Leukemia and Lymphoma Connect recently hosted a question & answer session with Oncologists around Bruton's tyrosine kinase (BTK) inhibitors. Below are some highlights from the session:

Respondents noted positive experiences using BTK inhibitors for the treatment of CLL & MCL; however, treatment costs and prior authorization requirements were noted as potential burdens.

• “I have a good experience with the BTK inhibitors in general. Specifically, regarding efficacy, many of my patients with CLL and MCL have had a good response, particularly in CLL that had long-lasting response.”
• “My experience has been quite good, especially in first-line setting. Patients seem to have a very excellent durable response lasting for many years.”
• “Multiple patients of mine have asked to stop treatment after 1 or 2 years of treatment, even though it's effective and they tolerate treatment well because they cannot afford the co-pay…”
• “We'll have to do a prior authorization usually. Sometimes the medications are expensive. We may need to get them some copay assistance or some foundation assistance, so they may have some copays, or we may have to go to the company to help figure out how to get it for them.”

Respondents shared varying experiences regarding their use of BTK inhibitors for conditions other than CLL or MCL.

• “I have used BTK inhibitors in chronic graft-versus-host disease. That is probably the space I use it the most in outside of CLL and MCL. It was the first drug approved for the treatment of chronic GVHD, so that's kind of where I've used it. I find it to be potentially not as effective as it is, say, in other disease states, though chronic GVHD is very challenging to treat.”
• “I have not used it for small lymphocytic lymphoma or chronic GVHD.”

Several respondents noted they counsel patients regarding the indefinite nature of treatment with BTK inhibitors.

• “I mention that the fact that we can treat until progression means that the treatment is safe and well tolerated enough to allow for indefinite treatment until progression, and I find that many patients like that rationale, understand the rationale.”
• “I tell them to expect that they could potentially be on it for a long time and that they could potentially do well, but then I don't have a particular time in which I expect them to stop it and that every time we see them, we continue to evaluate the risks and benefits of it. But as long as they're tolerating it well, I expect that they'll continue treatment almost indefinitely.”

Some respondents indicated they were excited about the future of non-covalent BTK inhibitors, while others were taking a wait-and-see approach, with more evidence needed.

• “They seem to be able to still reverse the inhibition of the BTK pathway and become effective again in the treatment of both CLL and mantle cell lymphoma, and it is hopeful that when they get approved I'll look at the clinical data, but the initial preliminary data that's coming out suggest that you can re-challenge patients who have failed standard covalent therapy with these new approaches and may have an opportunity to overcome the resistance that has occurred with the BTK inhibition, and I await further decisions pending clinical approval by the FDA.”