Tumor-infiltrating Lymphocytes Infusion Research Articles

A phase 2, multicenter study of TILs treatment in advanced tumors with alterations in the SWI/SNF complex: The TILTS study.

TPS2674 Background: Tumors associated with SWI/SNF complex (SWI/SNFc) mutations, mainly SMARCA4 and SMARCB1 loss, are a heterogeneous group of malignancies with rhabdoid features that typically affect young patients (pts). These are aggressive malignancies with poor prognosis for which no standard treatment is available. Despite not having a high tumor mutation burden, tumor infiltrating lymphocytes (TILs) are usually present in high numbers. The biologic reasons for this feature are not clearly understood but might be associated to changes in gene expression due to aberrant chromatin remodeling. However, these TILs indicate that tumor antigens are recognized by lymphocytes unveiling a vulnerability that can be exploited by immunotherapy. The objective of the TILTS study is to develop a personalized adoptive cell therapy using TILs in pts affected by these tumors. Methods: Single arm, multi center, phase 2 study of TILs in pts with advanced tumors associated with SWI/SNFc mutations. Pts are treated at 3 centers in Spain: Catalan Institute of Oncology (ICO), Barcelona, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, and Centro Integral Oncológico Clara Campal (HM CIOCC), Madrid. Primary endpoint is overall response rate (ORR) by RECIST 1.1. Secondary endpoints include toxicity evaluation, duration of response (DOR), progression-free survival (PFS) or overall survival (OS). After informed consent is obtained, tumor resection is performed. Total volume of tumor resected should be at least 1.5 cc to assure TIL isolation. Eligible pts enter the treatment phase. TILs are produced under GMP conditions. During the TILs manufacturing process, pts are allowed to receive standard treatment if clinically indicated. Before TIL infusion, pts receive non-myeloablative preconditioning lymphodepletion with daily intravenous (IV) cyclophosphamide (60 mg/kg; IV x2 doses) and daily fludarabine (25 mg/m2; IV x5 doses). Infusion of autologous TILs is given on Day 0 followed by administration of IL-2 at 600,000 international units (IU)/kg every 8-12 hours for a maximum of 6 doses. After 4 weeks, a new tumor biopsy is optional. First image evaluation is performed after 8 weeks from TIL infusion. Pts without progression enter the follow-up phase. An ancillary translational study will explore mechanisms of immunogenicity, antigen recognition, TILs anti-tumor activity, and changes in the stool microbiome and specific TCR population during treatment. Also, tumor immune microenvironment will be analyzed. Clinical trial information: 2023-504632-17-00 . [Table: see text]

Reduced dose fludarabine/cyclophosphamide lymphodepletion for tumor-infiltrating lymphocytes therapy (LN-144, lifileucel) in metastatic melanoma.

TPS9608 Background: Metastatic melanoma (MM) patients who have progressed following immune checkpoint inhibitors (ICI; anti–PD-1/CTLA-4 therapy) and targeted agents (BRAF/MEK inhibitors) have limited treatment options and dismal prognosis. An autologous tumor-infiltrating lymphocytes (TIL) therapy (LN-144, lifileucel) has demonstrated efficacy and durable responses in heavily pretreated advanced melanoma. In a phase II study of TIL therapy (lifileucel) with traditional lymphodepletion (LD), using fludarabine 25 mg/m2 for 5 days and cyclophosphamide (Cy) 60 mg/kg for 2 days, in 153 MM patients previously treated with ICI and BRAF/MEK inhibitors, an overall response rate (ORR) of 31% was noted, and the median duration of response (DOR) was not reached after 27.6 month follow up. We hypothesize that a reduced dose of Flu/Cy LD for TIL therapy will have similar TIL expansion and persistence post-infusion, resulting in similar efficacy with a reduced toxicity profile. Methods: Study NCT06151847 is a single-center, open-label phase II pilot trial evaluating the efficacy, in vivo persistence, and safety of TIL therapy after reduced dose Flu/Cy LD. Key inclusion criteria include unresectable or metastatic melanoma (stage IIIC-IV) with disease progression after one or more lines of therapy. Four of the 12 planned patients have been enrolled as of February 2, 2024. Central TIL manufacturing from at least a 1.5 cm tumor specimen involves ex vivo expansion through cell culture in the presence of the interleukin (IL)-2 and an anti-CD3 monoclonal antibody (1-150 x109 viable cells). Patients will receive an outpatient reduced-dose Flu/Cy LD regimen of Flu (30 mg/m2 on days -4, -3, -2, -1) and Cy (750 mg/m2 on days -4, -3, -2). Infusion of TIL will be performed on day 0 followed by high-dose IL-2 (600,000 IU/kg up to 6 doses). The primary objective will be to ascertain TIL persistence using T-cell receptor (TCR) sequencing at day 42 which will be compared to historical data already generated utilizing traditional Flu/Cy LD. The secondary objectives will be to evaluate the efficacy parameters including ORR, DOR, progression-free survival (PFS), and overall survival (OS), and the safety profile of TIL in combination with a reduced dose Flu/Cy LD regimen. Exploratory objectives will involvecorrelative analyses to characterize the immunome and microenvironment. If TIL persistence is roughly equivocal between the reduced and high-dose Flu/Cy LD regimens, the design of a larger-scale trial using reduced-dose Flu/Cy LD for TIL therapy may be considered. Study follow-up will continue for one year. Clinical trial information: NCT06151847 .

