Change in peripheral blood cytokines. Panel A shows the median change from baseline in peripheral blood cytokine concentration over time by dose of mRNA-2752 in Arm A and Arm B, and panel B shows cytokine fold change relative to C1D1 over time by dose of mRNA-2752 in Arm A and Arm B. Data are shown from samples from 125 patients. C1D1, cycle 1 day 1; IFN-γ, interferon gamma; IL, interleukin; IP-10, IFN-γ–induced protein 10; MCP-1, monocyte chemoattractant protein 1.

Representativeness of the Study Population.

Abstract Oral cavity squamous cell cancer (OCSCC) recurrence is linked to cancer stem cells (CSCs), which persist despite treatment. To enable reproducible CSC studies, we established a scalable system using the commercially available ATCC SCC-9 cell line subjected to physical and metabolic stress gradients—standard monolayer, AggreWell spheroids (moderate stress), and ultra-low attachment (ULA) spheroids (maximal stress)—in both nutrient-rich (RMk media) and nutrient-deficient (CSC media) conditions. SCC-9 cells were expanded in standard tissue culture flasks and seeded at defined concentrations into five experimental conditions: (1) standard attachment monolayer, (2) 24-well AggreWell 400 plates in RMk media, (3) 24-well AggreWell 400 plates in CSC media, (4) ULA plates in RMk media, and (5) ULA plates in CSC media. After four days, spheroids were imaged, dissociated with Accutase, and analyzed for CSC enrichment by flow cytometry. CD44 expression was quantified by median fluorescence intensity (MFI), and increased aldehyde dehydrogenase activity was detected using the Aldefluor assay. MFI for CD44 rose progressively with microenvironmental stress, from 18,340 (monolayer) to 42,924 (ULA plate in CSC media), representing a 2.3-fold increase. The double-positive CSC-like population (CD44high/Aldefluor+) was nearly absent in low-stress monolayer and moderate-stress AggreWell cultures, but increased to 0.12% in ULA RMk and tripled to 0.42% in ULA CSC media. These results demonstrate that both CSC prevalence and marker intensity can be systematically tuned by adjusting physical and metabolic stress. This protocol allows researchers to enhance CSC-like enrichment in a stepwise manner using a widely available OCSCC cell line. The methodology supports applications in drug testing, differentiation studies, and immune interaction assays, leveraging commercial plates and reagents for reproducibility across laboratories. The dynamic range of CSC induction provides a practical tool for studying OCSCC recurrence and therapeutic resistance. Citation Format: Anuleka Elapavaluru, Stephen Keysar, Herman Li, Antonio Jimeno, Minsoo Kim, Farshad N. Chowdhury. Modulating cancer stemness in commercial OCSCC spheroid cultures through microenvironmental stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 749.

PURPOSE:STAT3 is important in promoting a pro-oncogenic tumor microenvironment. This first randomized trial of a STAT3-targeting ASO with pembrolizumab assessed whether this first-line combination would improve outcomes compared with pembrolizumab alone in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS:This multicenter, randomized, open-label, controlled study (NCT05814666) enrolled patients with previously untreated R/M-HNSCC with positive PD-L1 expression (combined positive score [CPS] ≥1). Patients were stratified by CPS (1-19; ≥20) and randomized 2:1 to danvatirsen 3mg/kg IV weekly (with 2 loading doses in week 1) plus pembrolizumab 200mg IV every 3 weeks or pembrolizumab alone. Patients received 21-day treatment cycles until progressive disease, unacceptable toxicity, or voluntary withdrawal. Primary endpoint was overall response rate (ORR: partial + complete response per RECIST-v1.1). RESULTS:69 patients were randomized and 66 treated (51 [77.3%] male), 45 with danvatirsen + pembrolizumab, 21 with pembrolizumab alone. Enrolment was stopped due to lack of response in the CPS 1-19 cohort after ≥1 scan (~6 weeks of treatment) and in the CPS ≥20 cohort after ≥2 scans (~12 weeks). In the final analysis, ORRs were 15.6% and 14.3%, respectively (risk difference 1.3, P=1.0). The treatment-emergent adverse-event rate was increased in the combination arm (97.8% vs 85.7%), and the combination side effect profile was similar to previous danvatirsen studies. CONCLUSIONS:Combination danvatirsen + pembrolizumab did not improve ORR compared to pembrolizumab alone in first-line treatment of R/M-HNSCC. Further exploration of STAT3-targeted approaches is needed within the context of immunotherapy.

