Abstract CT287: LINNOVATE: A Phase 1/2 study of safety/efficacy using lurbinectedin, combined with ipilimumab, and nivolumab for advanced soft tissue sarcomas (NCT05876715)

Abstract Background: Sarcoma cells are most immunogenic earlier in the course of the disease. Therefore, immune checkpoint inhibitors such as ipilimumab (ipi) and nivolumab (nivo), that promote sustained T-cell activation by suppressing T regs would be most effective when given as first line therapy, together with a tumoricidal agent, such as lurbinectedin, whose plausible mechanism of action is not only to destroy the cancer cells and expose the tumor neoantigens for immune recognition, but also to destroy growth promoting factors in the tumor microenvironment. In the SAINT phase 2 study using ipi, nivo and trabectedin as first line therapy for advanced soft tissue sarcomas (STS; n=79), there were 6 complete responses, 14 partial responses, 49 stable disease, 25. 3% best response rate, 87. 3% disease control rate; median PFS, 6. 7 months, median OS, 24. 6 months (Gordon et al, Cancers vol. 15, 906, 2023). Lurbinectedin is a synthetic marine-derived agent and an analog of trabectedin. Therefore, we expect that lurbinectedin will be as effective as trabectedin when used together with ipi and nivo as first line therapy for advanced STS. Methods: Objective 1: Assess MTD of lurbinectedin. Objective 2: Evaluate PFS, OS, incidence and severity of adverse events; Correlative: Correlate response with ctDNA using Signatera. This is an open label, dose-seeking phase 1/2 study. The phase 1 part employs standard “cohort of three” design with a DLT window of 6 weeks. Treatment schedule: Ipi 1 mg/kg IV q 12 weeks; Nivo 3 mg/kg IV q 2 weeks; escalating doses of lurbinectedin from 2. 6 mg/m2 to 3. 2 mg/m2 IV q 3 weeks. Phase 2 part follows completion of phase 1 part wherein additional 28-34 participants will receive lurbinectedin at the MTD with fixed doses of Ipi and Nivo. Participants may continue treatment until significant disease progression or unacceptable toxicity occurs. Eligible patients are 18 years of age or older, previously treated in phase 1 and previously untreated in phase 2 with confirmed diagnosis of advanced STS, adequate hematologic and organ function, and no history of autoimmune disorder. To date, 6 patients in phase 1 have been dosed. Citation Format: Erlinda M. Gordon, Nadezhda Omelchenko, Samantha Jeffrey, Vaishali Kumar, Neal S. Chawla, Mahesh Seetharam, Victoria Chua, Ania Moradkhani, Doris Quon, Steven Wong, Sant Chawla. LINNOVATE: A Phase 1/2 study of safety/efficacy using lurbinectedin, combined with ipilimumab, and nivolumab for advanced soft tissue sarcomas (NCT05876715) abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (7Suppl): Abstract nr CT287.