PROPEL: A phase 1/2 trial of NKTR-214 (CD122-biased agonist) combined with anti-PD-1 (pembrolizumab) or anti-PD-L1 (atezolizumab) in patients (pts) with advanced solid tumors.

TPS3115Background: NKTR-214 is an investigational cytokine designed to target CD122 (IL-2Rβ) expressed on immune cells (CD8+ T cells and NK cells) in order to expand these tumor-killing cells. NKTR-214 monotherapy increases newly proliferative CD8+ T cells and NK cells in tumors and increases cell surface PD-1 and PD-L1 expression, demonstrating a potentially synergistic mechanism with anti-PD-1 therapy. NKTR-214 plus nivolumab resulted in rapid tumor responses in pts with metastatic melanoma (mM), non-small cell lung cancer (mNSCLC), and renal cell carcinoma. Given the early efficacy data and favorable safety profile of NKTR-214 plus nivolumab, PROPEL will evaluate the clinical benefit, safety and tolerability of NKTR-214 combined with pembrolizumab or atezolizumab. Methods: PROPEL (NCT03138889) will enroll approximately 60 pts in 2 separate arms concurrently. The first arm will evaluate NKTR-214 plus pembrolizumab in up to 30 select pts with locally advanced or mM, mNSCLC, or locally advanced or metasta...