Nicotine Pharmacokinetic Profile and Safety of the Tobacco Heating System 2.2 Menthol (THS 2.2 Menthol): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Nicotine Pharmacokinetic Profile and Safety of the Tobacco Heating System 2.2 Menthol (THS 2.2 Menthol) (NCT01967719), a randomized na study. The primary outcome is Maximum Concentration (Cmax) of Nicotine Following Single Use of mTHS 2.2, mCC and NNS.

2. Clinical Question

The question concerns nicotine pharmacokinetics: the rate and amount of nicotine absorbed, assessed through blood concentrations after product use. The primary endpoint was maximum concentration, or Cmax. That is a measure of the observed peak in the post-use concentration profile, not a direct measure of overall nicotine exposure or of a clinical health outcome.

The design compares products after single use in the same randomized crossover study. Participants were assigned to product sequences, with wash-out periods between use days. This structure allows product exposures to be observed within the study population under the specified sequence, but the registry record does not describe every detail of the randomization or analysis procedures. Results should therefore be read as pharmacokinetic findings from this study, rather than as evidence about longer-term product use or outcomes beyond those measured.

3. Trial Design

This was a randomized, open-label, controlled, crossover study conducted at a single center. The registry lists the phase as not applicable. The study enrolled 64 participants, and its status is completed. The recorded study start was 2013-10 and the primary completion was 2013-11.

Participants were assigned to sequences involving single use of mTHS 2.2, a menthol conventional cigarette, and nicotine nasal spray. In Group 1, the sequence descriptions place mTHS 2.2 and the conventional cigarette on separate intervention days, with a wash-out day between them. One sequence used mTHS 2.2 first; the other used the conventional cigarette first. Group 2 followed corresponding sequences involving mTHS 2.2 and nasal spray, again with a wash-out day between intervention days. The sequence descriptions identify Day 0 as a wash-out, Day 1 as the first intervention, Day 2 as a wash-out, and Day 3 as the second intervention.

The primary endpoint description says that blood sampling took place on Day 1 and Day 3. It includes a pre-use sample and multiple post-use samples over 24 hours after product use. The endpoint timeframe is listed as 3 days. The registry does not report the randomization method, sequence-generation procedure, allocation concealment, or the rationale for the wash-out interval.

The intervention comparisons were not parallel groups in which each participant received only one product. Rather, participants in the described sequences received more than one product on separate study days. This crossover structure is relevant when interpreting the comparison: the reported results arise from product exposures within a randomized sequence design. The registry lists 41 participants for each of the two Group 1 pharmacokinetic outcome entries and 17 for each of the Group 2 entries. These are the posted endpoint group counts; they should not be conflated with the overall enrollment of 64.

The study was open-label, so masking is listed as none. Whether laboratory staff or analysts were masked is not reported in the registry record. The rationale for the planned enrollment, the protocol’s sample-size justification, and any interim analyses are also not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Enrolled population = 64 subjects: 2 exposed to mTHS 2.2 and NNS at Admission but not randomized and 62 randomized as described below: * Sequence "mTHS 2.2 then mCC": 22 subjects * Sequence "mCC then mTHS 2.2": 22 subjects * Sequence "mTHS 2.2 then NNS": 9 subjects * Sequence "NNS then mTHS 2.2": 9 subjects

Washout Period of 1 Day (Day 0)

First Intervention (Day 1)

Reasons for not completing this period:

Washout Period of 1 Day (Day 2)

Second Intervention (Day 3)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Pharmacokinetics (PK) populations consisted of all the randomized subjects who completed at least 1 of the single use days (Days 1 or 3), and for whom at least 1 PK parameter could be derived. Subjects with major protocol deviations that impacted the evaluability of the results were excluded from the PK populations.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: PK population: all randomized subjects who completed at least 1 of the single-use days, with at least 1 derived PK parameter. 62 randomized subjects : 44 in Group 1, 18 in Group 2. PK population = 58 =\> 41 in Group 1 (2 withdrawn + 1 excluded due to major protocol deviation), 17 in Group 2 (1 withdrawn).

