Saturday, July 16, 2016

Rituxan Maintenance (It's Back)

Follicular Lymphoma, as most of us know, is a cancer with few answers. There are lots of questions (like the basic, "Which treatment is the best one?"), but 12 oncologists will give you 13 different answers. (I stole that line from Dr. C, the lymphoma specialist I saw years ago.)

Rituxan Maintenance is one of these FL-related issues with more questions than answers. There are a bunch of studies that have been done since I have started paying attention to these things, and they seem to go back and forth -- one will have evidence that RM is a good thing, and then another will say it's more bad than good. And still another will say is does some good, but it isn't necessary.

So it's hard to know what to make of Rituxan Maintenance. (And if you need a reminder of what it is and how it works -- and more detail on the controversies of whether it's worth doing -- here's Lymphomation's take.)

The most recent addition to the long conversation about Rituxan Maintenance comes from the journal Cancer, in an article called "Randomized phase 3 study in low-grade lymphoma comparing maintenance anti-CD20 antibody with observation after induction therapy: A trial of the ECOG-ACRIN Cancer Research Group (E1496)."

The study is a follow-up on a trial from the ECOG-ACRIN research group, which actually began the trial long ago (the fact that patients in the trial were given CVP chemotherapy is kind of a clue for me that this trial started long ago). Their initial finding was that Rituxan Maintenance increased Progression-Free Survival -- the time it takes from treatment until the disease comes back again. So patients who had RM went longer before another treatment than patients who just had the chemo and then observed.

For this study, several years later, they wanted to see if that benefit held up, and if any other benefits (like increased Overall Survival) came through.

So after receiving CVP chemo, 158 patients were given RM (Rituxan once a week for 6 months), and 153 were just observed. After a median of 11.5 years, they found that the Progression-Free Survival benenfit remained: RM patients went almost 5 years before needing treatment, while patients without went 1.3 years (that's a median time for both).

However, there was no difference in Overall Survival between the two groups. So Maintenance might give you a few years before you need another treatment, but you will live the same amount of time whether you get RM or not. This is pretty much in line with other Rituxan Maintenance studies, which find some benefit, but not an OS benefit -- at least not one that's great enough to say Maintenance is a good idea for everyone.

I like their conclusion, that RM "should be considered optional" for patients with indolent lymphoma.  There is some benefit, obviously, and someone who wants to hold of on another treatment within a couple of years might consider it.

As I have said before, studies about Rituxan Maintenance don't really give us answers. It seems like, if we wait a year or so, some other study is going to tell us something that might say the opposite of this.

I'll be very interested when, in a few years, we have enough of an understanding of Follicular Lymphoma biomarkers that we can look at a genetic sample and say with a little more likelihood that some patients will benefit from maintenance and some won't get much out of it.

I'm confident that we'll get to that point sometime soon. Until then? "Optional."

(At least until the next study that tells us that we should all do it.........)

1 comment:

Mark Sutter said...

The maintenance frequency as described seems more aggressive than in other studies ("So after receiving CVP chemo, 158 patients were given RM (Rituxan once a week for 6 months)" or was the program once a month for six months?