1748P - A prospective, phase II study of tislelizumab administered in combination with eribulin and anlotinib for patients (pts) with advanced adult oft tissue sarcoma (TEASTS)

Background

Our previous retrospective study demonstrated that eribulin combined with ICIs and anlotinib, a multi-targeted antiangiogenic tyrosine kinase inhibitor has shown some efficacy in STS. In this study we further investigated the efficacy and safety of the above-mentioned regimen in patients (pts) with advanced soft tissue sarcoma.

Methods

This is a single-arm, phase II study. Pts with advanced or metastasis STS that has progressed on prior chemotherapy receive tislelizumab 200mg Q3W (d1, iv), eribulin 1.1 mg/m2 (d1, d8, iv) and anlotinib 12 mg (d1-d14, po) every three weeks for 6 cycles, followed by two of the maintenance regimen until disease progression, intolerable toxicity and other discontinuation criteria. The primary endpoint was ORR. Secondary endpoints included PFS, DCR, AEs, OS.

Results

From May 2023 to April 2024, 26 patients were enrolled. All received at least one treatment and one tumor assessment. Median age was 57 years, 61.5% (16/26) were female. 69.2% (18/26) had L-type sarcomas (including 5 liposarcoma [LPS] and 13 leiomyosarcoma [LMS]), and 30.8% (8/26) had non-L-type sarcomas. Pts had received a median of 1 (range 1-3) prior regimens and the median follow-up was 5.5 months. Median PFS and OS were not reached. PFS and OS rates at 12m were 53% and 61.8%, respectively. ORR and DCR were 30.8% (8/26) and 84.6% (22/26). 8 pts achieved either a complete or partial response with an averaged DOR of 6.8 months and were still in the study cohort. Among them, 6 were L-type sarcoma (5 LMS, 1 LPS). 20 patients (76.9%) experienced treatment related adverse events (TRAEs), the most common TRAEs were myelosuppression, liver function abnormality and thyroid dysfunction. Grade 3/4 TRAEs occurred in 23.1% of pts, with no grade 5 events.

Conclusions

Tislelizumab+eribulin+anlotinib was well tolerated and showed encouraging efficacy compared to retrospective controls.

Clinical trial identification

ChiCTR2300071221.

Editorial acknowledgement

Funding

BeiGene. Ltd.

Disclosure

All authors have declared no conflicts of interest.