Change in proinflammatory cytokine gene expression over time by dose of mRNA-2752 in Arm A and Arm B. Data are shown from 22 patients, and are log2 fold change in gene expression relative to baseline. C1D2, cycle 1 day 2; C1D15, cycle 1 day 15; C2D1, cycle 2 day 1; IL, interleukin; Scr, screening.

PURPOSE:Messenger RNA (mRNA)-2752, a lipid nanoparticle‒encapsulated, mRNA-based therapeutic encoding OX40L, interleukin 36γ (IL-36γ), and IL-23, has demonstrated modulation of the tumor microenvironment (TME) and antitumor efficacy in combination with immune checkpoint inhibitors (CPI) in CPI-resistant models. PATIENTS AND METHODS:In this phase I study (NCT03739931) of intratumoral mRNA-2752 monotherapy (arm A) or mRNA-2752 plus durvalumab (arm B) in advanced solid tumors, the primary objectives were safety, tolerability, determination of maximum tolerated dose (MTD), and objective response rate (ORR) as per Response Evaluation Criteria in Solid Tumors version 1.1 in CPI-resistant melanoma (arm B only). RESULTS:Among 134 patients (arm A, n = 19 and arm B, n = 115), the MTD was not reached; a recommended dose for expansion of ≤8 mg was selected. Dose-limiting toxicities included two grade II cytokine-release syndrome events in arm B. Treatment-related adverse events (AE) were mostly grade I/II; grade III mRNA-2752-related AEs occurred in 1 patient (5.3%) in arm A and 29 patients (25.2%) in arm B. In the CPI-resistant melanoma cohort (n = 28), across doses, the confirmed ORR was 17.9% (95% CI, 6.1%‒36.9%), and the disease control rate was 42.9% (95% CI, 24.5%‒62.8%). Increased peripheral cytokine levels and sustained inflammatory responses in the TME were observed, particularly in patients with an objective response. CONCLUSIONS:mRNA-2752 monotherapy or in combination with durvalumab demonstrated antitumor activity with manageable safety in patients with heavily pretreated, relapsed, or resistant solid tumors, particularly in patients with CPI-resistant melanoma. In addition, biomarker analyses demonstrated a sustained inflammatory response within the TME. Together, these findings support the investigation of mRNA-based therapeutics for patients with advanced cancer.

The NCCN Guidelines for Head and Neck Cancers address tumors arising in the oral cavity (including mucosal lip), pharynx, larynx, and paranasal sinuses, as well as occult primary cancer, salivary gland cancer, and mucosal melanoma (MM). The specific site of disease, stage, and pathologic findings guide treatment (eg, the appropriate surgical procedure, radiation targets, dose and fractionation of radiation, indications for systemic therapy). The NCCN Head and Neck Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding management of nasopharynx cancer and ongoing research in this area.

Change in plasma IFN-γ and IL-23 cytokine and IL-23 mRNA concentration over time in (A) Arm A and (B) Arm B, and IL-23 and IFN-γ AUC at cycle 1 and cycle 2 in (C) Arm A and (D) Arm B, by dose of mRNA-2752. Panels A and C show the change in cytokine (IFN-γ and IL-23) and mRNA (IL-23) concentration (pg/mL) for each participant. Panels B and D show the cycle 1 and cycle 2 AUC of IFN-γ and IL-23 cytokines, where each dot is representative of an individual patient. For panels A and B, the IL-23 analyses dataset included 109 patients, and the IFN-γ analyses included 108 patients. AUC, area under the curve; IFN-γ, interferon gamma; IL, interleukin; mRNA, messenger RNA.

