The panel continues with a discussion of the treatment options and focuses on treatment with emicizumab.
Luigi Brunetti, PharmD, MPH: Now regarding emicizumab, Hemlibra, which we alluded to, I agree with your statement that we really should be considering this for many patients or at least educating our patients, especially those with inhibitors, which we’ll talk about in a bit. But what patients do you think are the ideal candidates for emicizumab, or Hemlibra?
Robert F. Sidonio, Jr, MD: That’s the question that everybody has right now. We’ll briefly talk about that, for inhibitor patients, I think it’s clear. There’s a tremendous benefit when you talk about cost, efficacy; no matter how you measure it, there’s a benefit. And so all of our inhibitor patients are on it. There are very few adults, I can think of really 1 or 2, who did not want to switch. And so it’s relatively rare. And the benefit has been pretty tremendous for them.
For the non-inhibitor patients, it becomes a little bit more challenging. There are clearly lots of patients who are doing very well on factor VIII prophylaxis. They feel very comfortable with it. And so we still have the majority of our patients on a previous factor VIII prophylaxis regimen. As soon as it became available, we took patients who had high annualized bleed rates, if their bleed rates were about 4% to 5% or higher. These are the kids who get into trouble, they miss doses, or they’re wrestling with their brother and they come in with some terrible muscle bleeds. For those patients, we put them on it as well, and we strongly advise the families to switch.
And for the kids who have terrible intravenous [IV] access—some people just have bad veins, it’s not anything that they decided—we definitely consider putting those patients on it as well. Then we did it for some patients who were having issues where the family just couldn’t do it, or the parents didn’t want to do it and the kid was skipping doses. I know it was a little bit paternalistic, but we really don’t want them to have any life-threatening bleeding events. Or for anybody who had an intracranial hemorrhage before and is struggling to do their prophylaxis, we put those patients on it.
So the remaining patients are the standard patients who you see and you’re considering prophylaxis for. And we’ve started to consider those patients. One of the big questions is, although the risk of antibodies against Hemlibra is really rare—I have not personally seen that in our practice—there was 1 example on the clinical trial, on the HAVEN 2 trial, where the patient developed it in 4 to 5 weeks.
But the big question is, do you start an infant on it, and what is the frequency of the dosing that you would use? Typically, it would be monthly just because of the vial size. But then you have this issue about factor VIII exposure. Inhibitor development, as we were talking about before, is developed typically in the first 20 to 30 exposures to factor VIII. And so a lot of the questions that we have are do we give that factor VIII early and see if they’re going to have that risk for inhibitors? Or do we start them on Hemlibra knowing that they may not hit 20 to 30 exposures until they’re about 10 or 11 years old?
And that may be OK because if they develop an inhibitor, it’ll be easier to manage. It may be more costly, and it may not work as well, we just don’t know that question.
So we discuss this with the families. These discussions are pretty long obviously because we’re factoring in the older plasma-derived products, the recombinant products, the standard half-life and extended ones, and now we’re talking about Hemlibra. So a new patient visit is over an hour long just because of this. We often have to bring them back and it’s still overwhelming. There are many options for the family. And we want to make sure that we don’t feel strongly about 1 option or the other, so we try to give that option to the family.
Luigi Brunetti, PharmD, MPH: Yes, and I think that’s very important, not just for hemophilia but in general. Involving patients and caregivers in treatment decisions helps improve adherence and buy in to the treatment. And ultimately as clinicians, that’s what we want, right? We want the therapy that someone’s going to buy into and actually continue to receive.
In terms of the adverse event profile for emicizumab or Hemlibra, how does that compare to factor VIII?
Giles Slocum, PharmD: This a subcutaneous injection. The adverse effect profile that we’ll see with this is similar to those insulin subcutaneous injections. So wanting to make sure we rotate sites, you get those injection site reactions. It’s one of the big things we see there. We already touched on how there is that rare risk for inhibitor production as well. But those are the main things; it’s fairly well tolerated. There are some other potential issues with it that aren’t adverse event issues. It’s a unique dosing profile we’ll get into and making sure we draw up correct amounts and things like that.