BACKGROUND: In a phase II study of axitinib for cytokine-refractory metastatic renal cell carcinoma, median overall survival (OS) was 29.9 months (95% CI, 20.3 to not estimable months).
PATIENTS AND METHODS: Long-term survival data were collected retrospectively from 52 patients with cytokine-refractory metastatic renal cell carcinoma who received axitinib in a completed phase II study (protocol 1), 11 of whom enrolled in a continuing access protocol (protocol 2), for the current observational study (protocol 3). In a post hoc analysis, the patients were grouped into quartiles based on cycle 1 day 1, 1- to 2-hour post-dose axitinib plasma levels to explore the impact of drug exposure on efficacy.
RESULTS: The 5-year survival rate was 20.6% (95% CI, 10.9%-32.4%), with a median follow-up of 5.9 years. Frequent all-grade adverse events were fatigue (n = 38; 73.1%), diarrhea (n = 34; 65.4%), hypertension (n = 33; 63.5%), and nausea (n = 33; 63.5%). Quartile 3 patients (axitinib level, 45.2-56.4 ng/mL; n = 12) had the best clinical outcome: objective response rate 82%, median progression-free survival (PFS) 28.3 months, and median OS that was not reached after 5 years.
CONCLUSIONS: Axitinib was well tolerated and provided an estimated 5-year survival rate of 20.6% for cytokine-refractory metastatic renal cell carcinoma. Exploratory analyses showed numerically higher objective response rate and longer OS and PFS in patients who achieved post-first-dose axitinib plasma concentrations within a specific range.
Written by:
Rini BI, de La Motte Rouge T, Harzstark AL, Michaelson MD, Liu G, Grünwald V, Ingrosso A, Tortorici MA, Bycott P, Kim S, Bloom J, Motzer RJ. Are you the author?
Department of Solid Tumor Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH.
Reference: Clin Genitourin Cancer. 2013 Jun;11(2):107-14.
doi: 10.1016/j.clgc.2012.12.004
PubMed Abstract
PMID: 23391371
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