A Ph 2 Study of Fosbretabulin in Subjects w Pancreatic or Gastrointestinal Neuroendocrine Tumors w Elevated Biomarkers

Subjects enrolled in this PNET/GI-NET study (OX4218s) will receive weekly dosing with
fosbretabulin for up to 3 cycles or approximately 9 weeks.

Inclusion Criteria:

- Ability to read, understand and provide written consent to participate in the study

- Age ≥ 18 years

- Biopsy-proven well-differentiated, low-to-intermediate-grade PNET or GI-NET with
elevated (> ULN) biomarkers (serotonin, 5-hydroxyindoleacetic acid (5-HIAA),
chromogranin A (CgA), neurokinin A, and neuron-specific enolase (NSE))

- Life expectancy > 12 weeks

- Must have received or may still be receiving one or more therapies including
octreotide or serotonin synthesis inhibitor (SSI) or other somatostatin analogues

- Confirmed progressive disease within 18 months of enrollment on study

- Recovered from prior radiation therapy or surgery

- Eastern Cooperative Oncology Group (ECOG) performance score 0-2

- Absolute neutrophil count (ANC) ≥ 1,500/µL (without growth factors)

- Platelet count ≥ 100,000/µL

- Adequate renal function as evidenced by serum creatinine

≤ 2.0 mg/dL (177 µmol/L)

- Adequate hepatic function: serum total bilirubin ≤ 2X greater than the upper limit of
normal (ULN) (≤ 3X ULN in subjects with liver metastases), aspartate aminotransferase)
AST) / alanine aminotransferase (AST) ≤ 2X the ULN for the local reference lab (≤ 5X
the ULN for subjects with liver metastases)

- Disease that can be assessed (evaluable) with imaging (CT, MRI, PET, radionuclide
imaging or other imaging modality)

- Women of childbearing potential as well as fertile men and their partners must use an
effective method of birth control

Exclusion Criteria:

- Inadequately controlled hypertension defined as BP > 150/100 mm Hg despite medication

- Prior history of hypertensive crisis or hypertensive encephalopathy

- Recent history (within 6 months of start of screening) of unstable angina pectoris
pattern, myocardial infarction (including non-Q wave MI), or NYHA (New York Heart
Association) Class III and IV Congestive Heart Failure (CHF)

- Subjects who have clinical evidence of carcinoid-induced heart disease

- History of prior cerebrovascular accident (CVA), including transient ischemic attach
(TIA)

- Known central nervous system (CNS) disease except for treated brain metastasis

- History of torsade de pointes, ventricular tachycardia or fibrillation, pathologic
sinus bradycardia (<60 bpm), heart block (excluding 1st degree block, being PR
interval prolongation only), congenital long QT syndrome or new ST segment elevation
or depression or new Q wave on ECG

- Corrected QT interval (QTc) > 480 msec

- Ongoing treatment with any drugs known to prolong the QTc interval, including
anti-arrhythmic medications (stable regimen of antidepressants of the selective
serotonin reuptake inhibitor (SSRI) class is allowed))

- Evidence of bleeding diathesis or significant coagulopathy (in the absence of
therapeutic anticoagulation)

- Significant vascular disease or recent peripheral arterial thrombosis

- Known intolerance of or hypersensitivity to fosbretabulin

- History of solid organ transplant or bone marrow transplant

- Any other intercurrent medical condition, including mental illness or substance abuse,
deemed by the Investigator to be likely to interfere with a subject's ability to sign
informed consent, cooperate and participate in the study, or interfere with the
interpretation of the results

- High grade or poorly differentiated NET

- NET tumor other than PNET or GI-NET

- No elevated biomarker (>ULN) that can be followed

- Received regional hepatic infusion therapy within 6 months of enrollment (RFA allowed
>6 months prior to enrollment)