Michael Weiss
Analyst · Ladenburg Thalmann. Please proceed
Yes, so for – we always feel most comfortable when there's a very on target, specific regulatory precedent. So with follicular lymphoma, as we discussed in the prepared remarks, copanlisib was approved using a certain patient population, certain endpoint and time. So we feel very good about that pathway. And same goes for marginal zone, where ibrutinib recently was approved. Again in certain marginal zone population, so we feel good about those regulatory pathways. With diffuse large B-cell, the only really recent precedent – there's actually been nothing approved for relapsed or refractory diffuse large B-cell. And then the most recent precedent was the CAR-T, which received full approval for truly refractory patients, third line, kind of just basically at least two prior lines of therapy refractory to prior treatment, kind of I'm not exact, but it's pretty close. So the CAR-T got a full approval based on complete response, but I – our understanding is that's not a – and I guess, if we want to go and cite the same exact patient population and do that strategy, but we've always been studying in intermediate population. So the intermediate population is for those unfortunate folks who fail front-line therapy, who are not eligible for transplant currently because there's nothing approved in that setting, and they'll receive a, what I describe as an alphabet soup of potential chemotherapies, whether it's EPOCH, GEMOX, B-R, R2, you get something off – I mean, technically off-label, but on at least standard of care today. And then if they fail one of those, then they become eligible for CAR-T. So in the middle, there's really no standard for what approvable? What would be approvable in accelerated approval setting? So that's why we're not as confident in that area. It's also – these are very challenging patients to treat, even the CAR-T, if you look – if you peel away the onion just one small layer, you see that I think the 6-month CR rate is down to about 30%. So it's a very challenging indication. And like I said, from a regulatory standpoint, we just don't have the kind of clarity that we have in some other areas. But our goal is to continue to push hard to find the right answer. We think U2 plus bendamustine with the early data looks quite compelling and exciting, and we'll continue with that. If that doesn't work, we'll just continue to build. I think the B-cell scenario, that's going to require a lot of multiple drugs. Like I said hopefully, we'll reach the hurdle with U2 plus benda. But if we don't, we've got a great trial up and running and we can continue to add drugs in to get there. So it's a – yes, from a regulatory standpoint, it's just hard to know for sure that what the hurdle will be.