Weitiao No. 3 (3) enhances the efficacy of anti-programmed cell death protein-1 immunotherapy by modulating the intestinal microbiota in an orthotopic model of gastric cancer mice.

OBJECTIVE: To explore the effects of Weitiao No. 3 (3, WD-3) on anti-programmed cell death protein-1 (PD-1) immunotherapy in gastric cancer (GC). METHODS: The intestinal microbiota was analyzed by 16S rDNA sequencing of fecal samples from three groups: healthy people (Health), GC patients (GC), and WD-3-treated GC patients (WD-3). Next, we established an orthotopic model of GC mice, which were treated with anti-PD-1, WD-3, or an inoculation of intestinal bacteria. Immune markers CD3, CD4, CD8, and forkhead box protein P3 (FOXP3), and the cell proliferation marker Ki67, were evaluated by immunohistochemistry. Cell apoptosis in GC tumors was assessed by terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling staining. Enzyme-linked immunosorbent assays (ELISAs) were performed to analyze the serum levels of the following cytokines in GC mice: tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-6, IL-10, interferon (IFN)-γ, and transforming growth factor (TGF)-ß. RESULTS: Sequencing data showed that there were significant differences in the composition of the gut microbial community among the three human groups. The gut bacteria in the three groups mainly comprised the phyla Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. At the genus level, the relative abundances of Bifidobacterium and Coprococcus showed significant decreases in the GC group, and an obvious increase in the WD-3 group, compared with the Health group. Interestingly, the relative abundance of Saccharopolyspora was only detected in the WD-3 group. The results of in vivo experiments in GC mice showed that WD-3 or anti-PD-1 treatment increased the levels of CD3+, CD4+, and CD8+ T cells, but decreased the levels of FOXP3+ regulatory T cells. Furthermore, WD-3 or PD-1 antibody treatment inhibited proliferation and promoted apoptosis of GC tumor cells. ELISA analysis showed that WD-3 or PD-1 antibody treatment facilitated TNF-α, IL-2, and IFN-γ expression, while suppressing IL-6, IL-10, and TGF-ß expression. Combination therapy with WD-3 and anti-PD-1 intensified all of these effects. CONCLUSION: WD-3 enhanced the immunotherapeutic efficacy of anti-PD-1 by modulating the intestinal microbiota in an orthotopic model of GC mice.

Pharmacokinetics, safety, and efficacy of an alternative dosing regimen of sasanlimab in participants with advanced NSCLC and other malignancies.

Background: Sasanlimab (PF-06801591), a humanized immunoglobulin G4 monoclonal antibody, binds to programmed cell death protein-1 (PD-1), preventing ligand (PD-L1) interaction. Objectives: To evaluate pharmacokinetics (PK), safety, tolerability, and efficacy of two subcutaneous sasanlimab dosing regimens. Design: An open-label study consisting of phases Ib and II. Phase Ib: non-randomized, dose escalation, and expansion study in Asian participants with advanced malignancies. Phase II: conducted globally in participants with non-small-cell lung cancer with PD-L1 positive or PD-L1 status unknown tumors; participants were randomized 1:2 to receive subcutaneous sasanlimab 300 mg once every 4 weeks (300 mg-Q4W) or 600 mg once every 6 weeks (600 mg-Q6W). Methods: Primary endpoint in phase Ib: dose-limiting toxicity (DLT) occurring in first treatment cycle; in phase II: C trough and AUC. Results: A total of 155 participants (phase Ib, n = 34; phase II, n = 121) received sasanlimab. Phase Ib: no DLT reported. Phase II: ratio of adjusted geometric mean for AUCtau was 231.2 (90% CI, 190.1-281.2) and C trough was 111.5 (90% CI, 86.3-144.0) following 600 mg-Q6W (test) versus 300 mg-Q4W (reference). Phase Ib: grade 3 treatment-related adverse events (TRAEs) occurred in 1/4 (25%) and 3/12 (25%) participants treated in 300 mg-Q4W dose escalation and expansion cohorts, respectively. Phase II: grade 3 TRAEs occurred in 3/41 (7.3%) and 3/80 (3.8%) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively; no grade 4/5 TRAEs. Phase II: confirmed objective response was observed in 11/41 (26.8% (95% CI, 14.2-42.9)) and 12/80 (15.0% (95% CI, 8.0-24.7)) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively. Conclusions: Phase Ib regimens were considered safe with no DLTs reported. In phase II, 600 mg-Q6W regimen criteria were met for AUCtau and C trough metrics to support PK-based extrapolation of efficacy of alternative regimen. Regimens were well tolerated, showing anti-tumor activity in participants with advanced solid tumors. Administration of sasanlimab at a dose of 600 mg-Q6W subcutaneously may serve as a convenient alternative to 300 mg-Q4W administration. Trial registration: NCT04181788 (ClinicalTrials.gov); 2019-003818-14 (EudraCT).

