KEYMAKER-U01 Umbrella Master Study: Studies of Investigational Agents With Either Pembrolizumab (MK-3475) Alone or With Pembrolizumab PLUS Chemotherapy in Participants With Non-small Cell Lung Cancer (NSCLC) (MK-3475-U01/KEYMAKER-U01)

This study is referred to as the "umbrella master protocol" for pembrolizumab (MK-3475) in the treatment of non-small cell lung cancer (NSCLC). This pembrolizumab NSCLC umbrella master protocol uses a platform design and consists of this master screening study and additional substudies. Each substudy will enroll a different population of NSCLC participants.

The following pembrolizumab substudies will evaluate the efficacy of different investigational agents in combination with pembrolizumab given in sequence or in combination with pembrolizumab PLUS chemotherapy: * KEYMAKER-U01 Substudy 01A: A Phase 1/2, Umbrella Study With Rolling Arms of Investigational Agents, With Pembrolizumab With or Without Chemotherapy in Treatment-Naive Participants With Stage IV Non-small Cell Lung Cancer (NSCLC) (MK-3475-01A) - NCT04165070 * KEYMAKER-U01 Substudy 2: A Phase 2, Umbrella Study with Rolling Arms of Investigational Agents in Combination with Pembrolizumab in Treatment Naïve Patients with PD-L1 Positive Advanced Non-small Cell Lung Cancer (NSCLC) (MK-3475-01B) - NCT04165083 * KEYMAKER-U01 Substudy 3: A Phase 2, Umbrella Study with Rolling Arms of Investigational Agents in Combination with Pembrolizumab in Patients with Advanced Non-small Cell Lung Cancer (NSCLC) Previously Treated with anti-PD-(L)1 Therapy (MK-3475-01C) - NCT04165096 * KEYMAKER-U01 Substudy 01E: A Phase 2 Umbrella Study With Rolling Arms of Investigational Agents With or Without Chemotherapy in Combination With Pembrolizumab in Treatment of Participants With Newly Diagnosed Resectable Stages II-IIIB (N2) Non-small Cell Lung Cancer (NSCLC) (MK-3475-01E) - NCT06788912 * KEYMAKER-U01 Substudy 01F: A Phase 1b/2 Umbrella Study With Rolling Arms of Investigational Agents for Second-line Treatment of Participants With Advanced or Metastatic Nonsquamous Non-small Cell Lung Cancer (NSCLC) With KRAS G12C Mutations (MK-3475-01F) - NCT number pending * KEYMAKER-U01 Substudy 01G: A Phase 2, Umbrella Study With Rolling Arms of Investigational Agents in Combination With Pembrolizumab With or Without Platinum-based Chemotherapy in Treatment-Naïve Participants With Stage IV Non-small Cell Lung Cancer (NSCLC) (MK-3475-01G) - NCT06731907 * KEYMAKER-U01 Substudy 01H: A Phase 2, Randomized, Umbrella Study With Rolling Arms of Investigational Agents in Participants with Previously Treated Stage IV Nonsquamous Non-small Cell Lung Cancer (NSCLC) (MK-3475-01H) - NCT06780085 * KEYMAKER-U01 Substudy 01I: A Phase 2, Randomized, Umbrella Study With Rolling Arms of Investigational Agents in Participants With Previously Treated Stage IV Squamous Non-small Cell Lung Cancer (NSCLC) (MK-3475-01I) - NCT06780098 * KEYMAKER-U01 Substudy 01J: A Randomized Phase 2 Umbrella Study With Rolling Arms of Investigational Agents for First-line Treatment of Participants With Advanced or Metastatic Nonsquamous Non-small Cell Lung Cancer (NSCLC) With KRAS G12C Mutations (MK-3475-01J) - NCT number pending

Inclusion Criteria: The main inclusion criteria include but are not limited to the following: * Has histologically- or cytologically-confirmed diagnosis of Stage IV squamous or nonsquamous NSCLC * Has measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 Exclusion Criteria: The main exclusion criteria include but are not limited to the following: * Has an active autoimmune disease that has required systemic treatment in the past 2 years * Has a history of (noninfectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease * Has an active infection requiring systemic therapy