Abstract 1657P
Background
Pazopanib is approved for use after the failure of chemotherapy for soft tissue sarcoma. We aimed to evaluate the clinical outcome and tolerability in a real-world setting.
Methods
Patients treated between June 2015 and August 2019 were reviewed. The response was assessed at 8 and 12 weeks using the Response Evaluation Criteria in Solid Tumors version 1.1. Survival analysis was performed using the Kaplan-Meier method. Toxicity was assessed using the Common Terminology Criteria v. 5.0.
Results
Forty-five patients (51% male) were identified; the median age at diagnosis was 28 years (IQR 23–45 years). The histology subtypes were 26.7% undifferentiated pleomorphic sarcoma (UPS), 15.6% synovial sarcoma (SS), 17% leiomyosarcoma, 8.9% alveolar soft part sarcoma, 8.9% fibrosarcoma, 6.7% epithelioid sarcoma, and 13.3% other types. The most common site for metastases was the lung (55.6%) and liver (13.3%). Pazopanib was used as the second-line and subsequent-line therapy in 46.7% and 53.3% of patients, respectively. At 8 weeks, the clinical benefits rate was 48.9% (7 partial response (PR), 15 stable diseases (SD)), and at 12 weeks, it was 35.5% (6 PR, 10 SD). The median duration of response was 7 months and 3 patients maintained a response more than 12 months; two UPS and 1 SS. The median progression-free survival (PFS) was 3 months (95% confidence interval (CI): 0.75–6.), and the median overall survival was 13 months (95% CI: 7–18.9). There was no statistical difference between using pazopanib as a second- or subsequent line therapy, 5 vs. 2.9 months (p = 0.44). Totally, 71% of patients were maintained on the full dose (800 mg) and led to discontinuation in 9.5% patients because of transaminitis, interstitial lung disease, or fatigue. The reported grade III/IV toxicities (9 patients) were hypertension, neutropenia, thrombocytopenia, anemia, diarrhea, and fatigue. The most common grade I and II toxicities were anemia 35.5%, hypothyroidism 35.1%, transaminitis 28.9%, thrombocytopenia 24.5%, neutropenia 22.2%, hypophosphatemia 21.6%, and hypertension 15.9%.
Conclusions
Pazopanib was found to be tolerable and effective with outcomes comparable to those reported in clinical trials. No difference in PFS was observed when used either as a second- or subsequent line therapy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.