FDA Aligns on Accelerated Approval Pathway for NovaBridge's Givastomig in Gastroesophageal Cancer

Clarification: This article concerns a regulatory pathway alignment, not a formal drug approval. The US FDA has not approved givastomig. The source material describes a Type B meeting outcome confirming eligibility for an accelerated approval pathway.

NovaBridge Biosciences announced on March 16, 2026, that the US FDA has aligned on givastomig's potential eligibility for an accelerated approval pathway in first-line HER2-negative, Claudin 18.2-positive (CLDN18.2+), PD-L1-positive gastroesophageal cancer (GEC). Givastomig (TJ033721/ABL111) is a bispecific antibody targeting CLDN18.2 and 4-1BB (CD137) that conditionally activates T cells in the tumor microenvironment. The molecule is being jointly developed by NovaBridge and ABL Bio. If givastomig advances through the accelerated approval pathway, it would be the first CLDN18.2 x 4-1BB bispecific antibody to reach the market for gastric cancer.

The alignment emerged from a Type B meeting with the US FDA, following which NovaBridge received written minutes confirming the agency's position. The company said it intends to initiate a registrational Phase 3 trial, combining givastomig with immunochemotherapy, as early as Q4 2026. The planned Phase 3 trial will use objective response rate (ORR) as its primary endpoint to support a potential accelerated approval submission. Final study design details remain under discussion with the agency.

The regulatory pathway alignment rests on data from a Phase 1b dose escalation and expansion study in first-line gastric cancer. At doses of 8 mg/kg and 12 mg/kg administered every two weeks, givastomig in combination with immunochemotherapy produced a 75% ORR across 52 evaluable patients, with 77% ORR at the lower dose and 73% at the higher dose. Median progression-free survival reached 16.9 months, with an 82% six-month landmark PFS rate among 53 evaluable patients. The company reported responses across a range of PD-L1 and CLDN18.2 expression levels and described tolerability as favorable, without dose-dependent toxicity. The study was open-label and single-arm, and detailed safety and efficacy data have not yet been publicly presented. NovaBridge said full expansion data are expected at a medical conference in the second half of 2026.

Givastomig enters a competitive and rapidly diversifying landscape for CLDN18.2-targeted therapies in gastric cancer. Zolbetuximab (Vyloy), an anti-CLDN18.2 monoclonal antibody developed by Astellas, received US FDA approval in 2024 for first-line CLDN18.2-positive, HER2-negative gastric or gastroesophageal junction adenocarcinoma in combination with chemotherapy. That approval established CLDN18.2 as a validated therapeutic target in this setting but did not incorporate immunotherapy into the backbone regimen. Givastomig's mechanism differs from zolbetuximab in that it engages the 4-1BB co-stimulatory pathway on T cells conditionally, only in the presence of CLDN18.2-expressing tumor cells, rather than relying on antibody-dependent cytotoxicity. Several other CLDN18.2-directed agents are in clinical development, including osemitamab (Transcenta, Phase 2/3), AZD5863 (AstraZeneca, Phase 1/2), the ADC IBI343 (Innovent, Phase 3), and the CAR-T therapy satricabtagene autoleucel (CARsgen/Innovent, Phase 2). No approved regimen currently combines a CLDN18.2-targeted agent with immunotherapy in the first-line setting, a gap givastomig is designed to address. Whether the Phase 1b response rates hold in a larger, controlled trial remains to be determined.

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