Good News on Guselkumab

The IL-23 blocker guselkumab (Tremfya) improved disease in people with active psoriatic arthritis (PsA). Improvement was maintained through the 1-year mark, including in those who had previously taken TNF inhibitors (TNFi), according to a study in ACR Open Rheumatology.

The study included 118 (31%) participants who had previously taken TNFis. Responses to guselkumab were maintained or increased through week 52 regardless of prior TNFi use. Rates for achieving 20% disease improvement at week 24 and week 52 were similar in TNFi-naive and TNFi-experienced patients who were randomized to receive 100 mg of guselkumab every 4 weeks (76% and 68%, respectively) and every 8 weeks (61% and 58%).

In TNFi-naive and TNFi-experienced patients, 62% and 64%, respectively, reported at least one adverse event; 4% and 6%, respectively, reported serious adverse events.

First author Christopher Ritchlin, MD, MPH, is a rheumatologist, immunologist, leading PsA researcher, and professor with University of Rochester Medical Center in New York. Here he discusses key findings with the Reading Room. The exchange has been edited for length and clarity.

What was the context for and key objectives of this study?

Ritchlin: We know that IL-23 blockers like guselkumab are extremely effective against psoriasis. We also know from prior studies that guselkumab is effective for the treatment of PsA.

This study is different from previous studies in that it includes patients who have previously been exposed to anti-TNF drugs, as well as those who are naïve to these agents. It was designed to look at longer-term outcomes in these patient groups out to 1 year.

How would you describe the key findings?

Ritchlin: Basically, this study showed that when you look at a variety of endpoints related to the skin -- meaning psoriasis response, response of the joints, response of the entheses -- this agent was effective out to a year in patients who had previously been exposed to anti-TNFs and those who were naïve.

Moreover, the safety profile was very strong in terms of adverse events, which were almost non-existent. Neither group experienced any opportunistic infections, tuberculosis, inflammatory bowel disease, or major adverse cardiovascular events.

What are the implications for day-to-day clinical practice?

Ritchlin: I think this shows that agents such as guselkumab that block IL-23 are effective for PsA as well as psoriasis.

This study shows this drug is effective against PsA in all sorts of manifestations. Having the data all the way out to a year really helps clinicians see how it performs over a long period.

What is the next clinical frontier for guselkumab?

Ritchlin: This research team has one study underway examining guselkumab as part of a combination therapy with an anti-TNF agent. We aim to determine whether this combination therapy might be effective in patients who have more resistant disease.

The safety profile of IL-23 inhibitors is so strong that we think this will allow us to combine them with other biologics -- something that's not been done before.

Key points

• Guselkumab effective against PsA to the 1-year mark
• Effective in patients who previously received TNFis
• Very few major adverse events reported

Read the study here and expert commentary on the clinical implications here.