Single-cell analysis reveals cellular and molecular factors counteracting HPV-positive oropharyngeal cancer immunotherapy outcomes.

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) induced by human papillomavirus (HPV-positive) is associated with better clinical outcomes than HPV-negative OPSCC. However, the clinical benefits of immunotherapy in patients with HPV-positive OPSCC remain unclear. METHODS: To identify the cellular and molecular factors that limited the benefits associated with HPV in OPSCC immunotherapy, we performed single-cell RNA (n=20) and T-cell receptor sequencing (n=10) analyses of tonsil or base of tongue tumor biopsies prior to immunotherapy. Primary findings from our single-cell analysis were confirmed through immunofluorescence experiments, and secondary validation analysis were performed via publicly available transcriptomics data sets. RESULTS: We found significantly higher transcriptional diversity of malignant cells among non-responders to immunotherapy, regardless of HPV infection status. We also observed a significantly larger proportion of CD4+ follicular helper T cells (Tfh) in HPV-positive tumors, potentially due to enhanced Tfh differentiation. Most importantly, CD8+ resident memory T cells (Trm) with elevated KLRB1 (encoding CD161) expression showed an association with dampened antitumor activity in patients with HPV-positive OPSCC, which may explain their heterogeneous clinical outcomes. Notably, all HPV-positive patients, whose Trm presented elevated KLRB1 levels, showed low expression of CLEC2D (encoding the CD161 ligand) in B cells, which may reduce tertiary lymphoid structure activity. Immunofluorescence of HPV-positive tumors treated with immune checkpoint blockade showed an inverse correlation between the density of CD161+ Trm and changes in tumor size. CONCLUSIONS: We found that CD161+ Trm counteracts clinical benefits associated with HPV in OPSCC immunotherapy. This suggests that targeted inhibition of CD161 in Trm could enhance the efficacy of immunotherapy in HPV-positive oropharyngeal cancers. TRIAL REGISTRATION NUMBER: NCT03737968.

Exploring Molecular Genetic Alterations and RAF Fusions in Melanoma: A Belvarafenib Expanded Access Program in Patients with RAS/RAF-Mutant Melanoma.

BACKGROUND: Melanoma incidence is on the rise in East Asia, yet studies of the molecular landscape are lacking in this population. We examined patients with melanoma who underwent next-generation sequencing (NGS) at a single tertiary center in South Korea, focusing on patients harboring NRAS or RAF alterations who received belvarafenib, a pan-RAF dimer inhibitor, through the Expanded Access Program (EAP). PATIENTS AND METHODS: Data were collected from 192 patients with melanoma who underwent NGS between November 2017 and May 2023. Variant call format data were obtained and annotated. Patients in the EAP received 450 mg twice daily doses of belvarafenib. RESULTS: Alterations in the RAS/RTK pathway were the most prevalent, with BRAF and NRAS alteration rates of 22.4% and 17.7%, respectively. NGS enabled additional detection of fusion mutations, including 6 BRAF and 1 RAF1 fusion. Sixteen patients with NRAS or RAF alterations received belvarafenib through the EAP, and disease control was observed in 50%, with 2 patients demonstrating remarkable responses. CONCLUSIONS: Our study highlights the value of NGS in detecting BRAF, NRAS mutations and RAF fusions, expanding possibilities for targeted therapies in malignant melanoma. Belvarafenib showed clinical benefit in patients harboring these alterations. Ongoing trials will provide further insights into the safety and efficacy of belvarafenib.

A Phase II Open-Label Randomized Clinical Trial of Preoperative Durvalumab or Durvalumab plus Tremelimumab in Resectable Head and Neck Squamous Cell Carcinoma.

