Alexey V. Danilov, MD, PhD: The exploratory analysis conducted by John Seymour, MBBS, PhD, and colleagues of the GALLIUM study specifically looked at patients who progressed within 24 months of starting therapy on study. What they have found is that patients who were enrolled in the obinutuzumab/chemotherapy arm actually had lower risk of developing early progressive disease compared to patients who were enrolled on the rituximab/chemotherapy arm. That hazard ratio was about 0.46, so there was a risk reduction from 17% to roughly 10%, which is quite significant for this patient population. This is a very tantalizing result, which raises a hypothesis that the combination of obinutuzumab with chemotherapy may somehow lower the risk of early disease progression. That certainly remains an unmet medical need in the therapy of follicular lymphoma, and these are very exciting data.

Carla Casulo, MD: The GALLIUM study did an exploratory analysis to see whether the use of obinutuzumab with chemotherapy would decrease the risk of patients with early disease progression. What they found is that there were many fewer early disease events in patients who received obinutuzumab/chemotherapy compared to rituximab/chemotherapy. There were about 19% to 20% of patients in the rituximab/chemotherapy-containing group who had early progression, which is compatible with what we saw in other studies. However, with the obinutuzumab treatment, there was only about a 12% risk of early progression. It definitely did reduce the risk of early disease events, and it also reduced the risk of death by about 34% or so.

That was very compelling. Whether that’s going to influence the use of obinutuzumab over rituximab remains to be seen, but the data definitely showed that there were a decreased number of disease-related events. Why that happened, we don’t really know.

The interpretation of this is that obinutuzumab seems to somehow affect the natural history of follicular lymphoma. Again, we don’t really know why these patients had a decreased number of disease-related events, so I think that remains to be seen.

Alexey V. Danilov, MD, PhD: While it is difficult to consider this data practice-changing right now, it is certainly hypothesis-generating data, which suggests that maybe patients who are suspected to be early progressors should receive a combination of obinutuzumab and chemotherapy. The problem, of course, is that we never necessarily know who those patients are. As we discussed earlier, there are some predictive factors that could potentially identify those patients for us. However, those factors do not work with certainty. Therefore, applying this data in everyday clinical practice may be somewhat difficult. I would say that in patients who present with features that have been associated with high risk of early progressive disease, including those that I mentioned before, such as high FLIPI [Follicular Lymphoma International Prognostic Index] score, advanced stage, high LDH [lactate dehydrogenase], and high beta-2 microglobulin, I would strongly consider the combination of obinutuzumab and chemotherapy over rituximab.

Carla Casulo, MD: I don’t think, at the current time, it impacts my decision to treat patients with follicular lymphoma, because obinutuzumab-containing chemotherapy and rituximab-containing chemotherapy have different adverse effect profiles. If you have someone who’s a little older, in whom you are thinking about using bendamustine, obinutuzumab may not be your first choice, because that group of patients are more likely to experience toxicity. I think that the decrease in disease-related events alone would not suffice, in my opinion, to choose one over the other, at least now. That is something that’s being investigated.

Transcript Edited for Clarity