June 11 (Reuters) - Celgene Corp's experimental drug for psoriatic arthritis maintained its ability to significantly reduce painful symptoms through 52 weeks of treatment, according to data from a late stage study being presented this week at a medical meeting.
The U.S. biotechnology company had previously released positive data from the 500-patient Phase III trial called Palace-1 that compared its drug, apremilast, to a placebo through 16 weeks of treatment.
The data being presented at the European League Against Rheumatism in Madrid followed those patients through 52 weeks of treatment to assess longer term effectiveness and safety of apremilast.
At 52 weeks, 63 percent of patients who received 20 milligrams of apremilast twice daily and 55 percent who took 30 mg of the Celgene drug twice a day achieved at least a 20 percent reduction in signs and symptoms of the disease, such as painful, swollen or tender joints - a measure known as ACR 20.
That represented an improvement over time of the ACR 20 rates seen at 16 weeks. At that point of the study, 31.5 percent of the 20 mg patients and 50.8 percent of the 30 mg patients had achieved ACR 20.
Improvements were also seen in the number of patients who achieved 50 percent and 70 percent reductions in signs and symptoms of the disease as well, Celgene said.
At 52 weeks, 24.8 percent of those who got the 20 mg dose reached ACR 50 and 15.4 percent achieved ACR 70. For the higher dose of apremilast, 24.6 percent achieved ACR 50 and 13.8 percent hit ACR 70.
Psoriatic arthritis is a chronic inflammatory condition in which joint pain is caused by the immune system attacking healthy tissues. It affects about 30 percent of those who suffer from the painful and unsightly skin condition psoriasis.
Celgene earlier this year applied for U.S. approval for apremilast to treat psoriatic arthritis based on the results of this and two other late stage trials. It is planning to seek U.S. approval for apremilast to treat psoriasis later this year.
Patients in the Palace-1 study had previously been treated with oral disease modifying drugs, such as methotrexate, and/or biotech treatments known as anti-TNF drugs, such at AbbVie's Humira. It also included patients who failed to be helped by prior treatment with anti-TNF drugs.
Apremilast is a pill that inhibits an enzyme known as phosphodiesterase 4, or PDE4, and acts to reduce inflammation.
No serious safety issues, such as major heart problems, cancers, opportunistic infections or tuberculosis were reported for the 52 weeks of the trial.
Based on the results, apremilast appears to be somewhat less effective but safer than the widely used injected biologic anti-TNF medicines.
"There is a high unmet medical need for additional efficacious, well-tolerated treatment options for patients with psoriatic arthritis," Dr. Arthur Kavanaugh, who will present the data in Madrid, said through an email.