Chromogranin A and neuron-specific enolase as prognostic markers in patients with advanced pNET treated with everolimus.

CONTEXT: Everolimus, an oral inhibitor of mammalian target of rapamycin, significantly prolongs progression-free survival (PFS) in patients with advanced pancreatic neuroendocrine tumors (pNET). Chromogranin A (CgA) and neuron-specific enolase (NSE) are considered general biomarkers of these tumors. OBJECTIVE: The objective of the study was to evaluate the prognostic value of CgA and NSE in patients with pNET treated with everolimus. PATIENTS AND METHODS: Patients with low- to intermediate-grade advanced pNET enrolled in two phase 2 studies [RAD001 in Advanced Neuroendocrine Tumors (RADIANT-1) and single institution phase II study at The University of Texas M. D. Anderson Cancer Center] received everolimus. Blood samples were collected and analyzed by a central laboratory at baseline and monthly thereafter. PFS and overall survival (OS) were evaluated in patients with elevated and nonelevated baseline CgA/NSE levels. RESULTS: In RADIANT-1, elevated vs. nonelevated baseline CgA was associated with shorter median PFS (8.34 vs. 15.64 months; P = 0.03) and OS (16.95 months vs. not reached; P < 0.001). Elevated vs. nonelevated baseline NSE resulted in shorter median PFS (7.75 vs. 12.29 months; P = 0.01) and OS (13.96 vs. 24.90 months; P = 0.005). Median PFS was prolonged in patients with early CgA or NSE response (11.0 vs. 5.0 months) compared with those without early biomarker response. More patients with CgA (87 vs. 50%) or NSE (81 vs. 14%) response experienced tumor shrinkage compared with those without response. CgA response data from the single-institution phase II study at The University of Texas M. D. Anderson Cancer Center study are consistent with data from the RADIANT-1 study. CONCLUSIONS: Elevated baseline CgA/NSE provided prognostic information on PFS and survival; early CgA/NSE responses are potential prognostic markers for treatment outcomes in patients with advanced pNET.

Daily oral everolimus activity in patients with metastatic pancreatic neuroendocrine tumors after failure of cytotoxic chemotherapy: a phase II trial.

PURPOSE No established treatment exists for pancreatic neuroendocrine tumor (NET) progression after failure of chemotherapy. Everolimus (RAD001), an oral inhibitor of mammalian target of rapamycin, in combination with octreotide has demonstrated encouraging antitumor activity in patients with NETs. PATIENTS AND METHODS This open-label, phase II study assessed the clinical activity of everolimus in patients with metastatic pancreatic NETs who experienced progression on or after chemotherapy. Patients were stratified by prior octreotide therapy (stratum 1: everolimus 10 mg/d, n = 115; stratum 2: everolimus 10 mg/d plus octreotide long-acting release [LAR], n = 45). Tumor assessments (using Response Evaluation Criteria in Solid Tumors) were performed every 3 months. Chromogranin A (CgA) and neuron-specific enolase (NSE) were assessed monthly if elevated at baseline. Trough concentrations of everolimus and octreotide were assessed. Results By central radiology review, in stratum 1, there were 11 partial responses (9.6%), 78 patients (67.8%) with stable disease (SD), and 16 patients (13.9%) with progressive disease; median progression-free survival (PFS) was 9.7 months. In stratum 2, there were two partial responses (4.4%), 36 patients (80%) with SD, and no patients with progressive disease; median PFS was 16.7 months. Patients with an early CgA or NSE response had a longer PFS compared with patients without an early response. Coadministration of octreotide LAR and everolimus did not impact exposure to either drug. Most adverse events were mild to moderate and were consistent with those previously seen with everolimus. CONCLUSION Daily everolimus, with or without concomitant octreotide LAR, demonstrates antitumor activity as measured by objective response rate and PFS and is well tolerated in patients with advanced pancreatic NETs after failure of prior systemic chemotherapy.