PURPOSE: Clinical implications of neoadjuvant immunotherapy in patients with locally advanced but resectable head and neck squamous cell carcinoma (HNSCC) remain largely unexplored. PATIENTS AND METHODS: Patients with resectable HNSCC were randomized to receive a single dose of preoperative durvalumab (D) with or without tremelimumab (T) before resection, followed by postoperative (chemo)radiotherapy based on multidisciplinary discretion and 1-year D treatment. Artificial intelligence (AI)-powered spatial distribution analysis of tumor-infiltrating lymphocytes and high-dimensional profiling of circulating immune cells tracked dynamic intratumoral and systemic immune responses. RESULTS: Of the 48 patients enrolled (D, 24 patients; D+T, 24 patients), 45 underwent surgical resection per protocol (D, 21 patients; D+T, 24 patients). D±T had a favorable safety profile and did not delay surgery. Distant recurrence-free survival (DRFS) was significantly better in patients treated with D+T than in those treated with D monotherapy. AI-powered whole-slide image analysis demonstrated that D+T significantly reshaped the tumor microenvironment toward immune-inflamed phenotypes, in contrast with the D monotherapy or cytotoxic chemotherapy. High-dimensional profiling of circulating immune cells revealed a significant expansion of T-cell subsets characterized by proliferation and activation in response to D+T therapy, which was rare following D monotherapy. Importantly, expansion of specific clusters in CD8+ T cells and non-regulatory CD4+ T cells with activation and exhaustion programs was associated with prolonged DRFS in patients treated with D+T. CONCLUSIONS: Preoperative D±T is feasible and may benefit patients with resectable HNSCC. Distinct changes in the tumor microenvironment and circulating immune cells were induced by each treatment regimen, warranting further investigation.

Prior antibiotic administration disrupts anti-PD-1 responses in advanced gastric cancer by altering the gut microbiome and systemic immune response.

Evidence on whether prior antibiotic (pATB) administration modulates outcomes of programmed cell death protein-1 (PD-1) inhibitors in advanced gastric cancer (AGC) is scarce. In this study, we find that pATB administration is consistently associated with poor progression-free survival (PFS) and overall survival (OS) in multiple cohorts consisting of patients with AGC treated with PD-1 inhibitors. In contrast, pATB does not affect outcomes among patients treated with irinotecan. Multivariable analysis of the overall patients treated with PD-1 inhibitors confirms that pATB administration independently predicts worse PFS and OS. Administration of pATBs is associated with diminished gut microbiome diversity, reduced abundance of Lactobacillus gasseri, and disproportional enrichment of circulating exhaustive CD8+ T cells, all of which are associated with worse outcomes. Considering the inferior treatment response and poor survival outcomes by pATB administration followed by PD-1 blockade, ATBs should be prescribed with caution in patients with AGC who are planning to receive PD-1 inhibitors.

Atezolizumab plus bevacizumab in patients with child-Pugh B advanced hepatocellular carcinoma.

Background: Atezolizumab plus bevacizumab (Ate/Bev) demonstrated promising efficacy and safety in patients with advanced hepatocellular carcinoma (HCC) in the phase III IMbrave150 trial. However, patients with Child-Pugh B HCC were excluded in the abovementioned prospective trial. Therefore, we aimed to investigate the efficacy and safety of Ate/Bev in patients with Child-Pugh B HCC. Methods: This multicenter retrospective study included 36 patients with Child-Pugh B advanced HCC who received Ate/Bev at four cancer referral centers between May 2020 and August 2021. Comparative analyses were performed with an independent cohort of patients with Child-Pugh A HCC from the same registry (n = 133). Results: All patients received Ate/Bev as first-line systemic treatment for advanced HCC. The objective response and disease control rates of patients in the Child-Pugh groups B and A were 11.1% and 58.3% and 34.6% and 76.7%, respectively. The median progression-free survival (PFS) and overall survival (OS) were 3.0 months [95% confidence interval (CI), 1.7-4.3) and 7.7 months (95% CI, 4.8-10.6) in the Child-Pugh B group, whereas the median PFS and OS were 9.6 months (95% CI, 5.1-14.2) and not reached (95% CI, not available) in the Child-Pugh A group, respectively. Compared to the Child-Pugh A group, grade 3-4 adverse events (AEs) were more common in the Child-Pugh B group (44.4% versus 15.8, p < 0.001), with the most frequent grade 3-4 AEs being gastrointestinal bleeding (n = 6, 16.7%), neutropenia (n = 5, 13.9%), and thrombocytopenia (n = 4, 11.1%). Conclusions: In the Child-Pugh B subgroup of patients with advanced HCC, Ate/Bev treatment showed modest clinical activity. However, due to the increased frequency of serious AEs, careful evaluation of treatment response and AE management is required in this subgroup of patients.

