NEW YORK (Reuters Health)—Aggregated results from three studies of patients with moderate to severe plaque psoriasis show that Eli Lilly’s injectable drug ixekizumab can completely resolve the plaques in about one third of cases after 12 weeks of treatment.
And with continued therapy every four weeks, at least half maintained or attained complete resolution of their psoriasis for the duration of the 60-week studies, according to the team led by Dr. Kenneth Gordon of Northwestern University Feinberg School of Medicine in Chicago.
Eli Lilly paid for the three UNCOVER studies and did the data analysis. The tests served as a basis for the U.S. Food and Drug Administration’s approval of the drug, sold under the brand name Taltz, in March. The results were published online by the New England Journal of Medicine.
About 1.5 million Americans are affected by plaque psoriasis. In all, 3,736 volunteers were tested at 100 sites worldwide. The patients in these studies had been dealing with the condition for an average of 20 years. The mean surface coverage area was more than 25% of the body.
In the early phase of the trial, people who received a subcutaneous injection every two weeks did a bit better than volunteers who received the drug every four weeks. More than 80% had complete or near-complete resolution of their plaques.
After the initial 12-week phase, the drug was given every four weeks or every 12 weeks.
Among those who had gotten the treatment every two weeks during the first 12 weeks of the study, 83.3% scored a 75% reduction in disease severity on the Psoriasis Area and Severity Index (PASI) by the end of follow-up therapy.
When the drug was given once a month during the full 60 weeks of the test, 74.4% had a 75% reduction in their PASI score.
When the drug was given every 12 weeks during the follow-up period, fewer than half the patients logged a 75% drop in their PASI score by the 60-week mark, regardless of whether they got ixekizumab every two weeks or every four weeks during the first 12 weeks of the study.
The researchers did not see any increase in cardiovascular problems during the 12-week induction therapy despite earlier indications that it might be a problem. During the 60-week test there were two deaths from vascular causes. A third death is attributed in the paper to “unknown causes.”
Inflammatory bowel disease appeared in 11 patients getting the drug versus 3 people given placebo injections. The researchers say “further evaluation is needed to understand the relationship.”
Among all volunteers with some degree of ixekizumab exposure, 6.7% had a serious adverse event; 4.4% discontinued the study because of side effects.
Just under 20% had nasopharyngitis, 10.0% had an upper respiratory tract infection, 10.4% had an injection site reaction, 6.5% reported headache and 5.2% had arthralgia.
Neutropenia rates were 8.6% (grade one), 2.6% (grade 2), 0.2% (grade 3) and 0.1% (grade 4).
Candida infections were also more common among ixekizumab recipients.
Dr. Gordon said the volunteers will continue to be followed beyond 60 weeks.
The drug works by blocking a protein that causes inflammation, which is believed to play a role in development of the autoimmune disorder characterized by red skin and thick, unsightly, scaly white patches.
Lilly spokesman J. Scott MacGregor says the list price will be about $4,000 per month depending on the stage of treatment, although costs to patients would actually be much lower because of discounts and because of the company’s co-pay assistance program.
“We don’t want out-of-pocket cost to prevent patients from getting Taltz,” MacGregor says in an email.