6. Primary Endpoint

The registry lists the primary outcome as Maximum Concentration (Cmax) of Nicotine Following Single Use of mTHS 2.2, mCC and NNS, measured over 3 days.

The primary endpoint was maximum concentration, or Cmax, of nicotine after single use of mTHS 2.2, a menthol conventional cigarette, and nicotine nasal spray. It is measured in ng/mL. The endpoint description states that geometric least-squares means were used, with 95% confidence intervals, and that concentrations were derived from multiple blood samples collected before and after product use on the intervention days.

Cmax captures the peak concentration in the measured blood profile after exposure. It is useful for describing the rate and amount of nicotine appearing in blood, which matches the stated pharmacokinetic objective. A peak measure is not the same as total exposure across the sampling period. It also does not by itself describe how long a concentration is maintained, the full shape of the concentration-time profile, or a health outcome.

In general, repeated sampling after use helps identify a measured peak more directly than a single post-use sample would. The interpretation still depends on the sampling schedule and the analysis population. The registry describes sampling before use and multiple times over 24 hours after use, but does not report the exact sampling times or the detailed procedures used to derive Cmax. Those details are not reported in the registry record.

The reported primary comparison is the geometric least-squares mean ratio for mTHS 2.2 relative to the conventional cigarette in Group 1. A ratio summarizes the relative peak concentrations on the analysis scale; it does not give the full distribution of individual participant values. The registry record does not report a corresponding sponsor analysis for the nasal-spray comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical features shape how the nicotine concentration findings should be read. The endpoint is continuous, the reported arm summaries are geometric least-squares means, and the sponsor’s Group 1 comparison is described as an analysis of variance (ANOVA) producing a geometric least-squares mean ratio. The confidence intervals quantify uncertainty around the estimates under the analysis model. They do not remove limitations arising from the study design or incomplete reporting.

What does a geometric least-squares mean describe?

A least-squares mean is a model-based mean estimate, rather than necessarily the simple arithmetic average of the observed values. The registry specifically identifies the reported estimates as geometric least-squares means. In general, geometric summaries are suited to measurements that are analyzed on a logarithmic scale, where multiplicative differences are more natural than additive differences. This can be useful for concentration data, which may have a right-skewed distribution. The registry does not report the exact transformation, covariates, or model specification, so those details should not be assumed.

The arm-specific values provide estimated concentration levels in ng/mL. The reported ratio expresses the relative comparison between the model-based estimates for the products. A ratio is distinct from a difference: it is not a subtraction of the two arm means. The posted ratio is 56.57, with a 95% confidence interval from 44.21 to 72.39. No extra calculation is needed to describe that reported result.

How should a confidence interval be understood?

In general, a confidence interval gives a range of values compatible with the data and the statistical model at the stated confidence level. A narrower interval indicates greater precision under that model, while a wider interval indicates less precision. It is not a guarantee that the true value lies in the interval, nor does it describe the spread of individual observations. Here, the registry reports 95% confidence intervals for the arm-specific geometric least-squares means and for the Group 1 ratio.

Confidence intervals depend on the analysis population, model assumptions, and way observations are handled. Because the registry does not provide the full model specification or detailed missing-data procedures, the reported intervals cannot be independently reproduced from the record alone. The interval is still useful as the registry’s reported measure of estimation uncertainty.

What does ANOVA contribute?

The sponsor’s Group 1 comparison is labeled ANOVA. In general, ANOVA is a modeling approach for comparing means across groups or conditions. In a crossover study, the appropriate model may need to account for the repeated observations and the sequence structure. The registry does not report enough detail to establish which terms were included in the model or how within-participant correlation was handled. It is therefore appropriate to identify the reported method as ANOVA without attributing unreported model features to it.

