The following article features coverage from the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Pazopanib showed antitumor efficacy among patients with unresectable or metastatic malignant/dedifferentiated (M/DD) soft fibrous tumors (SFT), according to a study to be presented at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.1

SFT is a rare tumor that responds poorly to chemotherapy. Because SFT demonstrates high VEGFR1/VEGFR2 expression and rich vasculature, this study evaluated pazopanib, a VEGFR inhibitor, in this population.

This international, single-arm phase 2 study evaluated pazopanib in 2 cohorts: among patients with typical SFT and those with M/DD SFT. This analysis is of the 34 patients in the M/DD cohort.

Patients received 800 mg per day of pazopanib until disease progression or toxicity. The median age was 61, median tumor size was 77 mm, and the median mitosis at diagnosis was 8 x 10 HPF.

According to the investigators, the Choi response criteria were more accurate than RECIST. The response rate according to the Choi criteria was 3% partial response (PR), 61% stable disease (SD), and 35% progressive disease (PD).

The median progression-free survival was 5.53 months (95% CI, 4.24-6.82) during a median follow-up of 15 months.

The overall survival rate at 18 months was 72%, but was 90% for patients who experienced PR or SD and 25% for patients with PD.

Common grade 3 to 4 adverse events were hypertension (12%) and neutropenia (9%).

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The investigators stated that these data suggest that pazopanib demonstrated antitumor activity among patients with M/DD SFT.

Read more of Cancer Therapy Advisor‘s coverage of the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting by visiting the conference page.

Reference

  1. Broto JM, Stacchiotti S, Lopez-Pousa A, et al. Multi-institutional European single-arm phase II trial of pazopanib in advanced malignant/dedifferentiated solitary fibrous tumors (SFT): a collaborative Spanish (GEIS), Italian (ISG), and French (FSG) sarcoma groups study. J Clin Oncol. 2017;35(suppl; abstr 11003).