This study is aimed to explore the antitumor activity and the safety profile of atezolizumab in pretreated advanced NSCLC patients with rare histological subtypes.

Inclusion Criteria:

• Locally advanced, relapsed or metastatic non-small cell lung cancer (NSCLC) - stage IIIB/IV according to 7th International Association for the Study of Lung Cancer (IASLC) classification
• Histologically confirmed diagnosis of non-small cell lung cancer (NSCLC) with rare histological subtype, according to World Health Organization (WHO) 2015 classification. Histologic subtype variants to be enrolled into the study include: colloid adenocarcinoma (or adenocarcinoma with colloid features); fetal adenocarcinoma (or adenocarcinoma with fetal features); large cell carcinoma (LCC); sarcomatoid carcinoma (pleomorphic, spindle cell, and/or giant cell carcinoma, carcinosarcoma, pulmonary blastoma); salivary gland-type tumors (mucoepidermoid carcinoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma), other and unclassified carcinomas (lymphoepithelioma-like carcinoma, NUT-nuclear protein in testis-carcinoma)
• Availability of tumor sample (material obtained from core-biopsy or surgical specimen) for central pathology revision is mandatory
• Availability of a formalin-fixed, paraffin-embedded (FFPE) tumor block or 7-10 unstained tumor slides suitable for PD-L1 expression assessment is mandatory. The assessment of PD-L1 expression will be performed by using both SP-142 and SP-263 antibody assays. The collection of tumor sample should be performed before patients are enrolled into the study
• Male and female and ≥ 18 years of age
• Life expectancy ≥ 12 weeks
• Progressive disease after or during at least one previous standard chemotherapy line
• Measurable disease per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1); clear radiological evidence of disease progression after previous treatment has to be documented
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2
• Patients with treated brain metastases with stable lesions for at least 2 weeks either off steroids or on a stable dose or decreasing dose of steroids (≤ 10 mg prednisone or equivalent daily) will be enrolled. Radiotherapy must have been completed a minimum of 14 days prior to registration, and patients must have recovered from adverse events (AEs) related to radiotherapy to < grade 1 (except alopecia)
• For Females: must be postmenopausal for at least 1 year before the screening visit, or are surgically sterile or not sexually active. Women of childbearing potential (WOCBP) must use 2 effective methods of contraception with a failure rate of less than 1% per year, during the entire study treatment period and for a period of 5 months after the last dose of study drug, or agree to practice true abstinence, when this is in line with the preferred and usual lifestyle of the subject. WOCBP must have a negative serum pregnancy test during the screening period
• Adequate haematological function defined by white blood cell (WBC) count ≥2,500/mm3 with absolute neutrophil count (ANC) ≥1,500/mm3, platelet count - Adequate hepatic function defined by a total bilirubin ≤ 1.5 x the upper limit of normal (ULN) range (except subjects with Gilbert Syndrome, who can have total bilirubin < 3.0 mg/dL), serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 x ULN (≤ 5 if liver function test elevations are due to liver metastases)
• Adequate renal function defined by a serum creatinine ≤ 1.5 x ULN or an estimated creatinine clearance of ≥ 30 mL/minute for patients with creatinine levels above institutional limits (if using the Cockcroft-Gault formula)
• Stable medical condition, including the absence of acute exacerbations of chronic illnesses, serious infections, or major surgery within 4 weeks before registration, and otherwise noted in other inclusion/exclusion criteria
• Recovered (i.e., ≤ Grade 1 toxicity) from effects of prior anticancer therapy, except alopecia
• Ability to comply with protocol requirements
• The patient is able to provide written informed consent. Voluntary written consent must be given before performance of any study-related procedure not part of standard medical care, with the understanding that the patient may withdraw consent at any time without prejudice to future medical care.

Exclusion Criteria:

• Prior treatment with Atezolizumab or any other immunotherapy agents (anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T-cell costimulation or immune checkpoint pathways)

• Known hypersensitivity to biopharmaceuticals produced in Chinese hamster ovary cells or any component of the atezolizumab formulation

• Concurrent anticancer treatment, immune therapy, or cytokine therapy, except for erythropoietin

• Major surgery for any reason within 4 weeks (or 2 weeks for minor surgery) from registration and/or if the subject has not fully recovery from the surgery within 4 weeks of registration

• Subjects receiving immunosuppressive agents such as steroids for any reason should be tapered off these drugs before initiation of the trial treatment. Corticosteroid therapy with a dose ≤ 10 mg prednisone or equivalent will be allowed. Note:

  1. Subjects receiving bisphosphonates or denosumab are eligible provided treatment was initiated at least 14 days before first dose of trial treatment
  2. Previous or ongoing administration of systemic steroids for the management of an acute allergic phenomenon is acceptable as long as it is anticipated that the administration of steroids will be completed in 14 days, or that the daily dose after 14 days will be ≤10 mg per day of equivalent prednisone

• Persisting toxicity related to prior therapy of grade >1 according to National Cancer Institute - Common Terminology Criteria Adverse Event (NCI-CTCAE) v. 4.03

• Known severe hypersensitivity reactions to chimeric or monoclonal antibodies, fusion proteins (grade ≥3 NCI-CTCAE v. 4.03)

• Patients with untreated, symptomatic and/or progressive brain metastases, or with carcinomatous meningitis. Subjects with brain metastases are eligible if metastases have been treated and there is no clinical evidence of progression for [lowest minimum is 2 weeks or more] after treatment is complete and within 28 days prior to the first dose of atezolizumab administration. In addition, subjects must be either off corticosteroids, or on a stable or decreasing dose of 10 mg daily prednisone (or equivalent)

• History of autoimmune disease, including, but not limited to myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vascular thrombosis associated with antiphospholipid syndrome, Wegener's granulomatosis, Sjögren's syndrome, Guillain-Barré syndrome, multiple sclerosis, vasculitis or glomerulonephritis. Subjects with diabetes mellitus type I, hypothyroidism only requiring hormone replacement or controlled hyperthyroidism, skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment, or conditions not expected to recur in the absence of an external trigger are permitted to enrol. Subjects with a condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of registration will be not eligible. Subjects requiring hormone replacement with corticosteroids are eligible if the steroids are administered only for the purpose of hormonal replacement and at doses ≤ 10 mg or 10 mg equivalent prednisone per day. Topical, ocular, intra-articular, intranasal, and inhalational corticosteroids (with minimal systemic absorption) are permitted

• Any medical condition requiring a systemic corticosteroid treatment at doses >10 mg prednisone per day or equivalent or other immunosuppressive therapies

• Other concurrent neoplasms

• Prior organ transplantation, including allogenic stem-cell transplantation

• Any medical condition, within 6 months before receiving the first dose of study drug, considered relevant by Investigator. Chronic stable atrial fibrillation on stable anticoagulant therapy is allowed. Patients who present particular clinical conditions or relevant comorbidity may be enrolled into the study upon discussion with the Study Coordinator

• Known human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS)

• Any positive test for hepatitis B virus or hepatitis C virus indicating acute or chronic infection

• Infection requiring intravenous (IV) antibiotic therapy or other serious infection within 14 days before the first dose of study drug

• History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitis obliterans), drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography (CT) scan

• Active tuberculosis

• Pregnancy or breastfeeding

• Vaccination within 4 weeks of the first dose of atezolizumab and while on trial is prohibited except for administration of inactivated vaccines (for example, inactivated flu vaccines)

• Unwilling or unable to comply with the protocol or cooperate fully with the investigator and site personnel