The Group 1 arms have posted counts of 41 participants each. The Group 2 arms have posted counts of 17 participants each. Counts indicate the number associated with the posted endpoint entries, but they do not by themselves explain exclusions, incomplete measurements, or how every participant contributed to the model. The population description says that eligible randomized subjects had completed at least one single-use day and had at least one derivable pharmacokinetic parameter; it also notes exclusion of subjects with major protocol deviations affecting evaluability. Additional flow details are not reported in the registry record.

Why is crossover structure relevant?

In general, a crossover design exposes participants to more than one condition at different times. This can allow a comparison that accounts for some stable differences between participants, but the analysis must also consider period and sequence effects and whether the wash-out adequately separates exposures. The registry describes randomized sequences and wash-out days between intervention days. It does not report a specific test for carryover, a period-effect analysis, or the model’s treatment of sequence. None should be inferred from the design label alone.

The open-label design means masking is listed as none. For an objective laboratory concentration, lack of masking may be less directly relevant to measurement than it can be for subjective outcomes, but it does not eliminate possible influences on behavior or study conduct. That is a general methodological consideration, not evidence that such influence occurred in this study. The record does not say whether laboratory personnel were masked.

What can a recalculation add?

A simple unadjusted recalculation from posted summary statistics can sometimes offer a separate descriptive comparison. It is not the same as the sponsor’s adjusted or model-based analysis, especially in a crossover setting where the analysis may use participant-level and sequence information unavailable in summary values. For this continuous endpoint, the registry record does not contain an estimable two-arm recalculation. Consequently, no recalculated ratio, interval, or p-value should be presented as if it were an independent confirmation of the sponsor result.

Planning illustrations, when based on an observed effect and conventional assumptions, are hypothetical calculations for future-study planning. In general, they do not show the probability that the completed study detected an effect, and they are not observed power. The protocol’s own sample-size justification is not reported in the registry record. Any sample-size illustration should therefore be kept separate from the observed pharmacokinetic findings.

Finally, nicotine concentrations may show variability beyond what a simple normal model would capture. In general, over-dispersion means the observed variation exceeds the variation assumed by a model; if present and not handled, uncertainty estimates may be too small. The registry does not report an over-dispersion assessment, so it is not possible to say whether it was present or how it was addressed. This is a general caution about model assumptions, not a claim about the data in this trial.

10. Analyses Reported by the Sponsor

The registry’s sponsor analysis for the Group 1 comparison is an ANOVA-based geometric least-squares mean ratio of 56.57, with a 95% confidence interval from 44.21 to 72.39. This is the posted formal comparison of mTHS 2.2 with the menthol conventional cigarette. The record does not report a p-value for this analysis.

No unadjusted recalculated comparison is available for this continuous endpoint in the registry record. The posted arm summaries do not contain the participant-level information needed to reproduce the crossover model or to verify its handling of sequence and repeated observations. A simple comparison derived from marginal summaries would not necessarily match the sponsor’s model-based estimate.

The record also does not include a formal sponsor comparison of mTHS 2.2 with nicotine nasal spray. The Group 2 means and confidence intervals are reported, but they do not replace a model-based contrast. There is no reported discrepancy between a sponsor result and a recalculation, because a recalculated result is not available. The sponsor’s posted Group 1 analysis should therefore be described as the available formal comparison, without treating it as independently reproduced.

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies Cmax as the primary endpoint and lists two outcome measures and two analyses. It does not report a multiplicity adjustment, a prespecified hierarchy for testing comparisons, or a detailed statistical analysis plan. Whether the study controlled the overall type I error across endpoints, products, or analyses is not reported in the registry record. In general, multiplicity matters when several hypotheses are tested, because interpreting each result separately can overstate the strength of evidence if no adjustment or prespecified strategy is used.

The record reports the primary endpoint for Group 1 and group estimates for Group 2, but does not report a formal sponsor contrast for the nasal-spray comparison. Without a posted testing plan, it is not possible to determine how the study intended to handle multiple product comparisons or whether any comparison was confirmatory beyond the stated primary objective.