Construction and validation of a synthetic phage-displayed nanobody library.

Nanobodies derived from camelids and sharks offer unique advantages in therapeutic applications due to their ability to bind to epitopes that were previously inaccessible. Traditional methods of nanobody development face challenges such as ethical concerns and antigen toxicity. Our study presents a synthetic, phagedisplayed nanobody library using trinucleotide-directed mutagenesis technology, which allows precise amino acid composition in complementarity-determining regions (CDRs), with a focus on CDR3 diversity. This approach avoids common problems such as frameshift mutations and stop codon insertions associated with other synthetic antibody library construction methods. By analyzing FDA-approved nanobodies and Protein Data Bank sequences, we designed sub-libraries with different CDR3 lengths and introduced amino acid substitutions to improve solubility. The validation of our library through the successful isolation of nanobodies against targets such as PD-1, ATXN1 and STAT3 demonstrates a versatile and ethical platform for the development of high specificity and affinity nanobodies and represents a significant advance in biotechnology.

Construction of a nomogram with IrAE and clinic character to predict the survival of advanced G/GEJ adenocarcinoma patients undergoing anti-PD-1 treatment.

Objective: This study aimed to develop and validate a survival prediction model and nomogram to predict survival in patients with advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma undergoing treatment with anti-programmed cell death 1 receptor (PD-1). This model incorporates immune-related adverse events (irAEs) alongside common clinical characteristics as predictive factors. Method: A dataset comprising 255 adult patients diagnosed with advanced G/GEJ adenocarcinoma was assembled. The irAEs affecting overall survival (OS) to a significant degree were identified and integrated as a candidate variable, together with 12 other candidate variables. These included gender, age, Eastern cooperative oncology group performance status (ECOG PS) score, tumor stage, human epidermal growth factor receptor 2 (HER2) expression status, presence of peritoneal and liver metastases, year and line of anti-PD-1 treatment, neutrophil-to-lymphocyte ratio (NLR), controlling nutritional status (CONUT) score, and Charlson comorbidity index (CCI). To mitigate timing bias related to irAEs, landmark analysis was employed. Variable selection was performed using the least absolute shrinkage and selection operator (LASSO) regression to pinpoint significant predictors, and the variance inflation factor was applied to address multicollinearity. Subsequently, a Cox regression analysis utilizing the forward likelihood ratio method was conducted to develop a survival prediction model, excluding variables that failed to satisfy the proportional hazards (PH) assumption. The model was developed using the entire dataset, then internally validated through bootstrap resampling and externally validated with a cohort from another Hospital. Furthermore, a nomogram was created to delineate the predictive model. Results: After consolidating irAEs from the skin and endocrine systems into a single protective irAE category and applying landmark analysis, variable selection was conducted for the prognostic prediction model along with other candidate variables. The finalized model comprised seven variables: ECOG PS score, tumor stage, HER2 expression status in tumor tissue, first-line anti-PD-1 treatment, peritoneal metastasis, CONUT score, and protective irAE. The overall concordance index for the model was 0.66. Calibration analysis verified the model's accuracy in aligning predicted outcomes with actual results. Clinical decision curve analysis indicated that utilizing this model for treatment decisions could enhance the net benefit regarding 1- and 2-year survival rates for patients. Conclusion: This study developed a prognostic prediction model by integrating common clinical characteristics of irAEs and G/GEJ adenocarcinoma. This model exhibits good clinical practicality and possesses accurate predictive ability for overall survival OS in patients with advanced G/GEJ adenocarcinoma.

Successful Treatment of Cutaneous Squamous Cell Cancer with Cemiplimab-A Report of Two Cases Demonstrating the Management of Pseudoprogression and Adverse Events.

