China-based Multitude Therapeutics has had AMT-116, a potentially first-in-class CD44v9-directed antibody-drug conjugate (ADC) with a TopI inhibitor payload at a drug-to-antibody ratio (DAR) of 7 to 8, placed on the China CDE breakthrough therapy track for previously treated EGFR wild-type, non-squamous non-small cell lung cancer (NSCLC) after anti-PD-1/PD-L1 therapy and platinum-based chemotherapy. AMT-116 is the only CD44v9 ADC currently in clinical development globally, and the designation targets a refractory NSCLC segment where PD-1 resistance and post-platinum progression leave few validated options beyond repeat chemo or unrelated targeted agents.

Early Phase I data support the buzz: in EGFR wild-type non-squamous NSCLC patients treated at 3 mg/kg or higher, objective response rate (ORR) was 40% (6 of 15) and disease control rate (DCR) was 93% (14 of 15), while the 5 mg/kg cohort posted an 80% ORR (4 of 5) and 100% DCR (5 of 5). CD44v9's expression across tumour-initiating and therapy-resistant cell populations gives the asset a differentiated tumour biology story versus HER3, TROP2, or B7-H3 conjugates, but the sample sizes are small, the safety ceiling at higher doses is not yet fully characterised, and histologic selection will matter.