Pazopanib of Benefit in Imatinib- and Sunitinib-Resistant GIST in French Phase II Trial

Key Points

  • Pazopanib increased progression-free survival in imatinib- and sunitinib-resistant GIST.
  • Benefit was observed among best supportive care patients switching to pazopanib after disease progression.

In a French phase II trial reported in The Lancet Oncology, Mir et al found that pazopanib (Votrient) plus best supportive care increased progression-free survival vs best supportive care in patients with advanced gastrointestinal stromal tumors (GIST) resistant to imatinib and sunitinib.

Study Details

In the trial, 81 patients were randomized to receive pazopanib at 800 mg/d plus best supportive care (n = 40) or best supportive care alone (n = 41). Patients in the control group were permitted to switch to pazopanib after disease progression.

Progression-Free Survival

Median follow-up was 26.4 months in the pazopanib group and 28.9 months in the control group. Progression-free survival at 4 months was 45.2% vs 17.6% (hazard ratio [HR] = 0.59, P = .029). Median progression-free survival was 3.4 vs 2.3 months (HR = 0.59, P = .03). Among 36 patients in the control group who switched to pazopanib, median progression-free survival from the start of pazopanib was 3.5 months.

Toxicity

Among all 76 patients who received pazopanib, grade ≥ 3 adverse events occurred in 72%, including hypertension in 38% of the pazopanib group and in 36% of the control group.

Pazopanib-related serious adverse events occurred in 35% and 17%, including pulmonary embolism in 9% and 7%. Three deaths were considered to be related to pazopanib, consisting of two due to pulmonary embolism and one due to hepatic cytolysis.

The investigators concluded: “Pazopanib plus best supportive care improves progression-free survival compared with best supportive care alone in patients with advanced GIST resistant to imatinib and sunitinib, with a toxicity profile similar to that reported for other sarcomas. This trial provides reference outcome data for future studies of targeted inhibitors in the third-line setting for these patients.”

The study was funded by GlaxoSmithKline, the French National Cancer Institute, and EuroSARC.

Jean-Yves Blay, MD, of Centre Léon Bérard, is the corresponding author of The Lancet Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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