Pharmacokinetic Exposures of mRNA-2752 components (IL-23, IL-36γ, and OX40L) by Dose of mRNA-2752.

A fundamental limitation of HLA-A matched humanized mice (mHM), generated with donor hematopoietic stem and progenitor cells and bearing patient-derived xenografts, is that the fidelity of the interaction between the immune system and implanted tumors is limited by lack of thymic T-cell education. We created a model with patient-matched thymic and tumor tissue by using patient peripheral blood mononuclear cells reprogrammed into induced pluripotent stem cells to generate stem cell-derived thymic organoids (sTOs). When implanted in thymectomized mHM, which were subsequently engrafted with patient melanoma tissue (autologous, or mHMTA), sTOs expressed thymic tissue markers EPCAM, KRT5, and KRT8 and contained developing double-positive T cells. mHMTA had more activated HLA-DR+ T cells in their spleens. Tumor growth in mHMTA was significantly slower compared with mHM, and both tumor volume and viable melanoma content were significantly decreased in mHMTA. This was associated with an increase of intratumoral activated T cells in mHMTA. Whole-exome sequencing followed by intratumoral heterogeneity analysis identified seven candidate neoantigens that were selected against in the mHMTA model, suggesting more effective identification and T cell-driven tumor clearance. This study shows the feasibility of generating patient-specific, thymus-bearing mice and provides a promising new tool in immunology and immunotherapy development.Significance: A humanized mouse xenograft model, in which T cells are educated in a patient-derived implanted thymic organoid autologous to the tumor, provides a more faithful and complete environment to study cancer immunity.

Changes in intratumoral heterogeneity in mHMTA PDXs can be explained by neoAg selection. A, NeoAg distribution across HLA alleles (B) Kullback–Leibler logos show enrichment of hydrophobic amino acids at position 9 in the neoAg pool. The height of each one letter amino acid code is the absolute enrichment relative to unselected peptides. Values above the x axis are positively enriched whereas those below are depleted. C, Distribution of estimated changes in variant allele frequency between the mHMTA and mHM models in all variants identified by exome sequencing. Values to the right of the dotted line represent variants that enriched, or underwent positive selection in mHMTA, whereas values to the left represent variants that underwent negative selection. D, Significant changes between mHM and mHMTA variant allele frequencies are plotted against the predicted HLA binding affinity for nine-mer peptides derived from each variant. The points are colored by which class I HLA molecule the peptide was predicted to bind. All significantly altered variants were found to produce at least two neoAgs. Error bars represent SE. E, Single letter codes for each amino acid are shown with the mutant residue outlined in each. The majority of mutations occurred at TCR contact residue locations (positions 3–8).

