|The following article features coverage from the European Society for Medical Oncology (ESMO) Congress 2021. Click here to read more of Cancer Therapy Advisor’s conference coverage.|
Sunitinib can prolong progression-free survival (PFS) in patients with malignant pheochromocytoma and paraganglioma (MPP), according to results from the FIRSTMAPPP study presented at the European Society for Medical Oncology (ESMO) Congress 2021.
“This is the highest level of evidence ever reached in this very rare cancer,” said Eric Baudin, MD, PhD, of Institut Gustave Roussy in Villejuif, France, when presenting the study results at the meeting.
“This is practice-changing,” he added. “Sunitinib becomes the therapeutic option with the most robust evidence of antitumor activity in progressive malignant pheochromocytoma and paraganglioma.”
The phase 2 FIRSTMAPPP study (ClinicalTrials.gov Identifier: NCT01371201) included 78 patients with unresectable, metastatic MPP. Pheochromocytoma and paraganglioma were each the primary tumor in 50% of cases, 40% of patients were previously untreated, 32% had SDHB mutations, and 60% had bone metastases.
The patients were randomly assigned to receive sunitinib at 37.5 mg per day (39 patients) or placebo (39 patients). Baseline characteristics were similar between the treatment arms.
The median treatment duration was 11 months with sunitinib and 4 months with placebo. A majority of patients in the placebo arm (87%) crossed over to the sunitinib arm after disease progression.
The study’s primary endpoint was PFS at 12 months. Using a 2-stage Simon design, the researchers calculated that at least 11 of 37 patients would need to be progression-free at 12 months in order for sunitinib to be considered effective.
This criterion was met, as 14 of 39 patients in the sunitinib arm were progression-free at 1 year. Specifically, the 12-month PFS rate was 35.9% with sunitinib and 18.9% with placebo.
Dr Baudin noted that the PFS rate in the placebo arm was within the 90% confidence interval confirming the Simon design’s conclusion, so sunitinib was considered effective.
At a median follow-up of 27.2 months, the median PFS was 8.9 months with sunitinib and 3.6 months with placebo.
The partial response (PR) rate was 31% in the sunitinib arm and 8% in the placebo arm. When looking only at patients in the sunitinib arm, the researchers found that patients with SDHB mutations had a higher PR rate than patients without these mutations — 50% and 26%, respectively.
Grade 3 or higher adverse events occurred in 72% of patients in the sunitinib arm and 51% of those in the placebo arm.
The most common grade 3-4 adverse events (in the sunitinib and placebo arms, respectively) were asthenia/fatigue (18% vs 3%), hypertension (10% vs 6% placebo), and bone pain (0% vs 10%).
One drug-related death occurred in each arm — rectal bleeding in the sunitinib arm and cerebrovascular ischemia in the placebo arm.
Disclosures: This research was supported by Pfizer. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Baudin E, Goichot B, Berruti A, et al. First International Randomized Study in Malignant Progressive Pheochromocytoma and Paragangliomas (FIRSTMAPPP): An academic double-blind trial investigating sunitinib. Presented at: European Society for Medical Oncology (ESMO) Congress 2021; September 16-21, 2021. Abstract 567O_PR.