Prevention of 5-FU-induced health-threatening toxicity by pretherapeutic DPD deficiency screening: Medical and economic assessment of a multiparametric approach.

Abstract

3601 Background: While 5-FU is the foundation of many in GI oncology treatments, pts with DPD deficiency can experience early-onset severe (5%) even fatal (0.3%) toxicities. This study aimed to confirm the pharmaco-economic benefits of pre-therapeutic screening for DPD deficiency using a multiparametric approach in a multicenter prospective cohort study (NCT01547923). Methods: Two parallel cohorts of pts treated with 5-FU-based chemotherapy for colorectal carcinoma were compared: Group A: initial DPD deficiency screening; Group B: no evaluation. Enrollment was based on 5-FU administration guidelines of each institution. DPD deficiency screening combined genotyping and phenotyping (ODPM Tox) (1,2,3). The 2 groups were to be compared in terms of early 5-FU-induced toxicity grade, toxicity cost and DPD screening cost. The enrollment was to be immediately closed in the case of proven 5-FU-related toxic death. Results: 1,130 pts were included from 06/01/2008 to 07/31/2012. Group A: no severe toxicity despite 1 pt with complete deficiency (pt not treated with 5-FU), 20 pts with partial deficiency had safe PK-monitored 5-FU (ODPM Protocol) with only one hospitalization due to toxicity. Group B: One death due to complete DPD deficiency, confirmed retrospectively. Enrollment prematurely closed after experts’ unanimous decision citing ethical concerns. 21 pts with partial DPD deficiency. 5 reported toxicity-related hospitalizations. Data treatment is ongoing. Conclusions: One complete deficiency occurred in both groups: Group A pt had safe treatment whereas Group B pt died due to 5-FU toxicity. Pre-therapeutic DPD deficiency screening using this multi-parametric approach should be performed before 5-FU-based treatment and PK-guided dose adaptation allows for safe treatment of even partially DPD deficient patients. Clinical trial information: NCT01547923. [Table: see text]