Susan M. O’Brien, MD, on common toxicities and adverse effects when treating patients with chronic lymphocytic leukemia.
Susan M. O’Brien, MD: If we look at the combination trials, we are seeing the adverse effects of each single-agent about the same [as in clinical trials], but not any synergistic toxicities. For example, when we add an antibody to a BTK inhibitor, you can get an infusion reaction with the antibody—which is the main adverse effect that we think of when we think of antibodies—then you can get the usual BTK inhibitor effects. If we’re talking about small molecules, the data for ibrutinib [Imbruvica] and venetoclax [Venclexta] combinations have suggested that you get the ibrutinib affects you expect to get and the venetoclax effects other than the risk for tumor lysis, with the most common one being neutropenia. There is some data to suggest that the ibrutinib adverse effects, particularly atrial fibrillation and hypertension, which are the important cardiovascular ones, are decreased in frequency. The reason for that may be that these combo trials are being designed to allow finite therapy. Obviously, if you’re not staying on a BTK inhibitor for 4 or 5 years, that’s going to limit your time exposure at which you can develop an adverse effect. We may see a reduction in the frequency of some of the BTK effects because of finite therapy. The good news is there’s been no odd toxicities. It’s really just the toxicity that you would expect to see with either agent being given.