Merck KGaA and Italian partner Newron Pharmaceuticals say they are encouraged by data on safinamide even though their investigational Parkinson's disease drug has missed its primary endpoint in a late-stage trial.

The firms announced the top-line results of a 544-patient 18-month extension trial (study 018) of a previously-reported six-month Phase III study of safinamide, assessing the long-term efficacy and safety of two doses (50mg and 100mg) as add-on therapy to levodopa in patients with advanced Parkinson’s disease. While the primary efficacy endpoint of study 018 measuring dyskinesia after 24 months of treatment was not met, the German firm's Merck Serono unit said "results of the exploratory analysis of the pre-specified main secondary endpoint were consistent with the effect on motor function" observed in the earlier study. The data also further support the safety profile of safinamide, the firm said.

Newron chief executive Luca Benatti said that "these results in such a rigorously-controlled long-term double blind study are particularly relevant as they address key questions in terms of long-term safety and maintenance of the effect on motor function of safinamide over time". These results 'may offer new hope to patients with Parkinson’s disease as they need to take medications for long periods of time," he added. Bernhard Kirschbaum, Merck Serono’s head of R&D, agreed the data was encouraging and noted that "the effect of safinamide on dyskinesia will be further explored in an ongoing dedicated pilot study.”

Analysts at broker Helvea were not too concerned about safinamide missing the primary endpoint either. They argue that the data from study 018 "have supportive character" for filing the drug in Parkinson's, saying "it is important to note that only 32% of patients showed troublesome diskinesia at baseline and this little number could explain the non-statistical results".

Helvea's Olav Zilian said that safinamide has "excellent prospects to make it to the market  as an innovative anti-PD medication". Peak sales are expected to reach 700 million euros for the drug which Merck licensed from Newron in 2006.