The purpose of this study is to assess the efficacy and safety of Camrelizumab plus chemotherapy in the treatment of adult participants with medically inoperable Stage I or IIA non-small cell lung cancer (NSCLC).

This trial will evaluate the safety and efficacy of camrelizumab in combination with chemotherapy, followed by camrelizumab alone after 4-6 cycles of combination in participants with medically inoperable stage I or IIA non-small cell lung cancer (NSCLC). The primary objective of this pilot study is to determine the Camrelizumab plus chemotherapy improves progression-free survival (PFS) . All the efficacy and safety are assessed by investigator : 1) response rate (ORR), 2) disease control rate (DCR); 3) overall survival (OS), 4) PFS rate of 1-year, 2-year, and 5-year; and 5) OS rate of 1-year, 2-year, and 5-year.

Explore objective is potential biomarker associated with efficacy.

Inclusion Criteria:

1. Patients aged ≥18 years, male and female are not limited;
2. Patients with ECOG score of 0-1;
3. Life expectancy ≥12 weeks;
4. Patients must have histologically- or cytologically-documented NSCLC (according to 2015 WHO Classification);
5. Patients with stage I - IIA (T1-T2bN0M0, tumor size ≤ 50mm) confirmed by radiographic；and medical inoperable, unable to undergo thoracic surgery, or refusing to surgery (according to the eighth edition of TNM staging);
6. Patients with measurable target lesions according to the RECIST 1.1 standard;
7. Patients have not received prior treatment for their NSCLC, including radiotherapy, chemotherapy, surgery and target drugs;
8. Can provide tumor tissue;
9. Adequate organ and marrow function;
10. Fertile female were required to have a serum or urine pregnancy test within 72 hours before the start dose of study medication and the result has been negative;If female of childbearing potential, is willing to use adequate contraception for the course of the study through 90 days after the last dose of study medication; if male with a female partner(s) of child-bearing potential, must agree to use adequate contraception starting with the first dose of study medication through 90 days after the last dose of study medication;
11. Provision of signed ICF.

Exclusion Criteria:

1. Known any distance metastases;
2. Patients with known EGFR gene mutation or ALK fusion mutation;
3. Patients with any active autoimmune disease or history of autoimmune disease;
4. Patients with innate or acquired immune deficiency, such as human immunodeficiency virus (HIV) infection, active hepatitis B, hepatitis C or co-infection with hepatitis B and hepatitis C;
5. Subjects requiring systemic treatment with corticosteroids (> 10 mg / day of prednisone or its equivalent) or other immunosuppressants within 14 days prior to the first administration;
6. Patient must not have received a live, attenuated vaccine within 4 weeks prior to the first administration;
7. Any therapy for NSCLC treatment;
8. Patients with other malignant tumors in the past 5 years;
9. Patients with previous or current pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiologic pneumonia, drug-induced pneumonia and active pneumonia confirmed by imaging;
10. Patients with cardiac insufficiency;
11. Routine urine test indicated that urine protein was >= (+ +), or 24-hour urine protein was >= 1g, or severe liver and kidney dysfunction;
12. Patients with severe infection or fever of unknown origin >38.5 ℃ within 4 weeks prior to the first administration;
13. Patients with known history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation;
14. Pregnant or lactating women; those with fertility who are unwilling or unable to take effective contraceptive measures;
15. Known allergies, hypersensitivity, or intolerance to camrelizumab or its excipients or to pemetrexed or to nab-paclitaxel;
16. Any condition that, in the opinion of the investigator, would interfere with evaluation of the study drug or interpretation of patient safety or study results，or the patient is unlikely to comply with study procedures, restrictions, and requirements.