduced exposure tobacco products

To date, we have no valid biomarkers that serve as proxies for tobacco-related disease to test potential reduced exposure products. This paper represents the deliberations of four workgroups that focused on four tobacco-related heath outcomes: Cancer, nonmalignant pulmonary disease, cardiovascular disease, and fetal toxicity. The goal of these workgroups was to identify biomarkers that offer some promise as measures of exposure or toxicity and ultimately may serve as indicators for future disease risk. Recommendations were based on the relationship of the biomarker to what is known about mechanisms of tobacco-related pathogenesis, the extent to which the biomarker differs among smokers and nonsmokers, and the sensitivity of the biomarker to changes in smoking status. Other promising biomarkers were discussed. No existing biomarkers have been demonstrated to be predictive of tobacco-related disease, which highlights the importance and urgency of conducting research in this area.

Nicotine psychopharmacology research contributions to United States and global tobacco regulation: a look back and a look forward

Nicotine has a long and storied history in physiology and pharmacology. Historically, it has been used as a tool to explore the nervous system, studied for its role in tobacco use, and more recently examined for its diverse potential medicinal uses. Psychopharmacology research has been pivotal in the science foundation for nicotine and tobacco product regulation.

The time for tobacco industry sponsored PREP evaluation has arrived

Rigorous and objective industry funded evaluation of potential reduced exposure products will require innovation and flexibility, but must begin now

Carcinogenicity studies of inhaled cigarette smoke in laboratory animals: old and new

A new study demonstrates that lifetime whole-body exposure of B6C3F1 mice to high doses of cigarette smoke robustly increases lung cancer incidence compared with sham exposed animals. This is the first study to demonstrate a strong effect of inhaled cigarette smoke on lung cancer in an animal model. This commentary attempts to put the new results in perspective with the existing literature on cigarette smoke inhalation studies in animals and discusses strengths, limitations and possible applications of available models.