Tuesday, July 29, 2014

Ibrutinib in 17P deleted CLL

Yesterday the FDA expanded the "label" (or the set of conditions that the drug is approved for) for ibrutinib.  See the ASCO news release here.

I think the news coverage missed the most important aspect of the change in the label.  Most of the coverage focused on the usefulness of the drug in patients with the dreaded 17P deletion (which I have written about quite a bit). The analysis was based upon the RESONATE trial (summarized here) in which the benefit of ibrutinib over ofatumumab was particularly striking and one other unpublished study in abstract form here.

Since ibrutinib is already approved for patients with "one prior regimen" at first blush, this would not change the group of people eligible for the drug.  I actually like to read the specifics of labeling information so I read the updated "label" (linked here) and was surprised that the language didn't distinguish between those patients who have been previously treated or not.

I was able to verify today that indeed, previously untreated patients with the 17P deletion are considered appropriate for the drug.  That is much bigger news than what I read.

I have a huge blog post I've been working on for some time - hopefully ready to go in next few weeks about utilizing newer molecular diagnostics to select therapy in CLL.  This new information corresponds to trends I have seen emerging where many of my CLL researcher colleagues have started using this drug in this setting.  Keep in mind, quite a few patients have abnormalities in TP53 (on 17P) and may not be aware of it due to insufficiency of current FISH testing. 

Another key trial in this population involves the recently approved idelalisib and rituximab in patients with untreated 17P deleted CLL (linked here).  In addition to those sites listed on clinical trials.gov it is also available at most of the places on this map (linked here)

Although the number of  CLL patients with 17P treated with this combination in the frontline setting is small, the overall response rate is 100% and the European Agencies have recommended frontline status for idelalisib in this setting as well. 

Thanks for reading