(P 116) UPDATE ON SAINT: RESULTS OF 100 PATIENTS TREATED WITH IPILIMUMAB (I), NIVOLUMAB (N) AND TRABECTEDIN (T) AS FIRST LINE THERAPY FOR ADVANCED SOFT TISSUE SARCOMA [NCT03138161]

Objective: Advanced soft tissue sarcoma is most often associated with a fatal outcome. Recently, we reported on the safety and efficacy of the SAINT protocol in 79 previously untreated patients with advanced soft tissue sarcoma. This report is an update of SAINT on 100 patients treated with SAINT earlier in the course of the disease.

Objectives: Primary: Evaluate best response rate by RECIST v1.1; Secondary: Assess progression-free survival (PFS) at 6 months and overall survival.

Methods: Eligible patients for this Phase 2 study are males or females ≥ 18 years of age with locally advanced unresectable or metastatic soft tissue sarcoma, previously untreated, with measurable disease by RECIST v1.1. Treatment protocol: (I) 1 mg/kg i.v. q 12 wks, (N) 3 mg/kg i.v. q 2 wks, (T) 1.2 mg/m2 CIV q 3 wks.

Results:

Results: Efficacy: One hundred patients were evaluated for efficacy. These subjects completed at least one treatment cycle and had a follow-up CT scan. The best responses were 7CR, 13PR, 64SD and 16PD with 20% ORR, 84% DCR. PFS rate at 6 months was 55%; Median PFS was 7.4 (95% CI: 5.4-9.4) months; Median OS was 27.2 (95% CI: 17.7-36.7) months. The best responders (CR and PR) were patients with LMS, UPS, LPS, synovial sarcoma, myxofibrosarcoma, endometrial stromal sarcoma, clear cell sarcoma, DSRCT, and chondrosarcoma. Notably, out of the 100 patients who participated in the study between 2017 and 2022, nineteen (19%) patients are still alive as of June 1, 2023, the data cut-off date.
Safety: Grade 3/4 TRAEs related to Trabectedin include both hematologic and non-hematologic toxicities: fatigue, nausea, vomiting, fever, exhaustion, dehydration, asthenia, cellulitis of port, anemia, neutropenia, thrombocytopenia, transaminitis, elevated CK. There were no hematologic toxicities related to Nivolumab or Ipilimumab. Grade 3/4 TRAEs include decreased TSH, increased T4, increased TSH, transaminitis, hyponatremia, dehydration, pruritus, and psoriasis.

Conclusion:

Conclusions: Taken together we have confirmed that (1) The SAINT regimen is a safe and effective first line therapy for advanced soft tissue sarcoma, and (2) Randomized studies are warranted to confirm whether the SAINT regimen is superior to standard first line therapy for advanced soft tissue sarcoma.