Advancements in Treating Psoriatic Arthritis

By Jasvinder Singh, MD, as told to Sonya Collins

What attracts me to research into psoriatic arthritis and other rheumatic diseases is that the discoveries we make can improve function and quality of life for people. It can give them the opportunity to once again enjoy life fully, spend time with their loved ones, and do the other things that bring them pleasure.

I’m a professor of medicine and epidemiology at the University of Alabama at Birmingham, a physician at the Birmingham Veterans Affairs Medical Center, and I co-authored the guidelines for the treatment of psoriatic arthritis.

A Revolution in Treatment Options

Psoriatic arthritis is almost undergoing a revolution in terms of the treatments that are available.

Much of the current research is focused on targeted therapies. That’s where the field is going. In the last 5 to 10 years, we’ve gone from traditional disease-modifying drugs to very specific treatments that target specific drivers of psoriatic arthritis.

We have medications that have been around for a long time that can inhibit many cells that are active in psoriatic arthritis. We also have these newer targeted drugs that stop just one of these molecules, rather than all of them.

The advantage of the older medications is that we have experience with them and a lot of long-term data about their safety.  The advantage of the new therapies, on the other hand, is that they’re more effective over time.

It’s possible, down the road, that we’ll find that the side effects of targeted drugs are more predictable than those of the older medications. Their side effects may also be more tolerable to people.

Most of the targeted drugs are given by injection just under the skin. Some of the most common side effects of medications, not just for psoriatic arthritis but in general, are  headaches and gastrointestinal issues like nausea. Since targeted drugs don’t go through the digestive system, the side effects may be milder.

The more targeted approach may upset the balance of the body a little less than those other drugs do. We don’t know that for sure, though.

Several targeted drugs are already approved and available for patients to use. This has really expanded the horizon for doctors and their patients to choose treatments that may control the disease better.

Predicting a Response to Treatment

Another important discovery that’s emerged in the last 10 years is that certain factors affect whether the drugs work or fail. Many sophisticated studies have shown that both smoking and obesity reduce the effectiveness of these drugs and how long their effects last.

So there are things patients can do on their own, in combination with their medications, to better manage their disease.

But it’s still hard to predict who’ll respond to which medication.

Psoriatic arthritis is not a single type of disease. For the longest time, we’ve described it as five different types. Beyond that, there may be different drivers of the disease at play in any given patient. We don’t have specific tests to see what those are and which drug would work best. For now, we choose medications based on the potential benefits and risks and what the patient prefers.

More importantly, across the life span of a patient, those drivers of the disease might change. It’s possible that a couple of them are active and that we can suppress them for a while with the available drugs. Then, the patient ages, develops other illnesses, and something else begins to drive the disease.

So it’s hard to predict who’ll respond to which medication. That response can also change over time. But the more we use these newer drugs, the more we’ll learn about them.

A Well-Stocked Toolbox

If someone’s response to a medication does change, we switch them to another drug if we can. That’s why we want to keep lots of medication choices in our toolbox. This is a lifelong condition, and we want to have options available for when we need them. And I think we’re in a very good place for that right now. 

Having said that, I’m happy to see strong and ongoing interest from drug companies in developing new products and additional targeted therapies, not just for psoriatic arthritis but for many autoimmune diseases.

This is only possible with clinical trials. I always encourage patients to consider participating in them. That’s how we learn and discover new therapies. There’s the potential — if the trial drug is safe and effective — that it benefits patients in the trial themselves.

We can’t promise that. But the benefit to other patients in the future, if the drug gets developed and approved, is immense. Because then the drug will be available to everybody.