Trastuzumab Combined With Ramucirumab and Paclitaxel in Patients With Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Advanced Gastric or Gastroesophageal Junction Cancer.

PURPOSE: Trastuzumab-containing chemotherapy is the recommended first-line regimen for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer. We evaluated the safety and efficacy of trastuzumab combined with ramucirumab and paclitaxel as second-line treatment for HER2-positive G/GEJ cancer. PATIENTS AND METHODS: Patients with HER2-positive advanced G/GEJ cancer who progressed after first-line treatment with trastuzumab-containing chemotherapy were enrolled from five centers in the Republic of Korea. Patients were administered a 28-day cycle of trastuzumab (once on days 1, 8, 15, and 22: 2 mg/kg followed by 4 mg/kg loading dose), ramucirumab (once on days 1 and 15: 8 mg/kg), and paclitaxel (once on days 1, 8, and 15: dose level 1, 80 mg/m2; or dose level -1, 70 mg/m2). Phase II was conducted with the recommended phase II dose (RP2D). Primary end points were determination of RP2D during phase Ib and investigator-assessed progression-free survival (PFS) in patients treated with RP2D. RESULTS: Dose-limiting toxicity at dose level 1 was not documented during phase Ib, and a full dose combination was selected as the RP2D. Among 50 patients with a median follow-up duration of 27.5 months (95% CI, 17.4 to 37.6), median PFS and overall survival were 7.1 months (95% CI, 4.8 to 9.4) and 13.6 months (95% CI, 9.4 to 17.7), respectively. Objective response rate was 54% (27 of 50, including one complete response), and disease control rate was 96% (48 of 50). Loss of HER2 expression was observed in 34.8% (8 of 23) patients after first-line treatment, and no definite association between HER2 expression and the outcome was revealed. Safety profiles were consistent with previous reports. CONCLUSION: Trastuzumab combined with ramucirumab and paclitaxel showed appreciable efficacy with manageable safety profiles in patients with previously treated HER2-positive G/GEJ cancer.

Fusobacterium nucleatum induces a tumor microenvironment with diminished adaptive immunity against colorectal cancers.

Background & Aims: Fusobacterium nucleatum (FN) plays a pivotal role in the development and progression of colorectal cancer by modulating antitumor immune responses. However, the impact of FN on immune regulation in the tumor microenvironment has not been fully elucidated. Methods: The abundance of FN was measured in 99 stage III CRC tumor tissues using quantitative polymerase chain reaction. Gene expression profiles were assessed and annotated using consensus molecular subtypes (CMS), Gene Ontology (GO) analysis, and deconvolution of individual immune cell types in the context of FN abundance. Immune profiling for tumor infiltrating T cells isolated from human tumor tissues was analyzed using flow cytometry. Ex vivo tumor-infiltrating T cells were stimulated in the presence or absence of FN to determine the direct effects of FN on immune cell phenotypes. Results: Gene expression profiles, CMS composition, abundance of immune cell subtypes, and survival outcomes differed depending on FN infection. We found that FN infection was associated with poorer disease-free survival and overall survival in stage III CRC patients. FN infection was associated with T cell depletion and enrichment of exhausted CD8+ and FoxP3+ regulatory T cells in the tumor microenvironment. The presence of FN in tumors was correlated with a suppressive tumor microenvironment in a T cell-dependent manner. Conclusion: FN enhanced the suppressive immune microenvironment with high depletion of CD8+ T cells and enrichment of FoxP3+ regulatory T cells in human colorectal cancer cases. Our findings suggest a potential association for FN in adaptive immunity, with biological and prognostic implications.

On-treatment derived neutrophil-to-lymphocyte ratio and survival with palbociclib and endocrine treatment: analysis of a multicenter retrospective cohort and the PALOMA-2/3 study with immune correlates.