IOV-3001, a modified interleukin-2 fusion protein, for potential use in tumor-infiltrating lymphocyte cell therapy regimens.

2552 Background: Tumor-infiltrating lymphocyte (TIL) cell therapy has shown promising efficacy in patients with solid tumor malignancies. Interleukin-2 (IL-2) administration after TIL infusion supports persistence and survival of infused TIL. Aldesleukin is a synthetic IL-2 with a short half-life administered every 8–12 hours, to support the expansion and persistence of the TIL in vivo. IOV-3001 is a modified dimeric IL-2 fused to palivizumab that has a longer half-life and potentially better safety profile, compared with aldesleukin. Here, we describe the preclinical activity, pharmacokinetics (PK), pharmacodynamics (PD), and in vivo safety profile of IOV-3001. Methods: Binding of IOV-3001 and aldesleukin to the IL-2 receptor (IL-2R), IL-2R-mediated activation via STAT5 phosphorylation, and T cell proliferation were assessed. Pharmacological activities of IOV-3001 and aldesleukin were evaluated in B16-F10 mice infused with pmel-1 T cells. Safety after a single dose of IOV-3001 (0.01–9.0 mg/kg) was assessed in cynomolgus monkeys across 3 independent studies. PK and PD parameters, clinical pathology, hematology, and histopathology were assessed. Results: Both IOV-3001 and aldesleukin induced comparable STAT5 phosphorylation and proliferation of T-cell subsets. Mice infused with pmel-1 T cells and subsequently treated with IOV-3001 or aldesleukin showed similar reductions in tumor burden. The half-life of IOV-3001 in cynomolgus monkeys ranged from 5–8 hours. IOV-3001 was well tolerated in monkeys across the dose range studied except for 1 animal administered IOV-3001 at the highest tested dose level, with recovery by Day 29. Inflammatory cytokines (IL-12 p40, IL-6, MCP-1) increased from 4 hours to ≤3 days after dosing and returned to baseline by Day 29. Fibrinogen, bilirubin, and triglycerides increased on Day 3 and returned to baseline by Day 29. No signs of capillary leak were observed. Increased numbers of hematopoietic cells were found in the bone marrow, spleen, and lymph nodes 3 days post dosing. During the 4-week recovery, these changes diminished or resolved, while bone marrow showed differential dose-dependent effects. IL-2–induced proinflammatory PD effects were observed, including >10-fold peak CD8+ T cell expansion in peripheral blood mononuclear cells at Day 5 versus preacclimation in most cynomolgus monkeys treated with IOV-3001. Conclusions: IOV-3001 exhibited a similar mechanism of action (MoA) to that of aldesleukin in vitro and has a longer half-life in vivo. PD effects were consistent with the MoA of IL-2. IOV-3001 showed a favorable preclinical safety profile. These results suggest a potentially improved safety profile for IOV-3001 with less frequent dosing compared with aldesleukin. These features of IOV-3001 strongly advocate for its development in TIL cell therapy regimens.

Developing innovative strategies of tumor‑infiltrating lymphocyte therapy for tumor treatment.

Cancer is the main cause of global mortality, and thus far, effective therapeutic strategies for cancer treatment are in high demand. Adoptive transfer of tumor‑infiltrating lymphocytes (TILs) represents a promising avenue in immunotherapy for the management of malignancies. The clinical safety and efficacy of TIL‑based therapy have been established through numerous rigorous clinical trials. However, the efficacy of TIL infusion in inducing an anti‑tumor response is limited to a subset of clinical patients with cancer. Therefore, there is an urgent need to develop innovative strategies aimed at enhancing the effectiveness of TIL‑based therapy. In the present review, the developmental history of TIL‑based therapy was systematically summarized and analyzed, while also presenting a unique perspective on enhancing the multi‑dimensional anti‑tumor capabilities of TILs. The insight and conclusions presented in this review may contribute to improving the efficacy of TIL‑based therapy and expediting its development.

