Abuse liability assessment of the JUUL system in two nicotine concentrations compared to combustible cigarette, nicotine gum and comparator electronic nicotine delivery system

Modelling the nicotine pharmacokinetic profile for e-cigarettes using real time monitoring of consumers' physiological measurements and mouth level exposure

Pharmacokinetic (PK) studies can provide essential information on abuse liability of nicotine and tobacco products but are intrusive and must be conducted in a clinical environment. The objective of the study was to explore whether changes in plasma nicotine levels following use of an e-cigarette can be predicted from real time monitoring of physiological parameters and mouth level exposure (MLE) to nicotine before, during, and after e-cigarette vaping, using wearable devices. Such an approach would allow an -effective pre-screening process, reducing the number of clinical studies, reducing the number of products to be tested and the number of blood draws required in a clinical PK study Establishing such a prediction model might facilitate the longitudinal collection of data on product use and nicotine expression among consumers using nicotine products in their normal environments, thereby reducing the need for intrusive clinical studies while generating PK data related to product use in the real world.An exploratory machine learning model was developed to predict changes in plasma nicotine levels following the use of an e-cigarette; from real time monitoring of physiological parameters and MLE to nicotine before, during, and after e-cigarette vaping. This preliminary study identified key parameters, such as heart rate (HR), heart rate variability (HRV), and physiological stress (PS) that may act as predictors for an individual's plasma nicotine response (PK curve). Relative to baseline measurements (per participant), HR showed a significant increase for nicotine containing e-liquids and was consistent across sessions (intra-participant). Imputing missing values and training the model on all data resulted in 57% improvement from the original'learning' data and achieved a median validation R2 of 0.70.The study is in its exploratory phase, with limitations including a small and non-diverse sample size and reliance on data from a single e-cigarette product. These findings necessitate further research for validation and to enhance the model's generalisability and applicability in real-world settings. This study serves as a foundational step towards developing non-intrusive PK models for nicotine product use.

Concurrent E-cigarette Use While Enrolled in a Smoking Cessation Program: Associations Between Frequency of Use, Motives for Use, and Smoking Cessation

INTRODUCTION

Trial evidence suggests that e-cigarettes may aid in quitting smoking, while observational studies have found conflicting results. However, many observational studies have not adjusted for important differences between e-cigarette users and non-users.

AIMS AND METHODS

We aimed to determine the association between e-cigarette use frequency and motivation to use e-cigarettes to quit smoking, and smoking cessation using data from Canada's largest smoking cessation program. Participants who completed a baseline assessment and 6-month follow-up questionnaire were divided post hoc into four groups based on their self-reported e-cigarette use during the 30 days before baseline: (1) non-users; (2) users of e-cigarettes not containing nicotine; (3) occasional users; and (4) frequent users. Occasional and frequent users were further divided into two groups based on whether they reported using e-cigarettes to quit smoking. Abstinence at 6-month follow-up (7-day point prevalence abstinence) was compared among groups.

RESULTS

Adjusted quit probabilities were significantly higher (both p < .001) for frequent baseline e-cigarette users (31.6%; 95% CI = 29.3%, 33.8%) than for non-users (25.8%; 25.3% and 26.3%) or occasional users (24.2%; 22.5% and 26.0%). Unadjusted proportions favored non-users over occasional users (p < .001), but this was not significant after adjustment (p = .06). People using e-cigarettes to quit smoking were not likelier than other users to be successful, but were likelier to report frequent e-cigarette use during follow-up.

CONCLUSIONS

Frequent baseline e-cigarette use predicted successful smoking cessation, compared to occasional and non-users. Use of e-cigarettes to quit did not predict smoking cessation but was associated with continued use during follow-up, perhaps due in part to planned transitions to e-cigarettes.

IMPLICATIONS

Prior observational studies investigating e-cigarette use for smoking cessation have found that occasional users have poorer outcomes than either frequent or non-users. Consistent with these studies, occasional users in our data also had poorer outcomes. However, after adjustment for variables associated with cessation success, we found that cessation probabilities did not differ between occasional and non-users. These findings are consistent with trial data showing the benefit of e-cigarette use among people trying to quit smoking. Results of this study suggest that differences between trials and previous observational studies may be because of unaddressed confounding in the latter.

