You can participate in research studies about arthritis by using our ArthritisPower app to join our patient-centered research registry.

On a dark blue background, there is a pink banner in the center with text that reads “CreakyJoints News.” In a yellow box above the banner, text reads “#ACR21.” In a purple box below the banner, text reads “American College of Rheumatology Convergence.” Text below this in white reads “2021 Highlights.” Below, there is another text bubble in pink with text that reads “Psoriatic Arthritis Update” and to the left is a circle with an image of a hand with a psoriasis patch and flared spot.
Credit: Tatiana Ayazo

At the American College of Rheumatology/Association of Rheumatology Health Professionals Annual Meeting this year — ACR Convergence 2021 — more than 16,500 attendees and 600 speakers from more than 100 countries gathered virtually to share the latest research and address the most pressing issues for people living with rheumatic disease.

The CreakyJoints team soaked it all in — listening, watching, and learning so we could bring you the most relevant information to ensure you know what you need to better manage your condition and get better care.

We combed through hundreds of studies, attended sessions from top psoriatic arthritis experts, and asked our team of patient and physician advisors to share the psoriatic arthritis updates they deemed most important for patients.

The result: Our curated, patient-friendly guide to psoriatic arthritis research and trends from ACR 2021. For more research breakthroughs from ACR 2021, check out our main guide: 100+ Arthritis & Rheumatic Disease Updates You Need to Know.

1. A new type of oral therapy (TYK2 inhibitors) is emerging for psoriatic arthritis

As more types of biologic therapies (which need to be given as injections or infusions) emerge for psoriatic arthritis, so too are new types of targeted medications that are taken as oral pills. At ACR this year, there was promising data on a couple of different therapies in a new class of drugs known as TYK2 inhibitors.

One therapy, deucravacitinib, has already been studied and shown to work well in psoriasis. At ACR, researchers led by Philip Mease, MD, presented data from a phase 2 clinical trial where different groups of PsA patients were randomized to take one of two deucravacitinib doses or a placebo for four months. Those on therapy were much more likely to achieve a 20 percent improvement in symptoms (ACR20) than those on placebo and no serious adverse events were reported.

There was also new data on another medication, brepocitinib, which is a combination of a TYK2 and JAK1 inhibitor. The results from this phase 2 trial, also led by Dr. Mease, showed that higher doses of the medication were associated with improvement relative to placebo, particularly when it came to minimal disease activity. About 35 percent of people on brepocitinib achieved minimal disease activity after 16 weeks compared to 3 percent on placebo.

Both medications are still being studied and not yet approved for treating psoriatic disease. More information will be needed on long-term safety, particularly because of similarities in how they work with JAK inhibitors, which are currently under review at the FDA for concerns and cardiac events and cancer risk.

2. Treating psoriatic arthritis with IL-23 inhibitors looks promising

Among the growing number of treatment options for psoriatic arthritis in recent years is a group of medications that target the immune system protein interleukin-23 (IL-23). A number of different studies presented at ACR this year provide more evidence for the effectiveness of these therapies.

One study on the IL-23 blocker guselkumab (Tremfya), which was FDA-approved last year for PsA, continued to follow clinical trial patients over two years. Researchers found what they call “durable” responses, meaning that the effectiveness of treatment lasted over time.

  • About 75 percent of people achieved what’s known as an ACR20 response, or a 20 percent improvement in symptoms after two years, regardless of whether they took the medication every four weeks or every eight weeks.
  • About 55 percent of people achieved an ACR50 response, or a 50 percent improvement in symptoms after two years, regardless of whether they took the medication every four weeks or every eight weeks.
  • About 35 percent of people achieved an ACR70 response, or a 70 percent improvement in symptoms after two years, regardless of whether they took the medication every four weeks or every eight weeks.

Risankizumab (Skyrizi) is another IL-23 blocker — approved for psoriasis but still being studied for psoriatic arthritis — that showed promising data from two phase 3 clinical trials at ACR. In the studies, about 1,400 PsA patients who already failed a DMARD or a biologic were randomized to get risankizumab or a placebo. After six months, significantly more people on the medication achieved an ACR20 response than on placebo (55 percent vs. 31 percent) as well as a minimal disease activity (25 percent vs. 11 percent). (Minimal disease activity is a different way of measuring how well someone with PsA is doing — more on this below.)

One benefit of IL-23 inhibitors relative to other therapies is their dosing schedule. After initial loading doses, risankizumab is given every three months; guselkemab every two months.

But while “IL-23 inhibitors clearly work,” as rheumatologist Eric Rudermman, MD, said in a RheumNow video, “the challenge is understanding where these drugs fit into our algorithm for treating psoriatic arthritis.” Studies that compare these drugs directly with other treatments are needed, he said “to decide if they are as good as or potentially better than some of the other drugs we already have.” IL-23 inhibitors are known to be effective for skin disease, which is why dermatologists love them, said Dr. Ruderman. More time and research is needed to see how they’ll be used for psoriatic arthritis.

