A phase II trial of panobinostat in patients with advanced pretreated soft tissue sarcoma. A study from the French Sarcoma Group

BACKGROUND: Soft tissue sarcomas (STS) are rare tumours for which treatment options are limited in the advanced setting. Histone deacetylase inhibitors have shown activity in preclinical models of STS. METHODS: We conducted a single-arm, open-label, multicentre phase II study to assess the efficacy and tolerability of panobinostat given orally, 40 mg thrice weekly in patients with advanced pretreated STS. The primary endpoint was the 3-month progression-free rate. RESULTS: Forty-seven STS patients were enrolled between January 2010 and December 2010. Median age was 59 (range 21–79) years, 22 (47%) patients were males. Panobinostat dose was lowered to 20 mg thrice weekly after nine patients were enrolled, based on the recommendation of an independent safety committee. The most common grade 3/4 adverse events were thrombocytopenia, fatigue, lymphopenia and anaemia. Forty-five patients were evaluable for the primary endpoint. Among them, nine patients (20%, 95% CI (10–35%)) were progression-free at 3 months. No partial response was seen, but 17 patients (36%) had stable disease (SD) as their best response. Six patients were progression-free at 6 months. CONCLUSION: Panobinostat was poorly tolerated at 40 mg thrice a week. Efficacy in unselected advanced STS was limited, although some patients had prolonged SD.