By Toni Clarke
(Reuters) - Celgene Corp said on Thursday its experimental treatment for psoriatic arthritis was effective in a late-stage clinical trial, with no significant safety issues.
The company said it expects to file for marketing approval of the drug, apremilast, in the first half of next year.
Psoriatic arthritis is a chronic, inflammatory disease that affects the joints and causes pain, stiffness and swelling. It is associated with the skin disorder, psoriasis.
The study, known as PALACE-1, is the first of three late-stage trials of the drug, a pill which inhibits an enzyme known as phosphodiesterase 4, or PDE4, and acts to damp down inflammation.
Celgene said a statistically significant proportion of patients in the 495-patient trial achieved a 20 percent improvement in symptoms at 24 weeks, as measured by a score determined by the American College of Rheumatology.
The company did not give the exact number of patients who achieved the benefit.
The company tested the drug at 20 mg and 30 mg. It said a significant proportion of patients taking the 20 mg and 30 mg doses achieved an improvement of 50 percent. A proportion of those taking the 30 mg dose even achieved a 70 percent improvement.
Analysts reacted with cautious optimism to the news.
"Although we need more detailed data to fully assess apremilast's overall profile in psoriatic arthritis, we feel this is much needed good news for Celgene," said Brian Abrahams, an analyst at Wells Fargo Securities, in a research note.
Still, Celgene's shares fell 1.4 percent to $62.43 in midday trading on Nasdaq.
The company said that a pilot study of apremilast as a treatment for rheumatoid arthritis, when given in combination with the treatment methotrexate, did not achieve its main goal. Data from a second study testing the drug without methotrexate are expected in the third quarter of this year.
Celgene said it is examining whether the methotrexate dampened the impact of apremilast in the combination study and said it plans to continue development of the drug in rheumatoid arthritis.
The company is also testing apremilast in psoriasis and expects to start reporting data from two late-stage studies by the end of this year, and to file for marketing approval in the second half of next year.
In Europe, the company plans to file for both the psoriasis and psoriatic arthritis indications together in the second half of the year.
Side effects were consistent with those seen in earlier trials, with gastrointestinal disturbances and upper respiratory tract infections the most common. However, they were not more prevalent in the treatment group than the placebo group.
"Overall, we view today's news as an incremental positive," said Geoff Meacham, an analyst at J.P. Morgan, in a research note. "However, more detailed efficacy and safety data are needed before the Street ascribes meaningful value to the apremilast program."
(Reporting by Toni Clarke; Editing by Bernadette Baum and Marguerita Choy)