Abuse liability of two electronic nicotine delivery systems compared with combustible cigarettes and nicotine gum from an open-label randomized crossover study

An assessment of the likelihood of use and abuse potential for new tobacco products is an important part of tobacco product regulation in the United States and abroad. This paper reports the results of a randomized, open-label, crossover clinical study that assessed factors related to product adoption and abuse liability (AL), comparing two closed electronic nicotine delivery system (ENDS) products to combustible cigarettes and nicotine gum, high- and low-AL comparator products, respectively. During an 11-day confinement period that included multiple product familiarization sessions, healthy adult smokers participated in AL test sessions to evaluate the abuse liability of each product. During these test sessions, changes in subjective measures; speed and amount of nicotine uptake; and maximum changes in physiological effects before, during, and after use of each assigned product were assessed over 4 h. Positive subjective effects measures scores such as product-liking and overall intent to use again were highest for cigarettes, followed by the Vuse ENDS, with nicotine gum consistently having the lowest scores. The PK results (Cmax and Tmax) of the Vuse ENDS products are between UB cigarettes and nicotine gum, which correlates with the subjective effects. All nicotine uptake measures for the Vuse ENDS products were lower than that of usual brand (UB) cigarettes, including peak nicotine uptake and overall nicotine uptake, and were either similar to or lower than nicotine gum. The time course of nicotine uptake after use of the ENDS was more similar to that of combustible cigarettes than nicotine gum. The results indicate that the AL of each ENDS product is lower than that of UB cigarettes and similar to that of nicotine gum.

E-cigarette puffing topography: The importance of assessing user behaviour to inform emissions testing

Analysis of the chemical composition of e-cigarette emissions is an important step in determining whether e-cigarettes offer both individual and population-level harm reduction potential. Commonly, e-cigarette emissions for chemical analysis are collected when using e-cigarettes according to standardised puffing regimens, such as those recommended by the International Organization for Standardization (ISO) or the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA). While the use of such standard puffing regimens affords a degree of uniformity between studies and are also recommended by regulatory authorities who require the submission of e-cigarette emissions data to make decisions regarding allowing a product to be commercially marketed, the standardised regimens do not necessarily reflect human puffing behaviour. This can lead to under- or over-estimating real-world emissions from e-cigarettes and inaccuracy in determining their harm reduction potential. In this review, we describe how human puffing behaviour (topography) information can be collected both in the clinical laboratory and in the real world using a variety of different methodologies. We further discuss how this information can be used to dictate e-cigarette puffing regimens for collecting emissions for chemical analyses and how this may lead to better predictions both of human yields of e-cigarette emissions constituents and of risk assessments to predict e-cigarette tobacco harm reduction potential.

Human abuse liability assessment of e-cigarettes: Why, what and how?

Cigarette smoking is the world's leading cause of preventable death and disease. Alternative nicotine products such as e-cigarettes have tobacco harm reduction potential, by providing smokers with an alternative form of nicotine delivery but with either the reduced presence or absence of the numerous harmful chemicals found in combustible cigarette smoke. One aspect of importance in determining the potential of e-cigarettes to provide a viable alternative to combustible cigarettes for smokers is their ability to cause dependence, also known as their abuse liability. E-cigarettes with little or no abuse liability would be unlikely to be used as a substitute for cigarettes, whereas at least some degree of abuse liability is acknowledged as supportive both to aiding cigarette substitution or complete cessation and to preventing relapse. Given this link between abuse liability and substitution efficacy, human studies assessing the abuse liability of e-cigarettes are important to determine their true harm reduction potential. In this review, the concept of tobacco product abuse liability is discussed, along with the primary elements-pharmacokinetics and pharmacodynamics (subjective effects)-that need to be assessed to determine abuse liability. The review also presents a number of human abuse liability study design considerations and discusses what existing studies in the literature tell us about the abuse liability and harm reduction potential of e-cigarettes.

Switching away from smoking at 12 months among adult JUUL users varying in recent history of quit attempts made with and without smoking cessation medication

Some smokers switch away from smoking using e-cigarettes, but guidelines recommend trying approved medications first. We analyzed switching in adult smokers using JUUL by their recent history of quit attempts and use of smoking cessation medications. Participants were 8511 adult (21+) established smokers (at baseline), in which 50.3% are daily smokers, in a longitudinal observational study who completed a survey 12 months after first purchasing a JUUL Starter Kit. At baseline, participants reported attempts to quit smoking in the prior year and use of pharmacotherapy (nicotine replacement therapy [NRT] or prescription medication) in their most recent attempt. The outcomes were switching (self-reported no past-30-day smoking) and 50%+ reductions in cigarette consumption. Multivariable analyses were adjusted for baseline covariates. Two thirds of the participants had made a quit attempt in the year before purchasing JUUL. Overall, 59% [58%, 60%] had switched at 12 months. Switching was more likely in those who had used NRT and who attempted quitting without medication versus those who used prescription medications or made no quit attempt. In adjusted multivariable analyses, only making a past-year quit attempt (vs. not) was associated with higher odds of switching (OR = 1.15 [1.04, 1.28]). Over 60% of dual users reduced cigarette consumption by ≥50%. These associations were largely similar in daily smokers. Twelve months after purchasing JUUL, almost all smokers reported either switching or reducing their smoking by 50%+, including those who had recently failed to quit smoking with approved pharmacotherapies. E-cigarettes provide an alternative route to abstinence from smoking for smokers with a history of cessation and cessation treatment failure.

