RCC: targeted therapies increase survival

The arrival of targeted therapies has dramatically improved outcomes for patients with renal cell carcinoma (RCC). With approvals of Bayer/Onyx Pharmaceuticals' Nexavar (sorafenib), Pfizer's Sutent (sunitinib), Novartis' Afinitor (everolimus) and Wyeth's Torisel (temsirolimus), doctors now have a anumber of agents to choose from to treat patients.

However, due to the fact that in subjects with advanced RCC, who are receiving therapy, their disease will ultimately progress, physicians must choose from the drugs available to best extend survival whilst preserving quality of life. This requires consideration of the overall treatment plan from the outset, so that when selecting which agent to start treatment with, the doctor must contemplate effective options for subsequent therapy.

Current retrospective data suggest that there is no cross-resistance between tyrosine kinase inhibitors (TKIs), which means that they can be effectively used in sequence. These data also hint to a preferred treatment sequence, where patients treated with sorafenib prior to sunitinib may experience longer periods of progression-free survival compared with those receiving sunitinib then sorafenib. Furthermore, Phase III evidence indicates that the mTOR inhibitor, everolimus, retains full efficacy in patients who have already been treated with both sorafenib and sunitinib. Therefore an optimal sequence, based on currently available evidence, might be two TKIs followed by an mTOR inhibitor.

Further to this, results from a Phase III study have shown that treatment with sunitinib achieved a median overall survival (OS) greater than two years in patients with metastatic RCC. The data support the recent publication of final guidance from the UK's National Institute for Health and Clinical Excellence (NICE), which recommends the use of sunitinib for the first-line treatment of advanced RCC.

The results, published in the online edition of the Journal of Clinical Oncology, also support a recent recommendation made by a group of oncologists in the UK to use sunitinib as a first-line treatment for metastatic RCC.

The trial data showed that the median OS for patients who received sunitinib versus interferon (IFN) alpha was 26.4 versus 21.8 months, respectively (p=0.051). However, an exploratory analysis of patients who received only one line of treatment (ie, no subsequent treatments after stopping their sunitinib or IFN alpha therapies) showed that sunitinib almost doubled the median OS compared to IFN alpha (28.1 vs 14.1 months; hazard ratio=0.647; p=0.003). This is a reflection of clinical practice in the UK where generally patients are only funded for one line of treatment at most.

According to Pfizer, before NICE guidance only one-third of primary care trusts (PCTs) were funding sunitinib to some extent. Since the guidelines were published, 90 per cent of PCTs have committed to full funding of sunitinib in accordance with NICE guidance. In 2007, Pfizer cut the price of sunitinib by 5 per cent and committed to providing one cycle/course of the treatment free of charge to every eligible patient in the UK, in an effort to increase patient access. This move amounts to an average saving of between 19 and 29 per cent per patient for the cost of treatment, depending upon the type and stage of their tumour. The average annual cost for a patient taking sunitinib is £24,168.

Matthew Dennis - Editor, Cancer Drug News