Abstract CT116: Preclinical antitumor activity and first-in-human phase I study of NB004/GDC-0570, a novel pan-PIM kinase inhibitor, in patients with advanced solid tumors

PIM proto-oncogenes encode a family of three serine/threonine kinases (PIM1, PIM2, PIM3), which are frequently overexpressed in human hematological malignancies and solid cancers. PIM kinases are promising cancer therapeutic targets for pharmacological inhibition. NB004 (aka GDC-0570) is a novel, potent, selective, orally available small molecule pan-PIM inhibitor, which exhibits antiproliferative activity as a single agent in a variety of preclinical models and can augment the activity of standard of care or targeted therapies, both in vitro and in vivo. In multiple patient-derived xenograft (PDX) models of human solid tumors, NB004 demonstrates both single agent and combination activity with agents targeting the RTK/RAS/MAPK pathways, including synergistic effects with KRAS inhibitors (KRASis). Remarkably, in NSCLC PDX models with acquired resistance to KRASis, strong combination efficacy was observed between NB004 and sotorasib, resulting in complete tumor regression. Based on the promising preclinical data, NB004 is currently being assessed in an open-label, first-in-human phase I clinical trial as monotherapy or combination therapy in patients with advanced solid tumors. The primary objective is to characterize the safety and tolerability and to recommend the phase 2 dose (RP2D). Secondary objectives include PK characterization and preliminary antitumor activity evaluation. In the phase I monotherapy dose escalation part, NB004 was administered daily in 5 dose levels, ranging from 75mg to 600mg, following a standard 3+3 design. As of December 22, 2023, a total of 18 patients were treated. Of the 13 patients (72.2%) who reported any treatment-related adverse events (TRAEs), 12 (66.7%) had Grade 1 or 2 TRAEs, 1 patient (5.6%) experienced Grade 3 neutrophil count decrease and white blood cell count decrease. No dose-limiting toxicity (DLT) or treatment-related serious adverse event (SAE) was reported, and PK exposure is in general dose proportional. These results warrant further evaluation of this drug in combination with other therapeutic agents. The combination part of the trial is currently open for enrollment (NCT05036291). Citation Format: Siqing Fu, Rachel E. Sanborn, Minxia Cai, Lijia Zhang, Yanhua Xu, Kui Lin. Preclinical antitumor activity and first-in-human phase I study of NB004/GDC-0570, a novel pan-PIM kinase inhibitor, in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT116.