Vertex Pharmaceuticals' non-opioid painkiller has succeeded in significantly reducing nerve pain in patients in a mid-stage trial, the company said on Wednesday, sending its shares up more than 7% in premarket trading.

The trial studied the drug, called VX-548, in patients with diabetic peripheral neuropathy, a type of nerve damage caused by high blood sugar.

The non-opioid painkiller is Vertex's next big bet as it seeks to expand beyond treatments for cystic fibrosis (CF), a genetic condition that results in serious lung infections, declining lung function and often early death.

The company is also testing the drug in keenly watched late-stage studies for acute pain, with data due in the first quarter of next year.

In a boost to its non-CF ambitions, Vertex recently gained approval for its sickle cell disease gene therapy with partner CRISPR Therapeutics based on a Nobel Prize-winning gene editing technology.

Treatment with VX-548 resulted in a statistically significant reduction in weekly average of daily pain intensity, as measured on a scale at 12 weeks, Vertex said.

On the scale, which ranges from 0 for no pain to 10 for worst pain imaginable, patients treated with the drug showed reductions of 2.26, 2.11 and 2.18 at the high, mid and low doses, respectively.

The study also included a reference arm of 100 milligram dose of pregabalin, also known as Lyrica, a medication that treats nerve pain.

The company plans to advance the study of the drug in a late-stage trial, following discussions with regulators.

It has also initiated a second mid-stage study that will evaluate the drug in patients with painful lumbosacral radiculopathy, which is pain caused by impairment or injury to nerve roots in the area of the lumbar spine.