Treating Recurrent Pericarditis With Rilonacept and What Future Research May Entail

In an interview with Pharmacy Times®, Jessica Farrell, PharmD, clinical pharmacist in the Division of Rheumatology, Albany Medical Center, and faculty professor in the Department of Pharmacy Practice, Albany College of Pharmacy and Health Sciences, discussed a recent abstract presented at the 2024 American College of Rheumatology Convergence, which evaluated rilonacept (Arcalyst; Regeneron, Kiniksa) as a treatment in recurrent pericarditis. Future research, Farrell suggested, could investigate the safety and feasibility of combining rilonacept with other immunosuppressive therapies (eg, biologics) in recurrent pericarditis as well as explore underlying causes of the disease with systemic Sjögren syndrome.

Pharmacy Times®: In a recent study, you sought out a standardized approach to treat recurrent pericarditis. For what reasons was rilonacept chose as the study drug?

Jessica Farrell, PharmD: Our abstract that we presented at the American College of Rheumatology [Convergence] this past November, was really just looking at our patient population that we have at our institution that are being treated for recurrent pericarditis. So, rilonacept (Arcalyst; Regeneron, Kiniksa) was approved for recurrent pericarditis...in 202[1], and [prior] to that, we [would] in patients...whoever may be refractory to those first-line options or had contraindications because of comorbidities, we would we would use interleukin (IL)-1 inhibition with anakinra (Kineret; Sobi), [which] is not FDA-approved for pericarditis. It is a daily injection, and some patients can have—[though] it works very well—injection site reactions to it, so that can be an issue. And then the other issue is access. So, it's an off-label indication, it's a specialty drug, so, a lot of times it requires fighting with the insurance company to get access to that. In our service at Albany Med, the rheumatology team, the physicians, cover the consult service, and at the hospital, we have anakinra on formulary, and that's our IL-1 inhibition that we can offer for patients that fit that category. But transition them outpatient, we—for many reasons—because of the access issues and because of the daily injections with anakinra, we started to transition our patients over to rilonacept. And that's really why, for a couple of those reasons, rilonacept is a weekly injection. So, you do a loading dose on day 0 and then it's a weekly one[-time] injection once a week.

Pharmacy Times: Was there anything notable about the study and its findings? What will you investigate in further research?

Farrell: I don't think there was really anything surprising. The patient population was pretty consistent with what we expected. We are rheumatology, so our patient population had a higher incidence of underlying autoimmune diseases, obviously. At some institutions, I imagine that cardiology gets consulted, and those might be more primary pericarditis or they don't have an underlying autoimmune disease.

The one thing that I think is surprising, is that...we were able to follow patients long enough where we did have patients that were in remission, so their pericardial effusion—if they had one—or symptoms resolved, and then we treated them, one of the focuses was really looking at how long do we treat these patients, and if we stop treatment with an IL-1 and inhibitor, do they get a recurrence of their pericarditis? And that was something that we were able to follow some patients long enough where we were able to taper them, and a majority of patients did well with tapering, but we did have a couple patients that did have recurrence and had to be restarted on the rilonacept. So, the question really, I think, in the literature and now that we have this "disease-modifying" therapy, is do you need to treat pericarditis indefinitely, and will patients have flares? The theory, I think, is that if it's viral-induced, once their immune system kind of gets reset and calms down, then it won't reoccur, but we really don't know. It's difficult to know the underlying cause, so you're treating patients almost empirically, and kind of seeing how they do.

And then, we have a couple patients—I just saw 1 in clinic last week—who are really anxious to come off their therapy. So, one of our patients is tapered out to 1 injection every 3 weeks, and he's...very nervous to come off of it. So, those are kind of the things that we wanted to look at in the trends within our population.

[As far as future research,] one of our clinicians has a strong interest in recurrent pericarditis, and we have a large patient population with Sjögren syndrome...there's still a lot like systemic Sjögren syndrome that we don't know about, and we don't have as much data to characterize those patients that if [the syndrome] is the underlying cause of their pericarditis or not, so that'll be interesting.

The other piece is—and this is a question I get a lot—in my experience...I've been in rheumatology for 15 years, so I've seen a lot with these medications, the different biologics and we have a lot of drugs that are immunosuppressive...in IL-1, [for example,] with anakinra, it's a very short-acting therapy and we don't really consider it immunosuppressive, so, you can add it on to other therapies. [For example,] say you have a patient [with lupus] who is on mycophenolate mofetil (CellCept; Genentech), you could add on anakinra for treatment of their recurrent pericarditis for a period of time and not be overly concerned that you're adding a big increased risk of infection. With rilonacept, because it's newer to being used in recurrent pericarditis, it's longer-acting—it's dosed every week—but we haven't seen issues with infection. So, that's a big question that I get from other colleagues, about whether we can layer this on with other immunosuppressive therapies. Mycophenolate mofetil is 1 thing, but then, what about biologics? What about, [for example,] if a patient is on belimumab (Benlysta; GSK) for lupus, could we add this on for treatment of their pericarditis for a short period of time? And we don't really have an answer to that yet.