Choosing a Hairy Cell Leukemia Treatment That Fits a Patient's Life

Dr. Kerry A. Rogers, a hematologist-oncologist and associate professor of internal medicine at The Ohio State University Comprehensive Cancer Center – James, treats hairy cell leukemia, chronic lymphocytic leukemia (CLL) and autoimmune hemolytic anemia. CURE spoke with her about how she helps patients choose a treatment, a real-world study of the targeted drug vemurafenib that she and colleagues at Mayo Clinic will present at the American Society of Hematology (ASH) annual meeting in December, and what she wants patients to know.

This transcript has been edited for length and clarity.

CURE: What drew you to hairy cell leukemia?

Rogers: I'm a hematologist at The Ohio State University, and I work in three main diseases: chronic lymphocytic leukemia, hairy cell leukemia and antibody-mediated hemolysis, which is autoimmune hemolytic anemia, both from warm autoantibodies and cold agglutinin disease. I've really enjoyed my work in hairy cell leukemia because it's such a special patient population, and the science of what we're doing to advance the field is so engaging.

There were two main things I focus on. One is that I thought the biology of the disease was interesting, and I really liked the patient population. I enjoy taking care of people with chronic leukemias because you get to help people live their best possible life over their lifespan. We can't currently cure hairy cell leukemia, so I like helping people have their disease interfere with their life as little as possible.

The other major thing that led me to do research in hairy cell leukemia is the scientific community. Even though it's a very rare adult leukemia, the effort from physicians, laboratory researchers and patient advocates has led to really interesting science and a really nice community of people trying to improve the lives of people living with hairy cell leukemia. That makes it a very special disease to work in.

CURE: What does care look like for patients with hairy cell leukemia in your clinic?

Rogers: I see people with hairy cell leukemia both when they need treatment and when they're on observation, either before or between treatments. There are important aspects of care that aren't just treating the disease, like supportive care. People with hairy cell leukemia live at a higher risk of infections and other forms of cancer, so we always review whether people are getting skin cancer screenings, and we recommend that.

There are good standard treatments for hairy cell leukemia, but there are also things we're still trying to learn as a field, and some people can get what is hopefully a better or more effective treatment by joining a clinical trial. So I like offering people both standard-of-care options and clinical trial options. Which treatment is right for someone usually depends on their disease features, which treatments are available, whether they've had treatment before, and their interest in and ability to take part in a research study. We do not have any placebo-controlled studies, so every option is a treatment that I think will be effective for the person.

CURE: Can you walk us through your recent study?

Rogers: Dr. Sameer Parikh and I have done a retrospective cohort study that includes patients at Ohio State and Mayo Clinic. Dr. Pomerantz, an internal medicine resident who works with him at Mayo Clinic, is really leading this effort. We put our resources together to look at the experience of people treated with vemurafenib.

Vemurafenib is an oral targeted drug that blocks a mutant form of a protein called BRAF, specifically BRAF V600E. It's highly effective in hairy cell leukemia and has been used in research trials. We've also used it off-label, because the drug is approved for melanoma but not hairy cell leukemia. It is in the NCCN guidelines, which are the U.S. guidelines for how cancers are treated, so we can prescribe it for hairy cell leukemia.

We have 53 patients between our institutions who were treated with it outside of a clinical trial. We wanted to look at why physicians chose the BRAF inhibitor, how well it worked and what side effects patients experienced, to inform the field about how we're actually using it in practice. That data will be presented at the ASH meeting in December. We're still doing some of the analysis, but we both think it adds good information, because it looks at the real-world way the drug was used. That can help other physicians use it better for their patients.

CURE: How does your work on chemotherapy-free treatment in CLL shape how you think about hairy cell leukemia?

Rogers: CLL is the most common adult leukemia, meaning more adults are living with CLL than any other form of leukemia, so it's a very different number of people compared with hairy cell leukemia. In CLL, multiple randomized phase 3 trials have shown that targeted drugs, both BTK inhibitors and BCL2 inhibitors, are more effective than chemoimmunotherapy, which is traditional chemotherapy given with an antibody. So we know the targeted drugs are safer and more effective there.

In hairy cell leukemia, we've seen a lot of evidence that targeted drugs without chemotherapy can work very well, like vemurafenib. We also led a study of a BTK inhibitor called ibrutinib, and we're participating in a study of venetoclax, a BCL2 inhibitor. So we know some of these targeted drugs work, but we don't yet know that they're more effective for patients than chemotherapy. Cladribine and pentostatin, with or without an antibody like rituximab or obinutuzumab, are extremely effective therapies. I don't think we're at the point of saying targeted drugs are better or safer than chemotherapy, but they are good options. The CLL experience makes me very willing to study them to see if they will be better.

CURE: How do you decide which approach is right for a patient?

Rogers: I personally think it's somewhat patient specific. Some people living with hairy cell leukemia might benefit more from chemotherapy and some more from targeted therapy, so you have to select the right therapy for that person.

