The U.S. Drug Enforcement Agency on Tuesday granted approval to Tilray, Inc. to import research-grade marijuana products from Canada for a clinical trial at the University of California San Diego.

Tilray, Inc.'s shares spiked more than 16 percent Tuesday morning on the news that it will provide a cannabinoids for a study on essential tremor (ET), a neurological movement disorder characterized by involuntary and rhythmic shaking. The clinical trial, which will start in 2019, will be conducted at the university's Center for Medicinal Cannabis Research (CMCR). According to the CMCR, current drugs to treat essential tremor (originally developed for high blood pressure or seizures) are ineffective for many patients.

According to the International Essential Tremor Foundation, the disorder strikes millions of Americans. Between 4.6 and 6.3 percent of the general population aged 65 and older suffer from ET.

Tilray's investigational product — a formulation of cannabidiol (CBD) and low-dose tetrahydrocannabinol (THC) — will be given to patients in capsule form.

The double-blind, placebo-control, cross-over clinical trial will enroll 16 adults who have been diagnosed with ET by a movement disorder neurologist. All  participants will be given an oral cannabis formulation with a 20:1 ratio of CBD to THC. After two-weeks, participants will taper off, followed by a washout period before crossing over to the alternate study arm.

"Tilray is proud to support this crucial research," says Catherine Jacobson, Tilray's director of clinical research. "If this study can identify cannabinoids as a potential treatment for patients suffering from essential tremor, we can conduct further research and potentially provide alternative effective methods of relief for the high numbers of patients with ET."

Tilray was first listed on NASDAQ in July at $17 a share and was trading this afternoon for $151.