Brodalumab, a drug being developed by Amgen Inc for treatment of psoriatic
arthritis has proven to be efficacious after a year of treatment, concludes a recent
The use of brodalumab for psoriatic arthritis resulted in a substantial improvement in skin condition and brought about a reduction in dactylitis, a condition that features the swelling of the fingers and toes and is commonly found in psoriatic arthritis patients, according to the study's lead researcher, Dr. Philip Mease, a rheumatologist at Swedish Medical Center in Seattle.
Psoriatic arthritis is a chronic inflammatory disease of the skin and joints and affects as many as 30% of people who suffer from psoriasis.
As in psoriasis, symptoms in psoriatic arthritis also come and go and vary from person to person. They even change locations over a period of time.
Brodalumab falls under a category of drugs called IL-17 inhibitors. IL-17 inhibitors block a signaling pathway that plays a vital role in triggering and developing inflammatory diseases.
A 68-patient trial of the biotech drug, brodalumab, was conducted and a 12-week data presented by Amben and its partner AstraZeneca Plc. The data showed the relative superiority of the drug over a placebo in terms of efficacy.
The patients were classified under 3 groups: Those who got 140 milligrams of brodalumab every two weeks, those who received 280 milligrams of the drug and those who received the placebo. At the end of the 12 weeks, patients from all the 3 groups were given the maximum dose over a span of the next 40 weeks. A significant improvement in the disease condition was noticed at the end of the trial.
Findings at the end of 52 weeks showed 71 percent of patients who from the start received the 140 mg dose, 56 percent of patients who received 280 mg from the beginning and 50 percent of the original placebo group had hit ACR20.
Findings at 12 weeks showed 37 percent of the minimum-dose group and 39 percent of the high-dose group had reached the goal of ACR20, whereas only 18 percent of the placebo group had hit the target.
ACR20 is a unit of measurement that signifies at least 20 percent improvement in signs and symptoms of psoriatic arthritis.
ACR50 indicates a 50 percent progress in disease signs and symptoms. This goal was reached by 47 percent of the original 140-mg patients and 27 percent of the original 280-mg patients at a year.
ACR70 was achieved by 22 percent of the first group and 7 percent of the second group.
Of the placebo group, those who switched to 280 mg, the ACR50 rate was 38 percent and ACR70, 14 percent.
Research firm ISI Group has predicted annual peak sales of about $2 billion for the drug.
Patients involved in the study suffered from psoriasis in varied degrees, and they had failed at least one therapy. About one half of them had stopped responding to injectable biologic medicines known as anti-TNF drugs, including Humira and Enbrel as the efficacy of anti-TNF drugs tends to diminish over a period of time.
"It's hopeful that this (anti-IL-17) mechanism is central enough that they're going to have responses despite the failure of anti-TNF therapy," Mease said.
Four cases of serious adverse events were reported, that included one patient who was severely infected and another one with complaint of abdominal pain, but no deaths were reported.
Mease, the study's lead researcher, also noted that psoriatic arthritis is a genetic disorder that distinguishes it from other types of arthritis.
"There are also certain genes that are present in people who develop the arthritis that are not present in people with psoriasis. So there seems to be a heavy genetic component for determining who gets psoriasis and goes on to get psoriatic arthritis," he said.
At present, psoriatic arthritis is treated based on the degree of pain experienced by the patient. The treatment begins with painkillers, such as ibuprofen or naproxen..
Mease said methotrexate is given to treat patients suffering from both arthritis and psoriasis. Other drugs included in the biologic therapy that are helpful in treating both conditions are adalimumab, etanercept, golimumab and infliximab.
Findings of the study were published June 12 in the New England Journal of Medicine. They will be presented at the European Congress of Rheumatology's annual meeting in Paris on Thursday.