Sunday, February 17, 2013


OK, enough with the screaming goats. Back to the cancer stuff.

Ibrutinib is in the news. It has received "Breakthrough Designation" by the FDA for Mantle Cell Lymphoma and Waldenstrom's Macroglobulinemia. Both are B cell lymphoma, like Follicular Lymphoma. Follicular is not included in this designation, though there was a small, phase I clinical trial for Ibrutinib for relapsed fNHL, and it looks like a promising treatment, based on results presented at ASH last December.

There are two issues worth discussing here. The first is the whole idea of "Breakthrough Designation," which I only recently learned about. Basically, a new treatment gets the designation if initial clinical trial results show that a treatment will be safe and effective for patients with life-threatening diseases, especially if the treatment represents a large improvement over current treatments. So, no new cold medicines will receive this designation. But a cancer treatment? Oh, yes.

That's a big deal. Cancer treatments can go through years of trials before they are available, to make sure they are safe for patients and that they are an improvement over existing treatments. And of course, we want that to happen. We don't want something unsafe, that's going to cause as many problems as it helps. And we don't want something that doesn't work as well as what we already have.  The FDA is a good thing, even if their processes are frustrating sometimes.

But they do have programs that help get treatments to people who need them. Orphaned status. Compassionate Use. And Breakthrough Designation.

More importantly, this designation by the FDA says something pretty important about Ibrutinib: it's a kick-ass treatment.

Ibrutinib is what is known as a BTK Inhibitor. That is, its purpose is to stop the workings of the BTK, or Bruton's Tyrosine KinaseHere's what happens:

B-cells (the white blood cells that go haywire when someone has Follicular Lymphoma and other NHLs) function by attaching to invaders: bacteria, viruses, other things that don't belong in the blood. The BTK is the part of the B cell that keeps it alive. The body wants this to happen, so the B-cell can keep up its fight against invaders. Cancer, of course, happens when something in the cell tells it to stop dying and to keep multiplying.

So, some B-cells = healthy. Too many B-cells that won't die  = lymphoma.

Since the BTK is one of the things that keeps a cancer cell alive, a BTK inhibitor (like Ibrutinib) will tell the B-cell that it's OK to die. Normal B-cell levels and functions = no more lymphoma.

There are people who say Ibrutinib and other BTK inhibitors are the real game-changers in fighting NHL. As always, I will keep my optimism on the cautious side. It does a job on lots of different B-cell lymphomas (and there are a bunch of them), but it doesn't wipe them out completely, by any means. My guess is that in the next few years, Ibrutinib will be combined with some other treatments that attack the cells in different ways. So maybe not a game-changer on its own, but an important role player for the team. (The NBA All-Star game starts in a little while; the comparison seemed apt.)

Keeping that hope going.....

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