Outcomes of capecitabine plus temozolomide combination therapy in patients with advanced or metastatic pancreatic neuroendocrine tumors: a retrospective observational single-center study

Background : Treatment strategies for patients with unresectable or recurrent pancreatic neuroendocrine tumors (pNETs) have been investigated, and combination therapy with capecitabine plus temozolomide (CAPTEM) has demonstrated favorable outcomes. In response to these results, the CAPTEM regimen has been widely used in several countries, including Western nations. However, it is yet to be approved in Japan, and its efficacy and safety in the Japanese population remain unclear. In the present study, we examined the efficacy and safety of CAPTEM in Japanese patients with unresectable or recurrent pNETs. Methods : Data were retrospectivelycollected from the medical records of the National Cancer Center Hospital. Results : Fifteen patients with pNETs had received CAPTEM therapy, and 47% of the patients had WHO Grade 2 disease and 47% had WHO Grade 3 disease. The objective response rates and disease control rates were 26.7 and 66.7%, respectively. The median observation period was 20.8 months. The median progression-free survival was 5.3 months (95% confidence interval [CI]: 0.9–NA), and 1-year survival rate was 81.2% (95%CI: 41.5–95.2%). The most common adverse events (AEs) associated with CAPTEM therapy were hematologic and gastrointestinal toxicities. One patient experienced CTCAE grade 3 neutropenia, but no AE-related deaths were observed. Conclusions : This is the first study conducted to demonstrate CAPTEM is a valuable regimen also in the Japanese population, consistent with its established efficacy outside Japan. As reported previously, CAPTEM therapy was associated with high disease control rates, and it could be a valuable regimen in the Japanese population.