TRANSCRIPTION:
DR RUGO: That is a complicated trial. And I think that we’re all still pondering the information, which is intriguing but perplexing at the same time. So in that trial, they showed that you could have an improvement in overall survival but not a significant improvement in progression-free survival, which was their primary endpoint. We don’t see that much.
And it was pointed out at the time of the presentation that we have seen that result in immunotherapy, immunotherapy trials in other cancers. But we haven’t seen it in breast cancer. So I think, as a unique trial, it’s an interesting one. CLEOPATRA also showed a bigger impact, relatively, on survival than on progression-free survival, but they did show a big difference in progression-free survival. So it may be that, as you get farther along in the course of therapy, that adding another antibody, in this case pertuzumab, to trastuzumab doesn’t help as much in terms of disease control because you’ve developed alternate mechanisms of resistance.
Explaining that survival difference is hard, because survival is a hard endpoint. And I think we need to understand in that patient population whether there were any differences in the treatment options available to the patients on either arm before we can universally incorporate pertuzumab into later-line therapy.
Now, I will say there’s 1 take-home message, which is that in patients who haven’t had pertuzumab with chemo, it’s reasonable to try and give it in the second-line setting if they’ve gotten an alternate therapy without pertuzumab. But I think other than that, we really need to wait for more information from the PHEREXA trial, quite an interesting and perplexing set of results.
T, AC