Pfizer has announced that axitinib (AG-013736), an investigational oral, selective inhibitor of VEGFR (vascular endothelial growth factor receptors) combined with gemcitabine showed a trend towards prolonged overall survival (OS) in patients with advanced pancreatic cancer, compared with gemcitabine alone, according to preliminary data from a randomised phase II trial.

These data were presented at the 43rd American Society of Clinical Oncology (ASCO) Annual Meeting this week, along with results from several other phase II studies evaluating the efficacy and safety of axitinib in metastatic refractory thyroid, renal cell, non-small cell lung (NSCLC) and breast cancer.

"Pancreatic cancer continues to be one of the most life-threatening and difficult-to-treat solid tumours," said lead study investigator Jean-Philippe Spano, MD, PhD, Hospital La Piti-Salpetriere. "Seeing an agent with this level of activity and tolerability at this stage in development is encouraging news for patients. These findings suggest that axitinib has anti-tumour activity in advanced pancreatic cancer and provide the basis for a phase III programme to further evaluate the potential benefits of this agent in pancreatic cancer patients."

Results from a randomised phase II study of 103 previously untreated patients with advanced pancreatic cancer demonstrated median overall survival with axitinib in combination with gemcitabine of 6.9 months compared with 5.6 months with gemcitabine alone. Axitinib combined with gemcitabine reduced the risk of death - by 26 per cent compared to gemcitabine alone.

The anti-tumour effects of single-agent axitinib in advanced refractory thyroid cancer were demonstrated in a single-arm, multi-centre phase II study of 60 patients who were iodine-refractory, or not suitable candidates for iodine treatment. This showed an objective response rate with axitinib of 30 per cent. 72 per cent of patients received a clinical benefit, meaning a partial response or stable disease was observed. Treatment duration range was 6-744 days, with 24 patients currently still on treatment.

A global trial of axitinib in advanced refractory thyroid cancer patients, who have become resistant to a commonly used chemotherapy, is ongoing.