DR FRIEDBERG: I think this is an important data set for people to be aware of. This was the large US Intergroup trial that randomized patients. Initially, it was 3 arms: CHOP alone, CHOP with rituximab or CHOP followed by iodine 131-tositumomab radioimmunotherapy consolidation. After about the first year and a half of the trial, the CHOP-alone arm was closed due to other data sets at that time suggesting the benefit of rituximab. So it became a large trial of R-CHOP compared to CHOP followed by radioimmunotherapy.
And the bottom line was that there were no significant differences in progression-free or overall survival between those 2 groups.
We did do a follow-up study in SWOG that I ran that combined, really, the 2 components. We gave R-CHOP up front, then radioimmunotherapy, and then rituximab maintenance, the “FULL” approach. That trial, because of the nature of the treatment and the maintenance portion, we’re hoping to be able to analyze in the next couple of years, because 1 big question on the table is, if we have given R-CHOP rather than CHOP, might the radioimmunotherapy have done even better? And there are arguments to make on both sides of that. Some people feel that if you give too much rituximab, you might limit the effect of radioimmunotherapy, but at any rate, that’s how this trial turned out.
DR LOVE: I’m just kind of curious about exactly how you use this treatment strategy, if at all.
DR VOSE: Neil, unfortunately it’s very underutilized, I think, sadly, because in some cases it’s actually pretty good treatment. But the case where we typically might use it would be an older-age patient and use it as an alternative to rituximab maintenance based upon the trial that we just talked about because it seems to be at least an equivalent option. And they have 2 trips to the doctor. They’re done with the treatment, and then they don’t have to come back continuously like with rituximab maintenance. So that would be kind of the situation where I might use it.
DR LOVE: Mike?
DR WILLIAMS: Yes. We use it in a very similar manner for older patients, where a very quick, concise therapy is beneficial. The other place where I think it needs to be thought of is especially the older patient who has a partial response to front-line therapy. The data from the FIT trial showed that those people had a considerable benefit from radioimmunotherapy as a consolidation after their initial induction. So a PR to initial immunochemotherapy can benefit a lot from the RIT.
DR LOVE: I just want to follow up, though, if I understood Julie correctly. You were saying that you would think, for example, if you had an older patient, travel issues, et cetera, who got R-chemo and, say, BR, that instead of R maintenance you would use radioimmunotherapy?
DR VOSE: Yes. I think the data would support that. Of course, none of the patients who got BR in this trial — they were CHOP-R.
DR LOVE: Right.
DR VOSE: But I think the data would support that. And I have used that.
DR LOVE: I’ve got to say, again, I’m not sure I’ve heard that one before. Mike, what do you think about that idea?
DR WILLIAMS: I think it’s a good option for patients.
DR LOVE: Interesting.
DR EVENS: That was the FIT study, where they randomized. It was not — most of the patients didn’t receive rituximab up front, only 15%.
DR LOVE: Right.
DR EVENS: A little bit apples to oranges, but it looked similar benefit to RIT maintenance versus 2 years of rituximab maintenance.
DR LOVE: I just wasn’t aware that people actually were doing that. Do you do that?
DR EVENS: I don’t. I don’t. But I am a big radioimmunotherapy fan generally. And I’d echo what Julie mentioned. Incredibly underutilized. And there’s — probably could do an hour on what are the reasons why, not as easy to use. It has to be given by Nuclear Medicine often. But I don’t reserve it just for older patients. I mean, I commonly use it second or third line. And when you look at the data, including in rituximab refractory, you have response rates over 70%, CR rates of about 15% and median progression-free survival of 8 to 10 months, which, frankly, if you match it up to bendamustine for 6 cycles is similar in potency. And it’s obviously incredibly easy to give, very well tolerated. So I use it very commonly second or third line.
DR LOVE: So Jon, I’m curious what your thoughts are about what you’ve heard, particularly this idea of replacing R maintenance.
DR FRIEDBERG: Right. I have used radioimmunotherapy as consolidation if there are aggressive elements in the tumor. There’s some older data that radioimmunotherapy has activity in transformed disease. So an approach to transformation or a follicular lymphoma with some elements of diffuse large B-cell lymphoma could be R-CHOP followed by radioimmunotherapy. I’ve done that.
DR FLOWERS: I tend to use it in the relapsed setting in the same way that Andy described. I’ve discussed it in consolidation much like what Julie and Jonathan mentioned but have had relatively few patients that have used this as a consolidation approach. But I think the data from the FIT trial strongly support that.
There are older data that Stephanie Gregory presented some years ago combining data from a number of trials that show that just like other therapies, the earlier that you use radioimmunotherapy, the better it works. And so we tend to use it in the second- or third-line setting. And it’s a very easy-to-tolerate therapy for patients that are able to get through it.