The pharmacokinetic population is described as randomized subjects who completed at least one single-use day and had at least one derivable pharmacokinetic parameter. Subjects with major protocol deviations affecting evaluability were excluded. This is not a full account of participant flow or of all analysis sets. The numbers included in other populations, the reasons for exclusion, and the handling of partial profiles are not reported in the registry record.

Missing-data procedures are not reported in the registry record. The record does not explain whether missing samples were imputed, how a profile with an incomplete sampling schedule was treated, or whether sensitivity analyses were conducted. In general, incomplete post-use sampling can affect identification of a peak concentration, but the available information does not establish that this affected the estimates in this study.

The crossover design also raises questions about period, sequence, and possible carryover effects. The sequence descriptions and wash-out days are reported, but planned checks or model terms addressing these issues are not. Interim analyses are not reported in the registry record. Neither their presence nor absence should be inferred from the posted outcome results.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports no serious adverse events for Group 1 among 44 participants at risk, and no serious adverse events for Group 2 among 18 participants at risk. The enrolled-but-not-randomized group had 2 participants at risk and no serious adverse events reported. Deaths are not reported in the registry record. No top serious-event terms are listed.

Other adverse events were reported for 12 of 44 participants at risk in Group 1 and 5 of 18 participants at risk in Group 2. The enrolled-but-not-randomized group had 0 other adverse events reported among 2 participants at risk. These are group-level safety counts in the registry; they do not identify the nature, timing, severity, or attribution of the other events. Those details are not reported in the registry record.

In general, an adverse-event count describes what was recorded during the specified safety observation, not whether an event was caused by a particular product. The registry does not provide product-specific safety counts by exposure period in the crossover sequences. The group figures should not be interpreted as direct product-to-product safety comparisons, and the absence of reported serious events in these groups does not establish the absence of risk.

The safety denominators differ from the pharmacokinetic endpoint counts. The registry does not explain the full relationship between these populations, so the figures should be read with their stated group denominators rather than treated as interchangeable with the PK analysis counts.

13. What the Result Does, and Does Not, Mean

The results describe nicotine peak concentrations following single use in a randomized, open-label crossover study of smoking, healthy subjects. The registry reports geometric least-squares mean Cmax values for mTHS 2.2 and the menthol conventional cigarette in Group 1, alongside a sponsor-reported ratio and 95% confidence interval. It also reports separate Group 2 estimates for mTHS 2.2 and nicotine nasal spray.

These findings address a pharmacokinetic question: the concentration of nicotine measured in blood after product use. They do not answer whether a product changes long-term health outcomes, whether repeated use produces the same profile, or whether users would behave differently outside the study setting. The trial’s primary outcome is a laboratory measure, not a clinical endpoint.

The ratio and confidence interval summarize the model-based Group 1 comparison and its statistical precision under the sponsor’s analysis. They do not describe every participant’s response, prove that the model assumptions are correct, or capture uncertainty from unreported design and analysis details. The registry does not report a formal mTHS 2.2 versus nasal-spray comparison, so the Group 2 estimates should not be presented as such a test.

The study was open-label and single-center, and the posted findings follow single-use interventions over the stated study period. Those features limit how far the results can be generalized beyond the measured setting. The record does not report the sample-size justification, detailed analysis plan, missing-data methods, or full participant flow. These omissions limit independent assessment of planning and analysis choices.

In short, the registry provides a model-based estimate of relative peak nicotine concentration for the Group 1 products and descriptive estimates for Group 2. Statistical interpretation should remain within that scope. The results do not establish a broader health effect, and they do not support a formal nasal-spray contrast absent a posted analysis.

