Immune checkpoint inhibitor rechallenge after pazopanib treatment in primary pulmonary angiosarcoma: A case report

Primary pulmonary angiosarcoma is a rare malignancy with limited therapeutic options. We report a case of primary pulmonary angiosarcoma in which tumor regression was achieved with immune checkpoint inhibitor (ICI) rechallenge following pazopanib therapy. The tumor showed strong PD-L1 expression and infiltration of CD3⁺, CD4⁺, and CD8⁺ T cells without CD20⁺ B cells. After disease control with atezolizumab, pazopanib induced tumor shrinkage but was followed by disease progression. Pembrolizumab rechallenge resulted in tumor regression and sustained benefit. This case suggests that sequential VEGF-targeted therapy and PD-1 blockade may contribute to renewed sensitivity to ICI in tumors with a T-cell-inflamed microenvironment.