Background: Cutaneous squamous cell carcinoma is a common malignancy, which frequently develops in the areas exposed to the sun. Patients with locally advanced disease in the head and neck region are frequently disqualified from surgical resection and require systemic treatment. Methods: In this report, we present the clinicopathological features and treatment of two patients who received cemiplimab, a monoclonal antibody targeting programmed cell death receptor 1 (PD-1). Results: An 80-year-old female and 82-year-old male patient were admitted to the hospital for the treatment of large tumors diagnosed as squamous cell carcinomas. In both patients, surgical treatment was not recommended due to the large dimensions of the tumors. These patients qualified for systemic treatment with cemiplimab. In the first patient, immunotherapy was interrupted due to adverse events. Nevertheless, a continuous regression of the tumor was observed despite treatment cessation. The second patient experienced a pseudoprogression, which is an increase in the tumor size caused by infiltration of immune cells. The treatment significantly reduced tumor size in both patients, which highly improved their quality of life. Conclusions: Cemiplimab offers clinical benefits in patients with cutaneous squamous cell carcinoma who are ineligible for surgical treatment. Systemic treatment can significantly improve the quality of life and reduce tumor diameters.

Epidermal growth factor receptor and programmed cell death-1 expression levels in peripheral T cell subsets of patients with non-small cell lung cancer.

Lung cancer is the leading cause of cancer-related deaths, in part due to its late diagnosis. Increased epidermal growth factor receptor (EGFR) expression in cancer cells is associated with a poor prognosis, and EGFR tyrosine kinase inhibitors are widely used in cancer treatment. This study aimed to clarify the relationship between EGFR expression on T cells and cancer prognosis in patients with non-small cell lung cancer (NSCLC). Forty patients with NSCLC and 40 healthy volunteers were included in this study. Peripheral CD4+T helper (Th1, Th2, Th9, Th17, Th1Th17, follicular and peripheral Th) and cytotoxic T lymphocyte (CD8+follicular and peripheral T) subsets were identified with flow cytometry according to their chemokine receptors. EGFR expression on T lymphocytes in relation to overall survival (OS) was investigated in patients with NSCLC. The patients [mean age (min-max) = 64.03 (45-83); 20 stage I-III and 20 stage IV] had increased EGFR expression on CD3+T, CD4+Th, Th1, Th2, and Th17 cells compared to the controls (p < 0.05). High EGFR expression on CD3+T, CD4+Th, Th1, and Th2 cells was associated with poor OS. Also, PD-1 expression on lymphocytes, CD3+T, and Th cells was increased in patients with NSCLC compared to controls. The high expression of EGFR and PD-1 on Th cells and the reduced percentage of lymphocytes and Th cells, especially in stage IV patients with NSCLC, revealed that increased EGFR activity may trigger apoptosis of Th cells and promote the development of metastases, while high EGFR expression on CD3+T, CD4+Th, Th1, and Th2 cells may be an independent poor prognostic marker in NSCLC.

Tislelizumab in previously treated, locally advanced unresectable/metastatic microsatellite instability-high/mismatch repair-deficient solid tumors.

Objective: The open-label, phase II RATIONALE-209 study evaluated tislelizumab (anti-programmed cell death protein 1 antibody) as a tissue-agnostic monotherapy for microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) tumors. Methods: Adults with previously treated, locally advanced unresectable or metastatic MSI-H/dMMR solid tumors were enrolled. Patients received tislelizumab 200 mg intravenously every 3 weeks. Objective response rate (ORR; primary endpoint), duration of response (DoR), and progression-free survival (PFS) were assessed by independent review committee (Response Evaluation Criteria in Solid Tumors v1.1). Results: Eighty patients were enrolled and treated; 75 (93.8%) patients had measurable disease at baseline. Most had metastatic disease and received at least one prior therapy for advanced/metastatic disease (n=79; 98.8%). At primary analysis (data cutoff July 8, 2021; median follow-up 15.2 months), overall ORR [46.7%; 95% confidence interval (95% CI), 35.1-58.6; one-sided P<0.0001] and ORR across tumor-specific subgroups [colorectal (n=46): 39.1% (95% CI, 25.1-54.6); gastric/gastroesophageal junction (n=9): 55.6% (95% CI, 21.2-86.3); others (n=20): 60.0% (95% CI, 36.1-80.9)] were significantly greater with tislelizumab vs. a prespecified historical control ORR of 10%; five (6.7%) patients had complete responses. Median DoR, PFS, and overall survival were not reached with long-term follow-up (data cutoff December 5, 2022; median follow-up 28.9 months). Tislelizumab was well tolerated with no unexpected safety signals. Treatment-related adverse events (TRAEs) of grade ≥3 occurred in 53.8% of patients; 7.5% of patients discontinued treatment due to TRAEs. Conclusions: Tislelizumab demonstrated a significant ORR improvement in patients with previously treated, locally advanced unresectable or metastatic MSI-H/dMMR tumors and was generally well tolerated.

