TQB2922 Injection Given Under the Skin With Chemotherapy as Initial Treatment for Colorectal Cancer That Has Spread

Inclusion Criteria:

* Voluntary participation with written informed consent and good compliance.
* Age 18 to 75 years, inclusive, at informed consent.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
* Life expectancy greater than 12 weeks.
* Histologically or cytologically confirmed unresectable metastatic colorectal cancer, staged according to the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) TNM classification, 8th edition (2017).
* RAS/BRAF wild-type status confirmed in tumor tissue.
* At least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
* Adequate laboratory results: hemoglobin \>=90 g/L; absolute neutrophil count \>=1.5 x 10\^9/L; platelets \>=100 x 10\^9/L; total bilirubin \<=1.5 times the upper limit of normal (ULN); alanine aminotransferase and aspartate aminotransferase \<=2.5 x ULN, or \<=5 x ULN with liver metastases; creatinine clearance \>=60 mL/min calculated using the modified Cockcroft-Gault formula; urine protein \<=1+, or, if \>=2+, 24-hour urine protein \<1 g measured within 7 days; prothrombin time, activated partial thromboplastin time, and international normalized ratio \<=1.5 x ULN in participants not receiving anticoagulation; thyroid-stimulating hormone \<=ULN, or, if abnormal, normal triiodothyronine and thyroxine (or their free fractions).
* Women of childbearing potential must have a negative serum or urine pregnancy test within 7 days before enrollment. Participants of reproductive potential must agree to effective contraception during the study and for 6 months after study completion, following protocol section 5.4.4

Exclusion Criteria:

* Known high microsatellite instability (MSI-H) or deficient mismatch repair (dMMR).
* Other malignancy within 3 years before the first dose or a concurrent malignancy. Protocol-permitted exceptions include other malignancies treated by surgery alone with 5 consecutive years of disease-free survival, and cured cervical carcinoma in situ, nonmelanoma skin cancer, or superficial bladder tumors (Ta, Tis, or T1).
* Disease affecting intravenous administration or venous blood collection, or factors affecting oral medication, such as inability to swallow, chronic diarrhea, or intestinal obstruction.
* Toxicities from prior treatment not recovered to grade \<=1 by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), version 6.0. Exceptions include grade 2 alopecia, peripheral neurotoxicity, or anemia; asymptomatic laboratory abnormalities without clinical significance; stable hypothyroidism on hormone replacement; and other toxicities judged not to pose a safety risk.
* Major surgery or significant traumatic injury within 4 weeks before the first dose, expected major surgery during the study (except protocol-permitted surgery), or a persistently unhealed wound or fracture.
* Poorly controlled active viral hepatitis. Hepatitis B surface antigen-positive participants may be screened if hepatitis B virus (HBV) DNA is \<2000 IU/mL (or 1 x 10\^4 copies/mL), or if at least 1 week of anti-HBV treatment before study start has reduced viral load at least 10-fold, and they agree to anti-HBV treatment throughout the study. Participants positive for hepatitis C virus (HCV) antibody or HCV RNA may be screened if judged stable by the investigator, or if receiving antiviral treatment at enrollment and continuing approved antiviral treatment during the study.
* History of noninfectious pneumonitis/interstitial lung disease requiring steroids, or current noninfectious pneumonitis/interstitial lung disease; or hospitalization or therapeutic antibiotics for active infection within 4 weeks before study treatment, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.
* History of psychiatric drug abuse that cannot be discontinued, or a psychiatric disorder.
* Planned or previous allogeneic bone marrow transplantation or solid organ transplantation.
* History of hepatic encephalopathy.
* Significant cardiovascular disease, including any of the following: New York Heart Association (NYHA) class II or higher cardiac dysfunction or left ventricular ejection fraction \<50%; clinically significant ventricular arrhythmia or arrhythmia requiring continuous antiarrhythmic therapy; unstable angina; myocardial infarction within 12 months; Fridericia-corrected QT interval \>450 ms in men or \>470 ms in women (an abnormal value may be assessed by the mean of 3 measurements at least 2 minutes apart); personal or family history of congenital long QT syndrome; arterial or venous thrombosis within 6 months before the first dose; systolic blood pressure \>=150 mmHg and/or diastolic blood pressure \>=90 mmHg despite standard treatment, or prior hypertensive encephalopathy/crisis; clinically significant tumor bleeding/perforation or grade \>=3 bleeding within 1 month before treatment; bleeding/coagulation disease while receiving warfarin, aspirin, or other antiplatelet agents (except maintenance aspirin \<=100 mg/day or clopidogrel \<=75 mg/day); or other bleeding signs/history judged unsuitable by the investigator.
* Poorly controlled diabetes with fasting blood glucose \>10 mmol/L.
* Active or uncontrolled serious infection of CTCAE grade \>=2.
* Renal failure requiring hemodialysis or peritoneal dialysis.
* History of immunodeficiency, including human immunodeficiency virus (HIV) positivity or another acquired or congenital immunodeficiency.
* Use of immunosuppressants or systemic or absorbable topical steroids for immunosuppression, with continued use required within 7 days before the first dose; except prednisone \<10 mg/day or an equivalent glucocorticoid dose.
* Epilepsy requiring treatment.
* Any of the following cancer-related conditions or treatments: chemotherapy/immunotherapy within 3 weeks, radiotherapy/small-molecule targeted therapy within 2 weeks, or treatment within 5 drug half-lives before the first dose (the shortest interval, as stated in the protocol); Chinese patent medicines with a National Medical Products Administration (NMPA)-approved anticancer indication within 2 weeks before the first dose; uncontrolled, symptomatic, or repeatedly drained pleural, peritoneal, or pericardial effusions (small, asymptomatic imaging-only effusions without drainage or treatment in the preceding 2 weeks are allowed); known central nervous system metastases and/or carcinomatous meningitis (except asymptomatic cases, or treated stable cases without imaging evidence of new/enlarging brain metastases for at least 2 weeks after brain-metastasis treatment and off steroids/anticonvulsants for at least 14 days before study treatment); or severe bone damage/spinal cord compression from bone metastases, including weight-bearing pathological fractures within 6 months or anticipated soon, or poorly controlled severe bone pain.
* Known allergy to excipients of the study drug.
* Prior antiangiogenic or anti-epidermal growth factor receptor (EGFR) targeted treatment, including bevacizumab, cetuximab, panitumumab, or aflibercept.
* Prior systemic treatment for advanced colorectal cancer. Adjuvant treatment is permitted if completed \>12 months before study start for oxaliplatin-containing chemotherapy, or \>6 months for chemotherapy without oxaliplatin, measured from the last chemotherapy dose.
* Receipt of another investigational anticancer drug within 4 weeks before the first dose.
* Any other condition that, in the investigator's judgment, seriously compromises safety or the ability to complete the study.