The drug, oligonucleotide therapeutic WVE-120102, is sent directly into the spinal canal.
The trial, which compared the drug with a placebo, showed a statistically significant 12.4% reduction in a disease-causing mutant huntingtin protein, the company said in a statement.
“An analysis to assess a dose response across treatment groups (2, 4, 8 or 16 mg) suggested a statistically significant response" in reduction of this protein "at the highest doses tested,” the statement said.
But “there was no difference" in total huntingtin protein compared with placebo, the Singapore company said.
When it comes to safety, the drug was “generally safe and well tolerated among patients receiving doses up to 16 mg in both single and multidose portions of the study,” Wave Life Sciences said.
The test was a Phase 1b/2a Precision-HD2 trial. Data from another Phase 1b/2a study, Precision-HD1, evaluating WVE-120101 in early manifest Huntington patients should be available in the second half of next year, Wave Life Sciences said.
The data do support “exploration of higher doses of WVE-120102, with the goal of maximizing mutant HTT reduction and avoiding a negative impact on the healthy huntingtin protein," said Michael Panzara, a physician and chief medical officer of Wave Life Sciences.
"We plan to initiate the 32 mg cohort imminently and look forward to sharing data in the second half of 2020."
Huntington disease, often appearing in adults in their 30s and 40s, “is a progressive brain disorder that causes uncontrolled movements, emotional problems, and loss of thinking ability,” the National Institutes of Health says.
The stock at last check stood at $8, off 49%. The drop follows a 55% decline Dec. 16, after Wave Life Sciences said it would abandon development of two Duchenne muscular dystrophy treatments.
The company’s shares are off 81% over the past year, compared with a 28% increase for the S&P 500 index.