Glaxo's pazopanib shows promise in ovarian cancer

By Ben Hirschler

LONDON, Sept 15 (Reuters) - GlaxoSmithKline's (GSK.L: Quote, Profile, Research, Stock Buzz) experimental drug pazopanib appears to be effective in fighting ovarian cancer, based on measurements of a biological marker used to predict tumour recurrence, researchers said on Monday.

Given the promising results, the world's second largest drugmaker said it planned to push ahead with a final-stage Phase III clinical trial of the once-daily pill in ovarian cancer.

Pazopanib, like Genentech (DNA.N: Quote, Profile, Research, Stock Buzz) and Roche's (ROG.VX: Quote, Profile, Research, Stock Buzz) blockbuster injection Avastin, works by inhibiting the formation of new blood vessels that feed tumours.

Results of a small Phase II study, involving 35 patients, showed that 31 percent of ovarian cancer patients had a greater than 50 percent decrease in blood levels of a protein called CA-125 when given the drug.

Because CA-125 levels rise when tumours are growing, the protein is used to predict the risk of tumours recurring and to test patients' response to chemotherapy.

The results were presented at the annual meeting of the European Society of Medical Oncology (ESMO) in Stockholm. "Many patients with ovarian cancer will have a recurrence of cancer following initial chemotherapy," said Michael Friedlander of the Prince of Wales Cancer Centre in Sydney.

"This study clearly demonstrates that pazopanib is an active, well-tolerated drug for women with recurrent ovarian cancer."

LUNG CANCER

A second Phase II study also suggested pazopanib may have a role to play in lung cancer, after 30 out of 35 patients treated with the drug before surgery saw their tumour size shrink by up to 85 percent.

However, Paolo Paoletti, Glaxo's senior vice president for oncology, told Reuters that further studies were needed before pazopanib was moved into Phase III testing in lung cancer.

Pazopanib is already in pivotal clinical tests as a treatment for breast cancer and has just completed a Phase III assessment in kidney cancer. It is also being assessed for other tumour types, including soft tissue sarcoma and cervical cancer.

Paoletti said the drug was most likely to win its first regulatory approval in kidney cancer, where it will compete with a number of other new products.

Pfizer (PFE.N: Quote, Profile, Research, Stock Buzz) and Bayer (BAYG.DE: Quote, Profile, Research, Stock Buzz) have recently introduced competing kidney cancer drugs called Sutent and Nexavar, while Novartis (NOVN.VX: Quote, Profile, Research, Stock Buzz) hopes to win a green light for its product Afinitor around the end of the year. (Editing by Simon Jessop)