BACKGROUND: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have been established as a standard treatment for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC); however, predictive biomarkers with translational relevance have not yet been elucidated. METHODS: Data from postmenopausal women who received the CDK4/6 inhibitor palbociclib and letrozole for HR-positive, HER2-negative ABC from tertiary referral centers were analyzed (N = 221; exploratory cohort). Pre- and on-treatment neutrophil-to-lymphocyte ratio (NLR) and derived NLR (dNLR; neutrophil/[leukocyte-neutrophil]) were correlated with survival outcomes. Data from the PALOMA-2 (NCT01740427) and PALOMA-3 studies (NCT01942135) involving patients treated with endocrine treatment with or without palbociclib were also analyzed (validation cohort). Prospectively enrolled patients (N = 20) were subjected to immunophenotyping with circulating immune cells to explore the biological implications of immune cell dynamics. RESULTS: In the exploratory cohort, palbociclib administration significantly reduced leukocyte, neutrophil, and lymphocyte counts on day 1 of cycle 2. Although the baseline dNLR was not significantly associated with progression-free survival (PFS), higher on-treatment dNLRs were associated with worse PFS (hazard ratio = 3.337, P < 0.001). In the PALOMA-2 validation cohort, higher on-treatment dNLRs were associated with inferior PFS in patients treated with palbociclib and letrozole (hazard ratio = 1.498, P = 0.009), and reduction in the dNLR after treatment was predictive of a survival benefit (hazard ratio = 1.555, P = 0.026). On-treatment dNLRs were also predictive of PFS following palbociclib and fulvestrant treatment in the PALOMA-3 validation cohort. Using flow cytometry analysis, we found that the CDK4/6 inhibitor prevented T cell exhaustion and diminished myeloid-derived suppressor cell frequency. CONCLUSIONS: On-treatment dNLR significantly predicted PFS in patients with HR-positive, HER2-negative ABC receiving palbociclib and endocrine treatment. Additionally, we observed putative systemic immune responses elicited by palbociclib, suggesting immunologic changes upon CDK4/6 inhibitor treatment.

Association of T Cell Senescence with Radiation Pneumonitis in Patients with Non-small Cell Lung Cancer.

PURPOSE: Associations between immunosenescence and radiation pneumonitis (RP) are largely unknown. We aimed to identify a peripheral blood T cell senescence biomarker to predict RP in patients with non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: Patients with locally advanced NSCLC who received definitive concurrent chemoradiotherapy (dCRT) were prospectively registered (cohort 1, n=23; cohort 2, n=31). Peripheral blood was collected at baseline, during dCRT, and at 1 month post-dCRT. Patients were dichotomized to grade ≥2 (G2+) RP and grade 0-1 (G0-1) RP. Flow cytometry was performed to assess phenotypes and functional properties of T cell subsets. RP incidence was estimated via competing risk analysis. RESULTS: Five and six patients exhibited G2+ RP following dCRT in cohorts 1 and 2, respectively. Patients with G2+ RP exhibited a more aged T cell pool and higher frequencies of senescent CD57+CD28-CD8+ T cells than patients with G0-1 RP at baseline, during dCRT, and at 1 month post-dCRT. These senescent cells exhibited increased granzyme B, IFN-γ, and TNF-α production. Higher baseline frequency of CD57+CD28-CD8+ T cells was an independent predictor of G2+ RP (hazard ratio, 8.42; 95% confidence interval, 2.58-27.45; P<0.001). Recursive partitioning analysis revealed three distinct risk groups stratified by baseline CD57+CD28-CD8+ T cell frequency and lung V20 Gy, with 1-year cumulative G2+ RP incidences of 50.0%, 16.7%, and 0% for high-, intermediate-, and low-risk groups, respectively (P=0.002). CONCLUSIONS: Higher baseline frequencies of CD57+CD28-CD8+ T cells correlated with increased G2+ RP risks. Our results suggest the need for further investigation of the role of T cell senescence on radiation-induced organ damage.

