Celgene Corp has been boosted by more impressive late-stage data on apremilast, an oral drug for psoriatic arthritis, this time in previously-untreated patients.

The company is presenting data from the 52-week PALACE 4 Phase III study of apremilast tested in PsA patients who have not taken systemic or biologic disease modifying antirheumatic drugs (DMARDs) at the American College of Rheumatology meeting in San Diego. The results from the 527-patient trial show that at week 16, patients on 20mg of the  first-in-class oral inhibitor of phosphodiesterase 4 (PDE4) achieved an ACR20 (ie a 20% improvement in the condition) response of 29.2% and 32.3% for 30mg aapremilast, compared with 16.9% for those on placebo.

After 52 weeks, 53.4% on the lower dose and 58.7% on 30mg achieved an ACR20 response. ACR50 and 70 was reached by 31.9% and 18.1% of patients, respectively, for apremilast 30mg. The compound was generally well-tolerated and discontinuation rates for diarrhoea and nausea were less than 2% over 52 weeks.

Commenting on the data, Alvin Wells, of the Rheumatology and Immunotherapy Center in Franklin, Wisconsin, noted that apremilast demonstrated long-term safety and tolerability and significant clinical benefit in treatment-naive patients. He added that "these encouraging results suggest that apremilast may have the potential to be used alone and as a first-line therapy". Celgene is also presenting various pooled data from the first three trials in the PALACE programme which, among other things, shows that apremilast significantly improves swollen and tender joints.

Treatment for PSA, which affects about 30% of the 125 million people worldwide who have psoriasis, currently involves injectable tumour necrosis factor (TNF) inhibitors, notably AbbVie's Humira (adalimumab) and Pfizer/Amgen's Enbrel (etanercept), once patients have not responded to DMARDs (at least in the UK). While the biologics are effective, the side effect profile can be a concern, due to the risk of infection and tuberculosis and many observers believe that apremilast will prove popular with patients and doctors due to the fact that it is oral, not injectable.

Apremilast was filed for PsA with the US Food and Drug Administration in the first quarter and will be submitted on both sides of the Atlantic for psoriasis before year-end. The European filing will also be for PsA.

Apremilast impresses for Behcet's disease

Celgene has also presented promising Phase II data on apremilast as a treatment for the rare inflammatory disorder Behcet’s disease. 71% of patients achieved complete response at week 12 in clearing oral ulcers and PharmaTimes will have more on the study later this week.