A phase I study of the safety and pharmacokinetics of DNIB0600A, an anti-NaPi2b antibody-drug-conjugate (ADC), in patients (pts) with non− small cell lung cancer (NSCLC) and platinum-resistant ovarian cancer (OC).

Developmental Therapeutics - Clinical Pharmacology and Experimental Therapeutics
Session Type and Session Title: 
Oral Abstract Session, Developmental Therapeutics - Clinical Pharmacology and Experimental Therapeutics
Abstract Number: 
J Clin Oncol 31, 2013 (suppl; abstr 2507)
Michael S. Gordon, David E. Gerber, Jeffrey R. Infante, Jian Xu, David S. Shames, Younjeong Choi, Robert S. Kahn, Kedan Lin, Katie Wood, Daniel J. Maslyar, Howard A. Burris; Pinnacle Oncology Hematology, Scottsdale, AZ; UT Southwestern Medical Center, Dallas, TX; Sarah Cannon Research Institute; Tennessee Oncology, Nashville, TN; Genentech, Inc., South San Francisco, CA; Genentech Inc., South San Francisco, CA

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Abstract Disclosures


Background: NaPi2b (SLC34A2) is a multi-transmembrane, sodium-dependent phosphate transporter expressed in non-squamous NSCLC and non-mucinous OC. DNIB0600A is an ADC consisting of a humanized IgG1 anti-NaPi2b monoclonal antibody and anti-mitotic agent, MMAE, that shows anti-proliferative activity in xenograft models. Methods: This study evaluated safety, pharmacokinetics, and pharmacodynamics of DNIB0600A (0.2-2.8 mg/kg) given every 3 weeks (q3w) to pts with NSCLC or OC. A traditional 3+3 design was used for dose escalation followed by expansion by disease at the recommended Phase 2 dose (RP2D). Tumor NaPi2b expression was evaluated in archival tissue. Anti-tumor activity was evaluated per RECIST 1.1. Results: As of 10 Dec 2012, 30 dose escalation pts have enrolled (16 NSCLC; 14 OC), median age 61 (range 45-78), PS 0-1, median number of prior regimens 5 (1-12), received a median of 3 (1-17) doses of DNIB0600A. No DLTs occurred at the maximum assessed dose of 2.8 mg/kg; enrollment in the expansion cohort at 2.4 mg/kg is ongoing. The most common related AEs regardless of Grade were fatigue (43%), decreased appetite (37%), nausea (30%), constipation, dysgeusia, vomiting, and peripheral neuropathy (each 17%), and diarrhea (13%). One pt at 1.8 mg/kg experienced a DLT (Grade 3 dyspnea), however, no additional DLTs occurred through the maximally administered dose of 2.8 mg/kg. Expansion at 2.4 mg/kg was selected based on totality of safety data. No accumulation of total antibody, free MMAE, or conjugated MMAE was observed. Exposure of each analyte was dose proportional. Approximately 70% of NSCLCs and 85% of OC expressed high levels (IHC 2+/3+) of NaPi2b. Of the 18 pts treated at dose levels 1.8-2.8 mg/kg (10 NSCLC; 8 OC) 3 pts had a confirmed partial response (PR) with response durations of 8.8+ (OC), 4.4+ (NSCLC), and 1.4+ (OC) months, censored at data cutoff, and 1 additional pt had an unconfirmed PR (OC). Dose expansion data will be presented. Conclusions: DNIB0600A administered q3w has an encouraging safety profile and evidence of anti-tumor activity in both NSCLC and OC. Further studies are planned. Clinical trial information: NCT01375842.