Vanda Pharmaceuticals says Phase III HETLIOZ study met sleep endpoint

A 37.1-minute placebo-adjusted advance in sleep onset marked a positive Phase III result as Vanda Pharmaceuticals Inc. NASDAQVNDA reported on Tuesday that its HETLIOZ study met the primary endpoint in adults with delayed sleep-wake phase disorder. Vanda plans to seek a third U.S. indication for the 20 mg medicine through a supplemental application; its Sept. 29 release gives no filing date.

The release says the trial enrolled 43 adults, while its efficacy table reports 20 participants on tasimelteon and 20 on placebo. It leaves the difference between the enrollment count and the table totals unexplained.

Vanda is a U.S. small-cap drug maker selling HETLIOZ and other specialty medicines. HETLIOZ has two existing U.S. uses; the proposed indication addresses a different circadian disorder.

Vanda shares NASDAQVNDA closed at US$5.03 on Nasdaq at 4 p.m. EDT on Sept. 29, down 2.71 per cent. That close preceded the company's evening release, so it is a pre-readout trading baseline.

Sleep Diaries Showed Earlier Sleep Onset

Participants received once-daily oral tasimelteon or matching placebo for 28 days in a randomized, double-blind study. In Vanda's reported primary analysis, the treatment group fell asleep 42.5 minutes earlier on average, against a 5.4-minute advance on placebo. The placebo-adjusted difference was 37.1 minutes (p=0.022), based on sleep diaries.

An exploratory analysis found a sleep-onset advance of at least 30 minutes in 12 of 20 tasimelteon recipients. Three of 20 placebo recipients met that threshold, with Vanda reporting p=0.008 for the comparison. That result was exploratory, separate from the trial's primary test.

Vanda said safety over the controlled period was consistent with the established HETLIOZ label and that it found no new safety signals. The Sept. 29 release did not give adverse-event rates or report FDA feedback accepting this trial design as sufficient for the proposed indication.

"We look forward to discussing these data with the FDA and pursuing a new indication for HETLIOZ® as the first ever approved treatment for DSWPD," Vanda president and chief executive Mihael H. Polymeropoulos said in the Sept. 29 release.

Vanda Plans Supplemental Application

HETLIOZ already has U.S. indications for Non-24-Hour Sleep-Wake Disorder in adults and nighttime sleep disturbances in Smith-Magenis syndrome. Vanda estimates delayed sleep-wake phase disorder affects roughly 0.5 million to 4.1 million U.S. adults. Those prevalence estimates do not measure diagnosed patients, insured access or potential HETLIOZ sales.

Vanda intends to discuss the trial results with the FDA and submit a supplemental new drug application for delayed sleep-wake phase disorder. The Sept. 29 release gives no date for either step.

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Vanda's Aug. 5 quarterly report put cash, equivalents and marketable securities at US$170 million on June 30. Based on that balance and anticipated product revenue, it expected funding through at least the end of 2027. HETLIOZ net product sales were US$5.6 million in the June quarter, down 66 per cent year over year; Vanda said about US$7 million of shipments arriving in July would be recognized in the following quarter.

The comparison screen includes Jazz Pharmaceuticals plc NASDAQJAZZ, which closed at US$232.35 on Nasdaq at 4 p.m. EDT on Sept. 29, and Harmony Biosciences Holdings, Inc. NASDAQHRMY. Those listings are market reference points; neither establishes demand for Vanda's proposed indication.

Vanda's Aug. 5 quarterly report lists a Dec. 12 FDA target action date for its separate Quimilza application for generalized pustular psoriasis. The Sept. 29 release gives no date for Vanda's planned HETLIOZ discussion or supplemental filing.