We found interesting the letter by Bachmeyer et al underscoring the importance of V600E BRAF mutation detection in ECD. We agree with their opinion that this new targeted therapy can be promising in this disease, which still has a poor prognosis.

Concerning our patient, he was initially treated with PEGylated interferon alfa-2b at doses of 180 μg once per week, with a good outcome. Nevertheless, several months ago, he persisted with asthenia and anorexia and showed hypermetabolism of the aorta and pleura in the positron emission tomography.

As reported previously, a high frequency of V600E BRAF mutation has been described in some patients with ECD, reaching up to 54% in some series ([1]). A few of these patients have been treated with vemurafenib, an inhibitor of mutant BRAF ([2]), with rapid clinical and radiologic improvement. Only cutaneous side effects were reported, but the treatment could be maintained in the followup.

For this reason, our patient was screened for this mutation and a positive result was reported. Considering this finding and the need to improve the clinical condition of our patient, he was invited to participate in a clinical trial with vemurafenib 4 months ago. He has been treated with a dose of 960 mg twice daily (total daily doses of 1,920 mg).

Until now, the new treatment has been very well tolerated, with important clinical improvement consisting of the disappearance of asthenia and a gain in weight of 8 kg. Furthermore, we observed a marked improvement in the positron emission tomography, with a reduction of bilateral pulmonary hypermetabolism in the fissure, septa, and upper lobes and disappearance of the pleural effusion.

We are hopeful with this new targeted therapy, but at the same time, we think that we have to be cautious while waiting for the final results of the treatment with vemurafenib in a larger group of ECD patients. In our opinion, this therapy should be considered for patients with severe and refractory ECD carrying the V600E BRAF mutation.