3. Hospitalizations for infections are decreasing among people with psoriatic arthritis

Biologic drugs — which have become commonly used to treat psoriatic arthritis over the last decade — are associated with an increased risk of infection, so a team of researchers from Boston University wanted to look at recent trends in serious infections in PsA. When they looked at 7 million hospital discharge records from 2012-1017, they found that there was a significant decrease in PsA patients who were hospitalized for sepsis (blood infection), skin and soft tissue infections, and urinary tract infections. There was no significant change in hospitalizations for pneumonia.

Noting that the findings were contrary to the research team’s initial hypothesis that infections would increase over the time period, study lead author Vagishwari Murugesan, MD, said that more research is needed to understand why. However, she said during a press conference at ACR that “we believe that better disease control and better control of inflammation can lead to decreased risk of infection in this subset of patients,” Healio Rheumatology reported.

4. Do doctors and patients care about the same issues when it comes to treating PsA? Mostly.

When it comes to treating PsA, how much do rheumatologists and patients prioritize the same issues? A study ledy by Phillip Mease, MD, looked at this by running focus groups with 53 PsA patients and by conducting interviews with 13 PsA expert doctors.

Researchers found that patients and doctors aligned on their main concerns: treating joint pain and swelling, fatigue, and disease activity. But while doctors ranked clinical symptoms such as enthesitis, dactylitis, and skin disease more highly, patients considered items such as access to care, future health uncertainty, and sleep quality to be more important than doctors did.

While it’s not surprising that doctor and patients prioritize different aspects of caring for a complex disease like PsA, it’s important for everyone to be aware of where these differences play out, so doctors can make sure they’re treating the whole patient, and patients can make sure they share their most important concerns with their doctor.

“This poster highlights the need to consider an approach to patient care in a holistic manner,” rheumatologist Swetha Ann Alexander, MD, said on RheumNow. “Some ways this can be addressed are better ancillary support such as social work to improve access to care, psychiatry, or sleep counseling to address insomnia and other comorbid psychiatric illnesses. Finally, empowering patients by disease education decreases future health uncertainty.”

5. Psoriatic arthritis patients should pay attention to eye pain and redness

Uveitis, a type of eye inflammation, is common in many rheumatic and inflammatory diseases, but it’s not something many patients know to look out for.

A team of Israeli researchers looked at 6,147 PsA patients diagnosed between 2005 and 2020 to see how common uveitis was compared to a group of 23,999 healthy controls. Uveitis was more than twice as common in PsA patients as it was in controls. Compared to controls, PsA patients with uveitis were more often younger and female. Among those with PsA, people diagnosed with uveitis were much more likely to have had a previous episode of uveitis.

They were also more often taking conventional synthetic DMARDs (such as methotrexate) or TNF blocker biologics. Among people taking other biologics (such as IL-17 or IL-23 blockers), there were no differences in uveitis occurrence.

A “high index of suspicion” is warranted in people with PsA who have uveitis symptoms and have already had the condition previously, according to the researchers. Symptoms include eye redness, pain, decreased or blurry vision, and light sensitivity.

 6. The microbiome may yield important clues about psoriatic disease — and who get it

Psoriatic disease, which includes psoriasis and psoriatic arthritis, is thought to be due to a combination of genetic and environmental factors — but how much of a role does either play? A team of researchers studied this in nine pairs of identical twins, where one twin had psoriatic disease and the other did not.

They specifically looked at gut and skin bacteria — known as the microbiome — collected from stool and skin samples (Samples were taken from healthy skin — not from areas with psoriasis plaques.) What they found: One bacteria strain (Ruminococcus bromii) was significantly less common in the twins with psoriatic disease compared to their unaffected siblings, which is a clue that it may be associated with disease.

Among skin samples, particularly in the scalp, researchers observed key differences in the bacterial makeup — notably, less diversity in the types of microbes in the twins with psoriatic disease.

More research is needed to understand how research like this can inform diagnosis and treatment. For one thing, experts don’t know whether this is cause or effect, or both: Does having psoriatic disease change your microbiome, or do changes in your microbiome trigger the onset of disease?

7. Peripheral spondyloarthritis is unique from psoriatic arthritis and axial spondyloarthritis

Spondyloarthritis is an umbrella term for a few different types of arthritis that have certain traits in common. It includes psoriatic arthritis and axial spondyloarthritis, but less is known about another form: peripheral spondyloarthritis. This condition shares symptoms with both PsA and axSpA, but as a new study shows, peripheral spondyloarthritis (pSpA) is separate and unique. And it needs to be better understood in order to improve diagnosis and treatment.

