Inclusion Criteria:

          -  Participant or legal representative is able to provide written informed prior to
             performing any protocol-related procedures

          -  Is willing and able to comply with scheduled visits, treatment schedule, laboratory
             testing and other requirements of the study

          -  Men or women at least 18 years of age with histologically or cytologically confirmed
             non-small cell lung cancer

          -  Previous history of other than lung cancer is allowed if no active treatment for that
             cancer within 1 year

          -  Life expectancy of at least 6 months

          -  De novo stage IV or recurrent NSCLC without actionable mutation (e.g. EGFR/ ALK/
             ROS-1) that was previously treated with either PD-1 / PD-L1 or the combination of
             PD1/PDL1 and cytotoxic chemotherapy, no more than 2 systemic regimens for metastatic
             disease with measurable disease *. Maintenance therapy will be considered part of the
             1 regimen

          -  At least 1 measurable lesion

          -  PDL1 TPS score less than 1% or unknown: first-line must be PD1/PDL1 inhibitor in
             combination with chemotherapy

          -  Early stage (I-III) NSCLC treated with adjuvant or neoadjuvant chemotherapy then
             PD1/PDL1 inhibitor treatment for recurrent disease

          -  Recurrent Unresectable stage III NSCLC treated with prior chemoradiation followed by
             maintenance PD1/PDL1 inhibitor with measurable disease

          -  Eastern Cooperative Group (ECOG) Performance Status 0 - 2

          -  Is able to swallow oral medications

          -  Adequate hematologic function

          -  Adequate organ function

        Exclusion Criteria:

          -  The presence of any other concurrent severe and/or uncontrolled medical condition that
             would, in the investigator or treating physician's judgement, cause unacceptable
             safety risks, contraindicate patient participation in the clinical study or compromise
             compliance with the protocol

          -  Has received investigational agents within 14 days or 5 half-lives of the compound or
             active metabolites, whichever is longer, before the first dose of study treatment

          -  Has a known hypersensitivity to atezolizumab or pirfenidone

          -  Has active medical or psychiatric illness that would interfere with the study
             treatment

          -  Has uncontrolled diabetes

          -  Has any of the following cardiac diagnoses:

        Unstable angina Myocardial infarction within 6 months Uncontrolled congestive heart failure
        Left ventricular ejection fraction < 35%

          -  Has a history of any Grade 3 or 4 toxicities to a prior checkpoint inhibitor treatment

          -  Is pregnant or breast feeding

          -  Uncontrolled HIV

          -  Clinically diagnosed with grade 2 or 3 radiation-induced lung injury within the last 3
             months prior to registering for the study

          -  Has a history of idiopathic pneumonitis that required systemic agent including steroid

          -  Has drug-induced pneumonitis

          -  Has evidence of active pneumonitis on screening chest computed tomography (CT) scan

          -  Smoker of more than 1 pack / day

          -  Has active peptic ulcer diagnosed within 4 weeks of enrollment

          -  Active infection requiring systemic treatment

          -  Current use of systemic antibacterial or antifungal agent

          -  Prior monoclonal antibody within 4 weeks before study Day 1 Exception: The use of
             denosumab

          -  Patient not recovered to ≤ Grade 1 from AEs due to agents administered more than 4
             weeks earlier

          -  Concurrent use of other investigational agents

          -  Uncontrolled or symptomatic brain metastasis or leptomeningeal disease that requires
             use of steroids

          -  Use of strong CYP1A2 inhibitors

          -  Previous history of cancer with active treatment within less than 1 year of enrollment

          -  Active auto-immune diseases