Emergence of chemoresistance in a metastatic basal cell carcinoma patient after complete response to hedgehog pathway inhibitor vismodegib (GDC-0449)

Abstract Vismodegib ( GDC ‐0449, G enentech, USA ), a small molecule inhibitor of the H edgehog signalling pathway, has potent anti‐tumour activity in advanced basal cell carcinoma ( BCC ). We report a case of a 67‐year‐old Australian man with metastatic BCC including pulmonary disease with malignant effusion who showed a dramatic complete response to vismodegib but subsequently experienced a recurrence of pulmonary disease, indicative of chemoresistance to vismodegib. This case is the first to illustrate chemoresistance in a patient with metastatic BCC , and demonstrates the need for closely monitoring metastatic BCC patients even after an apparently complete response.