Background:Disparities in cancer outcomes persist between racial, ethnic, and socioeconomic groups. One potential cause is lack of appropriate representation in dose-finding clinical trials. We investigated the extent of disparities in phase I clinical trials and recent changes in the setting of institutional efforts to mitigate disparities, legislative interventions, FDA guidance for sponsors and the COVID-19 pandemic. Methods:We performed a retrospective review of patients enrolled in phase I clinical trials at the University of Colorado Cancer Center in 2018-2019 and 2022-2023. We collected demographics, area deprivation index (ADI), tumor type and other clinical variables. Differences between cohorts were evaluated with t-tests, chi-Square test, or Fisher exact test. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Hazard ratios (HR), confidence intervals (CI) and p-values were derived using the Cox-proportional hazards method. Results:A total of 361 patients were included (209 and 152 in the 2018-2019 and 2022-2023 cohorts, respectively). The population consisted of 85.0% White, 3.3% Asian, 1.4% Black, 0.3% Native Hawaiian or Pacific Islander and no American Indian/Alaskan Native (AIAN) patients by race, and 9.1% Hispanic by ethnicity. The most common tumor type was colorectal cancer (18.3%). Compared to 2018-2019, we observed increases in non-English speakers from 1.9% (4/209) to 6.6% (10/152) (p = 0.028) and in translated informed consent forms (ICFs) from 1.4% (3/209) to 5.9% (9/152) (p = 0.033) in 2022-2023. There were no significant changes in race, ethnicity, insurance, or tumor type, although there was a moderate increase in Hispanic patients from 8.1% to 10.5%. There were no differences in clinical outcomes by race, ethnicity, or ADI scores in the overall study population. However, in the most common cancer type, colorectal cancer, higher ADI scores were associated with decreased median PFS and OS. Conclusion:The interventions resulted in an increase in accrual of non-English speaking patients, however, there was not yet a significant change in overall race and ethnicity. Our study confirms poorer outcomes for patients with higher ADI scores. Further research is warranted to understand disparities in clinical trial accrual, and intervention is needed to improve outcomes for disadvantaged patients.

BACKGROUND:mRNA-2416 is a novel lipid nanoparticle-encapsulated messenger RNA (mRNA) encoding human OX40 ligand (OX40L) for intratumoral (Itu) injection. OX40L plus immune checkpoint inhibitor (ICI) increased preclinical antitumor activity, thus mRNA-2416 plus ICI may potentiate antitumor activity. METHODS:This first-in-human, phase I/II, open-label, multicenter study examined the safety, tolerability, and efficacy of mRNA-2416 alone (arm A) or with durvalumab (arm B) in patients with advanced solid tumors or lymphoma (NCT03323398). Phase I primary objectives included assessment of safety/tolerability and maximum tolerated dose (MTD)/recommended dose for expansion; phase II arm B dose expansion assessed objective response rate in ovarian cancers. Secondary objectives included pharmacokinetics, disease control rate, duration of response, and progression-free survival (PFS). Assessments of immunologic response to treatment were exploratory. RESULTS:From August 2017 to August 2021, 79 patients were enrolled; 61 received treatment (arm A: 39, arm B: 22), including 16 in the expansion cohort. MTD was not reached. Treatment-related emergent adverse events were primarily grade 1/2, with 8 grade 3 and no grade 4/5 events. On-treatment tumor biopsies demonstrated increased OX40L protein expression, elevated PD-L1, and proinflammatory responses. Tumor shrinkage occurred in injected and surrounding non-injected tumors. Median (95% CI) PFS was 60.0 (50.0 to 108.0) and 50.0 (38.0 to 55.0) days for arms A and B, respectively. CONCLUSIONS:mRNA-2416 alone or with durvalumab was well tolerated. Pharmacodynamic analyses support Itu mRNA proof-of-concept. Predefined primary efficacy endpoints were not met in an exploratory cohort of ovarian cancer. Additional research is warranted to further inform this therapeutic approach.

