FDA Issues Complete Response Letter for Surufatinib in pNETS and epNETS

The FDA has issued a complete response letter for the new drug application for surufatinib (Sulanda) in patients with pancreatic neuroendocrine tumors (pNETS) and extra-pancreatic neuroendocrine tumors (epNETS), according to a press release from HUTCHMED.¹

Previously, the phase 3 SANET-p (NCT02589821) and SANET-ep trials (NCT02588170), assessing single-agent surufatinib in advanced pNETs and epNETs, were conducted in China, and 1 bridging study was done in the United States.² Despite being approved in China in June 2021 and December 2020 for pNETs and epNETS, respectively, the FDA concluded that findings from the trial do not support an approval in the United States at this time. Moreover, a multi-regional clinical trial is required for approval in the United States.

“Although this decision from the FDA is disappointing, we remain confident about the clinical value of surufatinib for [patients with NETs] and are committed to making surufatinib available to patients globally. We look forward to working with the [FDA] to evaluate its feedback. Throughout the duration of the U.S. review process, we have been transparent and collaborative with the FDA. There are very few treatments approved and used in these rare diseases, and patients and physicians would benefit from more options to address the unmet medical need. We look forward to continued engagement with the FDA on developing a plan to bring surufatinib to patients in the US,” Weiguo Su, MD, chief executive officer and chief scientific officer at HUTCHMED, said in the press release.

In the complete response letter, after assessing how applicable the single country study findings were to a United States population, the FDA highlighted the need for a multi-regional clinical trial that includes patients representative of those in the United States and for alignment with the current medical practice in the country. Additionally, the FDA cited concerns related to the pandemic and the inspection scheduling and access. Notably, there were no issues with surufatinib’s safety .

In the SANET-ep study, which led to the approval of surufatinib in China,2 patients had a median progression-free survival (PFS) of 9.2 months (95% CI, 7.4-11.1) in the surufatinib arm vs 3.8 months (95% CI, 7.4-5.7) in the placebo arm (HR, 0.334; 95% CI, 0.22-0.50; P <.0001). The most common treatment-related adverse effects in the surufatinib and placebo arms, respectively, were grade 3 or higher hypertension (36% vs 13%), proteinuria (19% vs 0%), and anemia (5% vs 3%).

Findings from the SANET-p study highlighted a reduction in disease progression or death by 51% after taking surufatinib.³ The median PFS was 10.9 months (95% CI, 7.5-13.8) in the surufatinib arm and 3.7 months (95% CI, 2.8-5.6) in the placebo arm (HR, 0.49; 95% CI, 0.32-0.76; P = .0011). The safety profile was consistent and manageable vs prior studies.

In May 2020, rolling submission for a new drug application for surufatinib in those with pNETs and epNETs was completed and the FDA formally accepted the application in June 2021.

Furthermore, HUTCHMED is working with those in Europe for the submission of the marketing authorization application, and surufatinib is currently under review. Additionally, a Japanese bridging study is ongoing.

References

1. HUTCHMED received complete response letter from the US FDA for surufatinib for the treatment of advanced neuroendocrine tumors. News Release. HUTCHMED. May 2, 2022. Accessed May 2, 2022. https://bit.ly/3vYoIWv
2. Xu J, Shen L, Zhou Z, et al. Surufatinib in advanced extrapancreatic neuroendocrine tumours (SANET-ep): a randomised, double-blind, placebo-controlled, phase 3 study. Lancet Oncol. 2020;21(11):1500-1512. doi:10.1016/S1470-2045(20)30496-4
3. Xu J, Shen L, Bai C, et al. Surufatinib in advanced pancreatic neuroendocrine tumours (SANET-p): a randomised, double-blind, placebo-controlled, phase 3 study. Lancet Oncol. 2020;21(11):1489-1499. doi:10.1016/S1470-2045(20)30493-9