Shares of Celgene Corp have risen after the firm said it intends to file apremilast as a treatment for psoriatic arthritis soon on the back of positive late-stage data.

The company gave details from the last two Phase III studies of the three-trial PALACE programme which show that statistical significance for the primary endpoint of ACR20 (ie a 20% improvement in their condition) at week 16 was achieved for patients receiving apremilast 20 mg and 30 mg twice-daily. The results from the two trials were consistent with previously-reported PALACE-1 data.

Patients in the active treatment arms also maintained statistically significant improvements in ACR20 through week 24. The overall safety profile was consistent with the PALACE-1 study and tolerability was improved over the Phase II programme.

The PALACE-1, 2 and 3 studies are ongoing, and the study extensions remain blinded until all patients complete week 52. Full data will be submitted later and Celgene noted that a filing with the US Food and Drug Administration for PsA is expected in the first quarter of 2013. A combined submission for PsA and moderate-to-severe psoriasis in Europe is also planned for the second half of 2013.

Two Phase III studies of apremilast in more than 1,200 patients with moderate-to-severe psoriasis (ESTEEM 1 and 2) are ongoing with data expected by the end of this year.

Apremilast is an oral small-molecule inhibitor of phosphodiesterase 4 which will be used to treat patients with PsA who had received or failed oral disease-modifying antirheumatic drugs (DMARDs), and/or an anti-tumour necrosis factor agent. In each of these studies, apremilast was used alone or in combination with oral DMARDs.

Celgene also published Phase II data showing that apremilast is a safe and tolerable treatment for Behcet’s disease, a rare inflammatory disorder characterised by recurrent oral and genital ulcers. Prevalence of BD is highest in the eastern Mediterranean, the Middle East and East Asia, but is classified as an orphan disease in the USA and Europe.