TRANSCENTA-B (Transcenta Holding Limited) released updated preclinical data on its proprietary LIV1-targeting antibody–drug conjugate (ADC) programme, TST013, at the 2026 AACR Annual Meeting. The release highlights two site-specific ADC candidates—ADC-2 and ADC-3—built on the novel humanised anti-LIV1 monoclonal antibody 48D6.

48D6 specificity and conjugation platform • Retrogenix cell microarray profiling showed no off-target binding across human proteins, underscoring high target specificity. • Two glycotransferase-mediated conjugates were generated: ADC-2 (topoisomerase I inhibitor payload) and ADC-3 (MMAE payload).

Pharmacokinetics • In Balb/c mice, ADC-2 achieved a 10.4–11.6-day half-life, markedly longer than the benchmark SGN-LIV1A analogue (3.7–3.9 days) and close to the naked antibody 48D6 (13.8–15.6 days), indicating favourable in-vivo stability.

Efficacy in patient-derived xenograft (PDX) models • Breast cancer (ER+/HER2-) and non-small cell lung cancer models: ADC-2, dosed at 6 mg/kg once weekly for four weeks, delivered potent tumour inhibition. • Prostate cancer: initial dosing with ADC-2 showed limited suppression; switching to ADC-3 from the third dose produced significant tumour growth inhibition. In a high-LIV1 prostate model, ADC-3 maintained >70-day tumour suppression post-treatment. • Prior data (2024 SABCS) also confirmed activity in triple-negative breast cancer models, widening the potential tumour spectrum.

Safety profile • Exploratory mouse studies found ADC-2 well tolerated up to a maximum tolerated dose of 60 mg/kg; transient minor lesions at this dose fully resolved by study end. • Safety assessment for ADC-3 remains pending.

Strategic implications The differentiated payload-driven efficacy, extended half-life and initial tolerability substantiate continued advancement of ADC-2 and ADC-3 for LIV1-positive solid tumours, including breast, prostate and lung cancers. Management emphasised the investigational nature of TST013 and cautioned that successful development and commercialisation are not guaranteed.