* Celgene says 41 pct of patients saw 20 pct improvement
* Safety profile remains benign; mostly nausea, diarrhea
* Subgroup of patients saw significantly better results
By Toni Clarke
Nov 13 Celgene Corp's experimental treatment for psoriatic arthritis, apremilast, proved to be modestly effective compared with leading treatments in a late-stage study, and it showed fewer side effects, according to data released by the company on Tuesday,
Data released at the annual meeting of the American College of Rheumatology showed that 41 percent of patients who took 30 milligrams of apremilast twice daily achieved a 20 percent improvement in symptoms after 16 weeks, compared with 19.4 percent who took a placebo.
Psoriatic arthritis is a chronic, inflammatory disease that affects the joints and causes pain, stiffness and swelling. It is associated with psoriasis, a skin disorder.
The study, known as PALACE-1, is the first of three late-stage trials of the drug, a pill that inhibits an enzyme known as phosphodiesterase 4, or PDE4, and acts to damp down inflammation. The results of the remaining trials will be released within the next several months.
Currently, psoriatic arthritis is treated with a variety of drugs, the most effective being injectable biologics such as Abbott Laboratories' Humira, Amgen Inc's Enbrel, and Johnson & Johnson's Remicade and Simponi.
The results met the main goal of the clinical trial, but they were not as robust as the biologics.
"While these efficacy results might be acceptable in a disease like psoriasis, we don't view them as sufficient for a disease characterized by ongoing joint destruction and progressive disability," said Geoffrey Porges, an analyst at Sanford Bernstein, in a recent research report based on an initial summary of the data.
A table compiled by Porges shows that between 50 percent and 57 percent of patients taking standard biologics achieved a 20 percent improvement in symptoms after 24 weeks in clinical trials.
Patients in the PALACE-1 trial took apremilast with or without a variety of other therapies. Celgene said that those who took apremilast alone - somewhat fewer than half the 500 patients in the trial - had a much better response than those who took the drug in combination with other treatments.
About 50.8 percent of those who took 30 milligrams of apremilast twice daily as a monotherapy experienced a 20 percent improvement in symptoms.
How important that figure will be to physicians remains to be seen since it is not the number Celgene will use to file for marketing approval with regulators.
Only 20 percent of patients taking apremilast in the study experienced a 50 percent improvement in symptoms, and only 11 percent saw in improvement of 70 percent or more after 16 weeks. Those figures are also lower than those seen with the biologics.
Celgene expects to file for U.S. approval of the drug in treating psoriatic arthritis in the first half of 2013.
On the plus side, apremilast appears considerably safer than the biologic drugs, which block a protein known as tumor necrosis factor and can increase the risk of infections, certain types of cancer, and tuberculosis.
The most common side effects with apremilast, which is also being tested as a treatment for psoriasis, were gastrointestinal disturbances such as nausea and diarrhea.
Celgene expects to begin reporting data from two late-stage studies of the drug in psoriasis by the end of this year and to file for marketing approval in the second half of next year.
In Europe, the company has said it plans to file for both the psoriasis and psoriatic arthritis indications together in the second half of the year.
(Reporting By Toni Clarke)