Genentech’s cancer drug Avastin has been approved in the USA for use in patients with non-small cell lung cancer, opening up a whole new growth channel for a drug that is already on track to make sales of more than $1.6 billion this year.

Avastin (bevacizumab) is already used to treat colorectal cancer, and the new indication comes at a perfect time for Genentech, as the firm’s third-quarter results statement – published earlier this week – suggested that uptake of the drug has just started to show signs of plateauing.

The approval is based on the pivotal E4599 trial, which showed a 20% increase in survival for patients treated with Avastin in combination with a platinum-based chemotherapy (carboplatin plus paclitaxel) compared to chemotherapy alone. Genentech claims Avastin is the first medicine to have been shown to extend survival in previously untreated patients with NSCLC beyond one year.

The green light in lung cancer is a major boost for Avastin, because it is much more common than colorectal cancer and the approved dosing is higher, driving up the cost of each course of therapy to more than $8,000 a month, compared to around $4,400 for colorectal cancer. Adding NSCLC to the label adds another $1 billion in potential sales for Avastin.

Genentech has said it will cap the yearly cost of Avastin in NSCLC patients at $55,000, and has set up a $50 million fund to assist patients who need help financing treatment with the drug.

Analysts have predicted could bring in anything between $4 billion and $8 billion a year at its peak, depending on the range of new indications it can muster. Genentech has already suffered some setbacks with the drug, however, as development in breast cancer has been delayed by at least a year, with approval not expected until late 2007, while trials in pancreatic and ovarian cancer have yielded disappointing results.

Outside the USA, Avastin is sold by Genentech's majority shareholder Roche, which reported $1.13 billion in revenues from the drug in the first half of 2006. Roche filed for approval of Avastin in NSCLC in the European Union in August.