Approval information

[Olga]

On April 26, 2012, the FDA approved pazopanib hydrochloride tablets (Votrient®, made by GlaxoSmithKline) for the treatment of patients with advanced soft tissue sarcoma (STS) who have received prior chemotherapy, based on the results of this trial:

Pazopanib for metastatic soft-tissue sarcoma (PALETTE): a randomised, double-blind, placebo-controlled phase 3 trial.
http://www.ncbi.nlm.nih.gov/pubmed/22595799

Median progression-free survival was 4·6 months (95% CI 3·7-4·8) for pazopanib compared with 1·6 months (0·9-1·8) for placebo (hazard ratio [HR] 0·31, 95% CI 0·24-0·40; p<0·0001). Overall survival was 12·5 months (10·6-14·8) with pazopanib versus 10·7 months (8·7-12·8) with placebo (HR 0·86, 0·67-1·11; p=0·25). The most common adverse events were fatigue (60 in the placebo group [49%] vs 155 in the pazopanib group [65%]), diarrhoea (20 [16%] vs 138 [58%]), nausea (34 [28%] vs 129 [54%]), weight loss (25 [20%] vs 115 [48%]), and hypertension (8 [7%] vs 99 [41%]).

246 STS patients were randomly assigned to receive pazopanib. I have no information re. if there were any ASPS patients between them.
As of now, ASPS patients can be prescribed pazopanib off label (because it is approved for the treatment of patients with advanced soft tissue sarcoma (STS) who have received prior chemotherapy and ASPS patients rarely receive any chemotherapy). There is no information if pazopanib will increase survival time in cases of the slow growing or a less advanced bulky disease given the danger of the resistance/overgrowth effect.
To clarify what I mean:
If the disease is a fast growing or in a really advanced state with the limited life expectancy let say 6 month - the stopping of the growth for 8 month will already increase the survival by at least 2 months even if the faster growth to follow. If the disease is a low growing and the life expectancy with doing nothing is 12 months and stopping of the growth for 8 months and a faster growth after produce an unknown result - depends on a speed of the growth after that. The hope is that the stability period would be longer than the no-treatment life expectancy but it is unknown now.
I welcome everyone with the experience in pazopanib to comment here and to start collecting its toxicity and its management data.