The current Journal of Clinical Oncology has the results of a study of Rituxan Maintenance in Follicular Lymphoma. In some ways, the study helps clarify the best way to use Rituxan Maintenance, though it raises some questions as well.
(We wouldn't really expect any kind of clear answer when it comes to treating Follicular Lymphoma, would we?)
The study is published in the article called "Rituximab Maintenance for a Maximum of 5 Years After Single-Agent Rituximab Induction in Follicular Lymphoma: Results of the Randomized Controlled Phase III Trial SAKK 35/0." Medical journal articles are pretty good about using straightforward titles, and this one is no different:
The article reports the results of a phase III clinical trial that looked at short-term and long-term use of Rituxan Maintenance after Rituxan induction therapy. In other words, patients were first given Rituxan for four weeks, and then if it seemed to work, they were split into two groups, with some getting Rituxan Maintenance every two months for 4 doses (or 8 months), and some getting it every two months for up to 5 years (or until they had an event). The measurement here was Event Free Survival (EFS), which is a little less common than many FL trials, which often use Progression Free Survival (which measures the disease getting worse) or Overall Survival (which measures death from any cause). EFS is a little broader, and the "events" can include death or disease progression, but also things like a secondary cancer, unacceptable toxicity, or using other treatments related to cancer.
The authors say that, while there are lots of studies that look at Rituxan Maintenance, those studies use lots of different time periods. Their aim here was to compare two different time periods directly to see which one worked best.
The plan had been to stop the study at about 5 years, with the expectation that there would have been 99 events to count. However, they stopped when they had reached 95 events, because the events stopped coming. I think that's good news -- both types of Maintenance seemed to work well.
In the end, though, they found that longer isn't necessarily better -- there was no real difference in Event Free Survival between the two groups -- neither approach seemed better than the other. There was also no difference in Overall Survival between the two groups, though the researchers want to continue looking at data for a longer time to see if that remains true.
However, the long-term group had a Progression-Free Survival that was much longer than the short-term group. (They kind of down-play this, though it seems significant to me. It's probably because their primary measure was EFS, and because the OS was the same, so it doesn't really matter on its own.)
The researchers point out several important things in their conclusion:
First, if there is no difference in EFS or OS between the two, then short-term seems the better option. It will be less expensive and cause less toxicity.
Second, there were more patients with "adverse events" in the long-term arm than the short-term. These include things like infections, which makes sense, since Rituxan kills off the B cells that fight infections.
Finally, they point out some of the limitations of their study, including their not measuring quality of life. It is possible that, for lots of reasons, long-term Maintenance could result in lower quality of life.
So in the end, the results are mixed. If anything, the study seems to back up the idea that Rituxan Maintenance can be a good thing (though they weren't trying to prove that it is better than waiting until Rituxan is needed before giving it), and the idea that short-term Maintenance is just as good as long-term, and maybe better, if you consider the cost.
Sorry, folks -- no Big Answers here. But I still feel OK knowing that even a small piece of the puzzle is being put into place.