FRIDAY, May 10, 2019 (Pharmacist's Briefing) -- Isradipine does not appear to slow progression of disability in patients with de novo Parkinson disease (PD), according to a study presented at the annual meeting of the American Academy of Neurology, held from May 4 to 10 in Philadelphia.
Tanya Simuni, M.D., from the Northwestern University Feinberg School of Medicine in Chicago, conducted a 36-month study to assess the efficacy of isradipine (10 mg daily) versus placebo for slowing progression of disability in de novo PD. A total of 336 participants were enrolled, with study retention of 95 percent.
The researchers found that the adjusted mean Unified Parkinson Disease Rating Scale (UPDRS) Part I to III score changes measured in the ON state at 36 months were 2.99 and 3.26 points in the isradipine and placebo groups, respectively, with a treatment effect of 0.27 points (95 percent confidence interval, −2.5 to 3.0; P = 0.85). No effect was seen for isradipine treatment in the key secondary outcomes in change in UPDRS-III in the OFF state, time to initiation and utilization of dopaminergic therapy, time to onset of motor complications, change in nonmotor disability, and quality-of-life measures. Edema was the most notable side effect of isradipine.
"Of course, this is disappointing news for everyone with Parkinson disease and their families, as well as the research community," Simuni said in a statement. "However, negative results are important because they provide a clear answer, especially for the drug that is commercially available. We will all continue to work to find a treatment that can slow down or even cure this disease."
Simuni disclosed financial ties to the pharmaceutical industry.