Phase III Trial Finds Pfizer’s Axitinib Better than Sorafenib at Boosting PFS in Renal Cell Cancer

Pfizer reported positive data from a Phase III study comparing its VEGF receptor inhibitor axitinib with sorafenib therapy, in patients with advanced renal cell carcinoma whose disease had progressed after prior therapy with sunitinib (Pfizer’s Sutent®), cytokines, bevacizumab, or temsirolimus (Pfizer’s Torisel®). The firm says it is now working with regulatory authorities globally with respect to filing submissions for axitinib.

The Phase III Axis 1032 study included 723 patients, who were randomized to receive either axitinib or sorafenib twice daily.  54% of patients had previously been treated using sunitinib-containing regimens, and 35% had received prior cytokine-based therapy. The results showed that compared with sorafenib therapy, axitinib increased median progression-free survival time by 43% among the overall patient population, from 4.7 months to 6.7 months (maximum 8.6 months). Importantly, benefits of the drug were evident in patients who had previously been treated with cytokines or sunitinib, Pfizer notes.

In previously cytokine-treated patients, axitinib therapy led to a median progression-free survival of 12.1 months, compared with 6.5 months for the sorafenib group. Among previously sunitinib-treated patients, progression-free survival was 4.8 months for those moved on to axitinib therapy, compared with 3.4 months for those given sorafenib. Secondary trial endpoints showed that the independently assessed objective response rate was 19.4% among the overall axitinib patient cohort, compared with 9.4% for the sorafenib cohort.  

Axitinib is separately being evaluated in a Phase III study in patients with treatment-naive renal cell carcinoma, and in Phase II studies against hepatocellular carcinoma, lung cancer, and thyroid cancer. 

Sutent is currently approved for the treatment of advanced and/or metastatic renal cell carcinoma (mRCC) and refractory gastrointestinal stromal tumors. In Europe the drug achieved sales of just under $1.1 billion in 2010, up 11% on 2010 figures.