The Imaginary Worlds of Cure Proportion Modeling: Survivorship and Reference Case Pricing of Transformative Therapies

On August 6, 2019 the Institute for Clinical and Economic Review (ICER) released a set of proposed adaptations to its value assessment framework methods where the intervention under review was considered a 'single or short-term transformativetherapy' (SST). These adaptations are intended to 'complement and build upon the upcoming update to the overall ICER assessment framework…'. The purpose of this commentary is to review the proposed cure proportion modeling reference case framework for assessing the value of SSTs together with ICER's 'recommendations for fair value-based pricing …'. Following previous commentaries on the ICER value assessment framework, the question raised is whether the proposed cure proportion modeling standards meet those of normal science: is the modeling proposed capable of generating value claims for the intervention that are credible, evaluable and replicable? The proposed standards for transformative therapies do not change the underlying commitment to reference case modeling. At the same time, the cure proportion modeling proposed adaptations have to be seen in the context of the concerns expressed by ICER that their reference case model can be used to justify substantial one-off SST pricing. This follows from the ICER incremental cost per QALY willingness to pay thresholds where the SST QALY gains are sufficient, at even a $50,000 QALY cut-off, to support SST pricing in the millions of dollars. ICER has two options: (i) abandon the imaginary reference case methodology, which is the ICER core business model and would represent an ironic reversal, or (ii) attempt to bolt-on adaptations, possibly incorporating revised survivorship profiles using cure proportion modeling, that supports a modified imaginary reference case 'rescue' model for SSTs designed specifically to generate pricing recommendations that may be considered affordable.