Definium Therapeutics said on Wednesday its LSD-based ​experimental pill significantly reduced anxiety symptoms in a late-stage study, meeting ‌the trial's main goal and sending the drug developer's ​shares up more than 20% premarket.

The 214-patient trial ⁠tested a single 100-microgram dose of DT120, a fast-dissolving tablet of lysergide, the chemical name for LSD, in adults with generalized anxiety disorder, ‌or GAD.

Patients on the drug had an 11.6-point drop on a standard anxiety rating scale at ‌week 12, compared with a 6.2-point drop for those ‌on ⁠a placebo.

The placebo-adjusted difference of 5.4 points ⁠was statistically significant and clinically meaningful, the company said.

RBC Capital Markets analyst Brian Abrahams said the data exceeded Wall Street's expectations and the efficacy seen with other ​therapies for the disease.

The ‌benefit emerged as early as two days after dosing and lasted throughout the 12-week study.

The drug belongs to a class of compounds known as psychedelic medicines.

Regulatory and investor ‌enthusiasm for psychedelic-based therapies has helped Definium shares more ​than triple so far this year.

In April, U.S. President Donald Trump signed an executive order directing ⁠federal agencies to speed up access to research and treatments based on psychedelic drugs for serious mental health conditions.

GAD is characterised ‌by persistent and excessive worry that can interfere with daily life. It affects about 26 million U.S. adults and is commonly treated with antidepressants, anti-anxiety medicines and psychotherapy.

No new drug has been approved for the condition in nearly two decades, according to Brian Barnett, a Cleveland Clinic psychiatrist who ‌worked on the study.

Unlike most anxiety medicines, which are typically taken regularly, ​DT120 is designed to be administered as a single dose during a monitored dosing session. It ⁠works by acting on brain receptors involved in mood and perception.

Most ⁠side effects were mild to moderate and temporary,occurring mainly on the day of dosing, with no ‌increase in suicidal thoughts.

The trial is Definium's second late-stage success for DT120, following a positive readout in a depression ​study in June.