K-679: A Novel Antibody Drug-loaded Unimicelle Conjugate Demonstrates Tumor-Selective Pharmacokinetics, Extensive Intratumoral Distribution and Superior Efficacy in Non-Clinical Animal Models

NAGOYA, Japan, April 6, 2026 /PRNewswire/ -- Kowa Company, Ltd. (Headquarters: Nagoya, Aichi Prefecture, Japan), today announced an upcoming presentation of non-clinical data for K‑679, its novel antibody drug-loaded unimicelle conjugate (ADUC) with unprecedented drug loading capacity. The compound, developed using Kowa's proprietary micelle technology, has demonstrated tumor-selective pharmacokinetics, extensive intratumoral distribution, and superior efficacy in EGFR-expressing solid tumors compared to conventional antibody drug conjugates (ADCs). The data will be presented at The American Association for Cancer Research (AACR) Annual Meeting 2026 to be held in San Diego, California, from April 17 to 22, 2026.

Presentation Details
Presentation Title: Selective intratumoral distribution and post-T-DXd activity of K-679, an ultra-high-DAR EGFR-targeted antibody drug-loaded unimicelle conjugate (ADUC)
Session Title: Antibody Technologies and Platforms 2
Presentation Date and Time: April 21, 2026, 9:00 a.m. – 12:00 p.m. CST (10:00 a.m. – 1:00 p.m. ET)
Poster Number: 4396
Presenter: Hideo Yoshida

The abstract of the presentation is available at  AACR Annual Meeting 2026 Itinerary Planner | Presentation

More information about the AACR Annual Meeting 2026 can be found on the event website at the following link: AACR Annual Meeting 2026 | Meetings | AACR

About K-679
K-679 is an Antibody Drug-loaded Unimicelle Conjugate (ADUC), a novel type of ADC using Kowa's proprietary micelle technology, currently in nonclinical development. The conjugate combines an anti-EGFR antibody with drug (DM1)-loaded unimicelles, which incorporate substantial quantities of payloads into a single-chain polymer. This innovative approach achieves an ultra-high DAR (Drug-to-Antibody Ratio) of approximately 45 DM1 molecules per antibody, significantly higher than conventional ADCs.

In non-clinical studies, K-679 has demonstrated tumor-selective pharmacokinetics, extensive intratumoral distribution, and concordant spatial pharmacodynamic effects in xenograft models, compared with a benchmark antibody-drug conjugate (ADC). K-679 also showed anti-tumor activity in colorectal patient-derived xenograft (PDX) models with low and heterogeneous epidermal growth factor receptor (EGFR) expression.

Media Contact:
Ian Mehr
Kowa Research Institute, Inc.
919-433-1600
imehr@kowaus.com

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