I think there's a lot of data really emerging that adding that fourth drug as an anti-CD38 antibody is very different than many of our other attempts to add in a fourth drug when they were cytotoxic agents or HDAC inhibitors or other fourth drug categories we were trying to add in. The biggest reason is because we know that the mechanism of action is different for the anti-CD38 antibody. We know that the tolerance of that treatment is pretty good as well. I think it's a win-win situation for patients.
What we're seeing is pretty significant speeding up of depth of response, achievement of MRD negativity early on, no matter what measurement tool you use. More importantly, the only safety signals that seem to be coming out are a higher risk a rate of infectious complications, and in the randomized trials that does bear out. There's a little bit more upper respiratory tract infection or pneumonia in the group that receives an anti-CD38.
I think we all know how to be vigilant with our patients about that, to use anti antibacterial prophylaxis, to use trimethoprim, for instance, as a way to not only prevent PJP but also perhaps reduce the antibacterial effect of these regimens. Then early and empiric use of IVIG if patients continue to have infectious complications are things that can be done to really mitigate that, which is the main potential adverse or safety event with the addition of an anti-CD38 in a quad regimen.