Spore Oil enhances the effect of cyclophosphamide inhibiting programmed death-1 and prolongs the survival of H22 tumor-bearing mice.

OBJECTIVE: To investigate the effect of Ganoderma Lucidum Spore Oil (GLSO) on the tumor growth and survival of H22 tumor-bearing mice treated with cyclophosphamide (CTX), and explore the underlying mechanism. METHODS: Allograft H22 hepatocellular carcinoma mouse model was applied to investigate the effect of GLSO on the tumor growth and survival of animals, and Kaplan-Meier survival analysis was used to analyze the life span. Plasma biochemical examination was used to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea (UREA) and creatinine (CRE). Western blot analysis was performed to detect Programmed Death-1 (PD-1), Programmed Death Ligand 1 (PD-L1), Janus Kinase 2 (JAK2), phosphorylated Signal Transducer and Activator of Transcription 3 (p-STAT3), and Signal Transducer and Activator of Transcription 3 (STAT3) expression. RESULTS: GLSO increased the anti-tumor effect of CTX and prolonged the survival of H22 tumor-bearing mice treated with CTX. Meanwhile, GLSO increased the thymus index and showed no obvious toxicity to liver functions of animals. GLSO also decreased the level of UREA in H22 tumor-bearing mice treated with CTX. Furthermore, GLSO could inhibit the expression of PD-1 in spleen, which was independent of JAK2 expression and STAT3 phosphorylation. However, GLSO did not affect the expression of PD-L1, JAK2, and p-STAT3 in tumor tissue. CONCLUSION: GLSO could strengthen the anti-tumor effect of CTX and prolong the life span of H22 tumor-bearing mice, while the underlying mechanism might be relevant to the amelioration effect of thymus function and inhibition of PD-1 expression in spleen. Furthermore, these findings implied the promising role of GLSO in combination with CTX to extend the survival of patients in clinical chemotherapy of hepatocellular carcinoma.

SIRPG expression positively associates with an inflamed tumor microenvironment and response to PD-1 blockade.

BACKGROUND: This study aimed to investigate the relationship between signal regulatory protein gamma (SIRPG) and tumor immune microenvironment phenotypes or T cell mediated-adaptive antitumor immunity, and its predictive value for response to PD-1 blockade in cancers. METHODS: Pan-cancer analysis of SIRPG expression and immune deconvolution was performed using transcriptomic data across 33 tumor types. Transcriptomic and clinical data from 157 patients with non-small-cell lung cancer (NSCLC) and melanoma received PD-1 blockade were analyzed. Expression characteristics of SIRPG were investigated using single-cell RNA sequencing (scRNA-seq) data of 103,599 cells. The effect of SIRPG expression was evaluated via SIRPG knockdown or overexpression in Jurkat T cells. RESULTS: The results showed that most cancers with high SIRPG expression had significantly higher abundance of T cells, B cells, NK cells, M1 macrophages and cytotoxic lymphocytes and increased expression level of immunomodulatory factors regulating immune cell recruitment, antigen presentation, T cell activation and cytotoxicity, but markedly lower abundance of neutrophils, M2 macrophages, and myeloid-derived suppressor cells. High SIRPG expression was associated with favorable response to PD-1 blockade in both NSCLC and melanoma. scRNA-seq data suggested SIRPG was mainly expressed in CD8+ exhausted T and CD4+ regulatory T cells, and positively associated with immune checkpoint expression including PDCD1 and CTLA4. In vitro test showed SIRPG expression in T cells could facilitate expression of PDCD1 and CTLA4. CONCLUSION: High SIRPG expression is associated with an inflamed immune phenotype in cancers and favorable response to PD-1 blockade, suggesting it would be a promising predictive biomarker for PD-1 blockade and novel immunotherapeutic target.

Safety of pembrolizumab as adjuvant therapy in a pooled analysis of phase 3 clinical trials of melanoma, non-small cell lung cancer, and renal cell carcinoma.

