Long-Term Survival Is Comparable between Palifermin-Treated and Placebo-Treated Patients (Pts) with Hematologic Malignancies (HM) Undergoing High-Dose Chemotherapy and Total Body Irradiation Followed by Autologous Hematopoietic Stem Cell Transplantation (HSCT).

Oral mucositis (OM) is a severely debilitating side effect of chemoradiotherapy that often causes significant pain, diminished quality of life, and increased risk of infections. Palifermin decreases the incidence and duration of severe OM in HM pts receiving myelotoxic therapy and HSCT. Palifermin safety and efficacy have not been established in the non-HM setting. Since the rHuKGF receptor is not expressed by HM, palifermin is not expected to interfere with long-term disease outcomes in this pt population.

Aim: We assessed palifermin’s effects on the long-term disease outcomes (survival, disease progression, secondary malignancies) in pts with HM.

Methods: Long-term follow-up data were pooled from a 1998 phase 2, double-blind, placebo-controlled study (n=86) and a 2000 double-blind, placebo-controlled phase 3 study (n=212). The analysis included 152 pts treated with palifermin and 146 pts treated with placebo. Pts were assessed at 6-month intervals during the first year and annually thereafter until death or loss to follow-up. The Kaplan-Meier (K–M) method provided estimates of the safety endpoints. Data reported here are as of August 2004.

Results: There were 298 pts (152 palifermin: 146 placebo) monitored for long-term follow-up. The median follow-up period was 23.3 months for palifermin and 23.5 months for placebo. The overall survival and progression-free survival curves (p=0.474 and p=0.253, respectively) are similar between the palifermin and placebo groups. Secondary malignancies occurred in only 6 of 152 (3%) palifermin and 5 of 146 (4%) placebo pts. All secondary malignancies were myelodysplastic syndromes: 9 patients with diagnoses of Non-Hodgkin’s lymphoma and 2 patients of Hodgkin’s Disease. The number of deaths was similar between the groups (30% palifermin; 27% placebo); most deaths occurred within 12 months of randomization and were attributable to the underlying HM disease.

Conclusion: Use of palifermin for the prevention of severe OM has shown no negative impact on long-term disease outcomes, including survival, in the HSCT setting for patients with HM.