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.

Soft tissue sarcomas, a look into the future: different treatments for different subtypes

 Soft tissue sarcomas (STS) are a heterogeneous group of rare malignancies frequently studied and treated as if they were one and the same disease. Evidence is emerging that distinct histopathological differences between the subtypes can significantly impact on optimal management of patients with STS. For the majority of patients with localized disease, surgery is the treatment of choice, sometimes combined with radiotherapy. For patients with advanced/refractory disease, there are a number of options. The first option is to consider cytotoxic chemotherapy with doxorubicin ± ifosfamide to reduce tumor size and make the tumor more amenable to surgery. If this is not possible, treatment should be aimed at reducing symptoms, improving patients' wellbeing and prolonging life. In this regard, understanding of the different biologies and sensitivities of the various histological subtypes of STS continues to expand, and an increasing number of targeted therapies are becoming available. Examples of more specific treatment options include taxanes in angiosarcoma, and trabectedin in leiomyosarcoma, liposarcoma and undifferentiated pleomorphic sarcoma. Although much remains to be learned about these rare malignancies, it is anticipated that small steps taken in recent years will lead to bigger leaps forward in future.

Trabectedin for desmoplastic small round cell tumours: a possible treatment option?

BACKGROUND

Desmoplastic small round cell tumour (DSRCT) is a rare sarcoma typically affecting young males and usually widely metastatic at presentation. Despite multimodal treatment approaches, the prognosis for DSRCT is extremely poor. Alkylator- and anthracyclines- based regimens are widely used as therapy and an initial response is common. Durable responses are exceptionally rare so further systemic treatment options for these patients represent an unmet medical need. We report two cases of metastatic, pretreated DSRCT patients achieving disease stabilisation with Trabectedin.

METHODS

Retrospective review of 2 patients with progressive DSRCT, treated with Trabectedin.

RESULTS

Two males aged 19 and 23 years treated with Trabectedin, 1.5 mg/m(2) over 24 hours 3 weekly for 6 and 5 cycles respectively. Best responses were stable disease in patient 1 and partial response (RECIST 1.1) in patient 2. Progression free survival was 4 months in both cases. Persistent neutropenia required 4 weekly administration in one patient but no other grade 3-4 toxicities occurred.

CONCLUSIONS

This report supports Trabectedin to be active and safe in pre-treated DSRCT patients. Further prospective and collaborative efforts are desirable to better define its role in the management of this disease.

Emerging therapies for sarcoma

STS are uncommon tumors of the connective tissues. The OS of patients with advanced sarcomas has improved in the last 20 years, but remains under 2 years. Drug discovery for this disease has been complicated by the fact that there are many different subtypes that comprise STS. In fact, emerging data suggest that each of these subtypes may represent a different entity, with a unique molecular profile and responsiveness to therapy. Testing of new agents and determining predictors for response in this heterogeneous disease is therefore of utmost importance.