Clinical response to therapy targeted at vascular endothelial growth factor in metastatic renal cell carcinoma: impact of patient characteristics and Von Hippel-Lindau gene status.

OBJECTIVE: To describe the relationship among patient characteristics, Von Hippel-Lindau (VHL) gene status and clinical outcome in metastatic renal cell carcinoma (RCC) in patients receiving vascular endothelial growth factor (VEGF)-targeted therapy. PATIENTS AND METHODS: All patients with metastatic RCC who received therapy with interferon-alpha plus bevacizumab, SU11248 or AG013736 at the authors' institution were considered. Clinical features were collected and activation status of the VHL gene (VHL) was determined from baseline paraffin-embedded tumour samples. Tumour response, time to tumour progression (TTP) and overall survival were recorded. RESULTS: Forty-three patients were evaluable for determination of VHL status and clinical response. There was an objective response in 18 patients (43%; 95% confidence interval 28-59%). The median TTP for the entire cohort was 8.1 months. There was an improved clinical outcome in patients with the following clinical features: male gender, lack of hepatic metastases, no previous radiation therapy and higher baseline haemoglobin level. Twenty-six patients (60%) had evidence of VHL mutation or promoter methylation; such patients had an objective response rate of 48%, vs 35% in patients with no VHL mutation or methylation. Patients with VHL methylation or a mutation predicted to truncate or shift the VHL reading frame had a median TTP of 13.3 months, vs 7.4 months in patients with none of these features (P = 0.06). CONCLUSION: VEGF-targeted therapy is active in metastatic RCC and the response can be associated with certain clinical features. The TTP with VEGF-targeted therapy might be prolonged in patients with VHL methylation or mutations that truncate or shift the VHL reading frame. Further investigation of VHL pathway components is needed to understand the biology of the response to VEGF-targeted agents in metastatic RCC.

A phase II trial of imatinib mesylate in patients with biochemical relapse of prostate cancer after definitive local therapy.

OBJECTIVE: To determine the biological effects of imatinib mesylate (STI-571, Gleevec; Novartis Pharmaceuticals, Inc., East Hanover, NJ, USA), as measured by prostate-specific antigen (PSA) kinetics in men with biochemical relapse of prostate cancer after definitive local therapy. PATIENTS AND METHODS: Men with prostate cancer, who had had definitive local therapy, with nonmetastatic recurrent disease as manifested by a rising PSA level, were enrolled on this phase II trial. Men received 400 mg of imatinib mesylate orally twice daily and continuously until disease progression or unacceptable toxicity. The PSA level was measured monthly. RESULTS: In all, 20 men with biochemically relapsed prostate cancer were treated. The median pretreatment PSA level was 5.4 ng/mL. Of the 19 evaluable men, one achieved a >or= 50% reduction in PSA level and two had decreases of <50%. For the 16 men in whom the on-treatment PSA doubling time (PSADT) could be calculated (those with increasing PSA level) the median PSADT did not increase significantly (5.8 vs 7.2 months, P = 0.64). Eleven of 20 men discontinued therapy due to toxicity and the trial was stopped early due to toxicity. CONCLUSIONS: Based on the lack of PSA modulation and pronounced toxicities leading to early closure of this trial, further study of single-agent imatinib mesylate at this dose (400 mg twice daily) cannot be recommended in this patient population.