Sorafenib, (Nexavar), is a new type of drug for advanced kidney cancer. It is a tablet that works by interfering with proteins, called kinases. Kinases are important in regulating how cells work and grow.

Doctors describe kidney cancer that has spread outside the kidney as advanced cancer. The treatment used most often in the UK for advanced kidney cancer is interferon alpha (IFN). IFN boosts the immune system to help fight the cancer. Doctors may prescribe sorafenib for people who can no longer take IFN, or for people for whom IFN isn't suitable.

Sorafenib works in 2 different ways:

• It blocks messages that tell the cancer cells to grow
• It stops the cancer from making blood vessels

Sorafenib is usually taken as two 200mg tablets twice a day for as long as the treatment is helping. It should be taken on an empty stomach at least two hours before a meal.

A large cancer research trial has tested the effectiveness of sorafenib in people with advanced kidney cancer. All the people who took part had already had other treatments, such as interferon or interleukin (IL-2).

The study found in people taking sorafenib the cancer stopped growing for longer than in people taking a sugar pill, placebo. When a cancer isn't growing doctors say the disease is stable. On average people taking sorafenib had stable disease for 5.5 months compared to 2.8 months for people taking the placebo.

In the study for every 100 people taking sorafenib:

• 10 had the cancer shrink (10%). (This is called a partial response)
• 74 had the cancer temporarily stop growing (74%) (This is called stable disease.)

By comparison for every 100 people taking the placebo

• 2 had the cancer shrink (2%)
• 53 had the cancer temporarily stop growing (53%)

So, 84% of people taking sorafenib had the cancer shrink or stop growing for a time compared to only 55% of people taking the placebo.

Overall, these are encouraging results and many experts feel that sorafenib may help people with advanced renal cell cancer to live for longer although it is still too early to say this for sure.

Generally most people taking sorafenib were able to cope with its side-effects. And, only a few people had to stop the treatment due to side-effects.

The most common side-effects were

• Skin rash
• Redness and soreness of the palms and soles of the feet
• High blood pressure
• Tiredness
• Hair loss
• Diarrhoea

Less common side effects included

• Chest pain (angina)
• Problems with bleeding

People taking sorafenib should have their blood pressure checked regularly because it can cause high blood pressure. Some people may need to take blood pressure tablets while taking sorafenib if their blood pressure is high.

Sorafenib is licensed for use in advanced kidney cancer in the UK for people who have had previous treatment with interferon-alpha or interleukin-2 and for people for whom who these treatments aren't suitable. Your specialist will be able to tell you whether sorafenib may be a possible treatment for you.

Unfortunately, sorafenib is not widely available in the UK. In England and Wales, the body that issues guidance on the use of new treatments in the NHS, the National Institute for Clinical Excellence (NICE) have still to give a ruling. In Scotland, the SMC (Scottish equivalent of NICE), have turned down sorafenib on cost grounds.

Reference

• Escudier, B et al Sorafenib in advanced clear cell renal cell carcinoma The New England Journal of Medicine 2007;356:125-134.