Timing And Data Are Critical To Winning Breakthrough Therapy Designation For Rare Disease Drugs

By Mwango Kashoki, M.D., M.P.H., Senior Vice President, Global Head of Regulatory Strategy

Nearly three-quarters of approved Breakthrough Therapies are orphan drugs—making Breakthrough Therapy Designation (BTD) foundational to rare disease drug development.

But BTD success isn’t driven by data alone. For rare disease programs, when you engage regulators and how you build and layer evidence often determine whether a BTD request accelerates development—or falls short. With small populations and limited data, strategy and timing matter more than ever. In this expert analysis, Parexel examines FDA trends and real-world experience to reveal how to:

• Get timing right: When you engage FDA can make or break BTD success
• Build with precision: How leading orphan programs layer pathways and evidence effectively
• Align early to win: What regulators expect—and how integrated clinical, regulatory and statistical planning accelerates approval