Refining Treatment Approaches for HER2+ Breast Cancer - Episode 12
Joyce O’Shaughnessy, MD: Let’s finish on subcutaneous approaches. That’s something new. Europe was doing this a lot with subcutaneous trastuzumab for a long time. We haven’t done that much in the United States, but now we have subcutaneous trastuzumab and pertuzumab. You have fixed-dose combinations. Lisa, you could tell us about the FeDeriCa trial, and VK, the PHranceSCa trial. We can see what’s going on in the real world with your experience.
Lisa Carey, MD, FASCO: FeDeriCa was the trial that got Phesgo, the subcutaneous Herceptin plus trastuzumab, approved. It was a neoadjuvant study. They had done individual studies with each drug, and this was a neoadjuvant study. It was a decent-size study. It was 500 patients, and it was AC [doxorubicin, cyclophosphamide] followed by THP [paclitaxel, trastuzumab, pertuzumab] in the usual fashion, or AC followed by THP with HP [trastuzumab, pertuzumab] being Phesgo, which is the subcutaneous version.
Then the adjuvant phase continued whatever they were assigned to up front. They looked at pharmacokinetics and found very similar pharmacokinetics. In fact, as I recall, the trough trastuzumab levels were actually maybe a little better in the subcutaneous formulation than in the IV [intravenous] formulation. They were very similar. PCR [pathologic complete response] rates were virtually identical, right? It was basically 60% for each. They looked like they were doing well. Their cardiac signals were not particularly different. They checked off the boxes, and this is where the approval came from.
Separately, when they’ve done studies of patient preference, the vast majority of patients would prefer the subcutaneous formulation. When the cost-effectiveness people get hold of it, it’s more cost effective. There’s a bunch of reasons. I’d be interested in hearing other people. I haven’t heard of anybody having strong dissenting reasons for this move. It’s going to be good for everybody and good for cost effectiveness and quality of care.
Joyce O’Shaughnessy, MD: VK, say a few words about the old patient-preference PHranceSCa study.
Vijayakrishna Gadi, MD: You guys may have heard about this investigator by the name of Joyce O’Shaughnessy. She presented this data at ESMO [European Society for Medical Oncology Congress]. In this trial, my understanding is that patients got preoperative therapy with PH, pertuzumab-trastuzumab; got surgery; and then were randomized. Half the patients received 3 cycles of subcutaneous and the other half continued with IV. Then they switched over for the next 3 cycles. After that they got to pick what they wanted to do. This is a small study, 160 patients. There aren’t any big differences that we’re going to see within terms of events of that nature, but patients preferred it. They liked the subcutaneous: 88% picked subcutaneous when given the option about what to do to continue. Overall, we’re looking at about a fourth of the time required to do subcutaneous administration in clinic vs the full time it takes to do pertuzumab and trastuzumab together as a combination, individually in the bag.
For those reasons, as you cited Lisa, the cost is going to be lower. Less chair time means less cost. Subcutaneous is going to need different resources in the clinic. The minute the drugs were available at our clinics, our formulary looked very hard to get these onboard. This is a slam-dunk winner.
I’ll share 1 anecdote. I had a single patient who, when offered this, said, “No, I want the IV version.” I asked her why. It turned out she had a baby during therapy, and this was her only time to be alone by herself. For that patient she picked the IV therapy. Otherwise, everybody else has been subcutaneous.
Transcript Edited for Clarity