Sequential Capecitabine/Temozolomide and Sunitinib Treatment in Patients With Metastatic Well-Differentiated Grade 1/Grade 2 Pancreatic Neuroendocrine Tumors

Objective The role of alternate sequential administration of sunitinib and capecitabine/temozolomide (CAPTEM) in metastatic pancreatic neuroendocrine tumors (PanNETs) remains unexplored. We thus aimed to analyze the efficacy and tolerability of this strategy in advanced grade 1/grade 2 PanNETs. Methods In total, data of 43 patients with metastatic PanNET were collected from a real-world database of a cancer center. Twenty-four patients were treated with sunitinib followed by CAPTEM (group 1), and 19 patients were treated with CAPTEM followed by sunitinib (group 2). Results Twenty-three patients were treated with first-line sunitinib or CAPTEM, and 20 patients were pretreated with somatostatin analog (SSA) or SSA in combination with transcatheter arterial chemoembolization. The objective response rate with first-line treatment was similar in both groups, whereas that with second-line treatment was higher in group 1 than in group 2, albeit with no significant differences (21.1% vs 5.3%, respectively; P = .205). Median progression-free survival (mPFS) for first-line and second-line treatments did not differ between the 2 groups (11 and 12 months vs 12 and 8 months, respectively). Following subgroup analyses, treatment with first-line sunitinib and sunitinib after pretreated SSA had a longer mPFS than that with second-line sunitinib after CAPTEM (11 months vs 8 months, respectively; P = .046), whereas treatment with first-line CAPTEM and CAPTEM after pretreated SSA had an mPFS similar to that of second-line CAPTEM after sunitinib treatment. CAPTEM and sunitinib had similar tolerability. Conclusion Alternating sunitinib and CAPTEM were well tolerated and associated with similar mPFS in grade 1/grade 2 PanNETs. However, larger prospective studies are required to investigate the efficacy of alternate sequential therapies for metastatic PanNET.