SAN DIEGO – Monthly use of intravenously administered secukinumab (Cosentyx) proved its efficacy over placebo in treating psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA) in two industry-sponsored, randomized, double-blinded, phase 3 trials of the drug’s second and newly approved route of administration.
The studies of the human monoclonal antibody secukinumab, an interleukin-17 inhibitor, were presented at the annual meeting of the American College of Rheumatology. A subcutaneously injectable formulation of the drug is available, and the Food and Drug Administration approved the IV form for the conditions in October, although at a recommended lower monthly dose than the new trials examined.
In the PsA trial, 191 patients took IV secukinumab, and 190 took placebo. For the primary endpoint, the percentages who reached at least a 50% improvement in American College of Rheumatology response criteria (ACR 50) at 16 weeks were 31.4% and 6.3%, respectively (P < .0001).
In the axSpA trial, 264 patients took IV secukinumab, and 262 took placebo. The primary endpoint, at least a 40% improvement in Assessment of the Spondyloarthritis International Society response criteria (ASAS 40), was met at 16 weeks by 40.9% and 22.9%, respectively (P < .0001).
“Both studies appear to present clear efficacy of IV route administration of secukinumab with no clear increase in safety signals,” consultant rheumatologist Nicola Goodson, MBChB, PhD, of Aintree University Hospital in Liverpool, England, said in an interview.
“Offering IV administration as an option to patients is helpful,” added Dr. Goodson, who was not involved with the study but is familiar with its findings.
As Dr. Goodson explained, secukinumab “was the first IL [interleukin]-17 inhibitor used to treat spondyloarthropathies, and we have been using subcutaneous secukinumab to treat psoriasis, psoriatic arthritis, and axial spondyloarthritis/ankylosing spondylitis since 2016 in the U.K. Our experience with this medication has been good with similar efficacy to anti-TNF [tumor necrosis factor] therapy in axial spondyloarthritis. The medication is generally well-tolerated, and the subcutaneous pen injection device is easy for patients to use.”
However, IV treatment may speed up onset of action, she said, and it may be useful in situations when compliance is a challenge.
PsA trial details
In the PsA trial, known as INVIGORATE-2, researchers recruited patients who met the CASPAR criteria for active PsA with symptoms for ≥ 6 months, and had ≥ 3 tender joints out of 78 joints and ≥ 3 swollen joints out of 76.
Participants with a mean age of 48, including 55% females, were randomized 1:1 to receive placebo or secukinumab (6 mg/kg at baseline followed by 3 mg/kg every 4 weeks). Those in the placebo group were switched to the same monthly doses of secukinumab at 16 weeks.
“Patients who switched from the placebo had a similar increase of efficacy as the original treated group,” rheumatologist Alan J. Kivitz, MD, of the Altoona Center for Clinical Research, in Duncansville, Penn., said in his presentation at the meeting. Specifically, at 52 weeks, the groups had similar ACR 50 response rates: 58% with secukinumab and 64% with placebo-to-secukinumab.
The fact that patients in the original placebo group who received 3 mg IV doses without 6-mg loading doses achieved ACR response rates similar to those who took secukinumab during the whole trial “could suggest that the IV loading dose may not be required. This would need to be explored in a randomized head-to-head study, but it’s an interesting observation that may reduce costs and exposure to higher doses of medication at the start of treatment,” Dr. Goodson said.
Among the patients who received secukinumab at any point in the study, 63% had a treatment-emergent adverse event, including 5.9% with serious events. One death was reported in the placebo group before week 16. No other deaths were reported.