Part one: abuse liability of Vuse Solo (G2) electronic nicotine delivery system relative to combustible cigarettes and nicotine gum

Abuse liability (AL) of electronic nicotine delivery systems (ENDS) is relevant as the category increases in popularity as a potentially less-harmful alternative to cigarette smoking. AL assessments are important to the FDA in determining if a new product is appropriate for the protection of public health. This paper reports the results for Vuse Solo (G2 cartridge design) compared to high and low AL-comparators evaluated in an open-label, randomized crossover confinement AL study. The confinement design was adapted from previous ambulatory studies of Vuse Solo (G1 cartridge design) and included product familiarization sessions before each four-hour test session in which subjective measures, nicotine pharmacokinetics (PK), and physiological endpoints were assessed following a single 10-min ad libitum product use session. Product liking, intent to use again, suppression of urge to smoke, and nicotine PK were lower after use of Vuse Solo compared to cigarettes and higher after use of Vuse Solo compared to nicotine gum. No significant differences in blood pressure or heart rate were observed between the products pre- to post-product use. These data reinforce previous research and provide the scientific evidence to support regulatory decisions demonstrating that Vuse Solo has an AL profile lower than that of combustible cigarettes but higher than that of nicotine gum and, therefore, may be a suitable replacement for cigarette smoking for some adult smokers.

Nicotine Delivery and Pharmacokinetics of an Electronic Cigarette Compared With Conventional Cigarettes in Chinese Adult Smokers: A Randomized Open-Label Crossover Clinical Study

INTRODUCTION

To evaluate the nicotine pharmacokinetics of a commercial electronic cigarette (e-cigarette) relative to conventional cigarettes in Chinese adult smokers.

AIMS AND METHODS

A randomized, open-label, crossover clinical study was conducted on 23 healthy adult Chinese smokers. In two sessions, subjects used either the e-cigarettes with 30 mg/g nicotine in e-liquid or conventional cigarettes of a given brand, at one puff every 30 seconds for a total of 10 puffs. Blood samples were collected at specified time points for 4 hours after the first puff. Subjective effects on desire-to-smoke and physiological parameters such as heart rate and oxyhemoglobin saturation levels were also examined before and after using the two products.

RESULTS

The baseline-adjusted maximum nicotine concentration (Cmax-BL), time-to-peak nicotine concentration (Tmax), and nicotine absorption rate (Cmax-BL divided by Tmax) were found to be similar for the e-cigarette versus those of conventional cigarettes (p > .05). Total nicotine exposure measured as the area-under-curve (AUC0-t-BL) was significantly lower for the e-cigarette relative to that of conventional cigarettes. In addition, the subjects found that e-cigarettes were well tolerated under controlled puffing conditions.

CONCLUSIONS

The test e-cigarettes achieved similar nicotine delivery and pharmacokinetic profiles to those of the comparator cigarettes, indicating that this e-cigarette could be a potential alternative to conventional cigarettes for those adult smokers.

IMPLICATIONS

There are no data in the published literature on the nicotine pharmacokinetics of e-cigarettes in Chinese smokers. To the best of our knowledge, this is the first study to evaluate the nicotine delivery and pharmacokinetic profile of a commercial e-cigarette brand compared with conventional cigarettes in Chinese adult smokers. After the use of test e-cigarettes, nicotine delivery and pharmacokinetic profile were similar to those of conventional cigarettes in Chinese adult smokers.

