Secukinumab demonstrates efficacy and safety in polymyalgia rheumatica: Results from the phase 3 REPLENISH trial

touchIMMUNOLOGY coverage of EULAR 2026

My name is Christian Dejaco, I’m a rheumatologist based in Italy, and I’m part of the team authoring the trial on secukinumab in polymyalgia rheumatica.

Could you describe the challenges associated with the treatment of PMR?

The biggest challenge in treating PMR is that glucocorticoids are still a mainstay of treatment, and many patients relapse in course and need long-term glucocorticoid treatment. The problem with long-term glucocorticoid treatment is that many patients, more than 50%, have adverse events. Therefore, we need new treatments to prevent glucocorticoid use in the long term.

What is the mechanism of action of secukinumab and rationale for its investigation in PMR?

Secukinumab is a monoclonal antibody against interleukin-17A, and it’s already well established for many diseases in rheumatology. In patients with PMR, interleukin-17 is elevated in serum, and it has also been found in tissue. Then in a phase 2 trial in GCA, treatment with secukinumab resulted in patients having fewer PMR symptoms, and that was the rationale to conduct the phase 3 trial.

What were the aims, design, and endpoints of the phase 3 study?

The study was a randomized, controlled, phase 3 trial. There were three treatment arms; one receiving secukinumab 300 mg, one receiving secukinumab 150 mg, and one placebo arm. All treatment arms received a 24-week taper of glucocorticoids. The study enrolled patients with a diagnosis of PMR and at least one recent relapse.

The primary objective was the achievement of sustained remission at Week 52, which was defined as achieving remission at Week 12 and maintaining remission up to Week 52. There were several secondary endpoints, such as the achievement of complete sustained remission, which is similar to sustained remission, but includes the maintenance of a normalized C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Other endpoints were the cumulative glucocorticoid dose, the impact of the treatment on glucocorticoid toxicity, or time until use of rescue or escape treatment.

How well were the primary and secondary endpoints met?

The trial actually met the primary and secondary endpoints. Concerning the primary endpoint, there was a significantly higher rate of achieving complete remission in both secukinumab groups compared to placebo. There was a delta between placebo and both secukinumab groups of around 20%.

In terms of the secondary endpoint, both secukinumab groups also achieved a higher rate of complete sustained remission. The overall response rate for that outcome was lower among all groups, but the delta of 20% between placebo and both secukinumab groups was maintained. There were also significant reductions in cumulative glucocorticoid dose, and that translated into less toxicity, as measured by the glucocorticoid toxicity index, where both secukinumab groups had lower scores as compared to the placebo group.

What is the potential clinical significance of these findings?

We expect approval of secukinumab in the next couple of months. Subsequently it will be another option to save glucocorticoids in our PMR patients who are refractory or have had one or more relapses.