Abstract 3605: Phase II study of pembrolizumab in conjunction with lymphodepletion, TIL ACT, and high- or low-dose IL-2 in patients with metastatic melanoma

Abstract Background: In metastatic melanoma (MM) patients (pts), adoptive cell transfer (ACT) using tumor-infiltrating lymphocytes (TIL) can yield lasting responses. However, TIL ACT with high-dose IL-2 has notable toxicities. Anti-PD1 (pembrolizumab) is FDA approved for MM treatment. Our study aimed to merge TIL infusion with anti-PD1 in two arms, comparing high (HD, arm 1) and low (LD, arm 2) IL-2 doses. Methods: After tumor harvest and TIL expansion, pts were lymphodepleted with cyclophosphamide and fludarabine, followed by infusion with their ex-vivo expanded TIL combined with IL-2 (arm 1: 720,000 IU/kg IV q 8 hrs up to 15 doses; arm 2: 2 million IU SC for 14 days). Pts were given 200 mg of IV anti-PD1 starting 21 days post-TIL infusion, followed by doses every 3 weeks for up to 2 years. Blood was taken before lymphodepletion and before the first two anti-PD1 doses for flow cytometry and cytokine analysis The primary endpoint of the study was determination of overall response rate by RECISTS 1.1 criteria. Enrollment aimed for 18 pts per arm, monitoring the primary ORR endpoint using a Bayesian rule. Enrollment would halt in any arm if the ORR dropped below 40%. Results: The median age was 50 years (n=14: 6 F and 8 M). Of these 14 pts, 8, 2, 2, and 2 had cutaneous, uveal, mucosal, or unknown primary melanoma. Pts had a median of 3 lines of prior therapies (range 1-6), including anti-PD-1 (n=13). In arm 1, one pt had a partial response (PR) for 10 months, 2 had stable disease (SD), 3 had progressive disease (PD), and 1 was not evaluable (NE). In arm 2, one pt had an ongoing PR for over 76 months, 1 had SD, and 5 had PD. Due to ORR <40% in each arm, enrollment was stopped after treatment of 14 pts. There was no significant different in progression-free survival or overall survival between the two arms (p=0.99 and p=0.71, respectively). In general, toxicity levels were comparable in both arms; however, pts in arm 2 had slightly lower grade 3 febrile neutropenia (57% vs. 71%) and shorter hospitalization (median 16 days vs. 18 days) than pts in Arm 1. While no correlation was observed between the phenotype of the TIL product and clinical response, both PR pts received high numbers of TIL (38.6 × 10^9 and 93.7 × 10^9; mean: 32.6 × 10^9 cells), with a high CD8+/CD4+ T cell ratio (284.7 and 2.7; median: 2.7). IL-2 dose did not affect circulating Treg frequency, phenotype, or proliferation by flow cytometry 3 weeks post TIL infusion. IL-2 dose was not associated with CD4+ non-Treg and CD8+ T cell phenotype or proliferation. Addition of anti-PD1 reduced expression of checkpoints but did not boost T cell proliferation. Conclusion: Our treatment strategy did not yield any distinct difference between low and high dose IL-2, suggesting the potential of low-dose IL-2 as an alternative. Anti-PD1 did not have any appreciable effect on immune states potentially due to the cohorts being comprised of a heavily pre-treated heterogenous pt population. Citation Format: Merve Hasanov, Simin Kiany, Marie-Andrée Forget, Roland L. Bassett, Michael A. Davies, Adi Diab, Jeffrey E. Gershenwald, Isabella C. Glitza, Jeffrey E. Lee, Anthony Lucci, Jennifer L. McQuade, Sapna P. Patel, Merrick I. Ross, Hussein A. Tawbi, Jennifer Wargo, Michael K. Wong, Chantale Bernatchez, Patrick Hwu, Cara Haymaker, Rodabe N. Amaria. Phase II study of pembrolizumab in conjunction with lymphodepletion, TIL ACT, and high- or low-dose IL-2 in patients with metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3605.

Tumor-Infiltrating Lymphocyte and Other Cell Therapies for Metastatic Melanoma.