YH29407 with anti-PD-1 ameliorates anti-tumor effects via increased T cell functionality and antigen presenting machinery in the tumor microenvironment.

Among cancer cells, indoleamine 2, 3-dioxygenase1 (IDO1) activity has been implicated in improving the proliferation and growth of cancer cells and suppressing immune cell activity. IDO1 is also responsible for the catabolism of tryptophan to kynurenine. Depletion of tryptophan and an increase in kynurenine exert important immunosuppressive functions by activating regulatory T cells and suppressing CD8+ T and natural killer (NK) cells. In this study, we compared the anti-tumor effects of YH29407, the best-in-class IDO1 inhibitor with improved pharmacodynamics and pharmacokinetics, with first and second-generation IDO1 inhibitors (epacadostat and BMS-986205, respectively). YH29407 treatment alone and anti-PD-1 (aPD-1) combination treatment induced significant tumor suppression compared with competing drugs. In particular, combination treatment showed the best anti-tumor effects, with most tumors reduced and complete responses. Our observations suggest that improved anti-tumor effects were caused by an increase in T cell infiltration and activity after YH29407 treatment. Notably, an immune depletion assay confirmed that YH29407 is closely related to CD8+ T cells. RNA-seq results showed that treatment with YH29407 increased the expression of genes involved in T cell function and antigen presentation in tumors expressing ZAP70, LCK, NFATC2, B2M, and MYD88 genes. Our results suggest that an IDO1 inhibitor, YH29407, has enhanced PK/PD compared to previous IDO1 inhibitors by causing a change in the population of CD8+ T cells including infiltrating T cells into the tumor. Ultimately, YH29407 overcame the limitations of the competing drugs and displayed potential as an immunotherapy strategy in combination with aPD-1.

First-line pembrolizumab versus dabrafenib/trametinib treatment for BRAF V600-mutant advanced melanoma.

BACKGROUND: Limited data are available to assist the selection between immune checkpoint inhibitors and BRAF/mitogen-activated protein kinase kinase inhibitors as first-line treatment for patients with BRAF-mutant advanced malignant melanoma. OBJECTIVE: To investigate the outcomes associated with first-line pembrolizumab or dabrafenib/trametinib treatment for advanced melanoma with activating BRAF V600 mutation. METHODS: Data of patients with BRAF V600-mutant melanoma who were treated with first-line pembrolizumab (n = 40) or dabrafenib/trametinib (n = 32) were analyzed. Tumor response, progression-free survival, and overall survival were evaluated. Immune evasion accompanied with emerging resistance to BRAF/mitogen-activated protein kinase kinase inhibitors was assessed. RESULTS: A longer overall survival was observed after first-line pembrolizumab treatment than after first-line dabrafenib/trametinib treatment (hazard ratio = 2.910, 95% CI: 1.552-5.459), although there were no significant differences in progression-free survival (P = .375) and response rate (P = .123). Emergence of resistance to dabrafenib/trametinib co-occurred with immune evasion, enabling melanoma cells to escape recognition and killing by Melan-A-specific CD8+ T cells. LIMITATIONS: Analysis was conducted in a retrospective manner. CONCLUSION: Pembrolizumab may be recommended over BRAF/mitogen-activated protein kinase kinase inhibitors as the first-line treatment in patients with advanced BRAF V600-mutant melanoma.

The presence and size of intrahepatic tumors determine the therapeutic efficacy of nivolumab in advanced hepatocellular carcinoma.

