Michael Jordan, MD, Differentiates Emapalumab Treatment in Pediatric Patients Versus Adults with HLH

As a pediatrician at the Cincinnati Children’s Hospital Medical Center, Michael Jordan, MD, often sees pediatric patients with primary hemophagocytic lymphohistiocytosis (HLH), which recently received emapalumab as its first US-Food-and-Drug-Administration (FDA)-approved drug this past November.

Before presenting data on the open-label pivotal study that evaluated emapalumab for the treatment of primary HLH, Dr. Jordan sat down with Rare Disease Report^® at the 60th ASH Annual Meeting & Exposition in San Diego, California, to discuss the key differences between treating pediatric and adult patients with HLH.

[Editor’s note: Transcript is slightly modified for readability.]

Jordan: “I'm a pediatrician, so I really only treat children, but I consult and confer on many cases, including cases of HLH in adults. There are a few fundamental differences.

We're talking about treatments right now, and 1 big difference—in terms of treatment—is the treatment regimens developed for HLH really were developed in very young children, and so their ability to tolerate the chemotherapy and the steroids in that regimen is actually much better than it is in adults. [When they] get the same sort of treatment, [theu] actually do very poorly. It's very, very toxic for them. It's really difficult with conventional therapy for adults to tolerate the therapy.

Additionally, in children, the disease is mostly due to inborn errors of the immune system. The immune system can't regulate itself. When we get infections or other sorts of things that turn on the immune system, they have a really hard time controlling that. In adults, it's still possible. [However], most of the time, what actually is causing HLH is malignancy.

Malignancy, in itself [and] in ways that are not fully understood, can drive the immune system to activate, and it can sometimes mimic an overactive immune system. Many adult patients with HLH actually have malignancies, whether they’re known or yet to be discovered.

Currently, treatment in adults is based on treatment in children. What most people do is they treat similarly, but [they] sort of back off on the dose and the intensity of the dose, or the frequency of the dosing.

Emapalumab is actually approved for treatment of primary HLH in both children and adults. As I mentioned, most of HLH in adults is what people would classify as secondary—so secondary to malignancy or some other things on that list. It's unclear how emapalumab may be used in those patients, but it is actually approved for use in adults with what's called primary HLH, [which] is sort of an HLH that’s a bit more related to inborn errors in the immune system.

One additional difference between caring for children and adults is that when you care for children, you also need to care for their parents because they're going through the process as well. It's frequently harder on the parents than it is on the child.”