BACKGROUND: The safety profile of adjuvant pembrolizumab was evaluated in a pooled analysis of 4 phase 3 clinical trials. METHODS: Patients had completely resected stage IIIA, IIIB, or IIIC melanoma per American Joint Committee on Cancer, 7th edition, criteria (AJCC-7; KEYNOTE-054); stage IIB or IIC melanoma per AJCC-8 (KEYNOTE-716); stage IB, II, or IIIA non-small cell lung cancer per AJCC-7 (PEARLS/KEYNOTE-091); or postnephrectomy/metastasectomy clear cell renal cell carcinoma at increased risk of recurrence (KEYNOTE-564). Patients received adjuvant pembrolizumab 200 mg (2 mg/kg up to 200 mg for pediatric patients) or placebo every 3 weeks for approximately 1 year. Adverse events (AEs) were summarized for patients who received ≥ 1 dose of treatment. RESULTS: Data were pooled from 4125 patients treated with pembrolizumab (n = 2060) or placebo (n = 2065). Median (range) duration of treatment was 11.1 months (0.0-18.9) with pembrolizumab and 11.2 months (0.0-18.1) with placebo. Treatment-related AEs occurred in 78.6 % (1620/2060) of patients in the pembrolizumab group (grade 3-5, 16.3 % [336/2060]) and 58.7 % (1212/2065) in the placebo group (grade 3-5, 3.5 % [72/2065]). Immune-mediated AEs (e.g. adrenal insufficiency, hypophysitis, and thyroiditis) occurred in 36.2 % (746/2060) of patients in the pembrolizumab group (grade 3-5, 8.6 % [177/2060]) and 8.4 % (174/2065) in the placebo group (grade 3-5, 1.1 % [23/2065]). Of patients with ≥ 1 immune-mediated AE or infusion reaction, systemic corticosteroids were required for 35.2 % (268/761) and 20.2 % (39/193) of patients in the pembrolizumab and placebo groups, respectively. CONCLUSIONS: Adjuvant pembrolizumab demonstrated a manageable safety profile that was comparable to prior reports in advanced disease.

Immunotherapy in the neoadjuvant treatment of gastrointestinal tumors: is the time ripe?

Immune checkpoint inhibitors (ICIs) revolutionized the management of mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) gastrointestinal (GI) cancers. Based on notable results observed in the metastatic setting, several clinical trials investigated ICIs as neoadjuvant treatment (NAT) for localized dMMR/MSI-H GI cancers, achieving striking results in terms of clinical and pathological responses and creating the opportunity to spare patients from neoadjuvant chemotherapy and/or radiotherapy and even surgical resection. Nevertheless, these impressive findings are mainly derived from small proof of concept phase II studies and there are still several open questions to address. Moreover, dMMR/MSI-H represents a limited subgroup accounting for less than 10% of GI cancers. Consequently, many efforts have been produced to investigate neoadjuvant ICIs also in mismatch repair-proficient/microsatellite stable (MSS) cancers, considering the potential synergistic effect in combining immune-targeted agents with standard therapies such as chemo and/or radiotherapy. However, results for combining ICIs to the standard of care in the unselected population are still unsatisfactory, without improvements in event-free survival in esophago-gastric adenocarcinoma for the addition of pembrolizumab to chemotherapy, and sometimes limited benefit in patients with locally advanced rectal cancer. Therefore, a major challenge will be to identify among the heterogenous spectrum of this disease, those patients that could take advantage of neoadjuvant immunotherapy and deliver the most effective treatment. In this review we discuss the rationale of NAT in GI malignancies, summarize the available evidence regarding the completed trials that evaluated this treatment strategy in both MSI-H and MSS tumors. Finally, we discuss ongoing studies and future perspectives to render neoadjuvant immunotherapy another arrow in the quiver for the treatment of locally advanced GI tumors.

Oral PD-L1 inhibitor GS-4224 selectively engages PD-L1 high cells and elicits pharmacodynamic responses in patients with advanced solid tumors.

