Durability and characteristics of objective tumor responses with the innate immune cell modulator Imprime PGG in combination with standard of care frontline treatment for patients (Pts) with metastatic non-squamous NSCLC.

3070 Background: Recently, we reported numeric improvements in objective tumor response (OTR) and overall survival (16.1 vs 11.6 months median; HR = 0.66) with Imprime PGG (PGG) in a randomized (2:1) phase 2 study in 92 patients (pts) with stage IV non-squamous NSCLC receiving standard of care carboplatin/ paclitaxel (C/P) and bevacizumab (B) treatment first line (Engel-Riedel W et al, Ann Onc 2014, 25(5):1-41). Here, we report on the durability and characteristics of tumor regressions. Methods: The impact of treatment on the burden of malignant lesions was evaluated by modified RECIST v1.0. Imaging assessments (CT of chest and abdomen every 6 wks) were reviewed centrally in an independent, blinded facility. Pts were removed from treatment upon disease progression. Results: PGG (vs ctrl) in combination with C/P/B achieved a 60.4% (vs 43.5%) OTR rate. Time to OTR was short (12 wks vs > 18 wks) and responses were durable: median duration of response was 10.3 mos vs 5.6 mos (KM), with OTR lasting ≥ 12 mos in...