The initial results of the Steady-PD3 study indicated that there was no effect, however a recent post -hoc analysis of the trial data has highlighted some interesting effects.
The Steady-PD3 study was a very large clinical trial evaluating whether a blood pressure medication called isradipine could slow the progression of Parkinson’s in people who have recently been diagnosed.
Isradipine is a drug that belongs to a class of medications called calcium channel blockers. They are used in the treatment of high blood pressure. Several large population studies have previously indicated that people being treated with calcium channel blockers have a reduced risk of developing Parkinson’s and isradipine has been shown to have beneficial effects in models of Parkinson’s.
These interesting findings led to a series of clinical trials that culminated in 2020, with the publication of the results of a large phase III clinical trial. The Steady-PD3 study involved 300 people – who had recently been diagnosed with Parkinson’s – being treated for 3 years with isradipine, and the results of the study indicated that the drug had no impact on the progression of Parkinson’s.
Recently, however, researchers involved in the study have been re-examining the trial data and they have identified some interesting effects. In particular, they found that participants in the study who were exposed to higher levels of isradipine were delayed in needing to start Parkinson’s treatment (like L-dopa) over 36 months when compared with individuals on the placebo treatment. It also reduced the amount of levodopa needed when medication was initiated.
It is important to remember that this analysis is post-hoc (after the results of the study are known) and the researchers acknowledge that these observations need to be investigated further. Caution must also be taken as high doses of the drug have been found to be intolerable and potentially hazardous to health. However, a better understanding of this effect may provide important insights into the underlying biology of Parkinson’s and our search for curative treatments.