Major progress in prolonging survival of patients with advanced melanoma has been made in the past decade because of the development and approval of immune checkpoint inhibitor and targeted therapies. However, for nonresponding or relapsing patients, their prognosis is still dismal. Based on clinical trial data, treatment with adoptive cell therapies holds great promise. In patients with metastatic melanoma progressing on or nonresponsive to single-agent anti-programmed cell death 1, infusion of tumor-infiltrating lymphocytes can produce responses in up to half of patients, with durable complete responses in up to 20%. Genetic modification of peripheral blood T cells with T-cell receptors derived from tumor-specific T cells, or with chimeric antigen receptors, has the potential to further improve treatment outcomes in this refractory population. In this review, we will discuss the historical development, current status, and future perspectives of adoptive T-cell therapies in melanoma.

Neoantigen-specific CD4+ tumor-infiltrating lymphocytes are potent effectors identified within adoptive cell therapy products for metastatic melanoma patients

BackgroundAdoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) is a promising immunotherapeutic approach for patients with advanced solid tumors. While numerous advances have been made, the contribution of neoantigen-specific CD4+T...

Tolerability and response of palliative radiotherapy in patients receiving tumor-infiltrating lymphocyte therapy.

e14527 Background: Tumor-infiltrating lymphocyte (TIL) therapy is an emerging therapeutic option for patients with metastatic tumors having progressed on multiple lines of systemic therapy. It is unknown how TIL therapy impacts the tolerability and effectiveness of palliative radiotherapy (RT). We herein present a case series of patients having received both TIL therapy and palliative RT along with the associated local responses and toxicity profiles. Methods: A single institution retrospective database review identified patients treated with TIL therapy following progression on ≥2 standard treatment(s) for metastatic disease. Patients were eligible for inclusion if they received palliative radiotherapy treatment within 1 year of TIL delivery as pre- or post-TIL therapy. Patient demographic data was collected and descriptive statistics reported. Radiographic imaging response was assigned in accordance with Response Evaluation Criteria in Solid Tumors (RECIST). Toxicities were graded in accordance with Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. Results: Between 2017–2021, a total of 10 patients receiving TIL therapy treated across 12 courses of palliative RT were included for analysis. 8 of 10 patients (80%) had a primary diagnosis of malignant melanoma and 2 (20%) had non-small cell lung cancer. RT was administered to 7 patients pre- and 3 patients post-TIL therapy. Within the pre-TIL cohort, 2 patients received RT between TIL harvest and infusion. Patients received an average total dose of 26 Gy (range, 8-45 Gy). Median patient follow-up after RT was 6 months. Of the patients who received RT prior to TIL therapy, 6 of 9 sites demonstrated at-least stable disease at the site of RT versus 1 of 3 sites receiving post-TIL RT. Across the cohort, 2 patients experienced Grade 1 toxicities associated with RT treatment. No Grade 2+ events were reported. Conclusions: Palliative RT appears to be safe and tolerable when delivered both prior to and post-TIL therapy. RT may be an option for bridging therapy between TIL harvest and infusion. Local response rates to RT were greater in patients receiving RT prior to TIL infusion. Further investigations are warranted to determine the optimal dose, fractionation, and timing of RT when integrating it into future TIL therapy protocols. [Table: see text]

Method for estimation of apoptotic cell fraction of cytotherapy using in vivo fluorine-19 magnetic resonance: pilot study in a patient with head and neck carcinoma receiving tumor-infiltrating lymphocytes labeled with perfluorocarbon nanoemulsion

BackgroundAdoptive transfer of T cells is a burgeoning cancer therapeutic approach. However, the fate of the cells, once transferred, is most often unknown. We describe the first clinical experience with...

Effect of a novel expansion process on tumor-infiltrating lymphocyte (TIL) polyfunctionality, cytotoxicity, and expansion, while preserving cells in a less differentiated and more stem-like phenotype.

