AMG 706 and Octreotide in Treating Patients With Low-Grade Neuroendocrine Tumors

RATIONALE: AMG 706 and octreotide may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the tumor.

PURPOSE: This phase II trial is studying how well AMG 706 and octreotide work in treating patients with low-grade neuroendocrine tumors.

OBJECTIVES:

Primary

* Determine the 4-month progression-free survival (PFS) of patients with low-grade neuroendocrine tumors treated with AMG 706 and octreotide acetate.

Secondary

* Determine the response rate and overall survival of patients treated with these drugs.
* Determine the toxicity and tolerability of AMG 706 in these patients.
* Determine the effect of AMG 706 on tumor perfusion by functional computerized tomography (CT) scan.
* Determine the effect of AMG 706 on tumor markers (e.g., chromogranin A, 5-hydroxyindoleacetic acid, and gastrin) specific for neuroendocrine tumors.
* Determine the effect of AMG 706 on serum vascular endothelial growth factor (VEGF) levels.
* Determine the expression of VEGF, VEGF receptor-2 (VEGFR-2), chromogranin A, human achaete-scute homolog-1 (hASH1), and Notch1 markers of neuroendocrine tumors.

OUTLINE: This is a multicenter study.

Patients receive oral AMG 706 and octreotide acetate intramuscularly once daily on days 1-28. Treatment repeats every 28 days in the absence of disease progression or unacceptable toxicity.

Plasma samples are collected at baseline, periodically during study treatment, and at 4 weeks after the completion of study treatment. Samples are used to determine plasma VEGF levels. Gene expression of downstream markers of Raf kinase expression (raf, MEK, and ERK) as well as hASH1 and Notch1 are evaluated at baseline. Tumor tissue collected at diagnosis or prior surgery is examined by reverse transcriptase-polymerase chain reaction assay. Contrast CT scans are conducted at baseline, day 2 of course 1, and week 8 to assess tumor perfusion.

After the completion of study treatment, patients are followed periodically for 5 years.

PROJECTED ACCRUAL: A total of 44 patients will be accrued for this study.

Eligibility Criteria:
Inclusion Criteria:

* Histologically confirmed low-grade neuroendocrine neoplasm
* Measurable disease
* Radiographic evidence of disease progression after any prior systemic therapy, chemoembolization, bland embolization, or observation, defined by either of the following:

  * Appearance of a new lesion
  * At least 20% increase in the longest diameter of any previously documented lesion or in the sum of the longest diameters of multiple lesions
* Tissue block from original diagnostic or surgical specimen required
* Concurrent stable-dose octreotide acetate required
* Eastern Cooperative Oncology Group (ECOG) performance status 0-2
* Negative pregnancy test
* Fertile patients must use effective contraception
* Must be able to receive a contrast-enhanced CT scan
* Absolute neutrophil count ≥ 1,000/mm³
* Platelet count ≥ 75,000/mm³
* Hemoglobin level ≥ 8.0 g/dL
* Bilirubin ≤ 2.0 times upper limit of normal (ULN)
* Aspartate aminotransferase (AST) ≤ 3 times ULN (5 times ULN if liver metastases are present)
* Left Ventricular Ejection Fraction (LVEF) ≥ institutional lower limit of normal as evaluated by echocardiography or multigated acquisition (MUGA) scan
* No history of uncontrolled hypertension (resting blood pressure \> 150/90 mm Hg)

  * Antihypertensive medications allowed if patients is stable on their current dose
* One prior systemic chemotherapy regimen for low-grade neuroendocrine neoplasm allowed

  * Chemoembolization is not considered systemic chemotherapy
* At least 4 weeks since prior major surgery, chemotherapy, radiation therapy, other systemic therapy, or local liver therapy

Exclusion criteria:

* Prior procedures that would adversely affect intestinal absorption
* Prior anti-vascular endothelial growth factors
* Concurrent chemotherapy or radiation therapy
* History of the following within the past 12 months:

  * New York Heart Association class III or IV congestive heart failure
  * Unstable angina pectoris
  * Myocardial infarction
  * Symptomatic cardiac arrhythmia
  * Cerebrovascular accident or transient ischemic attack
  * Arterial or venous thrombosis
* Known history of allergic reactions to AMG 706 or derivatives or to octreotide acetate injections
* Gastrointestinal tract disease resulting in an inability to take oral medication (i.e., ulcerative disease, uncontrolled nausea, vomiting, or diarrhea, bowel obstruction, or inability to swallow tablets)
* Pregnant or nursing
* Small cell lung cancer, medullary thyroid cancer, paraganglioma, or pheochromocytoma
* Requirement for intravenous alimentation