I'd have to listen to the interview again as Leslie did mention...

I'd have to listen to the interview again as Leslie did mention this quite specifically, but I believe the idea is to do the Phase 1b, then get straight into a registrational study, so in effect, a Phase 2 registrational study that allows the product to go to market after it's completed or the FDA is satisfied.

There's been a few of these go through in the past and I think a Phase 3 still follows, but it's done while the product is on the market. See here https://www.fda.gov/drugs/resources-information-approved-drugs/ongoing-cancer-accelerated-approvals
This is why they could potentially get Azer-cel to market and earning in a few (I read as 3 ish) years.

We've also seen the FDA pull approval from products that have gone through this process because they failed to demonstrate the benefits that they were supposed to. See an article here https://apnews.com/article/us-news-health-science-business-government-and-politics-019790c439dfd39a11868ede5d55b6e6 and here https://www.fda.gov/drugs/resources-information-approved-drugs/withdrawn-cancer-accelerated-approvals

Other associated info here.
https://www.fda.gov/patients/learn-about-drug-and-device-approvals/fast-track-breakthrough-therapy-accelerated-approval-priority-review