Finding the Optimal PsA Treatment

By Linda Rath | December 9, 2019

Few rheumatic diseases are as challenging to treat as psoriatic arthritis (PsA), mainly because it’s made up of at least five different symptom components. And that doesn’t take into account conditions that commonly occur with it, such as diabetes, inflammatory bowel disease (IBD) and the eye disorder uveitis.

“When we’re talking about PsA, we’re talking about multiple things, and some patients respond to certain treatments and others don’t,” notes Susan Goodman, MD, a rheumatologist at Hospital for Special Surgery in New York City.

Another complication: A treatment that might be effective for one symptom can make others worse. For example, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen ease joint inflammation but exacerbate IBD and psoriasis.

And even the best PsA medications aren’t uniformly effective.

“It’s not uncommon in a given patient to have joint symptoms get dramatically better and skin only moderately so, or vice versa,” says Jasvinder Singh, MD, a professor and rheumatologist at the University of Alabama, Birmingham.

He points out that though “the newer biologics are impressive for both skin and joints,” skin symptoms usually respond better. “Dermatologists can get 90% clearance, while we are trying to achieve [a 70% improvement in symptoms],” he says.

Finally, there are the real-world implications associated with arthritis drugs, such as side effects and cost. Given all the variables, experts say thoughtful shared decision-making between doctors and patients is the key to finding effective treatments.

Treatment Guidelines

To help inform doctor-patient discussions, the American College of Rheumatology (ACR) and National Psoriasis Foundation (NPF) teamed up to publish treatment guidelines in 2018. Most recommendations are conditional, meaning: “It depends on an individual’s circumstances.”

Dr. Singh, lead author of the guidelines, says their conditional nature and low quality of the supporting evidence reflect the lack of head-to head studies of PsA treatments.

“We tried to answer questions that are clinically relevant: What are the relative benefits and risks of different treatment options,” he says. “But there are only a handful of studies comparing one drug to another.”

Monotherapy

The guidelines recommend a TNF blocking biologic drug as therapy for people with active PsA who have never been treated or when other treatments haven’t worked. It’s a change from earlier guidelines, which usually preferred a step-up approach — often driven by insurers. That meant starting with the least expensive drug and working up to stronger, pricier ones if or when the disease got worse. The new guidelines also suggest switching to a different TNF blocker if the first one doesn’t work instead of to a different class of drugs.

But there are qualifications. Some patients can’t afford biologics like TNF blockers; others don’t want to risk side effects; others want a pill, not an injection or infusion. And people with certain conditions or risk factors, like congenital heart failure or recurrent infections, can’t use anti-TNF drugs. In these cases, methotrexate is the preferred option for newly diagnosed PsA patients. For those who switched to a TNF blocker from methotrexate, the next step might be an IL-17 inhibitor.

Most doctors will discuss switching therapies if you haven’t seen at least a 20% improvement in symptoms after 12 weeks of treatment.

Combination Therapy

Dr. Singh says the use of combination therapies in PsA is waning as more drugs that work for both skin and joints come on the market.

“There might still be patients who need additional support to get the best response for skin and joints — for example, a steroid cream plus a systemic medication — but I am hoping the use of dual therapies will decrease over time,” he says.

Nondrug Therapies

The ACR/NPF guidelines also place an emphasis on nondrug therapies. The authors say both drug and nondrug therapies “can ameliorate PsA symptoms and occasionally lead to remission.”

Dr. Singh says smoking cessation is particularly important and has solid evidence to back it up.

“Smoking cessation is a huge recommendation in our guidelines,” he says. “It has an effect not only on mortality and cardiac and lung health, but on disease activity and the failure rate of drugs. We tell patients who smoke that their medications won’t work as long or as well. And quitting smoking is very actionable. If you explain to patients how important it is, they usually can do it.”

“Weight loss and exercise are the other two big ones. We know they contribute to joint health. Exercise can also have a positive effect on mental health, muscle biology and range of motion. Patients usually say, ‘I’m so glad you talked to me about exercise and weight loss. That tells me they’re important.’”

Individualized Treatment

With the exception of lifestyle changes, most of the ACR/NPF recommendations are suggestions only. Whether they apply to any particular patient depends on many factors, including age, other health problems and patients themselves. Philip Mease, MD, is director of rheumatology research at Swedish Medical Center and a professor at the University of Washington School of Medicine, both in Seattle. He thinks it’s impossible to apply standardized systems to PsA treatment because every patient is different.

“Most people see a rheumatologist because musculoskeletal pain is bothering them more than skin problems. But for some, other symptoms are more important. If you have dactylitis (severe swelling) in one finger and are a concert violinist, that’s a disaster. The beauty of the doctor-patient conversation is that patients can prioritize what is most important to them,” he says.