Bridging approaches to facilitate innovation: building an approach for heated tobacco products from case studies in the food and drug domains a comparative review.

An increasing number of heated tobacco products (HTPs) have been commercialized in several countries over the last decade. To benefit public health, these products should have a lower health risk profile than cigarettes. This includes the need to be sufficiently acceptable to adults who smoke so that a reasonable proportion of those who do not want to quit smoking are persuaded to switch completely. Additionally, the product should not increase the likelihood of non-smokers starting to use tobacco or smokers increasing their total consumption of tobacco products. Part of this process involves iterative development of new product versions, leveraging lessons learned from consumer experiences with marketed products, and applying novel technologies to improve the consumer product offering. Risk assessment for these products may include pre-clinical quality, analytical and toxicity evaluations, pre-market clinical studies, and post-market surveillance studies. In recent years, approaches to bridge the assessment for modified or new products to data generated for reference products by comparing their equivalence were proposed. Here, we review the approaches taken for such bridging studies and relate them to product comparability and bridging approaches established in a diverse range of consumer and pharmaceutical products. This leads to a proposal for a logical, stepwise, and tiered bridging approach to effectively manage the introduction of new HTPs through scientific substantiation and have potential to increase the public health benefit by reducing risk and improving product acceptability for adult smokers without attracting non-smokers by new innovations.