TransThera Sciences (Nanjing), Inc. (HKEX: 2617) and Shanghai Allist Pharmaceuticals Co., Ltd. (SSE: 688578) have entered a clinical trial collaboration and supply agreement to run a Phase II study combining TransThera's dual AXL/FLT3 inhibitor TT-00973-MS with Allist's third-generation EGFR tyrosine kinase inhibitor firmonertinib mesylate in patients with locally advanced or metastatic non-small cell lung cancer harboring EGFR-sensitive mutations. Under the agreement, TransThera will sponsor and fund the Phase II study, while Allist will supply firmonertinib free of charge. Financial terms were not disclosed.
Deal context
TT-00973-MS is described by TransThera as an internally developed dual inhibitor of AXL and FLT3 receptor tyrosine kinases. AXL upregulation is a documented mechanism of acquired resistance to EGFR-targeted therapy in NSCLC, and preclinical data cited by the company show activity in AXL-overexpressing xenograft models. TransThera completed a Phase I trial of TT-00973-MS in patients with solid tumors as of December 31, 2025, reporting tolerability and responses in some patients; no detailed efficacy or pharmacokinetic data were disclosed in the announcement.
Firmonertinib mesylate is a third-generation EGFR-TKI developed by Allist, positioned in the same class as osimertinib. The drug holds Breakthrough Therapy Designation from both China's National Medical Products Administration and the US FDA across several EGFR mutation subtypes, including exon 20 insertion mutations and EGFR PACC mutations. The combination rationale is mechanism-based: firmonertinib suppresses EGFR-driven tumor growth while TT-00973-MS targets the AXL pathway that commonly mediates escape from EGFR inhibition.
The planned Phase II study is multi-center and open-label. Both parties have indicated intent to use Phase II results as the basis for deciding whether to jointly advance a Phase III trial, though no formal option rights or financial terms for that potential next stage have been defined.
TransThera has pursued a broader strategy of testing its kinase inhibitors in combination regimens across multiple tumor types. The company dosed the first patient in a Phase II trial of tinengotinib combined with fulvestrant in previously treated HR+/HER2-negative relapsed or metastatic breast cancer in March 2026, and in the same month received Phase II approval for tinengotinib combined with novel hormone therapy in metastatic castration-resistant prostate cancer in China. In April 2026, the company dosed the first patient in a confirmatory Phase III trial of tinengotinib monotherapy for advanced cholangiocarcinoma.