Ixekizumab Shows Promise in Phase 3 Trial of Radiographic Axial Spondyloarthritis

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by Alice Melao |

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Treatment with the monoclonal antibody Taltz (ixekizumab) significantly reduced the symptoms of radiographic axial spondyloarthritis (rad-axSpA) in patients participating in a Phase 3 clinical trial, early data show.

The study, called COAST-V (NCT02696785), met its primary and all key secondary endpoints, therapy developer Eli Lilly said in a news release.

The results showed that after 16 weeks of ixekizumab treatment, radiographic axial spondyloarthritis patients experienced a significant reduction in symptoms compared to a placebo. Patients had not received prior treatments with biologic disease-modifying anti-rheumatic drugs (bDMARD) and had a diagnosis of active ankylosing spondylitis.

The therapy’s effectiveness at trial was measured by an ASAS40 evaluation, which determines the percentage of patients who achieved a 40 percent improvement in disease symptoms such as pain, inflammation, and physical function.

“Many people with this chronic, debilitating disease are still searching for an effective treatment,” Lotus Mallbris, MD, PhD, vice president and immunology platform team leader at Lilly Bio-Medicines, said. “These initial results suggest that Taltz, if approved for this indication, may have the potential to help people with this challenging disease.”

COAST-V safety reports showed that the incidence of treatment-related adverse events was similar for ixekizumab and placebo groups. No new safety issues were reported, with the inhibitor showing a similar safety profile as was reported in previous trials in plaque psoriasis and psoriatic arthritis.

Top-line results of the COAST-V study will be submitted for presentation at scientific meetings and for publication in peer-reviewed journals later this year. Eli Lilly, which is leading the study, plans to file an application for regulatory approval of ixekizumab as treatment for ankylosing spondylitis after additional clinical data are collected.

Ixekizumab is an engineered antibody designed to specifically bind and inhibit the pro-inflammatory interleukin-17A (IL-17A) signaling molecule. The inhibitor, sold under the brand name Taltz, is approved by the U.S. Food and Drug Administration (FDA) to treat adult patients with active psoriatic arthritis or moderate-to-severe plaque psoriasis.

To date, Cosentyx (secukinumab) is the only IL-17 inhibitor approved by the FDA for the treatment of ankylosing spondylitis. Ixekizumab is expected to help prevent joint inflammation, bone erosion, and bone fusion in this patient population.

Eli Lilly is currently evaluating ixekizumab’s potential as a treatment for several ankylosing spondylitis subgroups in the ongoing COAST program, which includes three Phase 3 studies. Each is schudeled to last one year, including COAST-V, COAST-W (NCT02696798), and COAST-X (NCT02757352). All participants also can enroll in a long-term extension study to receive ixekizumab for up to two additional years.

The COAST-V trial is being conducted at 28 sites worldwide and has enrolled approximately 320 participants. Patients were randomized to receive ixekizumab, placebo, or Humira (adalimumab). Ixekizumab-treated patients received a starting dose of 80 mg or 160 mg for 14 weeks, followed by subcutaneous administration of 80 mg of ixekizumab once every two weeks or once every four weeks, for a total treatment duration of 52 weeks.

The COAST-W trial will evaluate the inhibitor’s safety and efficacy in patients with active ankylosing spondylitis who previously had an inadequate response to TNF inhibitors. The COAST-X trial will evaluate ixekizumab as a treatment for patients with non-radiographic ankylosing spondylitis who previously had not been treated with a bDMARD.

Both studies will compare the investigative antibody with a placebo in about 300 ankylosing spondylitis patients. Treatment protocol will be similar to that used in the COAST-V study.

These trials are currently recruiting participants. For additional information, visit trial registry websites: COAST-W and COAST-X.