Transcenta Therapeutics Presents New Data for its Novel LIV1-Targeting ADC TST013 Demonstrating Potent Anti-Tumor Activity in PDX Models of Prostate Cancer and ER Positive /HER2 Negative Breast Cancer

PRINCETON, N.J. and SUZHOU, China, April 23, 2026 (GLOBE NEWSWIRE) — Transcenta Therapeutics (HKEX: 06628), a global clinical stage biopharmaceutical company with fully-integrated capabilities in discovery, research, development and manufacturing of antibody-based therapeutics, today announced the presentation of preclinical data highlighting its proprietary LIV1-targeting antibody-drug conjugates (ADC) at the 2026 AACR Annual Meeting. The data demonstrate strong anti-tumor activity, differentiated payload-dependent efficacy, and favorable tolerability profiles, supporting further development in LIV1-positive solid tumors.

LIV1 is a member of the zinc transporter family, with limited normal tissue expression, and is found to be overexpressed with high prevalence in breast (93%), prostate (72%) and lung (10%) cancers, making it an attractive cell surface target for developing ADC therapeutics.

Transcenta Therapeutics has developed 48D6, a novel proprietary humanized anti-LIV1 monoclonal antibody with high affinity, specificity, and internalization capability. Using Retrogenix cell microarray technology, 48D6 demonstrated no non-specific interactions with other human proteins, confirming its high target specificity. Leveraging 48D6, Transcenta Therapeutics then generated two ADC candidates using a glycotransferase-mediated site-specific conjugation platform: ADC-2, conjugated with a Topoisomerase I inhibitor payload, and ADC-3, conjugated with MMAE.

Pharmacokinetic studies in Balb/c mice showed that ADC-2 exhibited a half-life of approximately 10.4–11.6 days, significantly longer than that of a benchmark SGN-LIV1A analog (3.7–3.9 days), and comparable to the naked antibody 48D6 (13.8–15.6 days), indicating favorable in vivo stability.

In vivo efficacy studies demonstrated that ADC-2 elicited potent anti-tumor activity in LIV1-expressing ER+/HER2- breast cancer and non-small cell lung cancer (NSCLC) patient-derived xenograft (PDX) models at a dose of 6 mg/kg administered once weekly for four weeks.

For LIV1 expressing prostate PDX models, ADC-2 demonstrated limited tumor growth inhibition after two doses. After MMAE-based ADC-3 replaced ADC-2 from the 3rd dose, ADC-3 inhibited the growth of the prostate tumor significantly. In a LIV1 high expressing prostate PDX, the tumor growth was suppressed by ADC-3 for more than 70 days after the dosing was stopped.

In exploratory toxicity studies to assess safety and tolerability, ADC-2 was well tolerated following repeated administrations in mice at all doses tested. Slight lesions were observed in 60 mg/kg group during the treatment period and fully recovered at the end of the recovery period. Based on these results, the maximum tolerated dose (MTD) of ADC-2 in mice was determined at 60 mg/kg. The safety and tolerability of ADC-3 has not yet been explored.

Collectively, these data demonstrate that Transcenta’s LIV1-targeting ADC-2 and ADC-3 programs exhibited strong anti-tumor activities as monotherapy in PDX models of ER+/HER2- breast cancer (representing ~60% of all breast cancers) and also prostate cancer. ADC-2 also displayed excellent tolerability profile in mice. Notably, Transcenta’s LIV1-targeting ADCs also demonstrated potent anti-tumor activity in triple-negative breast cancer (TNBC) tumor models, with data previously presented at the 2024 SABCS. These results support further investigation of Transcenta’s LIV1 ADCs in LIV1-positive solid tumors.

About Transcenta Therapeutics
Transcenta Therapeutics (HKEX: 06628) is a global clinical stage biopharmaceutical company with fully integrated capabilities in antibody-based biotherapeutics discovery, research, development and manufacturing.

Transcenta Therapeutics has established a global footprint, with its Headquarters and Discovery, Clinical and Translational Research Capabilities located in Suzhou, China, its Process and Product Development Center and Manufacturing Facility located in Hangzhou, China, and additional Clinical and Business Development Centers across China, the U.S. and Europe. Transcenta Therapeutics is developing a diverse pipeline of more than a dozen novel biologic therapies for oncology and selected non-oncology indications such as bone and kidney disorders.

Media Contact: pr@transcenta.com