BACKGROUND: Checkpoint inhibitors targeting the programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) pathway are effective therapies in a range of immunogenic cancer types. Blocking this pathway with an oral therapy could benefit patients through greater convenience, particularly in combination regimens, and allow flexible management of immune-mediated toxicities. METHODS: PD-L1 binding activity was assessed in engineered dimerization and primary cell target occupancy assays. Preclinical antitumor activity was evaluated in ex vivo and in vivo human PD-L1-expressing tumor models. Human safety, tolerability, pharmacokinetics, and biomarker activity were evaluated in an open-label, multicenter, sequential dose-escalation study in patients with advanced solid tumors. Biomarkers evaluated included target occupancy, flow cytometric immunophenotyping, plasma cytokine measurements, and T-cell receptor sequencing. RESULTS: GS-4224 binding caused dimerization of PD-L1, blocking its interaction with PD-1 and leading to reversal of T-cell inhibition and increased tumor killing in vitro and in vivo. The potency of GS-4224 was dependent on the density of cell surface PD-L1, with binding being most potent on PD-L1-high cells. In a phase 1 dose-escalation study in patients with advanced solid tumors, treatment was well tolerated at doses of 400-1,500 mg once daily. Administration of GS-4224 was associated with a dose-dependent increase in plasma GS-4224 exposure and reduction in free PD-L1 on peripheral blood T cells, an increase in Ki67 among the PD-1-positive T-cell subsets, and elevated plasma cytokines and chemokines. CONCLUSIONS: GS-4224 is a novel, orally bioavailable small molecule inhibitor of PD-L1. GS-4224 showed evidence of expected on-target biomarker activity, including engagement of PD-L1 and induction of immune-related pharmacodynamic responses consistent with PD-L1 blockade. TRIAL REGISTRATION NUMBER: NCT04049617.

Association between programmed cell death ligand-1 expression in patients with cervical cancer and apparent diffusion coefficient values: a promising tool for patient´s immunotherapy selection.

OBJECTIVE: To investigate the associations between apparent diffusion coefficient (ADC) values extracted from three different region of interest (ROI) position approaches and programmed cell death ligand-1 (PD-L1) expression, and evaluate the performance of the nomogram established based on ADC values and clinicopathological parameters in predicting PD-L1 expression in cervical cancer (CC) patients. METHODS: Through retrospective recruitment, a training cohort of 683 CC patients was created, and a validation cohort of 332 CC patients was prospectively recruited. ROIs were delineated using three different methods to measure the mean ADC (ADCmean), single-section ADC (ADCss), and the minimum ADC of tumors (ADCmin). Logistic regression was employed to identify independent factors related to PD-L1 expression. A nomogram was drawn based on ADC values combined with clinicopathological features, its discrimination and calibration performances were estimated using the area under the curve (AUC) of receiver operating characteristic and calibration curve. The clinical benefits were evaluated by decision curve analysis. RESULTS: The ADCmin independently correlated with PD-L1 expression. The nomogram constructed with ADCmin and other independent clinicopathological-related factors: FIGO staging, pathological grade, parametrial invasion, and lymph node status demonstrated excellent diagnostic performance (AUC = 0.912 and 0.903, respectively), good calibration capacities, and greater net benefits compared to the clinicopathological model in both the training and validation cohorts. CONCLUSION: ADCmin independently correlated PD-L1 expression, and the nomogram established with ADCmin and clinicopathological independent prognostic factors had a strong predictive performance for PD-L1 expression, thereby serving as a promising tool for selecting cases eligible for immunotherapy. CLINICAL RELEVANCE STATEMENT: The minimum ADC can serve as a reliable imaging biomarker related to PD-L1 expression; the established nomogram combines the minimum ADC and clinicopathological factors that can assist clinical immunotherapy decisions.

Digital spatial proteomic profiling reveals immune checkpoints as biomarkers in lymphoid aggregates and tumor microenvironment of desmoplastic melanoma.