2542 Background: Adoptive cell therapy using autologous TIL has shown durable responses in patients with metastatic melanoma and some epithelial tumors (Chesney JITC 2022; Schoenfeld SITC 2021; O’Malley SITC 2021). Data suggest that maintaining a higher proportion of less differentiated and more stem-like TIL can associate with persistence and response in patients with metastatic melanoma (Krishna Science 2020; Rosenberg Clin Cancer Res 2011). Here, we describe a novel TIL expansion process that increases TIL expansion and preserves cells in a less-differentiated and more stem-like phenotype with enhanced functional output. Methods: Tumors of various histologies, including lung, breast, and renal cancer, were fragmented and expanded using either a standard process or a newly developed process that uses a different combination of cytokines during the pre-rapid expansion protocol (pre-REP) stage and another combination of cytokines and a pathway inhibitor during the REP stage to control T-cell activation and differentiation. The expansion potential, viability, and phenotypic and functional attributes of the final TIL products were evaluated by a variety of assays. Results: When compared with standard TIL expansion, the novel process increased yield and viability while preserving TIL in a less differentiated and more functional state, as evidenced by increased expression of the memory-associated markers CD27, CD28, CD62L, and IL-7R, with reduced expression of the activation markers CD38, CD39, and CD69, and lower levels of the inhibitory markers LAG3, TIM3, TIGIT, and TOX. Importantly, the novel process led to a pronounced increase in the tumor-homing marker CXCR3 as well as TIL polyfunctionality as evidenced by increased co-expression of IFNγ, TNFα, and IL-2 while showing an enrichment in genes associated with stem-like cells and a reduction in exhaustion-associated genes. Pseudotime trajectory analysis also demonstrated that the new expansion process maintained TIL in a less differentiated and more stem-like state. Together, these phenotypic and functional characteristics translated into increased cytotoxicity even after repeated stimulation. Conclusions: Our novel TIL expansion process improves multiple metrics that correlate with both TIL persistence and response, including enhanced polyfunctionality, reduced inhibitory receptor expression and a less differentiated and more stem-like phenotype, while increasing yield. These effects may translate into a more vigorous and less differentiated TIL infusion product with improved cytotoxicity and persistence.

Abstract OT2-10-04: Treatment of advanced or metastatic triple-negative breast cancer with adoptive therapy of PD1+ tumor-infiltrating lymphocytes (TILS001 trial)

Abstract Background Metastatic triple-negative breast cancer (mTNBC) exhibits a particularly poor clinical outcome, generally with rapid progression and worse overall survival (OS) than other BC subtypes. Among the few therapeutic options, chemotherapy-based combinations are associated with increased toxicity and limited survival benefit, being treatment with sequential single agents, such as paclitaxel considered an appropriate first-line regimen for the metastatic setting for PDL-1 negative patients. Herein, there is an urgent need for clinically active agents for the mTNBC. Adoptive cell transfer (ACT)-based immunotherapy using ex vivo activated and expanded tumor-infiltrating lymphocytes (TILs) has shown promising therapeutic outcomes in some patients with metastatic tumors. The identification, selection, and enrichment of tumor-reactive lymphocytes at the early stages of the ACT generation could enhance their clinical activity. Thus, the selection of reactive T cells, such as PD1-positive (PD1+) TILs, could improve the responses achieved in those settings. TILS001 trial aims to explore the safety, tolerability and efficacy of selected PD1+ T-cell infusion with a previous pre-selection of mRNA PD1-high expression in patients with mTNBC. Study design: TILs001 trial is an open-label, single-arm, multicenter phase I/II prospective study with a two-stage design evaluating treatment with PD1+ TILs infusion in advanced or mTNBC, defined as HER2 negative and Hormonal Receptor < 10%. The study involves three different parts before PD1+TILs treatment. Tumor samples evaluable for PD1 mRNA expression and life expectancy ≥6 months are mandatory for part 1. Patients with high levels of PD1 mRNA, defined by the pre-specified cutoff, candidates for receiving a first-line taxane-based containing regimen and with at least 1 accessible target lesion to generate TILs are eligible for part 2. Finally, once the complete expansion of PD1+TILs is reached, patients will receive the non-myeloablative lymphodepleting chemotherapy regimen followed by PD1+TIL infusion and IL-2 treatment. Allogeneic hematopoietic stem cell transplantation, immune system-related disease or clinically active cerebral metastasis are not allowed. The primary objectives are to evaluate the safety and tolerability of the PD1+ TIL product, as per incidence of grade 3-5 adverse events (AE) or any grade AE that leads to treatment discontinuation and to assess the efficacy of ACT therapy with selected PD1+ TILs in mTNBC in terms of progression-free survival (PFS) at 6 months. The secondary endpoints are clinical benefit rate at 6 months (CBR6), overall response rate, duration of response (DoR), PFS and OS. Further translational research including immunophenotyping, TCR sequencing and mutational analysis will also be performed. The first 3 patients will be included in a safety run-in phase where safety will be evaluated 24h after PD1+/TILs infusion (before IL-2 treatment) and a phase II stage where efficacy will be evaluated, which will include up to 20 patients. Patients will be enrolled in 4 sites in Spain. Recruitment is expected to start by July 2022 and to be completed within 24 months. This study is financially supported by the Asociación Española Contra el Cáncer (GCAEC19010PRAT). NCT05451784 Citation Format: Nuria Chic, Eva Ciruelos, Cristina Saura, Europa-Azucena Gonzalez, Luís Álvarez-Vallina, Juan José Lasarte, Alena Gros, Lorea Villanueva, Jordi Canes, Laura Angelats, Aleix Prat, Tomás Pascual, Marta Santisteban, Manel Juan. Treatment of advanced or metastatic triple-negative breast cancer with adoptive therapy of PD1+ tumor-infiltrating lymphocytes (TILS001 trial). [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-10-04.

