ASH 2023 | Pirtobrutinib in R/R FL: results from the BRUIN study

So, I think people are getting to be more and more familiar with pirtobrutinib. This is a non-covalent BTK inhibitor, so it is mechanistically different than the BTK inhibitors that we’ve been using, the covalent class, drugs such as acalabrutinib and zanubrutinib. The BRUIN study was a very, very large Phase I/II study that enrolled over 700 patients, and because of that, they sort of enrolled multi-histology. What we reported up until this point is really the outcomes in CLL and mantle cell, and there’s updates here at this conference for both of those histologies, but this is the first time we’re actually sharing the results specifically in the subset of patients that had follicular lymphoma. So this was approximately 40 patients in the whole BRUIN study who had relapsed refractory follicular, a disease that has a multitude of options but, at least up until now, not a lot of BTK inhibitor activity. We found in this multiple relapsed cohort that had a median of three prior lines of therapy that the overall response rate was 50%, and actually, a small percentage, about 17%, actually achieved a complete remission. The median progression-free survival was about 5 to 6 months, so clearly not something that’s going to work for everybody. But there are some durable patients, including, I have a patient of my own who’s now been on pirtobrutinib for follicular lymphoma for years. So sort of exciting to see this drug work across B-cell malignancies, not just mantle cell and CLL, and I’m excited to share that data today.