By Bill Berkrot
(Reuters) - Previously untreated patients experienced significant and lasting reductions in signs and symptoms of psoriatic arthritis when given Celgene Corp's experimental oral drug, apremilast, according to data from a late stage clinical trial.
Patients taking either the 20 milligrams or 30 mg dose of apremilast twice a day had a statistically significant improvement in symptoms, such as painful, swollen joints, after 16 weeks of treatment compared with those who received a placebo, researchers said.
Signs and symptoms of the painful disease continued to improve on apremilast through a year of treatment, according to data to be presented next week at the American College of Rheumatology meeting in San Diego.
If approved, apremilast will compete with injected biotech medicines that have proved to be highly effective, but have more serious potential side effects, such as opportunistic infections and tuberculosis because the biologics suppress the immune system.
"Psoriatic arthritis can be one of the most crippling types of arthritis that we see," said Dr. Alvin Wells, the lead investigator of the 527-patient study who will present the data at the ACR meeting on Tuesday.
"To be able to have a patient that can take a pill twice a day, I think this is going to be a game changer, not only for me as a physician, but for my patients. They're going to have a new treatment option," added Wells, director of the Rheumatology and Immunotherapy Center in Franklin, Wisconsin.
The U.S. Food and Drug Administration is expected to make an decision on the drug in March.
Celgene has said sales of apremilast could reach $1.5 billion by 2017. Wall Street analysts' projections have been more modest, with RBC Capital Markets forecasting sales of $1 billion in 2017, while Cowen and Co sees annual sales reaching $475 million in 2018.
The primary goal of the study dubbed Palace 4 was a 20 percent reduction in signs and symptoms of the disease, known as ACR20, after 16 weeks versus placebo.
At that point, 29.2 percent of those who got the 20 mg dose and 32.3 percent to took 30 mg achieved ACR 20, compared with 16.9 percent on placebo.
After 52 weeks on the drug, 53.4 percent on the lower dose and 58.7 percent on the higher dose achieved an ACR20 response.
"These patients are on drug a long time so I want to see that it's going to last," said Wells, calling the results "a pretty dramatic response."
Placebo patients who did not respond early in the trial were switched to apremilast. By week 24 there were no longer any patients receiving placebo, Wells explained.
Researchers also looked at how many patients experienced improvements of 50 percent and 70 percent.
At 52 weeks, for those on the higher dose of apremilast, 31.9 percent had achieved ACR50 and 18.1 percent ACR70, researchers said.
About 125 million people worldwide suffer from the scaly skin condition psoriasis and about 30 percent of them can develop psoriatic arthritis, a chronic, progressive disease in which joints become swollen and inflamed.
Apremilast is the first drug in a new class of medicine called PDE4 inhibitors.
"It inhibits an enzyme involved in making all these angry proteins that get into the skin, causing psoriasis, and they also get into the joints, causing arthritis," Wells said.
The most common side effects with apremilast were diarrhea, nausea and headache. No more serious adverse side effects were reported, and fewer than 2 percent of patients in the study discontinued treatment due to side effects.
(Reporting by Bill Berkrot. Editing by Andre Grenon)