ASH Preview: Rituxan Maintenance

Another ASH preview: This one is for "Long Term Follow-up of the PRIMA Study: Half of Patients Receiving Rituximab Maintenance Remain Progression Free at 10 Years."

The PRIMA Study has been looking at the long-term effects of Rituxan Maintenance on Follicular Lymphoma for a while now, and this presentation will look at how patients have been doing after 10 years.

Rituxan Maintenance has been fairly controversial in the Follicular Lymphoma community. It's one of those topics where enthusiasm kind of flip-flops with every new study. One study will find a benefit to it, and then another will show that the benefit wasn't as great as it seemed, or that there were new drawbacks. But neither side has shown enough evidence to make everyone agree on a definite Yes or No to Maintenance.

The PRIMA study looked at FL patients who were given Rituxan + chemo (mostly CHOP, but some CVP or Fludarabine) as an initial treatment, between 2004 and 2007. This was followed by half of the patients (505 of them) being given Rituxan Maintenance (every 8 weeks for 2 years), and the rest (513) getting no Maintenance. There have been follow-up studies of the patients at 3 years and 6 years, and now at 10 years.

The results certainly back up a benefit for R-Maintenance. Those who received it had a median Progression Free Survival of over 10 years. For those who didn't get it, the median PFS was just over 4 years. At the 10 year follow-up mark, 51% of the Maintenance patients had not had their disease progress, while only 35% of the non-Maintenance patients had no progression. The median time to a new treatment was just over 6 years for the non-Maintenance group (that is, it took that long for half of them to need treatment), while the Maintenance group hadn't yet reached the median.

One of the arguments against R-Maintenance is that it means patients are being treated for a long time when they haven't necessarily shown a need to be treated. They might have a clean scan, but continue to get Rituxan anyway. Some argue that this could result in over-treatment, with unnecessary side effects and potential long-term problems. 

The argument that the researchers make here for the value of R-Maintenance is that, because Follicular Lymphoma patients are living longer, it's worth the risk of giving Rituxan for two extra years. If it means patients will then not need treatment for another 8 years (at least), it frees them from the side effects (including developing secondary cancers) that might come if they had to go through another round of chemotherapy or other treatment. It's a compelling argument.

On the other hand, despite the longer PFS, there is no Overall Survival benefit to Maintenance. Both groups had a median OS of about 80% at 10 years. There is a group of people in the FL community that says, while extended PFS is nice, Maintenance doesn't make anybody live longer, and that's really the ultimate goal. So maybe the extra cost, time, and potential side effects of the Maintenance aren't worth it.

I'm still on the fence about it, for what it's worth. I do think that OS is ultimately what we are all aiming for. But as someone who has managed, with just Rituxan, to go almost 8 years without further treatment, I can say that it's pretty nice to not have to stress out about going to the treatment room. There's certainly a Quality of Life argument to be made here. Patients who can go for years without further treatment? That's a worthy goal, too.

The ASH conference is always followed up with commentary from experts, and I'll be very interested to see what the experts have to say about this. Will some of those anti-Maintenance folks come around and change their minds? Will they point out something in the data that we can't see right now by just looking at the abstract? I have a feeling this is going to be one those presentations that gets lots of attention.

ASH is coming up very soon -- it starts next week. We won't have to wait for long to hear from real experts (and not just Cancer Nerds).