Case Report: Avelumab Therapy for Metastatic Merkel Cell Carcinoma
Posted: Tuesday, August 31, 2021
For patients with metastatic Merkel cell carcinoma, therapeutic intervention with the PD-L1 inhibitor avelumab followed by radiotherapy may improve survival outcomes, according to a case report published in Frontiers in Oncology. Results of such therapy for two patients with metastatic Merkel cell carcinoma and brain metastases were presented. “Avelumab can have intracerebral and systemic activity and, when combined with radiotherapy, can produce lasting disease control,” explained Giovanni Grignani, MD, of the Candiolo Cancer Institute, Italy, and colleagues.
The first patient was a 67-year-old woman who presented with a left axillary mass and lymphoedema. Immunohistochemistry was performed and revealed positive synaptophysin, cluster of differentiation 56, cytokeratin 7, and cytokeratin 20 expression. The patient received treatment with adjuvant chemotherapy. Months later, MRI revealed two brain metastases in the right medial temporal lobe and left occipital lobe. These findings led to treatment with 10 mg/kg of avelumab, which resulted in complete response by the occipital metastasis and partial response by the temporal metastasis. To reduce the size of the temporal mass, avelumab therapy was paused and the patient underwent both stereotactic radiosurgery and external-beam radiotherapy. Repeat MRI showed complete response by the temporal metastasis, and the patient resumed a normal, active lifestyle.
The second patient was a 66-year-old man who presented with a left parotid tumefaction. Biopsy of the parotid demonstrated a high-grade neuroendocrine carcinoma. Following adjuvant radiotherapy, a PET scan revealed retropectoral, retroclavicular, and right axillary node metastases, diagnosed as Merkel cell carcinoma. The patient was started on 10 mg/kg of avelumab therapy, which led to regression of the cerebellar metastasis that was also previously identified. Avelumab treatment was replaced with nivolumab therapy and was subsequently combined with corticosteroids to improve the patient’s outcome.
Disclosure: For full disclosures of the study authors, visit frontiersin.org.
