LAUSR

3006Background: PIVOT is an ongoing, open-label, phase 1/2 study of NKTR-214 (214; CD122-biased agonist) plus PD-1 inhibitor nivolumab (N) in patients (pts) with advanced cancers (MEL, RCC, NSCLC, TNBC, and UC). 214 monotherapy increases newly proliferative CD8+ T cells in tumors and increases cell surface PD-1 and PD-L1 expression, demonstrating a potentially synergistic mechanism with anti-PD-1 therapy. Methods: In P1 dose escalation, pts received 214 (0.003, 0.006 or 0.009 mg/kg) with N (240 mg or 360 mg) administered IV as outpatient Q2W or Q3W; in P2 expansion, the RP2D of 214 (0.006 mg/kg) with N (360 mg) Q3W was administered concurrently. Response was assessed Q8W by RECIST v1.1. Matched tumor samples were evaluated for changes from baseline in immune cell populations, gene expression, and T cell receptor repertoire. Tumor baseline and on treatment PD-L1 protein expression was assessed (28-8 IHC assay). Results: As of 7FEB2018, 162 pts (P1, n = 38; P2, n = 124) were evaluable for safety. The most c...