[1][2] The FDA's "breakthrough therapy" designation is not intended to imply that a drug is actually a "breakthrough" or that there is high-quality evidence of treatment efficacy for a particular condition;[3][4] rather, it allows the FDA to grant priority review to drug candidates if preliminary clinical trials indicate that the therapy may offer substantial treatment advantages over existing options for patients with serious or life-threatening diseases.
[8] Sponsors must apply for breakthrough status separately for each indication they intend to label the drug for.
The FDA works with the sponsor of the drug application to expedite the approval process.
[9] Critics have said that the name is misleading and provides companies that obtain a breakthrough designation for a drug candidate with a marketing advantage that may be undeserved.
It was never meant to imply that these drugs are actually "breakthroughs," and it does not ensure that they will provide clinical benefit, but still critics complain that they are based on preliminary evidence, including changes in surrogate markers such as laboratory measurements, that often don't reflect "meaningful clinical benefit.