Seaport Therapeutics (SPTX): Phase 2b depression data in 1H27 to validate the novel approach

Research evidence excerpt

Seaport Therapeutics (SPTX): Phase 2b depression data in 1H27 to validate the novel approach

Goldman Sachs Seaport Therapeutics (SPTX)

perform a sample size re-estimation (SSRE).

Separately, SPTX has dosed first participant in Ph1 driving simulation trial of GlyphAllo

(with data expected 2H26), designed to be a standard driving simulation study. These

studies are typically conducted with PM dosing and next day driving after a full night’s

sleep. For context, there is a full driving restriction for patients enrolled in the BOUY-1

trial in the US, and a shorter, six-hour driving restriction for patients enrolled in the EU.

Zurzuvae carries a black box warning due to its potential impact activities requiring

complex cognition, including driving. Per Zuzuvae’s labels, patients must not drive or

engage in potentially hazardous activities (such as operating machinery) for at least 12

hours after each dose. However, due to the therapeutic exposure levels of demonstrated

by GlyphAllo, which are comparable to those that occur naturally during the third

trimester of pregnancy and dropped to 15% of Cmax by eight hours post-dose following

administration, we see the potential for GlyphAllo to reduce or eliminate next-day

somnolence or drowsiness.

SPTX expects topline data from the Ph2b BUOY-1 trial in 1H27. Based on the results of

the Ph2b clinical trial, the company intends to consult with the FDA about the potential

to use this trial to support a registrational filing for MDD. While SPTX has not disclosed

guidance on the powering of BUOY-1, we note that a placebo-adjusted improvement of

0.3 on the primary endpoint of Hamilton Depression Rating Scale-17 (HAM-D-17) total

score has been typical of approved antidepressants.