Rare disease benchmarks: investment professionals' accuracy and beliefs.

Rare-disease assets account for a substantial and growing share of biopharmaceutical development and dealmaking, and published analyses provide benchmarks for their clinical, commercial and financial performance. Whether investment and business-development practitioners hold beliefs consistent with these benchmarks is largely unexamined. We surveyed 43 professionals across venture capital, pharmaceutical and biotechnology business development, asking them to estimate benchmarks for approval probability, acquisition timing, exit economics, time to peak sales and launch performance, and compared their responses with the published literature. Respondents were generally well calibrated on some structural characteristics visible through deal flow, such as the dominant modality for rare-disease assets, but systematically miscalibrated on specific magnitudes. Launch performance was the most underestimated, with 84% placing it below published levels, and most respondents underestimating how late acquisitions of rare-disease assets occur. Estimate accuracy was not associated with years of experience. These findings suggest a wide gap between published evidence and practitioner belief, which might lead some rare-disease assets to be assessed more conservatively than historical performance would justify.