A Study of AGS-1C4D4 Given in Combination With Gemcitabine in Subjects With Metastatic Pancreatic Cancer

A disease assessment will be performed at study week 8 (± 3 days) by the investigator. The
assessment will be based both on changes in clinical symptoms, and radiographic images.
Subjects without evidence of disease progression may continue to receive treatment based on
their original treatment assignment until disease progression or intolerability. Disease
assessments will be performed every 8 weeks during the extended period. A safety follow-up
visit will occur 4 weeks after the last dose infusion of AGS-1C4D4 and/or gemcitabine.

Post-Treatment: Subjects terminating from protocol therapy for reasons unrelated to
documented disease progression will be followed by telephone contact every 2 months until
they begin a new anticancer therapy, their disease progresses, they die, become lost to
follow-up or withdrawal consent for further follow-up, whichever of these events occurs
first.

Overall survival: All subjects will be followed by telephone contact every 2 months until
death, loss to follow-up, or withdrawal of consent, whichever of these events occurs first.

Inclusion Criteria:

- Pathologically confirmed metastatic adenocarcinoma of the pancreas (AJCC Stage IV).
Subjects with islet cell neoplasms are excluded

- Non-measurable or measurable disease based on the RECIST criteria

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1

- Life expectancy of > 3 months

- Hematologic function, as follows:

- Absolute neutrophil count (ANC) ≥ 1.5 x 109/L

- Platelet count ≥ 100 x 109/L

- Hemoglobin ≥ 9 g/dL (transfusion independent)

- Renal function, as follows:

- Creatinine ≤ 2.0 mg/dL

- Hepatic function, as follows:

- Aspartate aminotransferase (AST) ≤ 2.5 x ULN or ≤ 5 x ULN if known liver
metastases.

- Alanine aminotransferase (ALT) ≤ 2.5 x ULN or ≤ 5 x ULN if known liver
metastases

- Bilirubin ≤ 2 x ULN

- INR < 1.3 (or ≤ 3 if on warfarin for therapeutic anti-coagulation)

Exclusion Criteria:

- Prior systemic therapy for metastatic pancreatic cancer

- Subjects who have received adjuvant treatment with gemcitabine and who had
relapse metastatically are allowed

- Subjects with advanced local disease who have received treatment with
gemcitabine and in whom progression has been observed with the onset of
metastases less than 6 months are excluded

- Chemotherapy and/or radiation within 4 weeks of study enrollment

- Prior monoclonal antibody therapy within 60 days of study enrollment

- Known brain or leptomeningeal disease

- History of other primary malignancy, unless:

- Curatively resected non-melanomatous skin cancer

- Other malignancy curatively treated with no known active disease present and no
treatment administered for the last 3 years

- Active angina or Class III or IV Congestive Heart Failure (New York Heart Association
CHF Functional Classification System)

- Use of any investigational product within 4 weeks of study enrollment

- Major surgery (that requires general anesthesia) within 4 weeks before study
enrollment

- Women who are pregnant (confirmed by positive pregnancy test) or lactating

- Man or woman of childbearing potential not consenting to use adequate contraceptive
precautions during the course of the study and for 4 weeks after the last AGS-1C4D4
and/or gemcitabine infusion administration

- Subject known to be human immunodeficiency, hepatitis B or hepatitis C virus positive

- Active serious infection not controlled with antibiotics