Randomized double-blind, placebo-controlled study of topical diclofenac in the prevention of hand-foot syndrome in patients receiving capecitabine (the D-TORCH study)

INTRODUCTION: Hand-foot syndrome (HFS) is a common cutaneous side effect of capecitabine therapy. Apart from oral cyclooxygenase-2 (COX-2) inhibitor (celecoxib), there are no proven strategies for the prevention of HFS. However, celecoxib is associated with significant cardiotoxicity. To date, no study has evaluated the role of topical COX inhibitor, diclofenac. In this study, we aim to compare topical 1% diclofenac gel with placebo in the prevention of capecitabine-induced HFS. METHODS: This is a randomized, placebo-controlled, double-blind, parallel-group superiority trial: the Diclofenac Topical in Reducing Capecitabine induced HFS (D-TORCH) study. A total of 264 patients with breast and gastrointestinal malignancies will be randomly allocated (stratified by sex and type of therapy [monotherapy or combination regimen with capecitabine]) to receive either 1% topical diclofenac or placebo that will be applied over the palmar and dorsal surface of the hands twice daily whilst taking capecitabine for 12 weeks. The patients will be followed up until the end of four cycles. The primary objective of this study is to compare the effect of topical diclofenac with placebo in preventing HFS (incidence of NCI CTCAEv5.0 grade 2 or higher HFS). The secondary objective is to compare the effect of topical diclofenac with placebo on preventing all grades of HFS (incidence of NCI CTCv5.0 all grade HFS), time to develop HFS (from the start of capecitabine), patient-reported outcomes (PROs) (HF-HRQoL questionnaire), adherence with the application (self-reported), capecitabine dose changes (number of patients with dose modifications due to HFS) and safety profile (NCICTCv5.0 all grade HFS) DISCUSSION: The D-TORCH study aims to determine if 1% topical diclofenac reduces the incidence of grade 2 or higher HFS in patients receiving capecitabine. To date, there have been a lot of trials for hand-foot syndrome prevention using agents like pyridoxine, vitamin E, carvedilol, and various polyherbal formulations, but none has been found successful. If the trial meets the primary end point, 1% topical diclofenac will be the new standard of care for HFS prevention. TRIAL REGISTRATION: Clinical Trials Registry of India CTRI/2021/01/030592. Prospectively registered on January 19, 2021