Ionis offered feedback on the FDA’s guidance for developing natural history studies for rare disease drug development, praising some parts of the guidance but calling for more details.

Ionis suggested that the agency add three additional uses for natural history studies to the guidance—establishing the burden of disease, characterizing genetic mutations and biological consequences, and reducing trial burden in interventional studies.

The guidance should strongly encourage sponsors share with the public and community “not only methods, practical aspects and results, but also subject-level data in a timely fashion,” the drugmaker said. It also called for greater emphasis on interim analyses.

“Sponsors should be encouraged to adapt and revise their natural history study protocols based on ongoing data analysis and learnings to ensure the collection of most relevant natural history data,” Ionis said.