FT vs BTD vs AA - it's a jumble out there So I’ve been trying to make sense of Priority Review vs Fast Track vs Breakthrough Therapy vs AA designations. All seem to have unmet need, significant advantage over current SOC, treat serious/life threatening conditions, ability to show predicted benefit (via surrogate endpoints) as common elements between them. If a few of those elements are true, then there are 4 methods to speed up drug development and approval till a company gets to an NDA submission. They all seem bureaucratically similar but seem to differ in terms of where it is given by the FDA and the level of interaction with the FDA.
My interpretation:
Fast Track – speeds up FDA review, mostly for a new class of drugs, first of their kind or addresses a big treatment gap. More access to FDA for reviews. Rolling (as-is data) reviews vs waiting till end of a phase.
BTD – Fast track features + more senior level and intense commit from FDA. Speeds up further dev but not an approval in itself. Based on being safer/equal to existing and surrogate endpoints (projected benefits). Needs to be requested at end of phase 2. Precursor to an AA or Priority review designation.
AA program– not an actual approval to market, but allows a faster way to submit an NDA via projected benefit (surrogate endpoint) and more rolling reviews with senior advisors. Even faster if you have a priority review designation.
The designations can be combined based on benefits seen/demonstrated, like with Keytruda, which got BTD and AA for breast cancer in 2021. To me, this means if TLT gets a BTD and even an AA, they will still need to wait to file an NDA based on some pre-determined agreement wrt additional data. But it will make the company that much more attractive as a buy-out candidate given the safety profile, niche market and more than anything, the potential for a new and powerful class of metal-based drugs. In real world terms, might spike the shares higher but not up to its fullest potential till full approval or buyout. First things first. Let's see if they will tell us more in the Q1 MD&A.