LEADS BIOLABS-B(09887): Viloxin Receives U.S. FDA Fast Track Designation for First-Line Treatment of Advanced Biliary Tract Cancer

LEADS BIOLABS-B(09887) announced that the Company's core product Viloxin (opamtisumumab, a PD-L1/4-1BB bispecific antibody) has received Fast Track Designation from the U.S. Food and Drug Administration (FDA) for the first-line treatment of advanced biliary tract cancer (BTC). This is the second FDA Fast Track Designation granted to Viloxin, following the one for extrapulmonary neuroendocrine carcinoma (EP-NEC). Based on the promising data demonstrated by Viloxin in first-line BTC clinical studies, this Fast Track Designation took only 9 days from submission to approval. The FDA also recommended that the Company promptly engage in communication regarding the registration plan for Viloxin in combination with chemotherapy for BTC. This designation is expected to accelerate the development, registration, and commercialization process of Viloxin for the treatment of BTC in the United States. Fast Track Designation is intended to accelerate the development and review process of drugs and biologics that treat serious or life-threatening diseases and have the potential to address unmet medical needs. Upon receiving this designation, Viloxin will enjoy a range of policy support, including but not limited to: (i) the Company may obtain more frequent regulatory interactions with the FDA and receive customized guidance on key matters (including clinical trial design and data requirements), helping to optimize the development pathway; and (ii) when relevant eligibility criteria are met, the marketing application may be subject to rolling review, allowing completed portions to be submitted for review before the entire application is finalized, thereby potentially shortening the overall review time. Viloxin conditionally activates 4-1BB to expand T cells, and its differentiated advantage lies in its potential to overcome the limited benefit of immunotherapy in "cold tumors" and deliver long-tail survival benefits. The Company initiated its first monotherapy late-line Phase I/IIa basket trial in 2022, enrolling a total of 175 patients. The trial evaluated Viloxin across multiple cold tumor indications, including BTC, platinum-resistant ovarian cancer, PD-1-treated refractory late-line hepatocellular carcinoma (HCC), and late-line EP-NEC, all of which demonstrated survival benefit trends significantly prolonged compared to historical data. The relevant data are expected to be published in internationally authoritative journals. On this basis, Viloxin has rapidly advanced from early late-line exploration to frontline clinical development and has continued to make progress in regulatory designations. Currently, the clinical study of Viloxin for first-line treatment of BTC is being efficiently and orderly advanced. In April 2026, based on favorable safety characteristics and efficacy data, the Company successfully advanced the Phase II clinical study of first-line advanced BTC to the expansion stage and subsequently completed enrollment of all patients, demonstrating the drug's breakthrough potential in immunologically "cold tumors." This Fast Track Designation further clarifies the project's foreseeable registration pathway in the United States.