Study of Navtemadlin Plus Pembrolizumab as Maintenance Therapy in Locally Advanced and Metastatic Non-Small Cell Lung Cancer

Inclusion Criteria:

* ECOG 0-1
* Histologically or cytologically confirmed diagnosis of NSCLC documented as TP53WT
* Locally advanced or metastatic disease; must have completed up to 4 cycles of platinum-based chemo plus CPI and achieved a CR or PR per RECIST V1.1
* Adequate hematologic, hepatic and renal function (within 14 days)

Exclusion Criteria:

* Symptomatic or uncontrolled central nervous system (CNS) metastases
* Prior treatment with a MDM2 inhibitor
* Grade 2 or higher QTc prolongation (\>480 msec per NCI-CTCAE criteria version 5.0)
* History of bleeding diathesis; major hemorrhage or intracranial hemorrhage within 24 weeks
* History of major organ transplant
* Active pneumonitis or known history of interstitial lung disease, drug-related pneumonitis, or radiation pneumonitis
* Prior radiotherapy, cytoreductive therapy, cytokine therapy or any investigational therapy within 28 days
* Medical condition, serious intercurrent illness, psychiatric condition or other circumstance that, in the Investigator's judgment could jeopardize the subject's safety, or that could interfere with study objectives