BACKGROUND: Desmoplastic melanoma (DM) is a rare melanoma subtype characterized by dense fibrous stroma, a propensity for local recurrence, and a high response rate to programmed cell death protein 1 (PD-1) blockade. Occult sentinel lymph node positivity is significantly lower in both pure and mixed DM than in conventional melanoma, underscoring the need for better prognostic biomarkers to inform therapeutic strategies. METHODS: We assembled a tissue microarray comprising various cores of tumor, stroma, and lymphoid aggregates from 45 patients with histologically confirmed DM diagnosed between 1989 and 2018. Using a panel of 62 validated immune-oncology markers, we performed digital spatial profiling using the NanoString GeoMx platform and quantified expression in three tissue compartments defined by fluorescence colocalization (tumor (S100+/PMEL+/SYTO+), leukocytes (CD45+/SYTO+), and non-immune stroma (S100-/PMEL-/CD45-/SYTO+)). RESULTS: We observed higher expression of immune checkpoints (lymphocyte-activation gene 3 [LAG-3] and cytotoxic T-lymphocyte associated protein-4 [CTLA-4]) and cancer-associated fibroblast (CAF) markers (smooth muscle actin (SMA)) in the tumor compartments of pure DMs than mixed DMs. When comparing lymphoid aggregates (LA) to non-LA tumor cores, LAs were more enriched with CD20+B cells, but non-LA intratumoral leukocytes were more enriched with macrophage/monocytic markers (CD163, CD68, CD14) and had higher LAG-3 and CTLA-4 expression levels. Higher intratumoral PD-1 and LA-based LAG-3 expression appear to be associated with worse survival. CONCLUSIONS: Our proteomic analysis reveals an intra-tumoral population of SMA+CAFs enriched in pure DM. Additionally, increased expressions of immune checkpoints (LAG-3 and PD-1) in LA and within tumor were associated with poorer prognosis. These findings might have therapeutic implications and help guide treatment selection in addition to informing potential prognostic significance.

Outcomes in biomarker-selected subgroups from the KESTREL study of durvalumab and tremelimumab in recurrent or metastatic head and neck squamous cell carcinoma.

BACKGROUND: Selective biomarkers may improve outcomes in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) treated with immune checkpoint inhibitor therapy. We investigated three independent biomarkers for association with efficacy in the randomized, phase III KESTREL study (NCT02551159) of first-line durvalumab monotherapy or durvalumab plus tremelimumab versus the EXTREME regimen: programmed cell death ligand-1 (PD-L1) immunohistochemistry, blood tumor mutational burden (bTMB) via circulating tumor DNA, and neutrophil-to-lymphocyte ratio (NLR). METHODS: Tumor or blood samples from patients enrolled in the KESTREL study were analyzed for PD-L1, bTMB, and NLR. Associations with overall survival (OS) or objective response rates (ORRs) were evaluated based on prespecified cut-offs for PD-L1 (tumor cell [TC] ≥ 50%/immune cell ≥ 25% or TC ≥ 25%), bTMB (≥ 16 mutations [mut] per megabase [Mb]), and NLR (≤ 7). Ad hoc analyses of exploratory cut-offs were performed. RESULTS: Prespecified or exploratory cut-offs for PD-L1 did not enrich for ORR or OS for durvalumab monotherapy or durvalumab plus tremelimumab versus EXTREME. In the bTMB ≥ 16 mut/Mb subgroup, OS hazard ratios (95% confidence interval) for durvalumab monotherapy and durvalumab plus tremelimumab versus EXTREME were 0.90 (0.48-1.72) and 0.69 (0.39-1.25), respectively. Complete response rates were 8.6% with durvalumab plus tremelimumab and 4.3% with EXTREME (≥ 16 mut/Mb subgroup). No improvement in OS was observed for durvalumab monotherapy or durvalumab plus tremelimumab versus EXTREME at prespecified or exploratory NLR cut-offs. CONCLUSIONS: bTMB demonstrated potential utility for selecting patients with R/M HNSCC who benefited from durvalumab with or without tremelimumab versus EXTREME. Trial registration ClinicalTrials.gov identifier NCT02551159.

Immune checkpoint inhibitor monotherapy is sufficient to promote microenvironmental normalization via the type I interferon pathway in PD-L1-expressing head and neck cancer.

Immune checkpoint blockers (ICBs) targeting programmed cell death protein 1 (PD-1) have been proven to be an effective first-line therapy against programmed cell death 1 ligand 1 (PD-L1; also known as CD274 molecule)-expressing head and neck squamous cell carcinoma (HNSCC) in recent KEYNOTE-048 trial. However, associated changes in the tumor microenvironment (TME) and underlying mechanisms remain elusive. Oral tumors in C57/BL6 mice were induced by administering 7,12-dimethylbenzanthracene into the buccal mucosa. Single-cell suspension was isolated from tumor tissue; proliferating cells were injected subcutaneously into the left flank of mice to establish Ajou oral cancer (AOC) cell lines. Subsequently, a syngeneic PD-L1-expressing HNSCC model was developed by injecting AOC cells into the buccal or tongue area. The model recapitulated human HNSCC molecular features and showed reliable in vivo tumorigenicity with significant PD-L1 expression. ICB monotherapy induced global changes in the TME, including vascular normalization. Furthermore, the antitumor effect of ICB monotherapy was superior to those of other therapeutic agents, including cisplatin and inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2). The ICB-induced antitumorigenicity and TME normalization were alleviated by blocking the type I interferon pathway. In summary, ICB monotherapy is sufficient to induce TME normalization in the syngeneic model; the type I interferon pathway is indispensable in realizing the effects of ICBs. Furthermore, these results explain the underlying mechanism of the efficacy of ICB monotherapy against PD-L1-expressing HNSCC in the KEYNOTE-048 trial.

