Treatment patterns and clinical outcomes with pazopanib in patients with advanced soft tissue sarcomas in a compassionate use setting: results of the SPIRE study

Background: A named patient program (NPP) was designed to provide patients with advanced soft-tissue sarcoma (aSTS) access to pazopanib, a multitargeted tyrosine kinase inhibitor. The SPIRE study was a retrospective chart review of participating patients.Patients and methods: Eligibility criteria for the NPP and SPIRE mirrored those of the pivotal phase-III study, PALETTE, which compared pazopanib with placebo in patients 18 years with aSTS and whose disease had progressed during or following prior chemotherapy or were otherwise unsuitable for chemotherapy. Outcomes of interest included treatment patterns, treatment duration, relative dose intensity, progression-free survival (PFS), overall survival (OS), clinical benefit rate, adverse events (AEs) and reasons for treatment discontinuation.Results: A total of 211 patients were enrolled (median age 56 years; 60% female). Most patients received pazopanib in second- and third-line therapy (28.0% and 28.4%, respectively), followed by fourth line (19.0%) andfifth line (18.5%). The median duration of pazopanib treatment was 3.1 months (95% CI: 2.8-3.8), with a mean daily dose of 715mg equating to 92% of recommended dose. Median OS was 11.1 months and clinical benefit rate was 46%. There was evidence of some clinical benefit across most histological subtypes. At study end, 40% of patients were alive and of these, 18% remained on pazopanib. Thirteen percent (13%) of patients discontinued pazopanib due to AEs.Conclusions: The SPIRE study demonstrated activity of pazopanib in heavily pretreated aSTS patients in a compassionate use setting. No new safety concerns were noted. Reassuringly, the relative dose intensity of pazopanib was 92%.