Tectonic Therapeutic (TECX) Conference presentation summary

Trial overview

• Single-ascending-dose TX2100 was generally safe and well tolerated in healthy adults; PK findings support exploring weekly and every-other-week SC dosing.

• The Phase 1 trial assessed safety, tolerability, PK and immunogenicity; single-dose cohorts were randomized, double-blind and placebo-controlled, while the multiple-dose cohort was open-label.

• Data cutoff was July 26, 2026; 49 participants were enrolled, with follow-up complete through 56 days for cohorts A–C, E and F.

Rationale and preclinical findings

• APJ is enriched in endothelial cells, and apelin-driven APJ activation promotes sprouting angiogenesis; increased apelin expression is linked to telangiectasia and AVM formation in BMP9/ENG/ALK1 pathway loss-of-function.

• TX2100 is a selective VHH-Fc APJ antagonist that blocks apelin-driven signaling and is designed as an endothelial-enriched, pathology-biased anti-angiogenic therapy.

• A surrogate APJ antagonist reduced AVMs, bleeding and anemia in two HHT mouse models; 13-week GLP toxicology found a NOAEL of 100 mg/kg/week IV and SC in nonhuman primates.

Safety and tolerability

• TEAEs were mild to moderate and transient; two moderate events, myalgia and food poisoning, were considered unrelated to study drug by the investigator.

• No serious, severe (Grade ≥3), fatal or discontinuation-causing TEAEs were reported; no dose-limiting AEs or emerging safety issues were observed.

• No clinically significant or dose-related changes in vital signs, laboratory assessments or ECG parameters were observed; no blood pressure increases were reported.