ABL Bio's bispecific antibody Givastomig (TJ033721 / ABL111) received FDA Fast Track Designation on June 16 for first-line treatment of HER2-negative advanced or metastatic gastroesophageal adenocarcinoma — clearing the path for a Phase 3 registrational trial targeted to open in Q4 2026.
What the Drug Does
Givastomig is a bispecific antibody that simultaneously blocks Claudin 18.2 (CLDN18.2) — a protein overexpressed in gastric and pancreatic tumors — while activating 4-1BB, a co-stimulatory receptor that drives T-cell proliferation in the tumor microenvironment. The dual mechanism is designed to concentrate immune activation within CLDN18.2-rich tumors, sidestepping the systemic toxicity historically associated with non-targeted 4-1BB agonists.
The FDA designation covers Givastomig in combination with nivolumab (Bristol Myers Squibb's PD-1 inhibitor) and FOLFOX chemotherapy, targeting patients whose tumors are co-positive for CLDN18.2 and PD-L1.
Phase 1b Signal
Phase 1b data characterized as showing "compelling efficacy and tolerability" with "deep and durable" responses representing a "marked improvement relative to historical benchmarks for the standard of care." Full Phase 1b data are expected to be presented at a major medical conference in H2 2026. A randomized Phase 2 study is ongoing.
Phase 3 Timeline
NovaBridge Biosciences, the US-side co-developer, expects to initiate the Phase 3 registrational trial in Q4 2026. The FDA designation opens eligibility for rolling review submissions, Priority Review consideration, and accelerated approval pathways — each shortening the timeline to potential market authorization.
Market Context
The CLDN18.2-targeted space gained its first foothold when Zolbetuximab (Astellas/Genentech) secured FDA approval in combination with chemotherapy for CLDN18.2-positive gastric cancer. Givastomig adds a 4-1BB T-cell activation arm to the same target, differentiating it in a field where immunotherapy combinations are rapidly evolving.
Gastric cancer carries among the highest incidence rates globally, and South Korea records some of the world's highest rates per capita — reinforcing domestic strategic priority for CLDN18.2 pipeline development.
Partnership Structure
ABL Bio (KOSDAQ: 298380) retains development rights covering South Korea and Greater China. NovaBridge Biosciences (Nasdaq: NBP) leads worldwide development excluding those regions. NovaBridge shares rose approximately 10% in pre-market trading following the announcement.
What to Watch
Key catalysts: Phase 3 enrollment start in Q4 2026 and full Phase 1b data presentation at a global oncology conference in H2 2026. Positive Phase 3 interim data, if strong, could trigger regulatory submissions before year-end 2028.
Sources: Korea Herald; GlobeNewsWire / Manila Times; RTTNews — June 16, 2026.
