On May 20, 2011, the U. S. Food and Drug Administration approved sunitinib (Sutent Capsules, Pfizer, Inc.) for the treatment of progressive, well-differentiated pancreatic neuroendocrine tumors (pNET) in patients with unresectable, locally advanced, or metastatic disease.
The approval was based on a randomized, controlled trial of sunitinib, 37.5 mg/d, (n=86) orally versus placebo (n=85) in patients with unresectable, locally advanced, or metastatic well-differentiated pNET. Treatment with somatostatin analogs was allowed. The median age of patients was 57 years; 59% were Caucasian, and 48% were male.
The trial’s primary endpoint was investigator-assessed progression-free survival (PFS). After documented radiological progression, patients on the placebo arm were permitted to receive sunitinib. Sixty-nine per cent of the 85 patients allocated to receive placebo subsequently received sunitinib. Secondary endpoints included overall survival (OS) and overall response rate (ORR). Prior to the pre-specified interim analysis, an independent data monitoring committee recommended termination of the trial.
The median PFS was 10.2 and 5.4 months in the sunitinib and placebo arms, respectively, [HR 0.427 (95% CI: 0.271, 0.673), p < 0.001]. An improvement in PFS was observed in multiple patient subgroups, including prior somatostatin analog use. OS data were not mature at the time of the analysis. Investigator-determined ORR was 9.3% in the sunitinib arm. There were no complete responses. Safety was evaluated in 83 patients who received sunitinib during the double-blind portion of the above trial. The most common (> 30%) grade 1-4 adverse reactions were diarrhea, nausea, asthenia, vomiting, and fatigue. The most common (> 5%) grade 3-4 adverse reactions were neutropenia, hypertension, palmar-plantar erythrodysesthesia syndrome, and leukopenia.
On-study deaths occurred in 5 patients on sunitinib and 9 patients on placebo. Of the 5 sunitinib on-study deaths, one was due to cardiac failure and four were due to disease progression. An additional sunitinib patient was taken off study due to cardiac failure and died 2 months later.
Adverse events resulted in permanent discontinuation in 22% and 17% of patients in the sunitinib and placebo arms, respectively. Dose delays and/or reductions were necessary in 61% of sunitinib and 23% of placebo patients.
The recommended dose and schedule for sunitinib is 37.5 mg orally daily. Patients with severe or intolerable adverse reactions may require temporary dose reductions to 25 mg/daily or dose interruption.
Full prescribing information, including clinical trial information, safety, dosing, drug-drug interactions and contraindications is available at: http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021938s13s17s18lbl.pdf
Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System by completing a form online at http://www.fda.gov/medwatch/report.htm, by faxing (1-800-FDA-0178) or mailing the postage-paid address form provided online, or by telephone (1-800-FDA-1088).