Brad S. Kahl, MD: One of the more important abstracts presented at ASCO [American Society of Clinical Oncology Annual Meeting] this year was a head-to-head trial, acalabrutinib vs ibrutinib in previously treated CLL [chronic lymphocytic leukemia]. Dr John Byrd presented this in the oral session. This was a big trial, it had over 500 patients, and patients were randomized to ibrutinib vs acalabrutinib. Acalabrutinib is a so-called second-generation BTK [Bruton tyrosine kinase] inhibitor, so this trial is called ELEVATE-RR. This was the first presentation of the results.

The 2 patient populations were perfectly well balanced for baseline characteristics. With regard to efficacy, the 2 drugs performed very similarly. There’s no difference in the progression-free survival. The median for each drug came in at 38 months. Remember, this was a relapsed/refractory population, so the efficacy isn’t as good in relapsed/refractory disease as it is in front line. At 38 months is how both drugs performed for median progression-free survival. Acalabrutinib was deemed noninferior based on that, statistically.

When you start to look at tolerability issues, you start to see some advantages to the acalabrutinib. There was less risk for atrial fibrillation and atrial flutter with acalabrutinib. There was less risk for hypertension with acalabrutinib. These were statistically significant and clinically meaningful differences. There was also a better safety profile for acalabrutinib when it comes to bleeding events, diarrhea, and arthralgia. Acalabrutinib was a little worse than ibrutinib when it comes to headache and cough. When you look at the whole data set in total and look at the whole package, the conclusion of the investigators was that acalabrutinib is preferred over ibrutinib because efficacy is comparable and tolerability is better. I agree with that conclusion.

TRANSCRIPT EDITED FOR CLARITY