High response rate with extended dosing of cemiplimab in advanced cutaneous squamous cell carcinoma.

BACKGROUND: Cemiplimab (Libtayo®), a human monoclonal immunoglobulin G4 antibody to the programmed cell death-1 receptor, is approved for the treatment of patients with advanced cutaneous squamous cell carcinoma (CSCC), who are not candidates for curative surgery or curative radiation, using an every-3-weeks (Q3W) dosing interval. Pharmacokinetic modeling indicated that Ctrough of extended intravenous dosing of 600 mg every 4 weeks (Q4W) would be comparable to the approved intravenous dosage of 350 mg Q3W. We examined the efficacy, pharmacokinetics, and safety of cemiplimab dosed Q4W. METHODS: In this open-label, phase II trial (ClinicalTrials.gov identifier NCT02760498), the cohort of patients ≥18 years old with advanced CSCC received cemiplimab 600 mg intravenously Q4W for up to 48 weeks. Tumor measurements were recorded every 8 weeks. The primary endpoint was objective response rate by independent central review. RESULTS: Sixty-three patients with advanced CSCC were treated with cemiplimab. The median duration of follow-up was 22.4 months (range: 1.0-39.8). An objective response was observed in 39 patients (62%; 95% CI: 48.8% to 73.9%), with 22% of patients (n=14) achieving complete response and 40% (n=25) achieving partial response. The most common treatment-emergent adverse events were diarrhea, pruritus, and fatigue. CONCLUSIONS: Extended dosing of cemiplimab 600 mg intravenously Q4W exhibited substantial antitumor activity, rapid and durable responses, and an acceptable safety profile in patients with advanced CSCC. These results confirm that cemiplimab is a highly active therapy for advanced CSCC. Additional data would help ascertain the benefit-risk profile for the 600 mg intravenous dosing regimen compared with the approved regimen.

Mitochondria-targeted photodynamic therapy triggers GSDME-mediated pyroptosis and sensitizes anti-PD-1 therapy in colorectal cancer.

BACKGROUND: The effectiveness of immune checkpoint inhibitors in colorectal cancer (CRC) is limited due to the low tumor neoantigen load and low immune infiltration in most microsatellite-stable (MSS) tumors. This study aimed to develop a mitochondria-targeted photodynamic therapy (PDT) approach to provoke host antitumor immunity of MSS-CRC and elucidate the underlying molecular mechanisms. METHODS: The role and mechanism of mitochondria-targeted PDT in inhibiting CRC progression and inducing pyroptosis were evaluated both in vitro and in vivo. The immune effects of PDT sensitization on PD-1 blockade were also assessed in CT26 and 4T1 tumor-bearing mouse models. RESULTS: Here, we report that PDT using IR700DX-6T, a photosensitizer targeting the mitochondrial translocation protein, may trigger an antitumor immune response initiated by pyroptosis in CRC. Mechanistically, IR700DX-6T-PDT produced reactive oxygen species on light irradiation and promoted downstream p38 phosphorylation and active caspase3 (CASP3)-mediated cleavage of gasdermin E (GSDME), subsequently inducing pyroptosis. Furthermore, IR700DX-6T-PDT enhanced the sensitivity of MSS-CRC cells to PD-1 blockade. Decitabine, a demethylation drug used to treat hematologic neoplasms, disrupted the abnormal methylation pattern of GSDME in tumor cells, enhanced the efficacy of IR700DX-6T-PDT, and elicited a potent antitumor immune response in combination with PD-1 blockade and IR700DX-6T-PDT. CONCLUSION: Our work provides clear a understanding of immunogenic cell death triggered by mitochondria-targeted PDT, offering a new approach for enhancing the efficacy of PD-1 blockade in CRC.