Background Recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC) has a high recurrence rate after first-line immunotherapy or chemoimmunotherapy. The presence of a high density of tumor-infiltrating lymphocytes (TILs) in HNSCC tumors was shown to be associated with improved clinical outcomes. One-time autologous TIL cell therapy was evaluated in patients with recurrent and/or metastatic HNSCC.Methods C-145-03 (NCT03083873) was a phase 2 study of TIL in patients with recurrent and/or metastatic HNSCC assigned to 1 of 4 treatment cohorts: cohort 1, non-cryopreserved TIL; cohort 2, cryopreserved lifileucel (22-day manufacturing); cohort 3, cryopreserved lifileucel (16-day manufacturing); cohort 4, cryopreserved LN-145-S1 programmed cell death protein-1 (PD-1) selected. Patients underwent tumor resection for TIL generation. After preparative non-myeloablative lymphodepletion, patients received a single infusion of TIL followed by interleukin-2 (IL-2) infusion(s). The primary endpoint was investigator-assessed objective response rate (ORR) per Response Evaluation Criteria for Solid Tumors (RECIST) V.1.1. Secondary endpoints were investigator-assessed duration of response (DOR), disease control rate (DCR), progression-free survival, overall survival, and incidence of treatment-emergent adverse events.Results Overall, 53 patients received TIL: cohort 1 (n=8), cohort 2 (n=17), cohort 3 (n=16), cohort 4 (n=12). Median age was 57 years and most patients were males (87%; 46/53) with stage IV disease (98%; 52/53). Patients had a median of two prior lines of systemic therapy; 87% (46/53) of patients had prior anti-PD-1/programmed cell death ligand-1 therapy and 72% (38/53) had prior chemotherapy. The ORR was 11% (6/53) with six patients achieving partial response (cohort 1, n=3; cohort 2, n=1; cohort 4, n=2). At median follow-up of 17.9 months, the median DOR was 7.6 months. The DCR was 76% (40/53); 64% (34/53) of patients had stable disease. The safety profile was consistent with known toxicities associated with non-myeloablative lymphodepletion and IL-2 administration.Conclusions This study demonstrated the feasibility of consistently generating sufficient TIL from HNSCC tumors. Results from this study suggest TIL cell therapy may serve as a potential treatment option for patients with HNSCC and support further development, including TIL cell therapy combined with immune checkpoint inhibitors or other agents or with other TIL products.Trial registration number NCT03083873.

Interleukin (IL)-1 signaling has an essential role in tumor progression and immunosuppression and is linked to acquired resistance to anti-PD-1/PD-L1 treatment. Nadunolimab is an IL1RAP (IL-1 receptor accessory protein)-targeting antibody that blocks IL-1α/IL-1β signaling and has enhanced antibody-dependent cellular cytotoxicity. We investigated the safety and preliminary efficacy of nadunolimab with pembrolizumab in patients with metastatic solid tumors who had progressed on previous checkpoint inhibitor treatment, suggesting acquired checkpoint inhibitor resistance (NCT04452214). This phase 1b trial enrolled patients with metastatic disease who had exhausted or declined standard-of-care alternatives. Patients received nadunolimab (5 mg/kg) and standard-dose pembrolizumab. The primary objective was to assess safety. Secondary objectives were anti-tumor response as per iRECIST, pharmacokinetics, and changes in immune mediators. Fifteen patients with stage IV cancer (head and neck squamous cell carcinoma, non-small cell lung cancer, melanoma) entered the trial. Grade ≥ 3 adverse events were reported for 7 patients (47

Examination of T-cell development and activity in the mHMTA. A, Representative cytometry of the human CD45+ cells and HSPCs present in mHM and mHMTA bone marrow. B, Comparison of the average percentage of human CD45+ cells and CD34+ HSPCs within this CD45+ cell population within mHM and mHMTA bone marrow (P = 0.118 and 0.379, respectively, Wilcoxon rank-sum test). C, Comparison of peripheral human CD45+ lymphocytes in mHM and mHMTA (P = 0.728, Wilcoxon rank-sum test) and of CD19+ B cells in mHM and mHMTA (0.224, Wilcoxon rank-sum test). D, Cytometric analysis and a comparison of human CD45+ cells, as well as T-cell and B-cell populations, found in the spleens of mHM and mHMTA. E, Comparison of the average human CD45+ cell populations, human T cells, and human B cells on mHM and mHMTA spleens (P = 0.844, 0.450, and 0.646, Wilcoxon rank-sum test, respectively). F, IFNγ expression was detected in the spleen of both mHM and mHMTA (P < 0.005). G, Gating and representative cytometry of T cells in mHM and mHMTA show relative populations used to analyze T-cell activation. Purple boxes in the first panels show the T-cell populations gated in the remaining scatter plots. The red boxes show the CD8+ T-cell populations gated for subsequent analysis. H, Representative cytometry of the CD8+ T cells, gated from the red boxes in the previous panel. I, Comparisons of the ratio of HLA-DR + PD1– T cells with all HLA-DR+ T cells shows an increasingly activated T-cell population in mHMTA (P = 0.0207, two-group t test) and a nonsignificantly increased population of CD4+ T cells. J, Comparison of the HLA-DR + PD1– population with the total HLA-DR+ T-cell population among CD8+ T cells also reveals a trend toward increased activation in mHMTA. P values: *, ≤0.05.