Adoptive Cellular Therapy for Metastatic Melanoma: The Road to Commercialization and Treatment Guidelines for Clinicians.

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has been gaining promise as a therapeutic option for metastatic melanoma. By harnessing the power of patients' tumor-resident lymphocytes, TIL therapy has shown promise in delivering durable, complete responses for patients who have progressed with other treatments, including checkpoint inhibition. This form of personalized medicine has traditionally been limited to select academic facilities with the infrastructure and resources to generate TIL cells and care for patients during the treatment phase. In this review, the authors discuss the role of TIL therapy for patients with metastatic melanoma, including the current state of therapeutic options, logistics of TIL harvest and infusion, management of infusion-specific toxicities, and foundational steps for surgeons and oncologists to establish cell-based therapies in individual hospitals and cancer centers.

An exploratory clinical study of the efficacy and safety of tumor-infiltrating lymphocytes in the treatment of metastatic osteosarcoma

Objective: To explore the safety and efficacy of tumor-infiltrating lymphocytes (TILs) extracted from tumor tissue in patients with pulmonary metastasis of osteosarcoma, the TILs were amplified in vitro to reach clinical dosage and reinfused to the patients combined with high-dose interleukin 2 (IL-2). Methods: Twelve subjects with pathologically diagnosed osteosarcoma were enrolled from December 2019 to June 20, 2021 in Shanghai General Hospital. All subjects progressed with metastasis after standard chemotherapy and failed multiple lines of treatments. Fresh tumor tissue was obtained from the metastatic site and extracted and amplified by Good Manufacturing Practice (GMP) workshop to produce TILs to clinical treatment dosage (109-1011). High-dose IL-2 (100 000-200 000 U/kg) was administered immediately after autogenous TILs infusion to promote the activation, proliferation and antitumor cytolytic activity in vivo. Adverse events (AE) were graded according to Common Terminology Criteria for Adverse Events (CTCAE) standard and tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Results: One patient did not receive treatment due to failure in isolating TILs, total of 11 patients received a single re-infusion of autologous TILs. There were 10 males and 1 female with a median age of 19.9 years (12-33 years). Six of these patients received higher dose levels of 1.0×1010 TILs. The 11 patients were followed-up for 1 to 13 months and tolerated well. The most common adverse events reported were fever (10/11), constipation (3/11) and elevated gamma-glutamyl transferase (GGT) (3/11). The high incidence of fever was due to the IL-2 infusion. All patients experienced a transient drop in lymphocyte count and leukopenia leading to non-myeloid ablative lymphocyte clearance. The AE included grade 4 hematologic toxicity, including 8 cases of lymphocytopenia, 2 cases of neutropenia and 1 case of thrombocytopenia. No AE of neurotoxicity occurred. Of all the 11 patients, 9 patients got stable disease (SD) and 2 patients had progressive disease (PD). The disease control rate was 9/11. The median duration of SD was more than 4 months, and the maximum tumor volume decreased by close to 20%. Patient number 9 had sustained SD status for more than 6 months. Conclusions: TILs with in vitro expansion ability could be isolated from tumor tissues of advanced osteosarcoma patients. TILs amplified and reinfused in vitro have anti-osteosarcoma activity.

Efficacy and safety of autologous expanded tumor infiltrating lymphocytes (TILs) in multiple solid tumors.

