Effects of Heated Tobacco Product Flavor on Tobacco Use Behavior and Abuse Liability Among Menthol Cigarette Smokers

The public health success of FDA's proposed ban on menthol cigarettes hinges upon whether menthol smokers who are unable to quit smoking switch to non-menthol cigarettes (no public health gain) or to potentially lower harm alternatives like heated tobacco products (HTP). In 2019, FDA authorized an HTP called "IQOS" and its tobacco- and menthol-flavored "HeatSticks" (HS) as a modified risk tobacco product (MRTP). One issue relevant to FDA's future action regarding IQOS will be "whether and how certain flavors may help adult cigarette smokers reduce cigarette use and switch to potentially less harmful products" (FDA, 2018). Understanding the potential for HTPs like IQOS to reduce the health burden of cigarettes requires targeted research investigating the extent to which flavor availability is important for menthol smokers to switch to HTPs. For one tobacco product to substitute for another, their abuse liabilities should be congruent. Validated clinical lab methods exist for comparing tobacco product abuse liability by characterizing their nicotine delivery profiles (via plasma nicotine and puff topography) and reinforcing efficacy (via subjective and behavioral measures). Naturalistic assessment can validate clinical lab results regarding use patterns and product substitution.

The current study involves a two-arm, two-week, parallel group trial. The first week is an own brand (OB) menthol cigarette baseline, during which tobacco use will be assessed daily using ecological momentary assessment (EMA). On Monday and Friday, participants will complete clinical lab sessions that involve using OB cigarettes and responding to subjective measures and an Experimental Tobacco Marketplace (ETM) task that assesses willingness to substitute menthol cigarettes with an array of tobacco products including IQOS. During the next week, participants will be randomized to receive IQOS-menthol (n=25) or IQOS-tobacco (n=25); EMA and clinical lab visits will be repeated. Aim 1 assesses IQOS' abuse liability in a clinical lab setting. Outcomes include plasma nicotine levels, puffing behavior, responses about subjective effects, and product substitution from the ETM task. Aim 2 measures tobacco use patterns in naturalistic settings where participants will report daily OB and IQOS use outcomes via EMA. The overarching hypothesis is that, relative to OB, IQOS-menthol's abuse liability profile will differ less than IQOS-tobacco's, suggesting that menthol smokers will be more likely to substitute an HTP for combustible menthol cigarettes when a menthol-flavored HTP is available. Results will deepen our understanding of the public health impact of HTPs and policies that might restrict access to menthol-flavored MRTPs.