# Clinical Pharmacy Initiatives Contribute to the Excellent Efficacy of the Dabrafenib/Trametinib Combination for Iodine-Refractory Thyroid Carcinoma: A Case Report

## TL;DR

A 76-year-old woman with advanced thyroid cancer showed excellent treatment response and long-term disease control using dabrafenib and trametinib, aided by clinical pharmacy support.

## Contribution

Demonstrates how clinical pharmacy initiatives can optimize treatment outcomes in BRAF-mutated thyroid cancer patients.

## Key findings

- The patient achieved a complete metabolic response after nine months of dabrafenib/trametinib therapy.
- Clinical pharmacy support enabled prolonged treatment duration (one year) through AE management and dose adjustments.
- Disease remained controlled 25 months after treatment discontinuation.

## Abstract

A 76-year-old female patient presented with an iodine-refractory papillary thyroid carcinoma (PTC), diagnosed eight years earlier, with several lymph node recurrences requiring successive surgeries. Fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) imaging revealed a new unresectable loco-regional recurrence. The patient was diagnosed with a somatic BRAF V600E mutation. Therefore, dabrafenib and trametinib combination therapy was introduced and closely monitored by a dedicated multidisciplinary team, involving pharmaceutical consultations. As early as six weeks after treatment initiation, the patient reported multiple adverse events (AEs) to the clinical pharmacy team, who provided advice on resolving AEs or improving tolerance. Close interprofessional collaboration among healthcare workers involved in the care pathway allowed for the identification of the most opportune times for temporary suspension of treatment (four suspensions over seven months) or dose reduction (two reductions over 3.5 months). This resulted in a total treatment duration (one year) longer than the average times reported in the literature. The patient showed a rapid and excellent response to treatment immediately after initiation, culminating in a complete metabolic response assessed by [18F]FDG PET/CT imaging at nine months. Twenty-five months after treatment discontinuation, the disease remained controlled. Overall, dabrafenib and trametinib combination could offer excellent outcomes in selected patients with refractory BRAF-mutated PTC, with additional clinical pharmacy initiatives allowing for the optimized management of AEs and prolonged treatment periods.