• Maintenance phase: Up to 1 year. Subjects will be treated for up to 2 years (up to 1 year in each treatment phase) or until they experience progressive disease, unacceptable toxicity (not corrected with dose reduction), withdraw consent , or if the Investigator feels i t is no longer in their best interest to continue treatment. Duration of Follow -up: Subjects who discontinue study treatment should remain in the study and continue to be followed every 90 days (± 14 days) for: • Resolution of any SAEs attributed to treatment (see Section 7) • CT, MRI, or PET- CT scan assessment (see Section 6.1.2) • Vital status: subjects will be followed until either death or for a minimum of 18 months past administration of the first dose of chemotherapy to the last subject enrolled in the study, whichever comes first. Subjects may continue to be followed by the investigational physician or a third party by phone or review of medical records approximately every 90 days until withdrawal of consent, lost to follow-up, or death (by any cause). Additional information from a subject’s medical records relevant to this study may be provided to NantKwest as needed to understand the safety and efficacy of the regimen tested in this protocol. Reference Therapy, Dosage, and Mode of Administration: Not applicable. Evaluation of Endpoints: Safety: Safety endpoints include assessments of treatment -emergent AEs, SAEs, and clinically significant changes in safety laboratory tests, physical examinations, electrocardiograms (ECGs), echocardiograms (ECHOs), and vital signs. All subjects will be evaluable for toxicity from the time of their first study treatment.