ASH 2023 | The use of pirtobrutinib in Richter’s transformation: data from the BRUIN trial

So we’re also seeing an update to the Richter’s transformation population from the BRUIN trial. And so this was a very large study. Richter’s, of course, is a very hard malignancy to study. The patients are often sick. But not to mention this is a pretty rare complication of CLL/SLL occurring in maybe only to 2 to 10% of patients affected by this malignancy.

So BRUIN accrued patients at first with just relapsed/refractory Richter’s. But then the trial was expanded to also include frontline Richter’s patients. And so they accrued I think 80 some patients which I believe is the largest prospective trial in Richter’s transformation.

What we’re seeing at this year’s ASH is an update to what we saw at last year’s ASH, with now 18 months on average of follow-up. So we’re once again seeing activity of this drug. Most patients have some degree of lymph node reduction. However, when applying traditional response criteria, this response rate once again ends up being right around 50%. The median PFS isn’t too long, I think it’s just under four months. However, among responders we can see some degree of durability of responses, with some patients having responses of eight plus months.

So is this the end all be all for Richter’s transformation? No, I don’t think so. But I do think it could be used as a bridging strategy, or perhaps a palliative strategy for our less fit patients to be able to attain some degree of disease control for this very difficult to treat malignancy.