OBJECTIVES: To explore possible heterogeneity between approaches utilised in building cost effectiveness models for cell and gene therapies. Also, to seek common approaches and discuss likely strategies for cell and gene therapy modelling approaches.

METHODS: Cell and gene therapy products were identified, and a targeted literature review was carried out to identify publications and Health Technology Appraisals (HTAs) relating to these products. The structures of cost-effectiveness models were examined to look for common features.

RESULTS: Of the 10 identified products that had marketing authorisation granted in the EU, 9 had cost-effectiveness models built for them. One product had multiple model structures: in this case analysis focused on the model structure used for the product’s HTA assessment. 56% of the models used a Markov Structure (alone), with transition states ranging from 3 states to 6 states; 22% of products used partitioned survival models; 11% used a discrete event microsimulation model; and 11% used a 2-stage model (i.e., a decision tree for 12 months and a Markov transition state modelling thereafter).

CONCLUSIONS: Manufacturers and health economists are clearly attempting to use familiar modelling structures despite the obvious paucity of data and issues arising from using short-term data to model long-term disease benefits. These strategies appear to be quite effective in securing successful reimbursement. It seems sensible to assume that, where possible, a Markov model approach is the obvious starting point to demonstrate the cost effectiveness of cell and gene therapies. A less common approach is to use a discrete event microsimulation or a decision tree for the early phase of treatment and transition to a Markov model thereafter, which can allow for the modelling of more long-term effects.