Shares in Newron Pharmaceuticals have fallen almost 59% after the Italian drugmaker’s neuropathic low back pain drug ralfinamide disappointed in a Phase IIb/III trial.

The 12-week study enrolled 411 patients with chronic NLBP of at least moderate severity and “did not detect any significant difference” between ralfinamide and placebo. The Milan-headquartered company, which is listed on the SIX Swiss Exchange, said further analyses of additional endpoints are currently ongoing and will be reviewed with its external advisors.

After that, Newron says that “based on the multiple central nervous system effects seen in animal pharmacology models, and the excellent human safety data”, it will decide how to proceed further with the ralfinamide. Chief executive Luca Benatti, said “we are extremely surprised and disappointed by the results, based on the statistically significant benefits shown in a Phase II placebo-controlled trial, as well as the results from a large number of preclinical studies”.

He added that Newron will also review “our development resource needs going forward”. Mr Benatti said the firm has broad portfolio of products which is headed by the experimental Parkinson's treatment safinamide,a late-stage compound partnered with Merck KGaA. This, combined with existing cash resources and equity lines of credit, “gives Newron continued potential for growth and value generation”.