An abuse liability assessment of the glo tobacco heating product in comparison to combustible cigarettes and nicotine replacement therapy

Tobacco heating products (THPs) have reduced emissions of toxicants compared with cigarette smoke, and as they expose user to lower levels than smoking, have for a role to play in tobacco harm reduction. One key concern of Public Health is that new tobacco and nicotine products should not be more addictive than cigarettes. To assess their abuse liability, we determined nicotine pharmacokinetics and subjective effects of two THPs compared with conventional cigarettes and a nicotine replacement therapy (Nicotine inhaler). In a randomised, controlled, open-label, crossover study healthy adult smokers used a different study product in a 5 min ad libitum use session in each of four study periods. Product liking, overall intent to use again, urge for product and urge to smoke questionnaires were utilised to assess subjective effects. Nicotine uptake was greater for the cigarette (C_max = 22.7 ng/mL) than for either THP (8.6 and 10.5 ng/mL) and the NRT (2.3 ng/mL). Median T_max was significantly longer for the NRT (15.03 min) than for the tobacco products (4.05–6.03 min). Product liking and overall intent to use again was highest for the cigarette, and higher for the THPs than the NRT. Urge to smoke was reduced more by the cigarette than by the other three products. Urge to use the THPs was greater than the NRT. These findings suggest that the abuse liability of the THPs lies between that of subjects usual brand cigarettes and the NRT.

Nicotine delivery and cigarette equivalents from vaping a JUULpod

With patented nicotine salt technology, JUUL dominates the e-cigarette market. We reviewed studies of JUUL's nicotine pharmacokinetic profile and studies quantifying nicotine in a JUULpod, emitted in the aerosol and absorbed by users. Examined in eight studies, JUUL's peak nicotine levels were half to three-quarters that of a combustible cigarette in industry-conducted studies with JUUL-naïve users, while comparable to or greater than combustible cigarettes in independent studies of experienced e-cigarette users. JUUL Labs reports each 5% (nicotine-by-weight) cartridge contains approximately 40 mg nicotine per pod and is 'approximately equivalent to about 1 pack of cigarettes.' In five independent studies, nicotine in the liquid in a JUULpod ranged from 39.3 to 48.3 mg. Seven studies measured nicotine delivery via vaping-machine generated aerosols, varying in puffing regimes and equipment. One study estimated 68% transfer efficiency to the aerosol, measuring 28.8 mg nicotine per JUULpod. The other studies reported nicotine values ranging from 72 to 164 µg/puff. At 200 puffs, this is 14.4-32.8 mg of nicotine per pod with equivalence to 13-30 cigarettes. A study measuring nicotine levels in JUUL users during a 5-day controlled switch found equivalence to 18 cigarettes. One JUULpod appears capable of delivering the nicotine equivalent to smoking about a pack of cigarettes, with variability. In JUUL-naïve smokers, JUUL's nicotine boost was lower than that of combustible cigarettes; while in experienced users, JUUL was comparable. Minimising harshness and adaptive to user experience, JUUL's design facilitates initiation to a high nicotine, and ultimately, highly addictive vaping product.

Trajectories of Nicotine Use Leading to Dual and Cyclical Tobacco Product Use in Young Adults

INTRODUCTION

Young adult never-smokers who vape are at elevated risk of initiating cigarettes, while young adults who smoke often begin vaping to substitute or reduce cigarette use. Reasons underlying different use patterns of tobacco products are not well-understood.

AIMS AND METHODS

We conducted 1-on-1 qualitative interviews with young adults (N = 62) who vape in Los Angeles, California from June 2018 to June 2019. Participants were 18-25 years old (79% male; racially/ethnically diverse) and self-reported vaping ≥1x/week. We used a semi-structured interview guide and applied thematic analysis method to analyze data.

RESULTS

Young adults initiated vaping due to peer socialization and e-liquid flavor novelty. They often reported vaping (after first smoking) due to a belief that e-cigarettes are healthier, social pressure to quit smoking, and convenience of use. Participants reported smoking (after first vaping) when traveling outside of the United States where vaping products were less accessible, and cigarettes were normative. Many of the personal narratives described patterns of dual and cyclical use, which was often attributed to nicotine dependence and cost, or described as dependent upon the current environment (eg, at a party).

CONCLUSIONS

The current study characterizes nicotine use trajectories and reasons why young adults vape, and smoke cigarettes. Dual and cyclical use of both e-cigarettes and cigarettes was common; this pattern of use should be considered in policy and prevention work to address nicotine dependence among young people.

IMPLICATIONS

We display findings from the current study in a model depicting common trajectories of nicotine use, along with reasons for initiation, transitions between products, and dual/cyclical e-cigarette and combustible cigarette use.

A randomised, crossover, clinical study to assess nicotine pharmacokinetics and subjective effects of the BIDI® stick ENDS compared with combustible cigarettes and a comparator ENDS in adult smokers

BACKGROUND

Nicotine pharmacokinetic assessments of electronic nicotine delivery systems (ENDS) are crucial to understand their ability to provide an alternative to cigarette smoking. Subjective effects data also strongly contribute to this understanding. The BIDI® Stick is a disposable ENDS product which contains 59 mg/ml nicotine benzoate salt and various flavours.

