Decisions on Choosing LHRH Agonists for Treating Prostate Cancer

Transcript:Raoul S. Concepcion, MD: Again, I think there is this misconception that all LHRH agonists are the same. You use one, you use the other, it doesn’t really make any difference. And, I think for most community practices, the decision about what LHRH agonist to give is really based upon cost, trying to limit the number of choices, not trying to let each individual physician choose their own. From a business model standpoint, it’s just easier to say we’re only going to offer this particular brand. Some of the companies have better monitoring schemes for inventory, those types of things. But, let’s get back to, again, this concept that, potentially, this Atrigel system may actually have some benefit in having lower levels of testosterone. How does that play into your thinking in terms of, is there enough evidence there that you believe that that may actually be a superior product, whether we’re talking about biochemical recurrence or clearly in the metastatic castration-resistant prostate cancer patient?

Daniel R. Saltzstein, MD: Well, I think we discussed earlier about how we know the duration of action is probably longer than in the 7.5 mg dose, so we know it potentially lasts longer. If a patient accidentally misses an appointment, you still get good coverage and their testosterones are still castrate. But, I think Neal Shore is going to present some data here, pretty soon, that’s also going to show when they looked at their 7.5-mg dose and the 1 month, the 3 month, the 4 month, and the 6 month that they were able to achieve castration; again testosterone less than 20 in 90%, even higher, maybe 92% of the patients across the board. And, I think that differs from goserelin. I think that difference for just leuprolide acetate was maybe 70% in some of their older data. Now, again, it’s not a fair comparison because it’s not a head-to-head trial. It’s more just the trial from Eligard. And, again, from a practical standpoint in a community urology practice, we have to make sure, inventory wise, how we purchase the product, number 1. Number 2, we also have to look at safety, efficacy, and whether we’re going to achieve what we want scientifically. And, then, the most important aspect is how we’re able to make sure that our medical assistants aren’t given the drug before it’s time. And so, each of these companies has developed a monitoring system to make sure that we don’t infuse a drug before, otherwise we are stuck with the cost of the product.

Raoul S. Concepcion, MD: What about subQ versus IM?

Daniel R. Saltzstein, MD: Again, I think the IM is tolerated a little bit better. You would think it would be the other way, but there is a significant monocyte reaction with the Eligard. They do develop a little knot, a little redness. Usually it’s, in my estimation, very minimal. But, when you look at it across the scale, it’s probably less tolerated than the IM injection.

Raoul S. Concepcion, MD: I think it’s interesting. When you look at all the data in terms of how this developed going back to Shalley back in the 80s, and even some of Marc Garnick’s early data, everything is based on 28 days. But, yet the reimbursement scheme, you can’t give it before 30 days. And so, again, these very subtle sustained levels, lower levels for a prolonged period, is it going to make a difference potentially? Is it enough to again drive your clinical decision making?

Daniel R. Saltzstein, MD: Again, I think Ash discussed this. We don’t really know the data on microsurges and what the outcomes are. Again, in my gut, I think that it probably makes a difference if you can keep them castrate at 20 continuously versus having them escape that level. I think that makes a huge difference.

Raoul S. Concepcion, MD: I was actually surprised when I saw the Eligard data early on that they’ve always shown that they have continuous lower levels of testosterone less than 20, even less than 10 versus your traditional leuprolide acetate.

Transcript Edited for Clarity