Sunitinib Prolongs Progression Free Survival in Rare Neuroendocrine Tumors

The first randomized study in the rare endocrine tumor malignant pheochromocytoma and paraganglioma has found that sunitinib prolongs progression-free survival by more than five months.

The late breaking results of the FIRSTMAPPP trial were presented at the ESMO Congress 2021.

“This trial provides the highest level of evidence ever reached in this very rare cancer,” said study author Eric Baudin, chair, Neuro-Endocrine Tumours, Gustave Roussy – Cancer Campus, Villejuif, France. “The results are practice-changing. Sunitinib is a new option for these patients and becomes the therapy with the most robust indication of antitumor activity in progressive malignant pheochromocytoma and paraganglioma. Based on these findings, new recommendations may consider sunitinib as the first line therapy in patients with this condition.”

Malignant pheochromocytoma and paraganglioma (MPP) is a very rare neuroendocrine tumor, with an annual incidence of less than one per million. During an eight-year period, FIRSTMAPPP enrolled 78 patients with progressive MPP from 15 centers in four European countries. The average age was 53 years and 59 percent were men. Participants were randomly allocated to sunitinib or placebo. The primary endpoint of progression free survival (PFS) at 12 months was achieved by 35.9 percent of the sunitinib group, meaning that 14 out of 39 patients experienced no progression of their tumor for at least one year. The PFS rate in the placebo group was 18.9 percent. The median PFS was 8.9 versus 3.6 months in the sunitinib and placebo groups, respectively.

“This is a strong result, showing that the 12-month PFS rate with sunitinib was nearly double that seen with placebo,” said Juan Valle, consultant medical oncologist, University of Manchester and The Christie NHS Foundation Trust, Manchester, United Kingdom. “None of the treatment options we currently have for advanced MPP are supported by randomized clinical trial evidence. This disease is commonly treated using combined chemotherapy with cyclophosphamide, vincristine and dacarbazine, all quite old agents and all very toxic. Sunitinib will be much better tolerated.”

In the trial, severe adverse events occurred in 54 percent of patients in the sunitinib group versus 49 percent in the placebo group, the most frequent being asthaenia/fatigue (18 percent versus 3 percent) and hypertension (10 percent versus 6 percent). One death occurred in each arm.

“The study demonstrated that sunitinib 37.5 mg per day was tolerable,” said Baudin. “In particular, we know that two-thirds of patients with MPP have hypertension due to high levels of hormones, yet hypertension induced by the drug was manageable.”

“This study confirms the ability of trials to answer efficacy questions in patients with rare cancers,” said Valle. “It also highlights the crucial role of widespread collaboration in academic studies. We know that to access these treatments, patients need to be managed through expert centers. We must facilitate this if we are to ensure that patients are given the opportunity to receive these treatments and to be enrolled in the next generation of clinical trials for new therapies.”

Photo: Juan Valle, consultant medical oncologist, University of Manchester and The Christie NHS Foundation Trust, Manchester, United Kingdom

Author: Rare Daily Staff