The researchers looked at 4,185 patients diagnosed by their rheumatologist as having pure pSpA or pSpA combined with PsA or axSpA. People with pure pSpA had a high prevalence of disease in their peripheral joints, synovitis (swelling around the joints), enthesitis, and being positive for the HLA-B27 genetic marker.

What’s more, they had a significantly higher disease burden and lower use of biologic drugs than people with PsA or axSpA, which indicates their disease is not being well-managed.

Why do these distinctions matter? Because as experts learn more about which treatments can help certain SpA symptoms, the hope is that doctors will be able to tailor treatments to a patient’s unique needs.

8. Asking about back pain may help dermatologists identify early psoriatic arthritis

Knowing that many people with psoriatic arthritis have spinal (“axia”) involvement, German researchers developed a back pain screening tool for dermatologists to see if they could identify psoriasis patients who have early PsA with spinal symptoms.

Dermatologists referred psoriasis patients who met the following criteria for a rheumatology evaluation: under age 45, back pain for three or more months, and who had not taken biologic or targeted DMARDs in the 12 weeks prior to the screening. Out of 355 dermatology patients, 151 (42 percent) qualified to be referred to a rheumatologist; 14 people were ultimately diagnosed with PsA with axial symptoms.

“These are folks who may not volunteer that they’ve been having back pain when they’re getting a skin check with their psoriasis doctor,” said rheumatologist Pedro Castillo, MD, in a RheumNow video, noting that the simplicity of the screening questions makes it easier for other specialists to implement.

9. Experts are looking at lots of ways to predict which psoriasis patients will develop psoriatic arthritis — and when

This continues to be a very exciting area of research, and two studies at ACR addressed this issue from very different approaches. Cleveland Clinic researchers looked at a group of 384 people who were diagnosed with psoriasis and then psoriatic arthritis. When they evaluated a slew of risk factors to see which ones influenced how quickly people were diagnosed with PsA after psoriasis, they found one that stood out: age at psoriasis diagnosis.

People diagnosed with psoriasis at an older age develop psoriatic arthritis much sooner than people diagnosed with psoriasis at a younger age. For example, people diagnosed with psoriasis around age 40 progress to psoriatic arthritis about 12 years faster than those diagnosed with psoriasis around age 18.

This means if you’re diagnosed with psoriasis at an older age, you should pay more attention to symptoms of psoriatic arthritis (like joint pain and swelling, foot pain, and swollen digits) and bring them up to your doctor.

Meanwhile, a separate study from Canadian researchers looked at what’s known as epigenetic differences, or small changes that can affect how your DNA works in your body, between people who have psoriasis only versus those who went on to develop psoriatic arthritis.

They found a number of differences in certain markers that can distinguish between psoriasis patients that will develop PsA from those that will not. More research is needed to understand how information like this might be used to actually prevent the development of psoriatic arthritis.

10. More research questions the necessity of methotrexate for psoriatic arthritis

The disease-modifying antirheumatic drug methotrexate is a first-line therapy for rheumatoid arthritis, and it is commonly used for PsA as well. But just as research presented at ACR (from our ArthritisPower research registry) shows that many PsA patients would prefer a treatment plan that doesn’t include methotrexate, a German study shows that methotrexate might not be necessary when a patient is doing well on a biologic.

In the study, researchers conducted a randomized controlled trial with the biologic ustekinumab (Stelara) and methotrexate. There were four groups of patients taking ustekinumab. Two were also on methotrexate and either continued it or started a placebo instead of MTX. The other two had not yet started MTX and were given it or a placebo along with ustekinumab.

Researchers found that neither staring nor continuing methotrexate had a significant impact on such measures as arthritis, enthesitis, dactylitis, skin, quality of life measures, or functional measures. The researchers concluded that based on this data, there’s no evidence to add or maintain ongoing methotrexate when starting this ustekinumab. More research will be needed to see if these findings apply to other biologics.

“Methotrexate isn’t going anywhere,” said Pedro Castillo, MD, on, writing about this research. “We will continue to use it in the treatment of rheumatic disease seemingly indefinitely, but it is important to take note of patient preferences and to consider discontinuing it if a biologic is getting the job done.”

 11. Who gets to ‘minimal disease activity’ in psoriatic arthritis?

When there’s no cure for a disease like PsA, we need other ways to measure how well people are doing on a given treatment. Minimal disease activity (MDA) is a measure that is becoming more widely used for psoriatic arthritis specifically. It takes into account a number of factors, including joint pain and swelling, enthesitis, skin clearance, patient assessments of pain, disease activity, and daily function.

A study of 1,251 psoriatic arthritis patients, led by rheumatologist Alexis Ogdie, MD, found that minimal disease activity was achieved by just 22.5 percent of patients who after six months of starting either biologics or targeted oral DMARDs.