2536 Background: TIL therapy has been used extensively in metastatic melanoma patients for many years, now with ongoing efforts to commercialize treatment. The efficacy of TIL outside of melanoma is largely unknown thus we designed and implemented a trial using TIL manufactured at a single academic center for treatment refractory metastatic colorectal (CRC), pancreas (PDAC) and ovarian (OVA) cancers. Methods: Patients with CRC, PDAC and OVA refractory to standard therapies with ECOG PS 0-1 and normal organ function were eligible for TIL harvest. Ex vivo TIL expansion and manufacturing was conducted at the MD Anderson TIL lab under conditions that included IL2 and 41BB stimulation (using urelumab). All patients received a lymphodepletion regimen consisting of cyclophosphamide 60mg/kg days -7 and -6 and fludarabine 25mg/m2 days -5 through day -1, followed by infusion of pooled ex-vivo expanded TIL. Patients received up to 6 doses of high dose IL-2 (600,000 IU/kg) after TIL infusion. The primary endpoint was evaluation of the objective response rate (ORR) using RECIST 1.1 criteria with secondary endpoints including disease control rate, duration of response, PFS, OS and safety. Results: A total of 17 patients underwent TIL harvest and 16 were treated on protocol; including 8 CRC, 5 PDAC and 3 OVA. Median age was 57.5 (range 33-70) and 50% were females. Median number of lines of prior therapy was 2 (range 1-8). Median number of TIL infused was 76 X 109 (range 20.3 x 109-150 x 109). Median doses of cyclophosphamide and fludarabine administered were 2 (range, 2-2) and 3 (range, 1-5), respectively. Median doses of IL-2 administered was 6 (range, 1-6). There were no responders. Best response included prolonged SD in a patient with PDAC lasting until 18 months. Grade 3 or higher toxicities attributable to therapy was seen in 14 subjects (87.5%; 95% CI: 61.7 – 98.4) with the majority of toxicities representing expected pancytopenia from lymphodepletion. Infusion product analysis showed the presence of effector memory cells with high expression of CD39 irrespective of tumor type. Early on-treatment biopsy of PDAC patient with prolonged SD showed presence of proliferating (KI67+) CD4+ and CD8+ TIL. Conclusions: Generation of TIL at a single academic center for CRC, PDAC and OVA is feasible and treatment is associated with no new safety signals. For these tumor types, further research is required to identify host factors associated with resistance to TIL therapy and optimize manufacturing processes to create more effective TIL cell therapy. Clinical trial information: NCT03610490.

Genomic Correlates of Outcome in Tumor-Infiltrating Lymphocyte Therapy for Metastatic Melanoma.

Adoptive cell therapy (ACT) of tumor-infiltrating lymphocytes (TIL) historically yields a 40%-50% response rate in metastatic melanoma. However, the determinants of outcome are largely unknown. We investigated tumor-based genomic correlates of overall survival (OS), progression-free survival (PFS), and response to therapy by interrogating tumor samples initially collected to generate TIL infusion products. Whole-exome sequencing (WES) data from 64 samples indicated a positive correlation between neoantigen load and OS, but not PFS or response to therapy. RNA sequencing analysis of 34 samples showed that expression of PDE1C, RTKN2, and NGFR was enriched in responders who had improved PFS and OS. In contrast, the expression of ELFN1 was enriched in patients with unfavorable response, poor PFS and OS, whereas enhanced methylation of ELFN1 was observed in patients with favorable outcomes. Expression of ELFN1, NGFR, and PDE1C was mainly found in cancer-associated fibroblasts and endothelial cells in tumor tissues across different cancer types in publicly available single-cell RNA sequencing datasets, suggesting a role for elements of the tumor microenvironment in defining the outcome of TIL therapy. Our findings suggest that transcriptional features of melanomas correlate with outcomes after TIL therapy and may provide candidates to guide patient selection.

Adoptive cell therapy with tumor-infiltrating lymphocytes supported by checkpoint inhibition across multiple solid cancer types

BackgroundAdoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has shown remarkable results in malignant melanoma (MM), while studies on the potential in other cancer diagnoses are sparse. Further, the prospect...

Impact of Prior Treatment on the Efficacy of Adoptive Transfer of Tumor-Infiltrating Lymphocytes in Patients with Metastatic Melanoma.

Adoptive cell transfer (ACT) of autologous tumor-infiltrating lymphocytes (TIL) can mediate durable responses in patients with metastatic melanoma. This retrospective analysis provides long-term follow-up and describes the effect of prior therapy on outcomes after ACT-TIL. Patients with metastatic melanoma underwent surgical resection of a tumor for generation of TILs and were treated with a lymphodepleting preparative regimen followed by adoptive transfer of TILs and intravenous IL2. Clinical characteristics of enrolled patients and treatment characteristics of TIL infusion products over two decades of ACT were analyzed to identify predictors of objective response. Adoptive transfer of TILs mediated an objective response rate of 56% (108/192) and median melanoma-specific survival of 28.5 months in patients naïve to anti-programmed cell death-1 (PD-1) therapy compared with 24% (8/34) and 11.6 months in patients refractory to anti-PD-1 (aPD-1). Among patients with BRAF V600E/K-mutated disease, prior treatment with targeted molecular therapy was also associated with a decreased response rate (21% vs. 60%) and decreased survival (9.3 vs. 50.7 months) when compared with those patients naïve to targeted therapy. With a median potential follow-up of 89 months, 46 of 48 complete responders in the aPD-1-naïve cohort have ongoing responses after a single treatment and 10-year melanoma-specific survival of 96%. Patients previously treated with PD-1 or MAPK inhibition are significantly less likely to develop durable objective responses to ACT-TIL. While ACT-TIL is currently being investigated for treatment-refractory patients, it should also be considered as an initial treatment option for eligible patients with metastatic melanoma. See related commentary by Sznol, p. 5156.

