John F. Gerecitano, MD, PhD:This patient relapsed relatively soon after treatment and maintenance therapy with lenalidomide, so a little bit sooner than we would have expected based on the data. And when this patient relapsed, they relapsed in a bulky and symptomatic way. So, this patient had a high tumor burden with large bulky lymph nodes as well as ascites and fatigue from their disease. Their anemia was also recurrent and their platelets were a bit lower at the time of relapse than they were at the time of their initial diagnosis. Also, their LDH was high. These are all markers of high-burden disease.
In patients who fail initial chemotherapy or chemoimmunotherapy, there are more second-line choices than there are first-line choices at this stage. In patients with deletion 17p, the targeted therapies seemed to be most promising, and those include PI3-kinase inhibitors, BCL-2 inhibitors, B-cell receptor (BCR) inhibitors, and BTK inhibitors. All of these are reasonable choices in a patient like this. You do want to choose a therapy that’s likely to be active relatively quickly in a patient who has such symptomatic recurrences.
The rationale for starting venetoclax in this patient is that venetoclax is likely to lead to a response relatively quickly to alleviate the patient’s symptoms, and we know that venetoclax has a high degree of response in patients with deletion 17p.
The long-term safety profile for venetoclax is quite favorable. In fact, this is a drug that is tolerated very well by patients, and patients often feel better on the drug than they did before they started the drug. The short-term safety is the more important to be cognizant of, and that includes the risk of tumor lysis. The long-term safety concerns with venetoclax therapy are mostly hematologic, one of which is neutropenia. However, neutropenia was very easily managed for patients on venetoclax in phase I and phase II clinical trials to date.
The main concern with initiation of venetoclax therapy is the risk of tumor lysis syndrome. Tumor lysis syndrome is most common in patients with very high disease burden. And in the prescribing information for venetoclax, there are at least 3 categories listed for patients with different levels of risk for tumor lysis syndrome. In patients with the highest risk for tumor lysis syndrome, it’s recommended that they be treated in the inpatient setting where they can be monitored closely for tumor lysis syndrome, and where tumor lysis syndrome can be prevented by adequately hydrating patients with high doses of intravenous or oral fluidsbut most likely intravenous fluids are recommended—with treatment at baseline, with rasburicase in patients who have elevated uric acid levels, and with pretreatment with allopurinol to mitigate the risk of tumor lysis syndrome affecting the kidneys. In addition, patients need to be monitored closely for the electrolytes that can be out of whack with tumor lysis syndrome, especially potassium.
Transcript edited for clarity.
Case: A Young Male Patient with High-Risk CLL and Nodal Involvement