Pfizer’s sunitinib effective for pancreatic islet cell tumours

Treatment with Pfizer's tyrosine kinase inhibitor Sutent significantly prolonged progression-free survival with an "acceptable" safety profile in patients with progressive well-differentiated pancreatic islet cell tumours, data from a Phase III trial presented at the European Cancer Organisation/European Society of Medical Oncology meeting in Berlin, has revealed.

Investigators assessed the safety and efficacy of placebo or Sutent (sunitinib) 37.5 mg/day continuous daily dosing, with best supportive care, in 154 patients with well-differentiated pancreatic islet cell tumors not amenable to curative therapy. The trial was stopped early after a planned review by a data monitoring committee in February this year recommended that all patients should be offered sunitinib because of its efficacy.

The interim analysis presented this week showed that median progression-free survival was 11.1 months with sunitinib versus 5.5 months for placebo. The hazard ratio for progression-free survival was 0.397 in favour of sunitinib (p < 0.001), giving a 60% improvement. Lead investigator Dr Eric Raymond, from Hospital Beaujon, Clichy, France, said the key question now is does sunitinib improve significantly overall survival in this patient group? He said: “We are currently analysing the final data and we expect to see an overall survival benefit.”

Sutent is the standard of care for first-line treatment of metastatic renal cell cancer and has been shown in this tumour type to extend overall survival beyond two years. It has also been approved for the treatment of imatinib-resistant/intolerant gastrointestinal stromal tumours. Dr Raymond added: “There are few medical options for advanced pancreatic islet cell tumours so our trial is important because it opens up the possibility for future treatment." A Pfizer spokesperson said the company was “evaluating the data and considering its options” with respect to seeking a new indication for sunitinib. Pancreatic islet cell tumours are rare, with 2-4 cases per 1 million population every year.

The most common adverse events reported in the trial with sunitinib treatment were diarrhoea, nausea, vomiting, asthenia and fatigue. The most frequently reported grade 3/4 adverse events with sunitinib included neutropenia (12.3%), hypertension (8.8%) and abdominal pain, diarrhoea, hypoglycaemia, and palmar-plantar erythrodysaesthesia (7.0% each). By Rhonda Siddall in Berlin