Were there any differences between those who reached minimal disease activity and those who didn’t? Researchers found a few: Those in minimal disease activity tended to be younger and have a shorter duration of PsA. They were also less likely to be female, obese, or have a history of depression. More people who got to minimal disease activity were considered “biologic naive” — meaning they hadn’t taken a biologic before the study. They were also more likely to keep taking the therapy throughout the study.

While it may be disconcerting that such a low number of people (less than a quarter) achieved minimal disease activity, research like this helps doctors and patients identify ways to help patients do better on therapies. For instance, this study supports the importance of treating patients early in the course of the disease. It also highlights the need to address and treat other factors that may affect patients’ outcomes, such as depression.

You Can Participate in Psoriatic Arthritis Research Too

If you are diagnosed with psoriatic arthritis or another musculoskeletal condition, we encourage you to participate in future studies by joining CreakyJoints’ patient research registry, ArthritisPower. ArthritisPower is the first-ever patient-led, patient-centered research registry for joint, bone, and inflammatory skin conditions. Learn more and sign up here.

Alexander SA. Psoriatic Arthritis: “What Matters” to Patients, Physicians. RheumNow. November 12, 2021.

Castillo P. An Old Friend – Methotrexate in Psoriatic Arthritis. RheumNow. November 16, 2021. RheumNow.

Cheemalavagu S, et al. The Transition to Psoriatic Arthritis: What Factors Predict a Shorter Transition from Psoriasis to Psoriatic Arthritis? [abstract]. Arthritis & Rheumatology. November 2021.

Cruz Correa O, et al. Prediction of Psoriatic Arthritis in Patients with Psoriasis Using DNA Methylation Profiles [abstract]. Arthritis & Rheumatology. November 2021

Hijaze N, et al. Uveitis in Patients with Psoriatic Arthritis – a Database Analysis [abstract]. Arthritis & Rheumatology. November 2021.

Koehm M, et al. Neither Add-on nor Withdrawal of Methotrexate Impacts Efficacy of IL12/23 Inhibition in Active PsA: Data from a Multicenter Investigator-initiated Randomized Placebo-controlled Clinical Trial on Arthritis, Dactylitis, Enthesitis, Psoriasis, QoL and Function [abstract]. Arthritis & Rheumatology. November 2021.

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Mease P, et al. Efficacy and Safety of Brepocitinib (Tyrosine Kinase 2/Janus Kinase 1 Inhibitor) for the Treatment of Active Psoriatic Arthritis: Results from a Phase 2b Randomized Controlled Trial [abstract]. Arthritis & Rheumatology. November 2021.

Mease P, et al. Efficacy of Deucravacitinib, an Oral, Selective Tyrosine Kinase 2 Inhibitor, in Musculoskeletal Manifestations of Active PsA in a Phase 2, Randomized, Double-Blind, Placebo-Controlled Trial [abstract]. Arthritis & Rheumatology. November 2021.

Mease P, et al. “What Matters”: Patient and Clinician Perspectives in Psoriatic Arthritis Care [abstract]. Arthritis Care & Research. November 2021.

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Ogdie A, et al. Impact of Achieving Minimal Disease Activity on Patient-Reported Outcome Measures and Disease Activity Among Patients with Psoriatic Arthritis Treated with Biologic and Targeted Synthetic DMARDs [abstract]. Arthritis & Rheumatology. November 2021.

Ostor A, et al. Efficacy and Safety of Risankizumab for Active Psoriatic Arthritis: 24-Week Integrated Results from 2 Phase 3, Randomized, Double-blind Clinical Trials for CsDMARD-IR and Bio-IR Patients [abstract]. Arthritis & Rheumatology. November 2021.

Proft F, et al. Early Identification of Psoriatic Arthritis with Axial Involvement Among Patients with Psoriasis: A Prospective Multicenter Study [abstract]. Arthritis & Rheumatology. November 2021.

Psoriatic Arthritis Panel Discussion: ACR21. RheumNow. November 9, 2021.

PsA Perspectives – IL-23: Dr. Eric Ruderman. RheumNow. November 6, 2021.

Stott R. Serious infection-related hospitalizations drop for PsA despite uptick in biologic use. Healio Rheumatology. November 7, 2021.

Walsh J, et al. Impact of Treatment Experience on Patient Preferences and Disease Burden in Psoriatic Arthritis: Results from a Rheumatology Patient Research Registry [abstract].  Arthritis & Rheumatology. November 2021.

Ziade N, et al. What Is Peripheral SpondyloArthritis? Identifying Disease Phenotype and Burden: A Post Hoc Analysis of the ASAS-PerSpA International Study [abstract]. Arthritis & Rheumatology. November 2021.

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