A Study to See How Well and How Safely Different Treatments Work in a Group of Participants With Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria Cohort B1:

• Complete resection of the primary NSCLC with negative margins

• Confirmed stage II to select stage IIIB (T3N2) NSCLC of non-squamous (adenocarcinoma) histology

• Eastern cooperative oncology group (ECOG) performance status of 0 or 1

Inclusion Criteria Cohort B2:

• Evaluation by the operating attending surgeon and involved medical oncologist prior to study enrollment to verify study eligibility for complete surgical resection with curative intent

• Pathologically and/or histologically confirmed Stage II-IIIA and IIIB (T3N2 only) NSCLC of non-squamous (adenocarcinoma) histology

Inclusion Criteria Cohorts B1 and B2:

• Documented ALK fusion

Exclusion Criteria Cohort B1:

• NSCLC of squamous or mixed histology regardless of the presence of an ALK mutation

• Prior exposure to any systemic anti-cancer therapy

Exclusion Criteria Cohort B2:

• NSCLC of squamous or mixed histology regardless of the presence of an ALK mutation

• Known sensitivity to any component of alectinib, pemetrexed, cisplatin, or carboplatin

• Prior exposure to any systemic anti-cancer therapy

Exclusion Criteria Cohorts B1 and B2:

• Pregnancy or breastfeeding, or intention of becoming pregnant during the study