MA13.05 Nab-Paclitaxel Maintenance in Squamous Non-Small Cell Lung Cancer (NSCLC): Updated Results of the Phase III ABOUND.sqm Study

nab-Paclitaxel maintenance therapy after nab-paclitaxel/carboplatin induction in patients with advanced squamous NSCLC was evaluated in the phase III, randomized, controlled, open-label, multicenter ABOUND.sqm trial. At the 12-month follow-up, there was no statistically significant difference in progression-free survival (PFS) between patients randomized to maintenance nab-paclitaxel + best supportive care (BSC) vs BSC alone. However, a trend of an overall survival (OS) advantage was observed with nab-paclitaxel + BSC vs BSC alone. Here we report the 18-month follow-up of OS. Patients (aged ≥18 years) with histologically or cytologically confirmed stage IIIB/IV squamous NSCLC and no prior chemotherapy were eligible. Patients received four 21-day cycles of nab-paclitaxel 100 mg/m2 (days 1, 8, and 15) plus carboplatin AUC 6 (day 1) as induction. Patients with radiologically assessed complete or partial response or stable disease without clinical progression after 4 cycles were randomized 2:1 to maintenance nab-paclitaxel 100 mg/m2 (days 1 and 8 of each 21-day cycle) plus BSC or BSC alone until disease progression. The primary efficacy analysis was performed on the ITT population. PFS from randomization into the maintenance part of the study was the primary endpoint. Secondary endpoints included safety, OS (from randomization), and response. 420 patients received induction therapy; 202 were randomized to maintenance nab-paclitaxel + BSC (n = 136) or BSC alone (n = 66). The median PFS in patients in the nab-paclitaxel + BSC arm vs those in the BSC-alone arm was 3.1 vs 2.6 months (HR, 0.85; P = 0.349), respectively; the median OS was 17.8 vs 12.2 months (HR, 0.71; P = 0.058), respectively. The overall response rate was 69.1% vs 57.6% (RRR, 1.20; P = 0.087). Following the maintenance part, 73.5% (nab-paclitaxel + BSC) and 68.2% (BSC alone) of patients received subsequent anti-cancer treatment. Over the entire study, the most frequent grade 3/4 TEAEs were neutropenia (53.1% vs 50.0%) and anemia (33.1% vs 32.3%); only peripheral neuropathy occurred in ≥ 5% of patients during maintenance (13.1% in the nab-paclitaxel + BSC arm). Although PFS and OS differences were not statistically significant in the ITT population, the 18-month follow-up of OS demonstrated the feasibility of nab-paclitaxel maintenance therapy for patients with anced squamous NSCLC. ClinicalTrials.gov identifier: NCT02027428