14. Why This Trial Matters Statistically

This trial illustrates why the statistical design matters when the outcome is a concentration profile rather than a conventional clinical event. Cmax condenses repeated blood measurements into a peak summary. That can be a useful pharmacokinetic quantity, but it does not represent the full concentration-time curve. The timing and completeness of measurements, and the method used to derive the peak, are important for interpretation.

The crossover structure is also central. Participants followed randomized sequences and received interventions on separate days, with wash-out periods. In general, such designs can make within-participant comparisons informative, while requiring attention to period, sequence, and carryover. The registry describes the sequences but does not provide enough statistical detail to assess how those design features were modeled.

The result also demonstrates the distinction between a posted descriptive estimate and a formal comparison. The registry gives Group 2 mean estimates for mTHS 2.2 and nasal spray, but does not provide a sponsor contrast between them. Reading differences between separate estimates as if they were a reported hypothesis test would overstate what the record establishes. For Group 1, the formal ratio and its confidence interval are explicitly reported and can be interpreted as the sponsor’s model-based comparison.

Finally, the record highlights the value of transparent reporting. Details about analysis populations, missing data, model specification, multiplicity, and sample-size rationale affect how readers judge precision and reproducibility. When those details are not reported, conclusions should stay close to the posted endpoint and analysis rather than fill gaps with assumptions.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The findings concern single-use exposures in smoking, healthy subjects at a single center. The registry does not report how representative participants were of other populations, so generalization beyond the enrolled study population is uncertain. The open-label design means masking is listed as none; the record does not state whether laboratory staff or analysts were masked.

The reported Group 1 comparison is accompanied by an ANOVA label and a geometric least-squares mean ratio, but the full model specification is not reported in the registry record. Details such as covariates, period and sequence terms, and treatment of within-participant correlation are not available. The protocol’s sample-size justification and any interim analyses are also not reported.

The record does not report detailed sampling times beyond pre-use sampling and multiple post-use samples over 24 hours. Nor does it describe the exact procedure used to derive Cmax from those samples. These omissions make it difficult to assess the measurement and analysis choices independently. Missing-data handling, sensitivity analyses, and complete participant flow are not reported either.

The pharmacokinetic population excluded subjects with major protocol deviations affecting evaluability, but the detailed deviation criteria and exclusion counts are not reported. The endpoint counts differ by study group, and the record does not explain every difference between enrollment, safety populations, and the PK analysis population.

Only the sponsor’s Group 1 product comparison is formally reported. Group 2 has separate estimates for mTHS 2.2 and nasal spray, but no posted formal contrast. The registry also does not report a multiplicity strategy. Safety data are presented as group-level counts rather than product-specific results by crossover exposure period, and event details are limited. These reporting gaps restrict independent evaluation and should temper interpretation without changing what the posted estimates themselves say.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Nicotine Pharmacokinetic Profile and Safety of the Tobacco Heating System 2.2 Menthol (THS 2.2 Menthol) — NCT01967719.
• Registry record last updated 2020-03-18; status last verified 2020-03.
• Results first posted 2017-02-07.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT01967719 is a completed, randomized, open-label, controlled crossover study sponsored by Philip Morris Products S.A. It enrolled 64 smoking, healthy subjects at a single center. The recorded study start was 2013-10, and primary completion was 2013-11.

The primary objective was to assess nicotine pharmacokinetic profiles after single use of mTHS 2.2, a menthol conventional cigarette, and nicotine nasal spray. The primary endpoint was maximum nicotine concentration in blood, measured in ng/mL from samples collected before and after product use. The registry reports geometric least-squares means and 95% confidence intervals.

For Group 1, the registry reports a sponsor ANOVA comparison of mTHS 2.2 with the menthol conventional cigarette: a geometric least-squares mean ratio of 56.57, with a 95% confidence interval from 44.21 to 72.39. Group 2 estimates are reported for mTHS 2.2 and nasal spray, but a formal comparison is not reported in the registry record. Further details about the statistical plan, missing data, sample-size rationale, and full analysis populations are not reported in the registry record.