Sunitinib's Safety, Efficacy Confirmed
Results from an expanded access study of sunitinib confirm the safety and efficacy of the medication as a treatment for metastatic renal cell carcinoma (mRCC) and show that even poorer-risk patients can benefit.
Investigators led by Martin Gore, MD, of Royal Marsden Hospital NHS Trust in London, U.K., conducted the open-label trial in 52 countries where the drug had not yet received regulatory approval. The trial enrolled 4,572 patients with mRCC who were ineligible to participate in sunitinib clinical trials but had the potential to benefit. All patients received oral sunitinib at a starting dose of 50 mg/day for four weeks, followed by two weeks off treatment in repeated six-week cycles.
Overall median progression-free survival (PFS) was 9.5 months and median overall survival (OS) was 18.7 months, consistent with previous other mRCC trials. Sixty-five patients (2%) achieved a complete response and 603 (18%) had a partial response to the drug. In addition another 1,911 patients (56%) had stable disease for three months or longer.
Researchers presented findings in a poster at the European Multidisciplinary Cancer Congress in Stockholm.
Efficacy was maintained regardless of previous cytokine treatment status as well as in patients aged 65 years or older. Furthermore, patients in poorer-risk subgroups (ECOG performance status 2 or higher, non-clear cell histology, brain metastasis) still derived benefit but with reduced PFS and OS.
The sunitinib adverse event (AE) profile was manageable and consistent with previous trials. The most common non-hematologic treatment-related AE's of any grade were diarrhea, fatigue, and nausea (which occurred in 47%, 40%, and 36% of patients, respectively), and the most common hematologic AE of any grade was thrombocytopenia, which occurred in 23% of patients.
The most common treatment-related grade 3/4 AE's were fatigue, thrombocytopenia, hand-foot syndrome, asthenia, hypertension, and neutropenia, which occurred in 9%, 8%, 7%, 7%,6%, and 6% of patients, respectively.
In the pivotal phase 3 trial that enrolled 750 patients, sunitinib (which is made by Pfizer and marketed under the name Sutent) demonstrated a median OS of 26.4 months compared with 21.8 months with interferon-alpha in the first-line treatment of advanced RCC, a difference that was not statistically significant. In an exploratory analysis of patients who received protocol therapy only, the OS with sunitinib was 28.1 months versus 14.1 months with interferon-alpha, a difference that was statistically significant. Sunitinib is the first treatment to show a median OS of more than two years in the first-line treatment of advanced RCC.