Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2021; 9(18): 4829-4836
Published online Jun 26, 2021. doi: 10.12998/wjcc.v9.i18.4829
Long-term response to avelumab and management of oligoprogression in Merkel cell carcinoma: A case report
Inês Leão, Joana Marinho, Telma Costa
Inês Leão, Joana Marinho, Telma Costa, Department of Oncology, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia 4434-502, Portugal
Author contributions: All authors reviewed the literature and were involved in data collection, analysis and interpretation, manuscript writing, and approval of final article.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: Dr. Marinho reports grants from Merck KGaA, during the conduct of the study; personal fees from Merck KGaA, non-financial support from Servier, non-financial support from Astellas, non-financial support from Roche, non-financial support from Lilly, non-financial support from Merck, outside the submitted work. “The patient was treated in the expanded access program and avelumab was provided by Merck KGaA, as part of an Alliance between Merck KGaA and Pfizer”. The development of this publication was financially supported by Merck KGaA, Darmstadt, Germany through an independent medical writing grant, as part of an Alliance between Merck KGaA and Pfizer. The views and opinions described in this publication do not necessarily reflect those of the grantor.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Telma Costa, MD, Doctor, Department of Oncology, Centro Hospitalar Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia 4434-502, Portugal. telma.r.c.costa@gmail.com
Received: February 8, 2021
Peer-review started: February 8, 2021
First decision: April 25, 2021
Revised: May 4, 2021
Accepted: May 8, 2021
Article in press: May 8, 2021
Published online: June 26, 2021
Abstract
BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine neoplasia, with high risk of recurrence and metastasis and poor survival. Immune checkpoint inhibitors, like the anti-programmed death-ligand 1 agent avelumab, were recently approved for the treatment of advanced MCC. We, herein, report the first case of advanced MCC with oligoprogression managed with avelumab and local radical treatment.

CASE SUMMARY

A 61-year-old man was presented to the hospital with sporadic fever and an exudative malodorous mass (10 cm of diameter), located on the right gluteal region. The final diagnosis was MCC, cT4N3M1c (AJCC, TNM staging 8th edition, 2017), with invasion of adjacent muscle, in-transit metastasis, and bone lesions. Patient started chemotherapy (cisplatin and etoposide), and after six cycles, the main tumor increased, evidencing disease progression. Two months later, the patient started second line treatment with avelumab (under an early access program). After two cycles of treatment, the lesion started to decrease, achieving a major response. Local progression was documented after 16 cycles. However, as the tumor became resectable, salvage surgery was performed, while keeping the systemic treatment with avelumab. Since the patient developed bilateral pneumonia, immunotherapy was suspended. More than 2.5 years after surgery (last 19 mo without systemic therapy), the patient maintains complete local response and stable bone lesions.

CONCLUSION

This report highlights the efficacy and long-term response of avelumab on the management of a chemotherapy resistant advanced MCC, with evidence of oligoprogression, in combination with local radical treatment.

Keywords: Merkel cell carcinoma, Unresectable tumor, Avelumab, Oligoprogression, Surgery, Chemotherapy, Case report

Core Tip: This report highlights the efficacy and long-term response of avelumab on the management of a chemotherapy resistant advanced Merkel cell carcinoma. It shows also a successful approach to oligoprogression with local radical treatment, surgery, and radiotherapy, while maintaining systemic therapy with avelumab. The results support the effectiveness of this strategy for the management of unresectable Merkel cell carcinoma.