Safety Study of GC1118 (Recombinant Human Anti-EGFR Antibody) in Patients With Advanced Solid Cancer

Inclusion Criteria:

* Willing and able to sign a written informed consent
* Nineteen (19) years of age or older
* For Part A and Part C, all stage IV advanced solid cancers For Part B, stage IV of gastric cancer, colorectal cancer or other cancer
* Cohort1: Metastatic CRC (K-RAS wild), No prior treatment with EGFR antibody therapeutics
* Cohort2: Metastatic CRC (K-RAS wild), Progressed over EGFR antibody therapeutics
* Cohort3: Advanced gastric or gastroesophageal junction cancer(EGFR++ or +++ /HER2-)
* For Part A and Part C, refractory solid tumors to conventional therapy (Progressive disease during or after previous conventional therapy)
* Eastern Cooperative Oncology Group (ECOG) Performance Status of less than or equal to 1
* Life expectancy of greater than or equal to 3 months
* Availability of a new tumor biopsy or able to obtain unstained slides of tumor within 3 years
* For Part B, at least one measurable tumor mass by RECIST v1.1
* Acceptable laboratory parameters
* If all AEs caused by the previous anti-cancer therapies including surgery, chemotherapy and radiation therapy have recovered to CTCAE grade 1 or below (except alopecia)

Exclusion Criteria:

* Has had any major surgery or any therapy within the last 4 weeks and/or not recovered from prior therapy
* Has had chemotherapy, surgery or radiotherapy within the previous 4 weeks
* Confirmed brain metastases
* Chronic Hepatitis C or known HIV positive patients
* Liver Cirrhosis or active hepatitis B virus (HBV) carrier
* Clinically significant interstitial pulmonary disease
* Has received prior treatment with cetuximab or anti-EGFR antibody therapy is not permitted in Part B(however, allowed in Part A and Part C)
* Clinically significant cardiac disease or impaired cardiac function
* Acute or subacute intestinal obstruction or Inflammatory bowel disease
* Has had immunotherapy, chemotherapy or hormonal therapy prohibited as per study protocol
* Has participated in any study using an investigational drug during the previous 4 weeks
* Known hypersensitivity to the study drug
* History of second primary malignancy within 3 years prior to starting study treatment (excluding early gastric cancer, thyroid cancer, cervical cancer or skin cancer)
* Severe renal impairment
* Severe hepatic impairment
* Current active infection
* Known KRAS-mutation for Part A and Part C, Known KRAS-mutation for Part B or BRAF matant
* Medical or psychiatric illness that, in the opinion of the investigator, may affect compliance with scheduled visits
* Pregnant (potentially fertile patients) or lactating women
* Patients refuse to use acceptable forms of contraceptions from the time of consent through six months after the study drug administration