Inclusion Criteria:

1. The patient has well-differentiated or moderately-differentiated, histologically confirmed neuroendocrine carcinoma, including carcinoid of any location and islet cell tumors.
2. The patient has metastatic disease at the time of study entry.
3. The patient has a tumor measurable according to Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (Section 11), measurable by elevated tumor markers (eg, 24-hour urine 5-HIAA, chromogranin A, ACTH, gastrin, or other tumor specific biochemical markers), or both.
4. The patient is age = 18 years.
5. The patient's tumor has Ki-67 expression = 20%.
6. The patient is receiving depot octreotide therapy.
7. The patient has received 0-1 anticancer regimens in addition to depot octreotide,which may have included chemotherapy, interferon, chemoembolization, radiofrequency ablation, antiangiogenic therapy, other targeted treatments, or a combination of such treatments.
8. The patient is no longer a candidate for surgery, embolization, or radiofrequency ablation therapy.
9. The patient has experienced radiographic, biochemical, and/or scintigraphic disease progression while on a regimen that includes octreotide.
10. The patient has completed prior chemotherapy and/or radiotherapy with curative intent at least 3 weeks prior to the administration of the first dose of study therapy. Patients receiving palliative radiation therapy to bony metastases prior to the first dose of study medication are eligible.
11. The patient has a life expectancy of > 3 months.
12. The patient has an Eastern Cooperative Oncology Group performance status
13. The patient has adequate hematologic function as defined by absolute neutrophil count = 1500/µL, hemoglobin = 9 g/dL, and platelet count =100,000/µL.
14. The patient has adequate hepatic function as defined by a total bilirubin = 1.5 x the upper limit of normal (ULN), and aspartate transaminase (AST) and alanine transaminase (ALT) = 3 x the ULN (or = 5 x the ULN in the presence of known liver metastases).
15. The patient either has adequate coagulation function as defined by international normalized ratio (INR) = 1.5 and partial thromboplastin time (PTT) no more than 5 seconds above the ULN, or is on a stable dose of anticoagulant.
16. The patient has adequate renal function as defined by serum creatinine = 1.5 x the institutional ULN or creatinine clearance = 60 mL/min for patients with creatinine levels above the ULN.
17. The patient has fasting serum glucose < 120 mg/dL or below the ULN.
18. Because the teratogenicity of IMC-A12 is not known, women of childbearing potential (WOCBP) must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation.
19. The patient has the ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

1. The patient has uncontrolled brain or leptomeningeal metastases.
2. The patient has not recovered to grade = 1 from adverse events due to agents administered more than 4 weeks prior to study entry (except for alopecia).
3. The patient is receiving any other investigational agent(s).
4. The patient has received therapeutic radiolabeled somatostatin analogues.
5. The patient has received more than one prior regimen of chemotherapy in the metastatic setting.
6. The patient has a history of treatment with other agents targeting the IGF receptor.
7. The patient has a history of allergic reactions attributed to compounds of chemical or biologic composition similar to that of IMC-A12 or to octreotide.
8. The patient has poorly controlled diabetes mellitus. Patients with a history of diabetes mellitus are allowed to participate, provided that their blood glucose is within normal range (fasting glucose < 120 mg/dL or below the ULN) and that they are on a stable dietary or therapeutic regimen for this condition.
9. The patient has an uncontrolled intercurrent illness including, but not limited to, ongoing or active infection requiring parenteral antibiotics, symptomatic congestive heart failure, uncontrolled hypertension, clinically significant cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
10. The patient is pregnant or lactating.