[AACR 2026] NEOK Bio Highlights NEOK001, NEOK002

The San Diego Convention Center in the U.S., where AACR 2026 was held on April 17. / Photo by Reporter Sun-kyung Kim.

NEOK Bio, the U.S. subsidiary of ABL Bio, presented two posters at the American Association for Cancer Research (AACR 2026) on April 20, showcasing its next-generation bispecific antibody–drug conjugate (ADC) pipeline, NEOK001 and NEOK002.

The data highlight the potential of combining bispecific antibody technology with ADCs to overcome toxicity and efficacy limitations associated with conventional single-target ADCs.

NEOK001 Targets B7-H3 and ROR1, Demonstrates Improved Safety and Efficacy vs. Cetuximab

NEOK001 presentation poster / Photo by Reporter Sun-kyung Kim.

NEOK001 (ABL206) is a first-in-class bispecific ADC targeting both B7-H3 and ROR1. While B7-H3 is widely expressed across solid tumors, its presence in normal tissues raises safety concerns. ROR1, although more tumor-specific, shows heterogeneous expression, limiting its effectiveness as a standalone target.

To address this, NEOK001 was designed with a 2+2 symmetric structure that selectively binds tumor cells co-expressing both antigens. It is conjugated with SYNtecan E, a topoisomerase I inhibitor (exatecan)-based payload, to enhance tumor selectivity while minimizing off-target toxicity.

In vivo studies using cell line–derived (CDX) and patient-derived xenograft (PDX) models showed tumor growth inhibition in 81% and tumor regression in 54% of 37 PDX models, spanning small cell lung cancer (SCLC), non–small cell lung cancer (NSCLC), and ovarian cancer. Favorable tolerability was also confirmed in non-human primate studies.

NEOK Bio plans to initiate a global Phase 1 trial of NEOK001 within the year.

A presenter noted that the use of a stable TOPO1 inhibitor may reduce toxicity, particularly the risk of interstitial lung disease (ILD), with no lung toxicity observed to date—marking a clear improvement over earlier cetuximab-based approaches.

NEOK002 Targets EGFR and MUC1, Shows Durable Antitumor Activity

NEOK002 presentation poster / Photo by Reporter Sun-kyung Kim

NEOK002 (ABL209) is a best-in-class bispecific ADC targeting EGFR and MUC1.

Conventional EGFR-targeted therapies often affect normal skin cells, leading to significant dermatologic toxicity. NEOK002 was engineered with reduced EGFR binding affinity while maintaining strong binding to the tumor-specific MUC1 SEA domain, aiming to expand the therapeutic window and reduce skin toxicity.

In preclinical studies, NEOK002 inhibited tumor growth in all 36 PDX models tested, with tumor regression observed in 75% across multiple cancers, including lung, head and neck, esophageal, pancreatic, colorectal, and bladder cancer. In pancreatic models, near-complete responses were achieved at a low dose of 1.5 mg/kg.

The agent also demonstrated activity in KRAS-mutant tumors, with 6 of 9 models responding. In a KRAS G12C-mutant model (NCI-H1373), combination therapy with sotorasib resulted in sustained tumor reduction for approximately 57 days.

Non-human primate studies showed no severe skin toxicity, with only manageable and reversible adverse effects such as gastrointestinal toxicity, cytopenia, erythema, and hyperpigmentation.

A presenter emphasized that targeting the non-shedding SEA domain of MUC1 enables stable drug delivery without loss in circulation, and noted that the absence of skin toxicity distinguishes NEOK002 from cetuximab-based ADCs.