New therapeutic options in metastatic castration-resistant prostate cancer: Can cost-effectiveness analysis help in treatment decisions?
OBJECTIVE
To evaluate the cost-effectiveness of abiraterone, cabazitaxel, and enzalutamide compared to placebo for treatment of metastatic castration-resistant prostate cancer.


METHODS
A decision-tree model compared three treatment options for metastatic castration-resistant prostate cancer patients over 18 months from a societal perspective in 2012 USD. Chance nodes included baseline pain as a severity indicator, significant adverse effects (neutropenia, cardiac events, or seizures), and survival. Probabilities, survival rates, and health utilities were from clinical trials (COU-AA, TROPIC, and AFFIRM) and other published studies. Survival of enzalutamide was adjusted to match placebo groups across trials. Probabilistic sensitivity analyses, acceptability curves and net benefit calculations were performed.


RESULTS
Abiraterone was the most cost-effective of the treatments ($123.4 K/quality-adjusted life year) compared to placebo, enzalutamide was $437.6 K/quality-adjusted life year compared to abiraterone, and cabazitaxel was $351.9 K/quality-adjusted life year compared to enzalutamide. Enzalutamide and cabazitaxel were not cost-effective compared to placebo at $154.3 K/quality-adjusted life year and $163.2 K/quality-adjusted life year, respectively. Acceptability curves showed abiraterone was cost-effective 29.3% of the time with a willingness to pay threshold of $100 K. The model was sensitive to changes in cost of the drugs, life expectancy, and survival rate. Sensitivity analysis shows that enzalutamide can become the most cost-effective option if the price of the medication decreased by 26% and other drug costs remained the same.


CONCLUSIONS
Based on the cost-effective analysis, and survival adjustments necessary to match placebo groups, we would recommend abiraterone for treatment of metastatic castration-resistant prostate cancer despite not quite falling under the usually accepted willingness to pay threshold. Further analysis should examine comparative survival across the three drugs.
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA WilsonL@pharmacy.ucsf.edu.
Leslie
L
Wilson
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Jun
J
Tang
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Lixian
L
Zhong
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Gregory
G
Balani
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Gregory
G
Gipson
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Pin
P
Xiang
Department of Clinical Pharmacy, University of California, San Francisco, CA, USA.
Dawn
D
Yu
Stanford Cancer Institute, Stanford University, Stanford, CA, USA.
Sandy
S
Srinivas
D000736:Androstenes / Q000191:economics / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000191:economics / Q000627:therapeutic use; D001549:Benzamides; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D016527:Drug Costs; D005382:Financing, Personal / Q000191:economics; D006801:Humans; D008297:Male; D018803:Models, Economic; D009362:Neoplasm Metastasis; D009570:Nitriles; D010669:Phenylthiohydantoin / Q000031:analogs & derivatives* / Q000191:economics / Q000627:therapeutic use; D064129:Prostatic Neoplasms, Castration-Resistant / Q000188:drug therapy* / Q000191:economics / Q000473:pathology; D019057:Quality-Adjusted Life Years; D015996:Survival Rate; D043823:Taxoids / Q000191:economics / Q000627:therapeutic use*
D000736:Androstenes; D000970:Antineoplastic Agents; D001549:Benzamides; D009570:Nitriles; D043823:Taxoids; D010669:Phenylthiohydantoin; C552428:cabazitaxel; C540278:enzalutamide; C089740:abiraterone
Prostate cancer; androgen inhibition; castrate resistant; cost effectiveness; decision making