Comparative survival and cost of antifungal therapy: posaconazole versus standard antifungals in the treatment of refractory invasive aspergillosis

Abstract

Background:

Refractory invasive aspergillosis (IA) is a life-threatening condition. Cost of treatment, although secondary, is important if newer drugs are to be widely accepted. Posaconazole has been shown to have activity against aspergillosis.

Methods:

Analyses were conducted to compare the effectiveness and cost of posaconazole 800 mg/day with those of standard antifungal therapy, using Walsh et al. 2007 data. All-cause mortality and total drug costs were analyzed for three patient groups: All Refractory, Refractory Non-neutropenic, and Refractory Neutropenic IA Patients. Comparative survival analysis using Kaplan–Meier estimates after censoring data at 28, 42, 84, 182, and 365 days and Cox proportional hazard method was used to estimate hazard rates after controlling for difference in baseline neutropenia. For cost analysis, only antifungal drug acquisition cost was used.

Results:

Significantly more of the 94 patients treated with posaconazole remained alive at every time point compared with the 68 external control patients within the All Refractory group (p = 0.0001). Similar results were obtained for the other two groups. For the posaconazole-treated patients mean total drug costs were $11846 (±$12406), $12642 (±$11811), and $8903 (±$14345), and for the external controls total drug costs were $35537 (±$73059), $48097 (±$88702), and $13556 (±$16324) for the All Refractory, Refractory Non-neutropenic, and Neutropenic IA groups, respectively. Key limitations of the study included noninclusion of hospitalization or other drug costs, low patient numbers beyond 84 days, and the fact that the Walsh et al. 2007 study was completed before other newer antifungal agents (such as voriconazole and caspofungin) were available.

Conclusions:

Posaconazole appears to confer a survival benefit and reduced total drug cost compared with standard antifungal therapy, such as amphotericin B (lipid and nonlipid formulations), itraconazole, or both, to treat patients with probable or proven refractory IA.

Key words:

• Aspergillosis
• Cost
• Posaconazole
• Refractory
• Survival

Transparency

Declaration of funding

This study was funded by Schering-Plough Corporation, now Merck & Co., Inc., Whitehouse Station, NJ.

Declaration of financial/other relationships

R.H. received research funding from Merck & Co. and has served on advisory panels. S.R. received financial grants from Merck & Co. to conduct the statistical analysis and study design; and R.D. received financial grants from Merck & Co. to accomplish the project management, study design, and medical writing. At the time of the study, G.P. was an employee of Merck & Co. with stock ownership. Peer reviewers may receive honoraria from CMRO for their review work. Peer reviewer 1 has disclosed that he/she has received speaker fees from Pfizer, Merck, and Astellas and that he/she has acted as a consultant/advisor for Basilea. Peer reviewer 2 has disclosed that he/she has acted as a consultant/advisor to Schering-Plough, Merck, and Pfizer.

Acknowledgments

The authors thank Ann Yacono in association with ApotheCom for providing editorial assistance for the authors’ original work.