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Renal cancer is a disease which has traditionally been poorly served in terms of efficacious drug therapies. Although some degree of hope for renal cancer patients has emerged in the form of three new drugs which have recently entered the renal cancer market, there is still a substantial opportunity for drug developers and the late-stage development pipeline boasts several promising drugs
In 2007, an estimated 86,000 people in the seven major markets (US, Japan, France, Germany, Italy, Spain and the UK) will be diagnosed with renal cell carcinoma (RCC), the most common form of renal cancer. RCC accounts for around 85% of renal cancer cases overall.
Around 75-80% of RCC patients will be diagnosed with stage I-III disease, where the cancer has spread no further than one lymph node. Surgery, usually involving removal of the entire affected kidney, is the most commonly used type of treatment for these patients. In the majority of cases, this approach results in cure. However, a significant proportion of patients with stage I-III RCC suffer relapse after surgery. Most of these patients relapse with advanced disease.
The remaining 20-25% of patients present with advanced (stage IV) RCC. This means that the disease has already spread to other parts of the body or to more than one lymph node by the time the cancer is diagnosed. The prognosis for these patients is bleak. Surgery is not curative, and survival is typically limited to between one to two years. In the UK alone, there are predicted to be around 3,000 deaths from renal cancer in 2007.
Recent drug approvals provide much-needed extra therapeutic options
Until relatively recently, treatment options for patients with stage IV RCC were very limited. The only two drugs available to these patients were interferon alfa and interleukin-2, both of which are classified as cytokines, proteins that modulate the immune system. These two agents are both associated with very low response rates and considerable toxicity and thus, the demand for new drugs in this therapy area has been high.
Since 2005, three novel targeted therapies have been approved for RCC in the US and EU, providing much-needed additional treatment options for patients with advanced stage RCC. In clinical trials, these drugs have shown superior efficacy and tolerability compared to the traditionally used cytokine therapies.
Two of these drugs - Pfizer's Sutent (sunitinib) and Bayer/Onyx's Nexavar (sorafenib) - target receptors specific to the tumor, inhibiting tumor angiogenesis (growth of new blood vessels from the tumor). In this way, the tumor is starved of oxygen and nutrients and is prevented from growing. The third recently approved drug is Wyeth's Torisel (temsirolimus), which inhibits a protein that plays an important role in tumor growth. In addition, a fourth targeted therapy, Genentech/Roche's Avastin (bevacizumab), is being used to treat RCC in the US, and is expected to be approved in the EU in the near future. Like Sutent and Nexavar, this drug also inhibits angiogenesis.
Datamonitor physician survey shows swift uptake of targeted therapies
Based on a survey of 180 physicians, Datamonitor found that targeted therapies have experienced considerable uptake for RCC and are the predominant therapy class in most of the seven major pharmaceutical markets.
To date, Sutent is the drug showing the most promising efficacy in previously untreated RCC patients. In these patients, the drug increases progression-free survival by six months on average compared to interferon alfa. This has driven substantial uptake of the drug, making it the most prescribed first-line therapy in most of the seven major pharmaceutical markets.
Datamonitor found that Nexavar is the most commonly prescribed second-line therapy for RCC. However, there is a lack of evidence showing that this drug is efficacious as a second-line therapy in patients who initially received Sutent. Given that many second-line patients will have received Sutent as their initial therapy, and considering the lack of data for second-line regimens in these patients, this segment of the renal cancer market is set to become increasingly contested.
Substantial unmet needs persist despite recent advances in RCC
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. Sutent and Nexavar both improve progression-free survival, yet only Torisel has been shown to prolong the length of overall survival. A further area of considerable unmet need is the lack of efficacious adjuvant regimens to reduce the risk of relapse in surgically treated early-stage disease.
According to the RCC experts interviewed by Datamonitor in the course of its research, further progress with the treatment of RCC is likely to involve combinations of different therapies. 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.
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