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# PhRMA Rare Disease Day Comments
- URL: https://www.fdaweb.com/phrma-rare-disease-day-comments/
- Published: 2020-03-31T12:00:00.000Z
- Updated: 2026-09-14T16:09:25.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5146459

Pharmaceutical Research and Manufacturers of America (PhRMA) says the topics discussed at the FDA 2/24 Rare Disease Day public meeting were “valuable in generating a shared understanding of the issues facing manufacturers in rare disease drug development, especially regarding the use of natural history studies and registry data.” The association’s 3/29 comment [letter](https://www.regulations.gov/contentStreamer?documentId=FDA-2019-N-5646-0011&attachmentNumber=1&contentType=pdf&ref=fdaweb.com) says it believes that real-world data and its analysis to generate real-world evidence can be an important tool to inform rare disease drug development, including natural history studies.

PhRMA also said it believes it would be helpful for FDA to emphasize the acceptability of using Bayesian approaches in rare disease therapy development. “Bayesian methods have been proven scientifically and statistically valid, and should accordingly be leveraged as the basis of a substantial evidence determination to support regulatory decision-making, particularly in the context of rare disease therapy development,” the letter says. “PhRMA reiterates its prior recommendations that FDA issue stand-alone guidance addressing FDA’s current thinking on the use of Bayesian methodologies to support FDA regulatory decision-making.”