Economic evaluation of sipuleucel-T immunotherapy in castration-resistant prostate cancer

Abstract

The objective is to examine the cost–utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients. The addition of sipuleucel-T immunotherapy to standard treatment led to a gain of 0.37 quality-adjusted life-year (QALY) at an additional cost of US$104,536. The incremental cost–utility ratio was US$283,000 per QALY saved. Threshold sensitivity analyses indicated that a price reduction of at least 53%, or application in a group of patients resulting in the relative reduction in the mortality rate of at least 39%, ought to augment the economic value of this regimen. Sipuleucel-T immunotherapy treatment at the current price with 96.5% certainty is not cost-effective. The specific group of patients who will benefit more from the treatment should be revealed and treated, or the cost of the vaccine should be lowered significantly to increase its economic value. Accounting for crossover treatment in control patients improves sipuleucel-T's value (US$132,000 per QALY saved) although further investigation is necessary.

Keywords::

• castration-resistant prostate cancer
• cost–utility analysis
• immunotherapy
• prostate cancer
• quality-adjusted life year
• sipuleucel-T immunotherapy

Financial & competing interests disclosure

All the authors were involved in drafting the article or revising it critically for important intellectual content, and all the authors approved the final version to be published. P Holko had full access to all data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing assistance for the first draft was provided by Professional Editing Services from SPI Global. Post-revision editorial assistance was provided by Lingua-Dar. The authors thank the anonymous reviewers for their valuable comments.

Key issues

• Prostate cancer is the leading non-skin malignancy detected in men and is the second most common cause of cancer death in men.

• The objective of this study was to examine the cost–utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients added to standard care, compared with standard care only.

• The Markov process was carried out with a lifetime horizon; a cycle length of a month and a half cycle correction was employed.

• Effectiveness of sipuleucel-T immunotherapy, direct prostate cancer-related healthcare costs and utility values were obtained from the literature.

• The addition of sipuleucel-T immunotherapy to standard treatment in patients with castration-resistant prostate cancer led to a gain of 0.37 quality-adjusted life-year (95% CI: 0.02–0.82) at an additional cost of US$104,536 (95% CI: US$92,757–119,771). The incremental cost–utility ratio was US$283,000 (95% CI: US$130,000–1,571,000).

• Autologous cellular immunotherapy treatment at the current price with 96.5% certainty is not cost-effective when compared with threshold estimated at three times Gross Domestic Product per capita.

• Accounting for crossover treatment in control patients seems to improve the economic value of sipuleucel-T (US$132,000 per quality-adjusted life-year saved), although further investigation is necessary to credibly account for a crossover effect in a study with overall survival as a primary end point.