Testing the Addition of a Type of Drug Called Immunotherapy to the Usual Chemotherapy Treatment for Non-small Cell Lung Cancer, an ALCHEMIST Treatment Trial (Chemo-IO [ACCIO])

Inclusion Criteria: * A female of childbearing potential is a sexually mature female who: * Has not undergone a hysterectomy or bilateral oophorectomy; or * Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months) * Local testing of EGFR with no EGFR exon 19 deletion or EGFR L858 R mutation (applicable to non-squamous patients only) * Local testing of ALK with no ALK rearrangement (failed testing is considered negative) (applicable to non-squamous patients only) * Local testing of PD-L1 immunohistochemistry (IHC) using one of the following assays: DAKO 22C3, DAKO 28-8, EIL3N or SP263 * Completely resected stage IIA, IIB IIIA or IIIB (T3-4N2) non-small cell lung cancer (NSCLC) (squamous or non-squamous) with negative margins (complete R0 resection). Patients will be staged according to the 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual, 2017 * Note: Patients with pathologic N2 disease, completely resected, are eligible. However, patients known to have N2 disease prior to surgery are not eligible; guidelines do not recommend up-front surgery for this population * Complete recovery from surgery. Registration to A081801 must be 30-77 days following surgery * No prior neoadjuvant or adjuvant therapy for current lung cancer diagnosis * No prior allogeneic tissue/solid organ transplant * Patients must NOT have uncontrolled intercurrent illness including, bu…