METHODS

In this study, we assessed nicotine pharmacokinetics and subjective effects of 6 flavour variants of BIDI® Stick ENDS in adult smokers, compared to cigarettes and a comparator ENDS product. During each of eight study visits, 18 volunteer smoker subjects randomly used one of either their usual brand (UB) of cigarette, a BIDI® Stick ENDS, or a comparator ENDS (JUUL 59 mg/ml nicotine with Virginia Tobacco flavour), during both controlled (10 puffs, 30 s apart) and ad libitum (60 min) puffing sessions. Blood samples were collected at various time points and subjective effects questionnaires were administered.

RESULTS

Mean [SD] plasma nicotine Cmax 0-120 was not significantly different between BIDI® Stick ENDS with any flavour (range 15.3 [9.90] ng/ml for BIDI® Stick Winter to 17.6 [9.00] ng/ml for BIDI® Stick Classic) and UB cigarettes (16.2 [9.17] ng/ml). Mean [SD] AUC0-120 (range 569.7 [327.29] to 628.6 [408.99]  min*ng/ml for BIDI® Stick ENDS and 747.1 [325.48]  min*ng/ml for UB cigarettes) and median Tmax 0-120 (range 5-7 min for all BIDI® Stick ENDS and UB cigarettes) values were also not significantly different between BIDI® Stick ENDS and UB cigarettes, while subjective effects measures were also similar between BIDI® Stick ENDS and UB cigarettes. Mean [SD] plasma nicotine Cmax 0-120, AUC0-120, and median Tmax 0-120 were 6.8 [4.13] ng/ml, 243.6 [179.04] min*ng/ml, and 5 min, respectively, for JUUL ENDS. These values were significantly different compared with those for all BIDI® Stick ENDS and UB cigarettes for both Cmax 0-120 and AUC0-120 but not for Tmax 0-120.

CONCLUSIONS

BIDI® Stick ENDS delivered nicotine to users comparably to their UB combustible cigarette and higher than JUUL ENDS, and also elicited similar subjective effects such as satisfaction and relief. Thus, the BIDI® Stick ENDS may be a satisfying alternative to cigarettes among current smokers and may support their transitioning away from cigarette smoking.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier number NCT05072925).

Pharmacokinetic and subjective assessment of prototype JUUL2 electronic nicotine delivery system in two nicotine concentrations, JUUL system, IQOS, and combustible cigarette

RATIONALE

Electronic nicotine delivery systems and heated tobacco products are noncombustible alternatives for adult smokers. Evidence suggests sufficient nicotine delivery and satisfying effects are necessary to facilitate switching away from smoking; nicotine delivery varies across electronic nicotine delivery systems within limited nicotine concentrations.

OBJECTIVES

To assess the nicotine delivery and subjective effects of prototype JUUL2 System in two nicotine concentrations, currently-marketed US JUUL System ("JUUL"), IQOS-brand heated tobacco product, and combustible cigarettes.

METHODS

Adult smokers (N = 40) completed a 5-arm cross-over product-use laboratory confinement study. Nicotine pharmacokinetics and subjective effects were assessed following use of: (1) JUUL2 prototype 18 mg/mL nicotine; (2) JUUL2 prototype 40 mg/mL; (3) JUUL 59 mg/mL; (4) IQOS 18 mg/g; and (5) usual brand combustible cigarette, each evaluated during ad libitum (10 min) and controlled (5 min, 10 standardized puffs) use.

RESULTS

Nicotine delivery was greatest for combustible cigarettes, followed by JUUL2 prototype 40 mg/mL, IQOS, JUUL2 prototype 18 mg/mL, and JUUL 59 mg/mL. Nicotine delivery from JUUL2 prototype 18 mg/mL was significantly greater than JUUL 59 mg/mL after ad libitum use. JUUL products were significantly more satisfying and effective at reducing craving than IQOS. JUUL2 prototype 40 mg/mL was significantly more aversive than other JUUL products.

CONCLUSIONS

Prototype JUUL2 and JUUL 59 mg/mL products were rated higher than IQOS on subjective measures associated with switching away from smoking. The JUUL2 prototype 40 mg/mL produced aversive responses and would require modifications to be a viable product for adult smokers. Nicotine delivery and subjective responses to JUUL2 prototype 18 mg/mL suggest a product based on this prototype may facilitate increased switching among adult smokers.