Hollywood, FL—Sunitinib and pazopanib have long battled for supremacy in treating advanced renal-cell carcinoma (RCC). According to findings presented at the 2015 National Comprehensive Cancer Network (NCCN) conference, the newer drug, pazopanib, may have some advantage in terms of total cost of care, but survival outcomes were exactly the same.
An independent study from Humana comparing costs and health outcomes in initial therapy for RCC showed that sunitinib had a $12,000 higher mean total cost of care than pazopanib.
“Survival and treatment characteristics were similar for both index medications, but medication and total healthcare costs trended higher with sunitinib treatment, despite higher preindex total costs in the pazopanib group,” said coinvestigator Laura E. Happe, PharmD, MPH, Strategic Consultant, Humana, Louisville, KY.
“Nonadherence with sunitinib was associated with significantly higher total healthcare costs, which may indicate unfavorable tolerability with sunitinib treatment.” She emphasized that this is a hypothesis that was not proved in this study.
Sunitinib and pazopanib are 2 tyrosine kinase inhibitors (TKIs) approved by the FDA as first-line options for the treatment of patients with advanced RCC; clinical evidence and national guidelines do not differentiate between these therapies. Two comparative cost studies based on data from the COMPARZ and PISCES trials showed that pazopanib was less costly and more cost-effective than sunitinib, but these findings were based solely on clinical trial data.
First Real-World Comparison
“To our knowledge,” said Dr Happe, “this is the first head-to-head comparison of these 2 TKIs in a real-world setting. We are looking at our Humana global universe of millions of lives. This study was not funded by either manufacturer…which makes it a very unique analysis.”
The study was an observational retrospective cohort with up to 12 months of follow-up for 241 patients receiving sunitinib and 112 receiving pazopanib for at least 6 months.
Treatment interruptions were defined as therapy gaps >30 days. Adherence was quantified using proportion of days covered, which was calculated as days prescribed divided by total days of follow-up.
“We saw no difference in overall survival, which supports the COMPARZ trial,” said Dr Happe. “About 55% of patients remained alive after 1 year. Treatment interruptions and adherence were also the same. From everything we can garner from claims, in terms of efficacy, the drugs were the same.”
Treatment Cost Comparison
The investigators examined the mean total healthcare costs, broken down by component medical and pharmacy costs and stratified by adherent status.
“Total costs were the same,” Dr Happe reported. “Sunitinib was higher numerically ($76,624 vs $64,432), but this was a nonsignificant trend. The only component approaching statistical significance was pharmacy index medication, which reflects the price of the drug. Sunitinib was $5000 more expensive ($26,984 vs $21,404)….All other costs were the same.”
Although not statistically significant, pazopanib was numerically less expensive in total medical and pharmacy costs.
According to Dr Happe, one of the study’s most interesting findings was the significant difference in costs between drugs within the nonadherent subgroup. These were $82,730 for sunitinib and $65,040 for pazopanib (P = .01), she reported.
One suggestion for this difference was a possible increase in side effects with sunitinib, leading to greater cost of care.
“We don’t know what’s driving this difference in cost,” acknowledged Dr Happe. “Clinical trials have shown some differences in tolerability, meaning sunitinib may be less tolerable than pazopanib.”
Given the lack of difference in efficacy between sunitinib and pazopanib by NCCN or clinical trials, the higher costs of sunitinib will be an important consideration in choice of treatment, the investigators of this study concluded.
“We validated no clinical difference between these drugs,” said Dr Happe. “And from a medical standpoint, you are only looking at the price of the drug. If your health plan gets a good discount on one of these drugs, you might consider these drugs interchangeable.”