MA09.09 First-In-Human Phase 1 Study of ABBV-399, an Antibody-Drug Conjugate (ADC) Targeting C-Met, in Patients with Non-Small Cell Lung Cancer (NSCLC)

The c-Met receptor is overexpressed in ∼50% of patients with NSCLC. ABBV-399 is a first-in-class ADC composed of ABT-700, an anti–c-Met antibody, conjugated to monomethyl auristatin E (a microtubule inhibitor). Preclinical data support ABBV-399 as a unique strategy to deliver a potent cytotoxin directly to c-Met+ tumor cells. In a 3+3 dose-escalation design, ABBV-399 was administered at doses ranging from 0.15 to 3.3 mg/kg once every 21 days to patients with advanced metastatic solid tumors (NCT02099058). ABBV-399 was then studied in a dose-expansion cohort in 16 patients with advanced c-Met+ (immunohistochemistry [IHC] H-score ≥150) NSCLC that had progressed on ≥2 prior lines of therapy. ABBV-399 was also studied in combination with erlotinib in 10 patients with NSCLC, 8 of whom were c-Met+. Overexpression of c-Met was assessed by an IHC assay utilizing the SP44 antibody (Ventana; Tucson, AZ, USA). As of June 27, 2016, 48 patients with solid tumors received ≥1 dose of ABBV-399. The dose-limiting toxicity (DLT) for ABBV-399 was febrile neutropenia, which occurred in 2 patients (1 each at 3 and 3.3 mg/kg). There were no treatment-related deaths. Monotherapy treatment-related adverse events (AEs) occurring in ≥10% of patients (including all dose levels and all grades) were fatigue (25.0%), nausea (22.9%), neuropathy (14.6%), decreased appetite (12.5%), vomiting (12.5%), and hypoalbuminemia (10.4%). Based primarily on safety and tolerability, a 2.7-mg/kg dose was chosen for dose expansion in patients with c-Met+ advanced NSCLC. Three of 16 (19%) ABBV-399–treated c-Met+ NSCLC patients had a confirmed partial response (PR) with duration of response (DOR) 3+, 3, and 4.5 months. At week 12, 6 of 16 patients treated (37.5%) had disease control. Ten patients received ABBV-399 in combination with erlotinib. No DLTs were observed and AEs related to ABBV-399 occurring in ≥2 patients were acneiform rash (40.0%), fatigue (30.0%), and dry skin (20.0%). Three of 8 (37.5%) evaluable ABBV-399 + erlotinib-treated c-Met+ patients had a confirmed PR with DOR 2+, 4+, and 5+ months. Two of the 3 patients with PR had EGFR-mutated tumor, and previous TKI- and platinum-based chemotherapy had failed. ABBV-399 is well tolerated at a dose of 2.7 mg/kg every 21 days and has demonstrated antitumor activity in patients with c-Met+ NSCLC both as monotherapy and in combination with erlotinib. Updated data of antitumor activity and safety of ABBV-399 as monotherapy and in combination with erlotinib in c-Met+ NSCLC patients will be presented.