ALK201 FGFR2b ADC posts 24% ORR in refractory solid tumors with low ocular toxicity

ALK201 is a first-in-human FGFR2b-targeting antibody–drug conjugate from Allink Biotherapeutics, using a humanized anti-FGFR2b monoclonal antibody linked to the topoisomerase-I payload exatecan via a cleavable hydrophilic linker. In an ongoing Phase I/II multicenter dose-escalation study in refractory advanced solid tumors (NCT06656390), 38 patients were treated after a median of 3 prior lines, with 25 response-evaluable; ALK201 produced 6 partial responses for a 24% ORR and 68% DCR overall, while the ≥7.2 mg/kg dose range showed 35.7% ORR and 100% DCR in 14 evaluable patients. No DLTs were reported through 9.6 mg/kg Q3W and MTD was not reached; grade ≥3 TRAEs occurred in 23.7% and were described as reversible hematologic toxicities, while ocular AEs were grade 1 only in 10.5%—potentially useful differentiation for an FGFR-directed program, though cross-trial ADC benchmarks in later-line GI disease vary widely, from single-digit ORRs with conventional salvage chemotherapy to ~40–50% ORR with HER2-selected trastuzumab deruxtecan in gastric cancer.