What exactly is high-risk chronic lymphocytic leukemia (CLL), and how is it treated? Dr. Lyndsey Roeker discusses biomarkers that indicate high-risk CLL as well as treatment approaches that may be used for targeting specific subtypes of CLL.
Dr. Lyndsey Roeker is a hematologic oncologist at Memorial Sloan Kettering Cancer Center. Learn more about Dr. Roeker here.
Katherine:
We have an audience question. Mike wants to know, “What does it mean to have high-risk CLL?”
Dr. Roeker:
So, great question, and the interesting thing is that I think the answer to that question is evolving. So, deletion of 17p, deletion of 11q, and TP53 mutation have historically been markers of more aggressive disease or unfavorable CLL. In the era where we only had chemo and immunotherapy, we know that patients had less great outcomes. We know that the treatments tended to not work as well, and patients had disease that tended to come back faster, and things like that.
That’s all evolving in the era of targeted agents. We have some indication that probably patients who have more aggressive underlying disease biology, meaning disease that’s going to behave less well, kind of regardless of what we treat it with, certainly may derive less benefit, meaning that the treatment will work for less long. That being said, these treatments are still really effective for our patients who have traditionally high-risk disease. So, I think it still remains to be seen, in terms of long-term outcomes and what to expect for patients that have these traditionally high-risk characteristics.
Katherine:
Let’s run through a few potential results so we can understand how you might approach each patient type. If someone has deletion 17p, what is the approach?
Dr. Roeker:
So, there are two totally reasonable frontline treatment options.
So, BTK inhibitors, which are – the current approved ones are ibrutinib and acalabrutinib, are completely a reasonable approach in the frontline setting, meaning the first treatment that someone gets, and those are pills that you take daily. For ibrutinib, it’s once a day. For acalabrutinib, it’s twice a day, for as long as they’re working. And the idea is, with this approach, you keep on those medicines, and they keep the disease suppressed. So, that’s the first option.
The second totally reasonable option is a combination of venetoclax (Venclexta) and obinutuzumab (Gazyva). So, venetoclax is a pill and obinutuzumab is an IV medicine, and the way that this was studied was a total of one year of therapy. So, from the time you start until you’re done with all of your treatments, that’s a one-year course. And the drugs have different side effect profiles, and depending on other medical problems, patient preference about, let’s just take a pill and that’s easy, versus the combination of pill and IV medicines, either can be a completely reasonable choice.
It just depends a lot on patient and doctor preference.
Katherine:
What about the TP53 mutation?
Dr. Roeker:
So, both of those treatment options seem to work very well for TP53-mutated patients. We had that discussion about the possibility of chemoimmunotherapy for a small minority of patients, and for patients with a TP53 mutation, using chemoimmunotherapy up front is probably not the correct answer. It’s better to go with one of the targeted drug approaches.
Katherine:
How would you approach each patient type, if a patient is IGHV unmutated?
Dr. Roeker:
So, IGHV-unmutated is the same discussion. Chemoimmunotherapy is probably not going to provide a durable, meaning it’s not going to last for a long time. We’re not going to achieve that potential cure. So, for those patients, either the BTK inhibitor approach, or the venetoclax/obinutuzumab approach is completely a reasonable one to take.
Katherine:
And if they’re IGHV-mutated?
Dr. Roeker:
IGHV-mutated patients who are young and don’t have a lot of other medical problems, that’s when we add in the third option of chemoimmunotherapy. For many patients, it’s not wrong to choose either a BTK inhibitor or venetoclax/obinutuzumab, but it does add in that third potential option of chemoimmunotherapy.
Katherine:
Are there other markers that patients should know about?
Dr. Roeker:
So, TP53 mutation status, FISH, and karyotype kind of gets you most of them. Some centers do additional next-generation sequencing of other genes that have been associated with higher-risk disease, though really understanding how to interpret those results still remains somewhat unclear, and that’s still an area of research that people are doing, to really understand what those other mutations really mean for people.
