Laura J. Havrilesky, MD
A chronic shortage of the most commonly used taxane for ovarian cancer would add almost $9 million a month to the cost of care if half of newly diagnosed cases were affected, according to a model of transition to an alternative therapy.
Using docetaxel instead of paclitaxel would cost $16,107 per six cycles of therapy, or more than three times as much as a typical paclitaxel-carboplatin regimen. The estimate includes the higher cost of the taxane component of the regimen and costs associated with managing higher anticipated rates of adverse events with docetaxel, Laura J. Havrilesky, MD, reported at the 2012 SGO Annual Meeting.1
“Based on the expected 21,990 women in the United States who are diagnosed with ovarian cancer yearly, of whom at least 85% receive platinum-taxane chemotherapy, a drug shortage that affects approximately 50% of women initiating chemotherapy each month is expected to impact 779 women and cost thirdparty payers an additional $8,609,872 per month,” said Havrilesky, associate professor of Obstetrics and Gynecology at Duke University School of Medicine in Durham, North Carolina.
Last year, paclitaxel joined a list of more than 200 drugs for which supply could not keep up with demand. According to the FDA, the shortage of paclitaxel has resulted from a combination of manufacturing delays and increased demand. As of mid-June, paclitaxel remained on the shortage list posted on the FDA website.2
Most of the drugs on the list are generics, including a substantial number of oncology drugs. In many cases, alternatives—often more expensive alternatives—are available. The higher price of the alternative only begins to reflect the economic impact of drug shortages. In an effort to quantify the costs more completely, Havrilesky and colleagues examined paclitaxel as an example.
The investigators developed a modified Markov state transition model to estimate the economic impact of the paclitaxel shortage. They based the analysis on a comparison of two platinum-taxane regimens for newly diagnosed ovarian cancer, which each continued for six cycles:
Survival was assumed to be equivalent with the two regimens. Adverse-event data were derived from the Scottish Randomized Trial of Ovarian Cancer (SCOTROC).3 Costs of chemotherapy, hematopoietic support, and treatment of adverse events were estimated from national databases. Quality-of-life estimates came from utility scores of clinical trials involving women with metastatic breast cancer and ovarian cancer.
The cost considerations related to adverse events took into account only grade ≥2 neuropathy, febrile neutropenia, and grade 3-4 anemia. The adverse events were assumed not to occur until after the third cycle of therapy.
Grade ≥2 neuropathy automatically led to a switch from paclitaxel-carboplatin to docetaxelcarboplatin or from docetaxel-carboplatin to carboplatin alone. Investigators assumed that febrile neutropenia resulted in hospitalization in all cases, followed by prophylactic treatment with granulocyte- colony-stimulating factor for the last three cycles of therapy.
The estimated cost per cycle of therapy averaged $458 for paclitaxel-carboplatin and $2504 for docetaxel-carboplatin. Using the SCOTROC experience, Havrilesky and colleagues assumed that the docetaxel regimen would lead to more febrile neutropenia and grade 3-4 anemia, whereas paclitaxel would be associated with more neurotoxicity. The model yielded an average cost of $4939 for six cycles of paclitaxel-carboplatin versus $16,107 for docetaxel-carboplatin, a difference of $11,168 per patient treated for six cycles.
“Standard therapy [paclitaxel-carboplatin] was the dominant strategy—less expensive and more effective than the drug-shortage scenario—based on the lower cost and the more favorable quality-of-life profile of paclitaxel,” said Havrilesky.
Of nearly 22,000 women with newly diagnosed ovarian cancer each year, about 85% receive the paclitaxel-carboplatin regimen as initial chemotherapy. Assuming that the paclitaxel shortage would affect half of the women who otherwise would receive the standard regimen, the investigators estimated that treatment for 779 women would be affected each month, raising the cost of treatment by $8,699,872 per month (the difference between the $3,847,481 monthly cost of the standard regimen and $12,547,353 monthly for the docetaxel regimen).
The estimated monthly cost differential between the two regimens would lead to an additional $104,398,464 per year for treatment of newly diagnosed ovarian cancer.