A phase I study of DNIB0600A, an antibody-drug conjugate (ADC) targeting NaPi2b, in patients (pts) with non-small cell lung cancer (NSCLC) or platinum-resistant ovarian cancer (OC).

2504 Background: NaPi2b (SLC34A2) is a multi-transmembrane, sodium-dependent phosphate transporter expressed in ~70% non-squamous NSCLC and ~90% OC. DNIB0600A is an ADC consisting of a humanized IgG1 anti-NaPi2b monoclonal antibody conjugated to an anti-mitotic agent MMAE that shows anti-proliferative activity in xenograft models . Methods: This study evaluated safety and activity of DNIB0600A (0.2-2.8 mg/kg) given by intravenous infusion every 3 weeks (q3w) to pts with NSCLC or platinum-resistant OC. A traditional 3+3 design was used for dose escalation followed by expansion at the recommended Phase 2 dose (RP2D) of 2.4 mg/kg in patients with NSCLC and OC. Tumor NaPi2b expression was evaluated by immunohistochemistry (IHC) in archival tissue. Results: As of 10 Dec 2013, 73 pts have enrolled (43 NSCLC; 30 OC), median age 62 (range 39-85), PS 0-1, median number of prior regimens 3 (1-10) in NSCLC, and 5 (1-12) in OC. Pts received a median of 4 (range 1-28) cycles of DNIB0600A. One pt experienced a DLT (Gra...