Efficacy and safety of surufatinib in unresectable or metastatic grade 3 pancreatic neuroendocrine tumors (NET G3): Real-world analysis.

657 Background: Currently, there is limited exploration regarding the treatment of NET G3, resulting in restricted treatment options. Therapeutics for NET G1/2 may serve as an alternative. Surufatinib, with its potent targeting of VEGFRs, FGFR1, and CSF-1R, not only exerts inhibitory effects on tumor angiogenesis but also modulates the immune microenvironment. Due to its demonstrated efficacy and manageable safety profile, it has secured approval for the treatment of G1/2 NETs. Methods: This is a multi-center real-world study that retrospectively analyzes the clinical data of pts with NET G3 who received surufatinib-based treatment from December 2021 to February 2024, aiming to assess its efficacy and safety. Eligible pts were unresectable or metastatic p-NET with ki-67>20%. The primary endpoint was PFS, with secondary endpoints were ORR, DCR, and safety. Results: As of September 2024, data from 37 pts were analyzed. The median age was 54 years (range: 32-80), with 59.5% male. The median Ki-67 index was 30% (range: 25-70%), and 94.6% of the cases were non-functional p-NETs, with 89.2% having liver metastases and 35.1% having bone metastases. In terms of prior treatments, 18.9%, 40.5%, and 40.5% of pts had received 0, 1, and ≥2 systemic therapies, respectively. Among them, 81.1% had previously undergone chemotherapy, 35.1% had received interventional therapy of liver metastases, and 13.5% with everolimus or anti-angiogenic agents. 48.6% pts had surufatinib-based combination treatment. The median PFS was 9.30 months (mo, 95% CI: 8.02–13.02), with an ORR of 21.6% and a DCR of 81.1%. First-line (1L) treatment showed a higher ORR (42.9% vs. 16.7%) and a trend of better PFS (9.67 vs. 9.04 mo, p=0.7) compared to ≥2L treatment. Combination therapy improved ORR (33.3% vs. 10.5%) with a similar PFS (9.30 vs. 9.44 mo, p=0.93) compared to surufatinib monotherapy. Liver metastases had limited impact on PFS (9.93 vs 9.30 mo, p=0.55). Common grade ≥3 adverse events included hypertension (8.1%), proteinuria (5.4%), and elevated bilirubin (5.4%). Conclusions: Surufatinib has demonstrated initial efficacy and manageable safety in pts with NET G3, providing a new treatment option for these pts. First-line therapy may be a favorable factor for improving PFS. To delve deeper into these findings, additional subgroup analyses, with a particular emphasis on pts with ep-NET G3 will be conducted in the future.