Celltrion and Portrai expand $87.75M joint R&D program to additional indications

SEOUL, KOREA — December 8, 2025 — Portrai Inc. today announced the expansion of its joint R&D program with Celltrion, extending the original $87.75M partnership to cover additional oncology indications including gastric and colorectal cancers. The expansion comes following successful spatial-biology-guided validation of two lead candidates over the past 12 months.

The expanded agreement introduces a formal joint R&D steering committee co-chaired by executive leadership from both organizations, and unlocks additional milestone-based funding tied to IND-enabling progression of POR-series assets.

Expanded Scope

Under the expanded program, Celltrion and Portrai will pursue joint discovery and validation work across three additional therapeutic areas:

• Gastric oncology — Spatial-PK profiling of novel ADC candidates against CLDN18.2 and related targets, with validation across 400+ patient samples from Portrai’s gastric cancer atlas.
• Colorectal oncology — De-risking ADC delivery to microsatellite-stable CRC tumors using Portrai’s TME-PK framework and single-cell level biodistribution analysis.
• Lung adenocarcinoma expansion — Deepening the existing lung program with additional modalities including RPT candidates, leveraging Portrai’s POR006-class validation infrastructure.

Leadership commentary

“The past year has validated what we set out to prove: that spatial biology can de-risk therapeutic decisions at every stage. Expanding this partnership is a natural next step for us and for Celltrion.” — Daeseung Lee, Co-founder & CEO, Portrai Inc.

A corresponding statement from Celltrion’s executive leadership will be released via their investor relations channel. Portrai and Celltrion will host a joint investor briefing on December 15, 2025 — registration details available via the Portrai BD team.

About the partnership

The Celltrion × Portrai joint R&D program launched in 2023 as one of the largest Korean TechBio partnerships to date. The original $87.75M commitment focused on lung oncology ADCs. With this expansion, the program becomes one of the largest spatial-biology-driven therapeutic partnerships globally.