A pilot study of autologous tumor-infiltrating lymphocytes (LN-145) in adult patients with undifferentiated pleomorphic sarcoma or dedifferentiated liposarcoma.

e23566 Background: Advanced undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated liposarcoma (DDLS) are difficult to treat soft tissue sarcomas with response rates to first line systemic therapy between 10-30%. However, both UPS and DDLPS have been shown to have measurable tumor infiltrating lymphocyte (TIL) populations. LN-144 (lifileucel), an autologous TIL product derived from unresectable or metastatic melanoma, was shown to have an overall response rate (ORR) of 36% in heavily pretreated melanoma patients with a median DOR of 19.7 months. We hypothesized that generation and infusion of LN-145, an autologous TIL product from non-melanoma solid tumors, in this case UPS and DDLPS, would be both safe and feasible. Methods: NCT05607095 is a single center multi-cohort pilot trial with Cohort 2 enrolling patients with metastatic or unresectable UPS or DDLS to undergo autologous TIL therapy with LN-145. Eligible patients had to receive at least 1 prior line of systemic therapy, a lesion at least 1.5 cm in size available for TIL harvest, and adequate organ function and performance status (ECOG 0-1). After surgical excision of suitable tumor for TIL expansion, successful LN-145 product generation was determined by characteristics that meet pre-specified criteria in the LN-145 IND. Patients then underwent nonmyeloablative lymphodepletion with cyclophosphamide (60 mg/kg x 2 doses) and fludarabine (25 mg/m 2 x 5 doses). LN-145 was then infused and expanded with intravenous interleukin 2 (600,000 IU/kg up to 6 doses). Primary endpoints of the trial were feasibility, defined as ³6 of 10 harvested pts undergoing LN-145 therapy, and safety, defined by the incidence of Grade ³3 adverse events (AE) as measured by CTCAE v5.0. Key secondary endpoints included estimated LN-145 manufacture rates and efficacy (ORR) utilizing RECIST 1.1. Exploratory endpoints include persistence of LN-145 cells and immune correlates in tissue and peripheral blood and their potential association with objective response and toxicity. Safety and efficacy measures will be summarized using point estimates and a Clopper Pearson exact confidence interval will be used. The final results of the primary feasibility and safety endpoints and secondary feasibility endpoint for the first 10 enrolled patients as well as and preliminary secondary efficacy and exploratory correlative studies through week 12 for 7 treated patients will be reported as late-breaking abstract after data lock on March 1, 2026. Clinical trial information: NCT05607095 .