Purpose: Inter-tumoral heterogeneity at the differential lesion level raises the possibility of distinct organ-specific responses to immune checkpoint inhibitors (ICIs). We aimed to comprehensively examine the clinicopathological factors to predict and assess the efficacy of nivolumab, programmed cell death protein 1 (PD-1) blockade at an individual tumor site-specific level in patients with advanced hepatocellular carcinoma (aHCC). Patients and Methods: We enrolled 261 aHCC patients treated with nivolumab between 2012 and 2018. Eighty-one clinicopathological factors were comprehensively collected and analyzed. The association between all variables and survival outcomes was evaluated. According to tumor site, the organ-specific responses were assessed based on the Response Evaluation Criteria in Solid Tumors, version 1.1. Results: The liver was the most commonly involved organ (75.1%), followed by the lungs (37.5%) and lymph nodes (LNs, 11.5%). The liver of nonresponders was more frequently the organ of progression, while the lungs of responders were more frequently the organs of response. Among the 455 individual lesions (liver, n = 248; lung, n = 124; LN, n = 35; others including bone or soft tissues, n = 48), intrahepatic tumors showed the least response (10.1%), followed by lung (24.2%) and LN tumors (37.1%), indicating the presence of distinct organ-specific responses to nivolumab. In intrahepatic tumors, the organ-specific response rate decreased as the size increased (13% for ⩽50 mm, 8.1% for 50-100 mm, and 5.5% for >100 mm). In the subgroup analysis according to tumor location, patients with lung only metastasis (⩾30 mm) showed the best progression-free survival (PFS) and overall survival (OS). In contrast, primary HCC (⩾100 mm) without lung metastasis had the worst PFS and OS. Comprehensive analyses also revealed that liver function and systemic inflammatory indices, such as neutrophil-to-lymphocyte ratio (NLR), were significantly associated with PFS and OS. Conclusion: The presence and size of liver tumors, liver function, and NLR are key factors determining the response to nivolumab in aHCC. These clinical factors should be considered when treating patients with advanced HCC with PD-1 blockade.

Hyperprogressive disease during PD-1 blockade in patients with advanced gastric cancer.

BACKGROUND: Investigations for programmed cell death-1 (PD-1) blockade-induced hyperprogressive disease (HPD) have not been stringently conducted in patients with advanced gastric cancer (AGC). We explored the occurrence of HPD and its clinical implications in patients with AGC and treated with PD-1 inhibitors. METHODS: We enrolled 169 patients with AGC and treated with either the PD-1 blockade (nivolumab or pembrolizumab; N = 112) or irinotecan monotherapy (N = 57) as a single agent. Tumour growth dynamics based on tumour growth kinetics and tumour growth rate (TGR) and time to treatment failure were analysed to define HPD. The incidence, clinical consequences and predictive markers of HPD were investigated. RESULTS: The optimal criteria for HPD were 4-fold increases in both tumour growth kinetics and TGR ratios and a 40% increase in TGR based on the analysis for patients treated with irinotecan. In total, 10.7% (12/112) of patients experienced HPD after PD-1 inhibitor treatment. Patients with HPD had both shorter progression-free survival (hazard ratio: 2.318; 95% confidence interval: 1.205-4.460) and overall survival (hazard ratio: 2.542; 95% confidence interval: 1.314-4.918) than patients with progressive disease without HPD, losing opportunities for subsequent systemic treatments. Although other variables including PD-L1 expression were not associated with the occurrence of HPD, hypoalbuminemia (<3.25 mg/dL) at baseline was significantly associated with the occurrence of HPD (P < 0.001) and inferior survival outcomes. CONCLUSIONS: HPD occurs in a proportion of patients with AGC and treated with PD-1 inhibitors. PD-1 inhibitor-induced HPD is associated with worse outcome, loss of eligibility for subsequent treatment and hypoalbuminemia, warranting further investigation.

Phase II Clinical Trial of Eribulin-Gemcitabine Combination Therapy in Previously Treated Patients With Advanced Liposarcoma or Leiomyosarcoma.