For example, some people find out they have hairy cell leukemia when they have an infection, including life-threatening infections. In those cases, you wouldn't want to give a chemotherapy that's going to really suppress the immune system. You can use a targeted drug like vemurafenib to treat the leukemia and let the immune system recover, and then maybe use a purine nucleoside analog like pentostatin or cladribine later on. Then you might have someone who is healthy, doesn't have infections and wants what will give them the longest remission we know of, which right now is cladribine with rituximab, a regimen called CDR. Having a discussion with someone is the way to select the best treatment for them.

Participation in clinical trials is what's going to resolve this for us. In both the United States and Europe, there are trials comparing a vemurafenib-based therapy with a cladribine-based therapy. The Italians are doing one, and Dr. Jae Park in the U.S. is leading a study, open at Ohio State, that randomly assigns people to vemurafenib-based or cladribine-based treatment as their first treatment. That will help us learn the differences between chemotherapy and chemotherapy-free treatments in how long they work and their side effects. Studies that were completed a while ago in CLL are now ongoing in hairy cell leukemia, which is really exciting, and I'm glad we can offer that study to patients at Ohio State.

CURE: Can you share an example of when a targeted drug made a difference?

Rogers: I can't share specifics about my own patients, but I can talk about a patient I know of. I have friends from internal medicine residency, and we have a group text. During the pandemic, one of my friends was working in Seattle and had a patient who had been in the ICU with severe COVID-19 for a long time. Well into that ICU stay, they learned this person actually had hairy cell leukemia. They rightfully thought it wasn't appropriate to give chemotherapy to someone critically ill from a prolonged COVID-19 infection, because it suppresses the immune system, especially against viruses.

She asked in our chat whether anyone knew how to help, and I ended up talking with one of her colleagues in hematology and oncology in Washington. They were able to get the patient vemurafenib. It effectively treated the hairy cell leukemia, and he recovered from COVID-19 and was discharged to a rehab facility.

One thing I really like is that sometimes I'm able to help people I don't even know. Her colleague, who was great, didn't know this was a use of vemurafenib that could help, and after we talked she was very excited to have an option for her patient. But if my friend hadn't asked, I wouldn't have been able to connect with a physician on the other side of the country. That's one of the reasons I like working in hairy cell leukemia. You can make a big impact. Because the disease is so rare, other physicians who haven't seen it before really want to help their patients but aren't always sure what the options are.

CURE: What would you say to a patient who is worried about side effects?

Rogers: Side effects are a major concern for a lot of people, and that's important. Even though cladribine and pentostatin are cytotoxic chemotherapies, you don't get some of the side effects people expect. You don't really see alopecia, the technical word for hair loss. You can see nausea, but it usually doesn't last beyond a day and is usually controlled with medication. In many cases, you don't see the peripheral neuropathy people think of with chemotherapy for other cancers. But you do see fatigue, low blood counts and infection risk. So it's important to talk with patients about the realities of this type of chemotherapy, because what they're picturing, based on family members who had chemotherapy for other cancers, often doesn't match.

With targeted drugs like vemurafenib, people think, "It's not chemotherapy, so it's going to be safer or easier to take." In some ways that's true. Vemurafenib suppresses the immune system less, and you can see faster blood count recovery. For patients with infections, that's huge. But it can still cause some really difficult side effects. It can cause joint inflammation or swelling so severe that people can't function until we reduce the dose, stop the drug or treat it with something like steroids. It can also cause full-body rashes that are very troublesome for patients.

One of the best things to do is have a very realistic talk about any drug a patient is considering: what the most serious side effects are, even if they're rare, and what the common ones are. Then make sure they know that if they have a side effect that isn't acceptable to them or really affects their life, we'll help them through it or change treatments if we need to. That doesn't happen very often, but it's important to acknowledge that side effects are meaningful.

CURE: What is the most important thing patients with hairy cell leukemia can do?

Rogers: Make sure you get educated on what's important for this type of leukemia. Sometimes if you read general information about leukemia, you end up thinking, "Oh no, I can't eat fruit anymore," when that's not really a thing. That's for people getting intensive treatment for acute leukemia. Or people worry that because they need treatment, they're going to die of their leukemia, when in most cases that's not true.

So learn about your specific type of leukemia, and then think about what matters most to you in your life. Sometimes it's being able to care for small children, so you don't want a treatment with a lot of visits. Sometimes it's finishing treatment as quickly as possible to get back to what you were doing. Sometimes it's doing everything you can to maintain your health outside of the leukemia when you don't need treatment. Treatment is always going to have some impact on your life. But when you're thinking about what's right for you, think about what's most meaningful to you for the treatment experience, and have an open talk with your doctor about that.

CURE: Is there anything else you want patients to know?

Rogers: Hairy cell leukemia has an excellent community of patients and patient advocacy, especially through the Hairy Cell Leukemia Foundation, and a great scientific community of physicians and laboratory researchers working on this disease. Some people don't want to be involved in that or meet others living with their condition, and that's OK. But I've seen a lot of people benefit from engaging with this community. With a rare cancer, people can feel isolated or less connected to others who share similar experiences. So I'd really like people to know that even though hairy cell leukemia is rare, a lot of people care about advancing the field and making things better for people with hairy cell leukemia.

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