Psoriatic Arthritis Clinical Case Review

Philip Mease, MD, rheumatologist at Swedish Health Services in Washington, discusses the treatment options for this case.

Editor’s note: The following is an automatically generated transcript of the above video.

"So it was pretty clear. We have a diagnosis of psoriatic arthritis here superimposed on a patient's ongoing history of psoriasis, which has been present for about 10 years. If we think about what is involved in this diagnosis, we see that she has arthritis, enthesitis. Remember, she has Achilles tendon and plantar fascia evidence of pain. She has dactylitis of that left fourth toe. We see that she has some inflammation in the sacroiliac joint so we could potentially classify her as having axial psoriatic arthritis, and then she has obviously skin and nail disease, the nails with the pitting, as you recall.

So as we think about treatments, I tend to go with the so-called GRAPPA treatment guidelines from 2021, and as you know, the way the GRAPPA treatment guidelines are organized is that we organize them by the specific clinical domain that's involved, and in her case, that's going to be all of these that we've mentioned, arthritis, enthesitis, dactylitis, spondylitis, skin and nail disease, and we know that there is strong evidence for the TNF inhibitor class, the IL-17 inhibitor class, and the JAK inhibitor class to benefit all of these domains. The PDE4 inhibitor apremilast, the IL-12/23 inhibitor ustekinumab, and the IL-23 inhibitors affect positively most of these domains, but there's a little bit of uncertainty yet about whether or not they're fully beneficial in the spine. The reason for this is that there were trials with ustekinumab and one of the IL-23 inhibitors in ankylosing spondylitis that failed to show differentiation from placebo in ankylosing spondylitis, but on the other hand, in data from a phase three trial of one of the IL-23 inhibitors guselkumab, it was shown that there appeared to be at least symptomatic benefit from that agent in the spine of patients with axial PSA. So it's possible that there's enough difference between the axial component of PSA and the axial component of ankylosing spondylitis to potentially justify use of these drugs in axial PSA, but that's still to be fully determined, and we're waiting for the results of a large trial of guselkumab and axial PSA to help us understand that.

There's a really important contextual factor in this case, and that is that she is interested in having a child and so wants to become pregnant and potentially breastfeed. She's concerned about whether or not any of these medications that we might recommend for treatment of her psoriatic arthritis might have an adverse effect on the fetus or impact the newborn through breastfeeding. We are not entirely sure with most of these medications, and generally, they have an advisement that is just not known whether they may be a problem in patients with pregnancy, and so we then come to the fact that one of the TNF inhibitors, certolizumab, has an interesting construct in which instead of an FC component, it has two pegylated molecules, which prolong the half-life of the drug and then also allow it to be active because of the business end of the molecule, the FAB portion, but without an FC portion, and so that we have learned that it does not cross the placenta and does not cross through breast milk, and so it has become codified by the FDA as being safe to use in pregnancy and breastfeeding."