PURPOSE: Monotherapy with eribulin or gemcitabine has been found to be moderately effective in treating soft-tissue sarcomas (STS). In this study, we evaluated the efficacy and safety of eribulin-gemcitabine combination therapy for the two most common histologic types of STS, liposarcoma and leiomyosarcoma. PATIENTS AND METHODS: In this nonrandomized, multicenter, phase II study, we included patients with progressive disease who had received one or two courses of chemotherapy that included doxorubicin. Patients were administered 1.4 mg/m2 eribulin and 1,000 mg/m2 gemcitabine on days 1 and 8 every 3 weeks. The primary endpoint was progression-free survival rate at 12 weeks (PFSR12wks), with null and alternative hypotheses of PFSR12wks ≤20.0% and ≥40.0%, respectively. Exploratory biomarker analyses with next-generation sequencing (NGS) were performed on pretreatment tumor samples. RESULTS: Among the 37 patients included, the overall PFSR12wks was 73.0%, achieving the primary endpoint. The objective response rate, disease control rate, median progression-free survival, and median overall survival were 16.2%, 78.4%, 5.6 months, and 31.9 months, respectively, without differences according to histologic type. New safety signals and treatment-related deaths were not documented. NGS-based transcriptome analysis revealed that functional enrichment in the TGFß pathway was mostly associated with a poor outcome, whereas single genetic alterations largely failed to predict treatment outcome. CONCLUSIONS: Eribulin-gemcitabine combination therapy showed promising activity and an acceptable safety profile in patients with liposarcoma or leiomyosarcoma. Gene expression profiling with pathway enrichment analysis would have possibilities to have predictive value for survival outcome, necessitating further investigation to confirm.

The Development of AXL Inhibitors in Lung Cancer: Recent Progress and Challenges.

AXL, along with MER and TYRO3, is a receptor tyrosine kinase from the TAM family. Although AXL itself is not thought to be a potent oncogenic driver, overexpression of AXL is known to trigger tumor cell growth, survival, invasion, metastasis, angiogenesis, epithelial to mesenchymal transition, and immune suppression. Overexpression of AXL is associated with therapy resistance and poor prognosis. Therefore, it is being studied as a marker of prognosis in cancer treatment or as a target in various cancer types. Recently, many preclinical and clinical studies on agents with various mechanisms targeting AXL have been actively conducted. They include small molecule inhibitors, monoclonal antibodies, and antibody-drug conjugates. This article reviewed the fundamental role of AXL in solid tumors, and the development in research of AXL inhibitors in recent years. Emphasis was placed on the function of AXL in acquired therapy resistance in patients with non-small cell lung cancer (NSCLC). Since clinical needs increase in NSCLC patients with acquired resistance after initial therapy, recent research efforts have focused on a combination treatment with AXL inhibitors and tyrosine kinase inhibitors or immunotherapy to overcome resistance. Lastly, we deal with challenges and limitations encountered in the development of AXL inhibitors.

SKI-G-801, an AXL kinase inhibitor, blocks metastasis through inducing anti-tumor immune responses and potentiates anti-PD-1 therapy in mouse cancer models.

OBJECTIVES: AXL-mediated activation of aberrant tyrosine kinase drives various oncogenic processes and facilitates an immunosuppressive microenvironment. We evaluated the anti-tumor and anti-metastatic activities of SKI-G-801, a small-molecule inhibitor of AXL, alone and in combination with anti-PD-1 therapy. METHODS: In vitro pAXL inhibition by SKI-G-801 was performed in both human and mouse cancer cell lines. Immunocompetent mouse models of tumor were established to measure anti-metastatic potential of SKI-G-801. Furthermore, SKI-G-801, anti-PD-1 or their combination was administered as an adjuvant or neoadjuvant in the 4T1 tumor model to assess their potential for clinical application. RESULTS: SKI-G-801 robustly inhibited pAXL expression in various cell lines. SKI-G-801 alone or in combination with anti-PD-1 potently inhibited metastasis in B16F10 melanoma, CT26 colon and 4T1 breast models. SKI-G-801 inhibited the growth of B16F10 and 4T1 tumor-bearing mice but not immune-deficient mice. An antibody depletion assay revealed that CD8+ T cells significantly contributed to SKI-G-801-mediated survival. Anti-PD-1 and combination group were observed the increased CD8+Ki67+ and effector T cells and M1 macrophage and decreased M2 macrophage, and granulocytic myeloid-derived suppressor cell (G-MDSC) compared to the control group. The neoadjuvant combination of SKI-G-801 and anti-PD-1 therapy achieved superior survival benefits by inducing more profound T-cell responses in the 4T1 syngeneic mouse model. CONCLUSION: SKI-G-801 significantly suppressed tumor metastasis and growth by enhancing anti-tumor immune responses. Our results suggest that SKI-G-801 has the potential to overcome anti-PD-1 therapy resistance and allow more patients to benefit from anti-PD-1 therapy.

