Palifermin Reduces Estimated Downstream Costs of Autologous Stem Cell Transplant (SCT): Analysis of Phase 3 Trial Results.
Authors: Elting L.S. , Shih Y.C.T. , Stiff P.J. , Bensinger W. , Cantor S.B. , Cooksley C. , Spielberger R. 
Published: October 2019

Introduction: Oral mucositis is a frequent and debilitating complication in patients (pts) who undergo high-dose chemotherapy (HDC) with SCT support and is associated with significantly worse clinical and economic outcomes in such settings (Sonis et al, J Clin Oncol, 2001). In a phase 3 randomized, placebo-controlled, double-blind clinical trial of palifermin in pts with hematologic malignancies undergoing HDC and total body irradiation (TBI) with auto-SCT support, palifermin (a rHuKGF molecule) has been shown to reduce the incidence, severity, and duration of oral mucositis as well as its downstream outcomes (bacteremia, febrile neutropenia [FN], total parenteral nutrition [TPN], and intubation) and hospitalization in this population (Spielberger, et al, ASCO, 2003). We estimated the expected impact of palifermin on the hospital costs of transplantation.

Methods: We classified the 212 pts from the phase 3 trial by presence of downstream outcomes of oral mucositis (bacteremia, FN, TPN, intubation) and by the number of hospital days. The cost of hospital days was not collected in the clinical trial, hence, we estimated cost from the hospital claims of a nationally representative sample of pts with hematologic malignancies who underwent auto-SCT after TBI. We obtained charges from the National Inpatient Sample (NIS, 2000–2001), transformed them into costs using state-specific Medicare cost-to-charge ratios for operating and capital costs for urban centers, and adjusted them to 2003 U.S. dollars using the Consumer Price Index for medical care. We computed the mean cost per hospital day for NIS pts with 0, one, or more of the 4 downstream outcomes (FN, bacteremia, TPN, intubation), and applied these costs to the number of hospital days of clinical trial pts with corresponding downstream outcomes. We compared the estimated total hospital costs of palifermin pts to placebo pts. Out-pt costs of SCT were not estimated and the cost of palifermin has not yet been determined, therefore neither was included in this analysis.

Results: The age and sex distributions of NIS and clinical trial pts were virtually identical as were the mean hospital days (22.52 vs. 22.87 days), but non-Hispanic whites were more common in the clinical trial population (79% vs. 63%). In pts with hematologic malignancies, the national mean cost per hospital day for auto SCT after TBI was $2,702, ranging from $2,572 per day when no downstream outcomes occurred to > $5,000 per day when all 4 downstream outcomes occurred. Applying these differing costs to the differing outcomes of clinical trial pts, the mean cost per pt was $61,160 with palifermin and $76,104 with placebo, yielding a mean savings of $14,943 per pt (95% CI: $12,043–$17,845) in this population. Savings will be partially offset by the cost of palifermin and may vary among centers, particularly those that perform outpatient transplants. Extrapolations of these data to the allogeneic and autologous non-TBI settings also will be presented.

Conclusion: The clinical efficacy of palifermin should lead to significant hospital cost savings for pts with hematologic malignancies undergoing auto-SCT following HDC and TBI. The magnitude of savings will depend on the cost of the drug.