Apremilast fails to deliver clinical benefits in active ankylosing spondylitis

Use of apremilast does not provide any clinical benefit in patients with active ankylosing spondylitis (AS), but the safety and tolerability of this treatment are consistent with its known profile, reports a study.

The investigators conducted this phase III, multicentre, double-blind, placebo-controlled study to examine the efficacy and safety of apremilast, an oral phosphodiesterase 4 inhibitor, in patients with active AS. A total of 490 patients were randomly assigned in a 1:1:1 ratio to placebo (n=164), apremilast 20 mg twice daily (n=163), and apremilast 30 mg twice daily (n=163) for 24 weeks, followed by a long-term extension phase up to 5 years.

Assessment of the Spondyloarthritis international Society 20 (ASAS20) response at week 16 was the primary outcome. In addition, the investigators assessed the effect of treatment on radiographic outcomes after 104 weeks using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS).

Participants did not meet the primary endpoint of ASAS20 response at week 16 (apremilast 30 mg twice daily: 33 percent; apremilast 20 mg twice daily: 35 percent; placebo: 37 percent; p=0.44 vs placebo). Mean changes at week 104 from baseline in mSASSS were 0.83 (standard deviation [SD], 3.6), 0.98 (SD, 2.2), and 0.57 (SD, 1.9) in patients randomly assigned to placebo, apremilast 20 mg twice daily, and apremilast 30 mg twice daily, respectively.

In addition, diarrhoea, nasopharyngitis, nausea, and upper respiratory infection were the most reported adverse events through week 104.