Tremfya approval in U.S. for psoriatic arthritis looks likely

Tremfya (guselkumab), is approved by the U.S. Food and Drug Administration (FDA) and regulators elsewhere for the treatment of adults with moderate to severe plaque psoriasis. It is an IL-23 inhibitor that is very successful at improving skin psoriasis. It was approved in Europe in 2019 for active psoriatic arthritis, and the latest data released by the Janssen Pharmaceutical Companies of Johnson & Johnson strongly suggests that their biologic is likely to win FDA approval for psoriatic arthritis in the near future.

The clinical trials discussed here included psoriatic arthritis patients who had previously tried a biologic in the TNF alpha inhibitor class, as well as patients new to biologics. In 52 week data (the second half of it “open label,” meaning the researchers knew the patient was receiving Tremfya), roughly 60-75% of patients on Tremfya achieved a 20% improvement in a composite score of a set of symptoms of psoriatic arthritis. This is known as ACR20, which has long been the standard by which proposed psoriatic arthritis treatments were judged. But the new generation of psoriasis treatments is upping the game, as they are delivering 50% improvements in psoriatic arthritis symptoms in significant numbers (ACR50). In these trials, Tremfya achieved ACR50 for roughly 40-50% of those who entered the study.

Tremfya also demonstrated again that it does very well at improving skin symptoms of psoriasis for the vast majority of patients. (Most people with psoriatic arthritis also have visible psoriasis.) In a different trial of psoriasis patients, Tremfya has shown sustained, four-year improvement in a common measure of psoriasis severity. Roughly 80% of patients achieve a PASI 90 score, which represents a 90% improvement in a set of psoriasis symptoms compared to when the patient began the study.

(For years, PASI 75 was the standard measure in clinical trials, but the new generation of psoriasis treatments achieve PASI 90 and PASI 100 in a large number of patients, raising the bar of what is achievable for many people with psoriasis.)

Tremfya’s safety profile is also strong, with roughly 1% of patients having a significant health issue from it per year.

Janssen is also the company behind other treatments for psoriatic disease: Simponi Aria (golimumab), a TNF inhibitor for active psoriatic arthritis; and the blockbusters Remicade, (infliximab), a TNF inhibitor for psoriatic arthritis and plaque psoriasis, and Stelara (ustekinumab), an IL-12/IL-23 inhibitor for active psoriatic arthritis and those 12 and older with moderate to severe plaque psoriasis.

The IL-23 (without inhibiting IL-12) inhibitors represent a valuable addition to the psoriasis and psoriatic arthritis treatment arsenal. We will be hearing a lot about Tremfya for many years.

[Last updated 6-6-2020]