Clinical efficacy of T-cell therapy after short-term BRAF-inhibitor priming in patients with checkpoint inhibitor-resistant metastatic melanoma

PurposeDespite impressive response rates following adoptive transfer of autologous tumor-infiltrating lymphocytes (TILs) in patients with metastatic melanoma, improvement is needed to increase the efficacy and broaden the applicability of this...

In-depth immune and molecular profiling of melanoma patients receiving adoptive T-cell therapy reveals biomarkers of efficacy in ATATIL study.

2533 Background: Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) has demonstrated a curative potential for patients with metastatic melanoma (MM). Nevertheless, activity remains unsatisfactory in many patients, requiring development of biomarkers that predict therapeutic efficacy. We report results of a single-center phase I study to assess feasibility, safety and efficacy of TIL-ACT in MM patients (NCT03475134). Methods: Patients with MM refractory to at least one prior line of therapy received TIL therapy with lymphodepleting chemotherapy before T-cell infusion, followed by high-dose interleukin-2. RDG- and FDG-PET imaging was performed before and after TIL infusion. Multispectral immuno-fluorescence (mIF) imaging and bulk-RNA sequencing (Seq) were performed on tumor samples pre-ACT and post-ACT (day+30 and upon progression). Single-cell RNA-Seq and TCR-Seq were performed on pre-ACT tumor and ACT product, as well as on tumor-reactive and neoantigen-specific TILs and on longitudinal blood samples. Results: As of 02/02/2021, thirteen patients (enrolled between March 2018 and December 2020) have successfully completed TIL-ACT therapy, with a median follow-up of 9.5 months (IQR 3.0 -24.6). Median age was 53 years (range 20-69) and all were previously treated with PD-1 based blockade. Median number of TILs infused was 55.0 x109 cells (range 12.8-84.7). The best overall response rate by RECIST 1.1 and disease control rate in evaluable patients was 41.7% (5/12) and 50% (6/12) respectively at 3 months. Two patients have an ongoing near-complete response at 3 years. Up to data cut-off, 10 patients have progressed by RECIST v1.1, with median PFS of 4.8 months (95% CI 1.5 - 9.6), while median OS is not reached. mIF revealed biomarkers of response, which may allow proper identification of patients in subsequent studies. In addition, deep sequencing of bulk and neoepitope-specific TIL clonotypes highlighted transcriptomic signatures revealing cell programs regulating in vitro expansion, in vivo blood persistence as well as tumor infiltration post-ACT. RGD-PET data will also be presented. Conclusions: We demonstrate reproducibility of TIL-ACT in our center, consistently with previous reports. Comprehensive translational studies reveal immune correlates of clinical responses that contribute to the understanding of mechanisms of TIL potency and will guide the development of next-generation cell products. Clinical trial information: NCT03475134.

MicroRNA expression patterns in tumor infiltrating lymphocytes are strongly associated with response to adoptive cell transfer therapy.

Adoptive cell transfer (ACT) using autologous tumor infiltrating lymphocytes (TILs) was previously shown to yield clinical response in metastatic melanoma patients as an advanced line. Unfortunately, there is no reliable marker for predicting who will benefit from the treatment. We analyzed TIL samples from the infusion bags used for treatment of 57 metastatic melanoma patients and compared their microRNA profiles. The discovery cohort included six responding patients and seven patients with progressive disease, as defined by RECIST1.1. High throughput analysis with NanoString nCounter demonstrated significantly higher levels of miR-34a-5p and miR-22-3p among TIL from non-responders. These results were validated in TIL infusion bag samples from an independent cohort of 44 patients, using qRT-PCR of the individual microRNAs. Using classification trees, a data-driven predictive model for response was built, based on the level of expression of these microRNAs. Patients that achieved stable disease were classified with responders, setting apart the patients with progressive disease. Moreover, the expression levels of miR-34a-5p in the infused TIL created distinct survival groups, which strongly supports its role as a potential biomarker for TIL-ACT therapy. Indeed, when tested against autologous melanoma cells, miRLow TIL cultures exhibited significantly higher cytotoxic activity than miRHigh TIL cultures, and expressed features of terminally exhausted effectors. Finally, overexpression of miR-34a-5p or miR-22-3p in TIL inhibited their cytotoxic ability in vitro. Overall, we show that a two-microRNA signature correlates with failure of TIL-ACT therapy and survival in melanoma patients.