AT03-65

AT03-65 is a differentiated antibody-drug conjugate (ADC) developed by Axcynsis Therapeutics for the treatment of advanced, recurrent, or metastatic CLDN6-positive solid tumors in patients who have progressed on or after standard systemic treatments or for whom no standard therapies are available. The drug consists of a recombinant anti-CLDN6 monoclonal antibody engineered for high affinity and specificity to CLDN6, which is overexpressed in various cancers such as lung, ovarian, endometrial, uterine, testicular, and gastric cancers but minimally expressed in normal tissues. Upon binding to CLDN6-expressing tumor cells, the ADC is internalized into lysosomes where it releases its cytotoxic payload—AxcynDOT™, a proprietary derivative of trabectedin with enhanced potency and improved safety profile compared to trabectedin itself. This mechanism enables direct killing of CLDN6-positive tumor cells as well as bystander killing effects on neighboring CLDN6-negative tumor cells. Preclinical studies have shown promising anti-tumor activity and favorable safety profiles. As of early 2025, AT03-65 has received FDA clearance for an IND application and is entering Phase 1 clinical trials in the United States[1][2][3][4][5].

Other names

AT03 65AT-03 65AT 03 65