Predicting treatment outcomes using 18F-FDG PET biomarkers in patients with non-small-cell lung cancer receiving chemoimmunotherapy.

BACKGROUND: Predictive markers for treatment response and survival outcome have not been identified in patients with advanced non-small-cell lung cancer (NSCLC) receiving chemoimmunotherapy. We aimed to evaluate whether imaging biomarkers of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and routinely assessed clinico-laboratory values were associated with clinical outcomes in patients with advanced NSCLC receiving pembrolizumab plus platinum-doublet chemotherapy as a first-line treatment. METHODS: We retrospectively enrolled 52 patients with advanced NSCLC who underwent baseline 18F-FDG PET/CT before treatment initiation. PET/CT parameters and clinico-laboratory variables, constituting the prognostic immunotherapy scoring system, were collected. Optimal cut-off values for PET/CT parameters were determined using the maximized log-rank test for progression-free survival (PFS). A multivariate prediction model was developed based on Cox models for PFS, and a scoring system was established based on hazard ratios of the predictive factors. RESULTS: During the median follow-up period of 16.7 months (95% confidence interval: 15.7-17.7 months), 43 (82.7%) and 31 (59.6%) patients experienced disease progression and death, respectively. Objective response was observed in 23 (44.2%) patients. In the multivariate analysis, maximum standardized uptake value, metabolic tumour volume2.5, total lesion glycolysis2.5, and bone marrow-to-liver uptake ratio from the PET/CT variables and neutrophil-to-lymphocyte ratio (NLR) from the clinico-laboratory variables were independently associated with PFS. The scoring system based on these independent predictive variables significantly predicted the treatment response, PFS, and overall survival. CONCLUSION: PET/CT variables and NLR were useful biomarkers for predicting outcomes of patients with NSCLC receiving pembrolizumab and chemotherapy as a first-line treatment, suggesting their potential as effective markers for combined PD-1 blockade and chemotherapy.

Antibody-Drug Conjugates: A New Addition to the Treatment Landscape of EGFR-Mutant Non-Small Cell Lung Cancer.

The emergence of treatment resistance to targeted agents is currently inevitable and inherently heterogeneous in cancer, presenting significant challenges for improving survival outcomes in patients. This is not an exception for cancers harboring EGFR mutations, one of the most prevalently observed oncogenic alterations in non-small cell lung cancer (NSCLC) targeted clinically. Currently, numerous efforts have attempted to delay or overcome acquired resistance to EGFR-tyrosine kinase inhibitors (TKI), changing the treatment landscape of EGFR-mutant NSCLC. Haikala and colleagues have developed a unique strategy using patritumab deruxtecan, an antibody-drug conjugate targeting human epidermal growth factor receptor 3 (HER3) linked to exatecan derivatives, for treating EGFR-mutant NSCLC. By incorporating EGFR TKIs to upregulate surface HER3 expression, the antitumor efficacy of patritumab deruxtecan was augmented in various preclinical models. In parallel, Jänne and colleagues reported the clinical activity of patrimumab deruxtecan in patients with EGFR-mutant NSCLC with prior EGFR TKI treatment. These two studies provide the grounds for hopeful anticipation for a novel strategy that concurrently targets compensatory feedback loops in addition to oncogenic signaling pathways.See related article by Haikala et al., p. 130.

Patritumab Deruxtecan: Paving the Way for EGFR-TKI-Resistant NSCLC.

HER3 is ubiquitously expressed in EGFR-mutant non-small cell lung cancer (NSCLC) irrespective of resistant mechanisms to EGFR tyrosine kinase inhibitors, thus garnering attention as a valuable therapeutic target. In this issue of Cancer Discovery, Jänne and colleagues highlight early clinical data supporting patritumab deruxtecan as a potentially appreciable agent for previously treated EGFR-mutant NSCLC.See related article by Jänne et al., p. 74.