OBJECTIVES: In the context of evaluating immuno-oncology (I-O) therapies, several innovative methods have been developed to address the challenges of extrapolating survival curves beyond their observation periods. The goal of this study was to summarize perceptions of innovative methodologies through an experts’ survey.

METHODS: A survey was administered by a one hour telephone interview to 10 academics with expertise in survival extrapolation for I-O therapies in the context of HTA in Australia (1), Canada (1), France (2), Portugal (1), Sweden (2), the Netherlands (1) and the UK (2).

RESULTS: Eight out of ten experts perceived differences in shape of survival curves for I-O agents vs. other oncology drugs, although six experts believed that traditional methods are adequate for I-O survival extrapolation. The majority of experts (8/10) indicated parametric models as preferred in their country over innovative methods in case of all oncology drugs. This perception was found to likely be driven by unfamiliarity with the innovative methods by authorities. Nevertheless, 7 experts agreed that innovative methods are more useful for providing realistic extrapolations of survival in I-O products compared to traditional models due to their ability to reflect specific patterns of survival. All experts agreed that the acceptability of new methods by authorities is expected to grow over time with greater familiarity due to increasing use.

CONCLUSIONS: This study suggests that limited familiarity of innovative methods for survival extrapolation by HTA bodies currently restricts the acceptability of these methods by authorities. However, this trend may shift with more exposure to these methods, as there is a perception among experts that they provide better survival extrapolations for I-O drugs. This underscores the need for more studies applying innovative methods of survival extrapolation to increase their awareness and acceptability.