Tarabadkar Erica S, Thomas Hannah, Blom Astrid, Parvathaneni Upendra, Olencki Thomas, Nghiem Paul, Bhatia Shailender
Department of Internal Medicine/Division of Dermatology, University of Washington, Seattle, WA, USA.
Department of Dermatology, Hôpital Ambroise Paré, Boulogne-Billancourt, France.
Am J Case Rep. 2018 Apr 30;19:505-511. doi: 10.12659/AJCR.908649.
BACKGROUND Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer. The estimated 5-year survival of patients with metastatic disease is approximately 14%. Cytotoxic chemotherapy is associated with a modest median progression-free survival (PFS) of only 3 months. In recent studies, immunotherapy with anti-PD-1/anti-PD-L1 antibodies has demonstrated a high response rate in immunocompetent patients (>50% in chemotherapy-naïve patients) and responses are typically durable. However, approximately 50% of immunocompetent patients do not respond to immunotherapy. In addition, immunosuppressed patients have limited therapeutic options. Hence, there is a significant unmet need for effective treatments in these subpopulations. CASE REPORT We describe 5 patients (out of 24 total) with metastatic MCC who were treated with a vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI), either pazopanib (n=4) or cabozantinib (n=1), with clinical benefit. One patient had a complete response to pazopanib after 3 months of therapy. Four patients had stabilization of disease that lasted from 5 months to 3.5 years. In an immunosuppressed patient with psoriatic arthritis, stabilization of MCC was also associated with improvement in his arthritis that allowed cessation of immunosuppression. Patients did not develop any unusual toxicities from VEGFR-TKIs. CONCLUSIONS Treatment with VEGFR-TKIs demonstrated clinical benefit in this selected small group of patients with metastatic MCC. Prospective investigation of VEGFR-TKIs is warranted in this population, especially in patients with disease refractory to immunotherapy.
默克尔细胞癌(MCC)是一种罕见但侵袭性强的神经内分泌皮肤癌。转移性疾病患者的估计5年生存率约为14%。细胞毒性化疗的中位无进展生存期(PFS)仅约3个月。在最近的研究中,抗PD-1/抗PD-L1抗体免疫疗法在免疫功能正常的患者中显示出高缓解率(初治化疗患者中>50%),且缓解通常持久。然而,约50%的免疫功能正常患者对免疫疗法无反应。此外,免疫抑制患者的治疗选择有限。因此,这些亚组患者对有效治疗存在重大未满足需求。病例报告:我们描述了24例转移性MCC患者中的5例接受血管内皮生长因子受体(VEGFR)酪氨酸激酶抑制剂(TKI)治疗并获得临床获益,其中4例使用帕唑帕尼,1例使用卡博替尼。1例患者在治疗3个月后对帕唑帕尼完全缓解。4例患者病情稳定,持续时间为5个月至3.5年。在1例患有银屑病关节炎的免疫抑制患者中,MCC病情稳定还伴随着关节炎改善,从而可以停止免疫抑制。患者未出现VEGFR-TKIs的任何异常毒性。结论:VEGFR-TKIs治疗在这一选定的小群体转移性MCC患者中显示出临床获益。有必要对该人群进行VEGFR-TKIs的前瞻性研究,尤其是对免疫疗法难治的患者。