Shanghai Allist Pharmaceuticals (SSE: 688578) has licensed exclusive Greater China rights to AST12608/ARR-002, a dual-targeting MUC16/NaPi2b tetravalent antibody-drug conjugate, from Pennsylvania-based ArriVent BioPharma (Nasdaq: AVBP). The deal terms include up to USD 80.6 million in combined upfront and milestone payments, plus tiered royalties in the mid-single to low-double digit percentage range.
The deal covers mainland China, Hong Kong, Macau, and Taiwan. ArriVent retains all rights outside Greater China, including the FDA investigational new drug application cleared in May 2026. ArriVent has said first-in-human dosing was planned for the second half of 2026, making this an IND-stage transaction with no human efficacy or safety data at signing.
AST12608/ARR-002 is described by the companies as a potential first-in-class asset based on its tetravalent bispecific architecture, which the companies say is designed to bind MUC16 and NaPi2b simultaneously on a single construct. Preclinical data presented at the American Association for Cancer Research annual meeting in 2026 showed enhanced internalization compared with monospecific antibody controls, superior in vivo efficacy over single-target ADCs in an OVCAR-3 patient-derived xenograft model, and a tolerability profile that the companies said suggested a wider therapeutic window than comparator agents in the same class. The primary indications are ovarian cancer and endometrial cancer, with broader solid tumor applicability cited.
The transaction is the second licensing deal between the two companies and structurally inverts their first. In 2021, Allist out-licensed firmonertinib, a third-generation EGFR tyrosine kinase inhibitor, to ArriVent for ex-China rights in a deal that included a USD 40 million upfront payment, equity in ArriVent, and up to USD 765 million in milestones. Here, ArriVent is the licensor and Allist the in-licensee, with a total ceiling of USD 80.6 million — a fraction of the 2021 deal's headline value, consistent with Greater China-only scope and the absence of any clinical data at signing. Allist is separately building a combination oncology portfolio around firmonertinib: in May 2026 it announced a collaboration with TransThera Sciences to evaluate the AXL/FLT3 inhibitor TT-00973 alongside firmonertinib in EGFR-mutant non-small cell lung cancer, and that combination received China Phase II approval in July 2026.