Inclusion Criteria:
1. Histological diagnosis of extensive-stage small cell lung cancer (ES-SCLC). Unequivocally confirmed diagnosis of SCLC by histology preferably including the presence of neuroendocrine features by immunohistochemistry.
2. Centrally confirmed tumor tissue viability for vaccine preparation.
3. No previous cancer treatment for advanced disease
4. Life expectancy at least 16 weeks
5. ECOG performance status 0 or 1.
6. Adequate normal organ and marrow function as defined below:
Absolute neutrophil count ≥ 1.5 x 109 cells/L Platelets ≥ 100 x 109/L Hemoglobin ≥ 9 g/dL Aspartate and alanine aminotransferases (AST, ALT) ≤ 2.5 x upper limit of normal (ULN) (≤ 5 x ULN, if documented liver metastases are present) Total bilirubin ≤ 2 x ULN (except patients with documented Gilbert's syndrome) Creatinine \< 2 mg/dl (or a glomerular filtration rate \> 60)
7. Prior palliative radiotherapy must have been completed at least 2 weeks prior to start the study treatment (subjects may receive localized palliative radiotherapy while receiving study drug).
8. Subjects with brain metastases are eligible if they are asymptomatic, are treated, or are neurological stable for at least 2 weeks without the use of steroids, or on a stable or decreasing dose of \< 10 mg daily prednisone or equivalent.
9. Must be willing and able to accept one leukapheresis procedures
10. Written informed consent of approved by the investigator's Institutional Review Board (IRB)/Independent Ethics Committee (IEC), prior to the performance of any trial activities.
11. Male or female subjects aged ≥ 18 years.
12. Measurable disease by RECIST.1.1 criteria.
13. Highly effective contraception for both male and female subjects throughout the study and for at least 30 days after the last atezolizumab treatment administration if the risk of conception exists.
14. Negative serum pregnancy test at screening for women of childbearing potential. Female subjects must either be of non-reproductive potential (ie, post-menopausal by history: ≥60 years old and no menses for ≥1 year without an alternative medical cause; OR history of hysterectomy, OR history of bilateral tubal ligation, OR history of bilateral oophorectomy) or must have a negative serum pregnancy test upon study entry.
15. Central negative serologic determination to HBsAg, Anti-HBc, HBV, HCV, HCV RNA, HIV-I RNA, Agp24 IIIV + AC IIIV ½ (MLIA) serum, IgG antigen core v. hepatitis B, RPR (Ac reaginic Lues-RPR, serum), Ac anti-HTLV I/II (if the patient came from an endemic zone), Ac anti-Trypanosoma Cruzi, Chagas, (if a patient came from the endemic zone), when RPR positive or doubtful for confirmation: IgG T. pallidum (ELISA) immunoglobulin M (IgM) T. pallidum (ELISA), when IgG T. Pallidum doubtful: Pt confirmatory immunoglobulin G (IgG)/IGM, T pallidum (LIA).
Exclusion Criteria:
1. Prior chemotherapy for extensive-stage ES-SCLC
2. Any prior anti-PD-1/PD-L1 antibody therapy
3. History of, or significant evidence of risk for, severe chronic inflammatory or autoimmune disease
4. Potential requirement for systemic corticosteroids or concurrent immunosuppressive drugs based on prior history or received systemic steroids within the last 2 weeks prior to enrollment (inhaled or topical steroids at standard doses are allowed)
5. Human immunodeficiency virus (HIV) seropositivity, active Hepatitis B or C seropositivity
6. Dementia or significantly altered mental status that would prohibit the understanding or rendering of informed consent and compliance with the requirements of this protocol
7. Pregnancy or breastfeeding; female patients must be surgically sterile or be postmenopausal for two years or must agree to use effective contraception during the period of treatment and 6 months after; all female patients with reproductive potential must have a negative pregnancy test (serum/urine) within 24 hours from starting the conditioning chemotherapy; the definition of effective contraception will be based on the judgment of the study investigators; patients who are breastfeeding are not allowed on study
8. Any unresolved toxicity (CTCAE grade 2) from previous anti-cancer therapy. Subjects with irreversible toxicity that is not reasonably expected to be exacerbated by the investigational product may be included (e.g., hearing loss, peripheral neuropathy).
9. Active or prior documented autoimmune disease within the past 2 years NOTE: Subjects with vitiligo, Grave's disease, or psoriasis not requiring systemic treatment (within the past 2 years) are not excluded. For phase I cohort, patients with autoimmune paraneoplastic syndromes will be also excluded.
10. Any syndrome that requires systemic corticosteroid/immunosuppressive medication EXCEPT for syndromes which would not be expected to recur in the absence of an external trigger (vitiligo, autoimmune thyroiditis, or type 1 diabetes mellitus are permitted to enroll)
11. Active or prior documented inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis).
12. History of primary immunodeficiency.
13. History of allogeneic organ transplant. 14 History of hypersensitivity to atezolizumab / ADC vaccine or any excipient.
15- Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, uncontrolled hypertension, unstable angina pectoris, cardiac arrhythmia, active peptic ulcer disease or gastritis, active bleeding diathesis including any subject known to have evidence of acute or chronic hepatitis B or C or psychiatric illness/social situations that would limit compliance with study requirements or compromise the ability of the subject to give written informed consent.
16- Known history of active tuberculosis. 17- Subjects with previous malignancies (except for non-melanoma skin cancer, and cancer in situ of the bladder, gastric, colon, cervical/dysplasia, melanoma, breast) are excluded unless a complete remission was achieved at least 5 years prior to study entry and no additional therapy is required or anticipated to be required during the study period.
18- Receipt of live attenuated vaccination within 30 days prior to study entry or within 30 days of receiving atezolizumab.
19- Prior allogeneic stem-cell transplantation. 20- Known severe hypersensitivity reactions to monoclonal antibodies (Grade ≥ 3 NCI-CTCAE v 5.0), any history of anaphylaxis, or uncontrolled asthma.
21- Female patients who are pregnant or breastfeeding or male or female patients of reproductive potential who are not willing to employ highly effective birth control from screening to 180 days after the last dose of ADC + atezolizumab combination therapy.
