How DMARDs and Biologics Work to Treat Psoriatic Arthritis

Treatment for psoriatic arthritis, or PsA, differs from person to person. Someone with mild PsA may be able to relieve their joint pain with just lifestyle modifications, and by avoiding inflammatory habits that make PsA symptoms worse (such as smoking).  

For moderate to severe PsA, however, a more aggressive treatment plan may be necessary. For those who qualify, disease-modifying antirheumatic drugs (DMARDs) and biologics may be appropriate.

The goal of DMARDs and biologics is to “decrease the inflammation … rather than just mask or cover up some of the symptoms,” says Bobby Buka, MD, dermatologist and assistant clinical professor at The Mount Sinai Hospital. “If we can do that and prevent some of the inflammation in the joint space … we can preserve the joint [and] keep it healthy for the long term.”

Versions of DMARDs have been around since the 1930s—when patients literally used injectable gold to treat their rheumatic diseases (and “gold therapy” is still available today, although rarely used due to its side effects). Since then, many different agents have been used to find what brings the most relief with the fewest side effects.

Today, people with PsA have a number of DMARDs to choose from that are highly effective. “They’ve got a lower side effect profile. They are very well tolerated,” says Dr. Buka.

One subcategory of DMARDs is biologics, which target specific parts of the immune system that drive inflammation. Biologics are delivered via injection, which you can do at home, or infusion, which is done by a healthcare professional. You don’t need to worry about a daily trip to the clinic: These injections or infusions are delivered as little as once every three months.

Here’s how they work: When the immune system is actively attacking something (in this case, the joint space), it releases inflammatory proteins, which lead to swelling, pain, and redness in the area. The purpose of inflammation is to make the area undesirable to the perceived “threat,” but it can also damage the healthy tissue in the area—especially if inflammation is chronic. 

Biologics work by targeting those inflammatory proteins. “Like a sponge, these biologics suck those up so that they don’t create tissue destruction or joint destruction,” says Dr. Buka.

While older treatments for PsA caused many harsh side effects, biologics only have two main side effects: soreness at the injection site, and an increased risk of infections, such as the common cold (due to the suppression of the immune system). 

“[Biologics] are fabulously effective. They’re really taking our treatment of psoriasis and psoriatic arthritis to new heights,” says Dr. Buka. “We can clear or nearly clear a patient with both psoriasis and psoriatic arthritis with these biologic agents.”