The NCCN Guidelines for Head and Neck Cancers address tumors arising in the oral cavity (including mucosal lip), pharynx, larynx, and paranasal sinuses, as well as occult primary cancer, salivary gland cancer, and mucosal melanoma (MM). The specific site of disease, stage, and pathologic findings guide treatment (eg, the appropriate surgical procedure, radiation targets, dose and fractionation of radiation, indications for systemic therapy). The NCCN Head and Neck Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding management of nasopharynx cancer and ongoing research in this area.

3517 Background: DSP107 is a bi-specific fusion protein composed of sequences from the extracellular domain of SIRPα and 4-1BBL. The SIRPα arm selectively targets CD47 overexpressed on tumor cells, while simultaneously anchoring trimeric 4-1BBL to the tumor, to engage and co-stimulate 4-1BB on activated immune cells in the tumor microenvironment. This results in tumor-localized, conditional activation of innate and adaptive immune responses. Phase 1 data demonstrated an excellent safety profile with no RBC binding and no hematological, hepatic or other dose limiting toxicities (DLTs). Here we describe safety and efficacy data from a Phase 2 microsatellite stable (MSS) colorectal (CRC) expansion cohort in which patients were treated with DSP107 alone or with atezolizumab (NCT04440735). Methods: Metastatic/unresectable MSS CRC patients who progressed following 2 lines of therapy including standard chemotherapy ± targeted antibodies (n = 50), were randomized to receive weekly IV DSP107 infusions (10 mg/kg/dose) alone or with atezolizumab (1200 mg) Q3W during 3-week treatment cycles. The majority (76%) had liver metastases. Study objectives were safety, tolerability and preliminary efficacy. Restaging imaging was performed every 2 months and evaluated by RECIST v1.1 criteria. Results: DSP107 monotherapy and with atezolizumab was well tolerated with no DLTs. The most frequent TRAEs were infusion-related reactions (IRR; 38% Grade 1 or 2, 4% Grade 3), fatigue (12% Grade 1 or 2, 4% Grade 3), Grade 1 or 2 nausea (14%) and Grade 1 or 2 anemia (10%). IRRs were managed during subsequent infusions by reducing the infusion rate and administering IV fluids. The median OS from the efficacy-evaluable patients who received DSP107 monotherapy (n = 19) and combination therapy with atezolizumab (n = 21) has not been reached but currently (Dec 2024 cutoff) stands at 7.6 and 14.6 months, respectively. Disease control was demonstrated in 26% (monotherapy) and 62% (combination) of evaluable patients including a patient who achieved complete response ( > 2.5 years) and a patient with a deep (86% target lesion reduction) and durable ( > 16 months) confirmed partial response and disappearance of pulmonary and hepatic metastases. Immunofluorescence analysis of baseline tumor biopsies (n = 16) demonstrated moderate to high levels of CD47 expression in 15/16 biopsies ( > 120 H-Score), and very high levels of CD47 expression ( > 170 H-Score) in all 7 samples collected from liver metastases. Conclusions: These data suggest that the combination of DSP107 with PD(L)1 blockade has anti-tumor activity and provides clinical benefit in third line metastatic MSS CRC including in patients with liver metastases. Updated survival data will be presented at the conference. A Phase 2 randomized controlled study is currently in planning to confirm this preliminary efficacy signal. Clinical trial information: NCT04440735 .