Meta-analysis of pazopanib and trabectedin effectiveness in previously treated metastatic synovial sarcoma (second-line setting and beyond)

Background: This study examined the efficacy/effectiveness of pazopanib and trabectedin in previously treated metastatic synovial sarcoma (mSS). Materials & methods: A literature search identified studies (2002-2019) reporting outcomes of pazopanib and trabectedin in previously treated mSS, including median overall survival (mOS) and overall response rate (ORR). A meta-analysis was conducted and sensitivity analyses examined outcomes by agent (pazopanib/trabectedin), study type (clinical trial [CT] or real-world [RW]) and sample size. Results: Sixteen studies were included (pazopanib: n = 7; trabectedin: n = 9). Pooled mOS was 10.4 months and was consistent across agents and in RW and CT (pazopanib: 10.3; trabectedin: 10.4; CT: 10.8; RW: 9.9). ORR results were more variable (pooled ORR: 14.7%). ORR was consistently higher for RW (17.7%) than for CT (9.5%) and for pazopanib (18.9%) compared with trabectedin (12.3%). Conclusion: Poor outcomes across agents and settings highlight a need for novel treatments with improved efficacy. This study serves as a benchmark for efficacy estimates in this rare disease.

Targeting cancer testis antigens in synovial sarcoma

Synovial sarcoma (SS) is a rare cancer that disproportionately affects children and young adults. Cancer testis antigens (CTAs) are proteins that are expressed early in embryonic development, but generally not expressed in normal tissue. They are aberrantly expressed in many different cancer types and are an attractive therapeutic target for immunotherapies. CTAs are expressed at high levels in SS. This high level of CTA expression makes SS an ideal cancer for treatment strategies aimed at harnessing the immune system to recognize aberrant CTA expression and fight against the cancer. Pivotal clinical trials are now underway, with the potential to dramatically alter the landscape of SS management and treatment from current standards of care. In this review, we describe the rationale for targeting CTAs in SS with a focus on NY-ESO-1 and MAGE-A4, the current state of vaccine and T-cell receptor-based therapies, and consider emerging opportunities for future development.