Renal cancer has traditionally been poorly served in terms of efficacious therapies, claims a new report, but in the last two years, “some degree of hope” for patients has emerged in the form of three new drugs, plus Roche/Genentech’s Avastin.
According to a study by Datamonitor, in 2007, an estimated 86,000 people in the seven major markets were diagnosed with renal cell carcinoma, the most common form of kidney cancer. 75–80% of them will be diagnosed with Stage I–III disease, where the cancer has spread no further than one lymph node, and surgery will resolve the problem in the majority of cases.
However, a significant proportion of patients with Stage I–III RCC suffer relapse after surgery, and with advanced (Stage IV) disease. Datamonitor oncology analyst Tom Gray says that “the prognosis for these patients is bleak” and until recently, treatment options for patients with Stage IV RCC were very limited.
The only two drugs available were interferon alfa and interleukin-2, but these two agents are both associated with very low response rates and considerable toxicity. However three drugs have come along that have shown superior efficacy and tolerability compared to the traditionally used cytokine therapies.
Two of these, Pfizer’s Sutent (sunitinib) and Bayer/Onyx’s Nexavar (sorafenib), inhibit tumour angiogenesis, while the third recently approved drug is Wyeth’s Torisel (temsirolimus), which inhibits a protein that plays an important role in tumor growth. Dr Gray notes that in addition to these three therapies, Avastin (bevacizumab) is being used to treat RCC in the USA, and has just been approved in Europe.
Based on a survey of 180 physicians, Datamonitor found that targeted therapies have experienced considerable uptake for RCC and to date, Sutent is the drug showing the most promising efficacy in previously-untreated RCC patients. Nexavar is next, but the report claims that “there is a lack of evidence showing that this drug is efficacious as a second-line therapy in patients who initially received Sutent”.
Datamonitor concludes by saying that while the newly-available therapies in RCC “have been a welcome step forward in the treatment of the disease, there is still much scope left for improving treatment outcomes”, as only Torisel has been shown to prolong the length of overall survival. Citing RCC experts, Dr Gray said that further research is likely to involve combinations of different treatments, noting that “in addition to the targeted therapies currently available, there are several promising targeted agents in the late-phase pipeline, providing a multitude of possibilities for potential future regimens”.
