Novel Strategies for HER2+ Metastatic Breast Cancer; Biosimilars

Transcript:Adam M. Brufsky, MD, PhD: Speaking of novel strategies for HER2+ breast cancer, there have been a number that are very, very close now to clinical application, approval by the regulatory authorities. And the first of those I want to touch on is biosimilar trastuzumab. I know, Hope, at this year’s ESMO meeting, you’re going to talk more about that. You had one presentation at ASCO this year. Can you fill us in on where we are with that?

Hope S. Rugo, MD: So, the whole idea of biosimilars to me is quite exciting. We have already approved biosimilars for the treatment of autoimmune diseases, and now, for supportive care with filgrastim. And the idea with biosimilars is that you’re actually creating an agent that is biologically similar, and it’s different from these small chemicals, like letrozole, where you can just make it and put it into the market because chemically it’s the same. These actually have big regulatory guidelines for how they’re going to be demonstrated to be similar, not more immunogenic and relatively safe. So, you want similar safety. We studied biosimilar trastuzumab in comparison to commercially available trastuzumab in combination with a taxane of choice as first-line therapy for metastatic HER2+ breast cancer, and showed equivalent response rates, which was the primary endpoint.

The initial response rates were at 24 weeks, which was the primary endpoint, but our secondary endpoints included progression-free survival and overall survival, which we’re presenting at ESMO, and they’re also equivalent. But, what’s important is we’re nowhere near overall survival median, which is certainly encouraging at 48 weeks because we shouldn’t be. And PFS, actually, we haven’t even gotten to the 50% event. So, it looks really good, and we also have shown no additional immunogenicity, cardiac toxicity. Safety is similar, and I think this will lead to approval of biosimilar trastuzumab in Europe, where the patent is already done for the commercially available trastuzumab, and later in the United States. But, most importantly, I’m hoping that the competition will lead to a better cost and then better access for trastuzumab around the world. I think it’s always surprising to us to see how few countries really have access to trastuzumab the way we use it. There also will be a neoadjuvant trastuzumab that will be presented and show equivalent results, as well, at the same poster discussion session at ESMO.

Adam M. Brufsky, MD, PhD: So, in Europe, gentlemen, do you think that biosimilar trastuzumab will become the standard of care, once approved?

Ahmad Awada, MD, PhD: In my country, I can say that the authorities encourage using biosimilars for financial reasons.

Michael Untch, MD: Provided that the safety and efficacy are similar, the answer is clearly, yes, because, obviously, our economies need those kind of new drugs if they have the same efficiency. But, I would wait for the results. I still believe, Hope, what you are telling us. You are giving us, I think, a presentation, but I want to see the data.

Hope S. Rugo, MD: I think what’s really important here, to me, is the competition that will reduce the prices, and that’s going to be critical for these countries where they have access to 9 weeks of adjuvant trastuzumab and that’s it, or none, and you have to pay out of pocket. This is a drug that saves lives and we need to make it more available.

Transcript Edited for Clarity