PureTech Founded Entity Seaport Therapeutics Presents Additional Pharmacokinetic Data from Phase 1 Clinical Trial of GlyphAgo™ at the 39th European College of Neuropsychopharmacology (ECNP) Congress

BOSTON, October 09, 2026--PureTech Health plc (LSE: PRTC) ("PureTech" or the "Company"), a hub-and-spoke biotherapeutics company dedicated to giving life to science and transforming innovation into value, notes that its Founded Entity, Seaport Therapeutics, today announced the presentation of Phase 1 clinical data for GlyphAgo™ (SPT-320 or Glyph Agomelatine) at the 39th European College of Neuropsychopharmacology (ECNP) Congress, taking place October 10-13, 2026, in Munich, Germany. The poster represents the first scientific presentation of data from the GlyphAgo Phase 1 program and provides detailed pharmacokinetic (PK) analyses supporting previously reported topline results and reinforcing GlyphAgo's differentiated profile.

GlyphAgo is a novel, "Glyphed" oral prodrug of agomelatine designed to enhance lymphatic absorption and bypass first-pass liver metabolism. In the Phase 1 program, GlyphAgo demonstrated a statistically significant 6.8-fold increase in bioavailability of agomelatine compared to unmodified agomelatine and showed significantly lower (10-fold) PK variability. GlyphAgo achieved therapeutically relevant exposure of agomelatine at substantially lower doses that are designed to reduce liver exposure. Seaport believes this approach has the potential to reduce the risk of liver enzyme elevations and reduce the need for routine liver function monitoring that has historically limited agomelatine's clinical use.

Seaport has initiated a Phase 2a clinical trial evaluating GlyphAgo in adults with generalized anxiety disorder and sleep disturbance, with topline results expected in early 2028. Seaport also plans to initiate a Phase 2/3 clinical trial evaluating the efficacy and safety of GlyphAgo in patients with generalized anxiety disorder in the first half of 2027.

The full text of the announcement from Seaport is as follows:

Seaport Therapeutics Presents Additional Pharmacokinetic Data from Phase 1 Clinical Trial of GlyphAgo™ at the 39th European College of Neuropsychopharmacology (ECNP) Congress

First scientific presentation of detailed PK data demonstrates dose-dependent increases in agomelatine exposure, no food effect, and no accumulation of exposure over seven days of dosing

Detailed data reinforces previously reported topline results demonstrating that GlyphAgo achieved a statistically significant 6.8-fold increase in agomelatine bioavailability and substantially lower (10-fold) PK variability compared to unmodified agomelatine

Agomelatine levels comparable to those seen with efficacious doses of the unmodified drug were achieved at substantially lower doses, intended to reduce hepatic exposure and the potential for liver enzyme elevations