TPS3185 Background: KRAS is one of the most frequently mutated oncogenes in human cancers, with the G12C mutant isoform accounting for ~15% of all KRAS mutations. Despite their promising antitumor activity and manageable safety profile in advanced solid tumors, first-generation KRAS G12C inhibitors are often limited by acquired resistance in the monotherapy setting. MK-1084 is a next-generation, highly potent and selective KRAS G12C–GDP covalent inhibitor that exerts downstream regulation of the MAPK pathway. EGFR-mediated reactivation of RAS-MAPK signaling is proposed as a key driver of resistance to KRAS G12C inhibitors, particularly in colorectal cancer (CRC). The combination of KRAS G12C inhibitors and EGFR-targeted monoclonal antibodies has demonstrated clinical benefit in KRAS G12C-mutated CRC and non-small cell lung cancer (NSCLC), supporting the potential of this mutation as a clinically-relevant target across tumor types. KANDLELIT-014 (NCT07209111) is a phase 2, randomized, open-label, multicenter, tumor-agnostic study of MK-1084 as monotherapy and in combination with EGFR inhibitor cetuximab in participants with previously treated advanced solid tumors harboring a KRAS G12C mutation. Methods: Eligible participants are aged ≥18 years with histological or blood-based KRAS G12C-mutated locally advanced unresectable or metastatic solid tumors (other than CRC) that have progressed on or following standard-of-care systemic treatment, or for whom no satisfactory alternative treatment options are available. Additional eligibility criteria include an ECOG PS score of 0 or 1 and measurable disease per RECIST v1.1. Participants were excluded if they had uncontrolled, significant cardiovascular or cerebrovascular diseases; an additional progressive active malignancy that required treatment within the past 3 years; or active CNS metastases, carcinomatous meningitis, or primary brain tumors. Participants will be randomly assigned 1:1 to receive MK-1084 100 mg orally once daily as monotherapy (Arm 1) or in combination with cetuximab 500 mg/m 2 intravenously every 2 weeks (Arm 2) until discontinuation criteria are met. Randomization will be stratified according to the following tumor groups: NSCLC, pancreatic ductal adenocarcinoma, endometrial cancer, biliary tract cancer, and other solid tumors. The primary end points are ORR per RECIST v1.1 as assessed by blinded independent central review (BICR), safety, and tolerability. Key secondary end points include OS, DOR per RECIST v1.1 by BICR, and PFS per RECIST v1.1 by BICR. Imaging will be performed every 6 weeks until Week 18, every 8 weeks until Week 50, and every 12 weeks thereafter until disease progression or discontinuation. AEs will be evaluated from randomization to 30 days after the last dose of study treatment per NCI CTCAE v5.0. This global study is actively enrolling. Clinical trial information: NCT07209111 .

Malignant melanoma is a prevalent and aggressive cancer, with globally increasing incidences. While immune checkpoint inhibitors (ICIs) have prolonged the survival of patients with advanced melanoma over the last decade, this improvement comes with the risk of severe immune-related adverse events (irAEs). This systematic review investigates patient baseline characteristics (BCs) as predictive factors for developing severe gastrointestinal, hepatic, and pulmonary irAEs in patients treated with ipilimumab (anti-CTLA-4) and/or nivolumab/pembrolizumab (anti-PD-1). A systematic literature search was conducted in the Ovid databases MEDLINE and EMBASE on 22 April 2022, following the PRISMA guidelines. Out of 1694 articles, 13 were included in the final analysis. We analyzed BCs and the occurrence of severe colitis, hepatitis, and pneumonitis in 22 treatment arms and 3 treatment groups: anti-CTLA-4 (n = 2904), anti-PD-1 (n = 1301), or combination therapy (n = 822). However, missing data preclude a direct comparison of individual BCs and the association to specific irAEs between studies. Descriptive analysis did not identify any significant association between median age, gender distribution, or performance status and severe colitis, hepatitis, or pneumonitis for any of the three treatment groups. We call for greater transparency and standardization in the reporting of patient-specific irAEs.

Regulatory T cells (Tregs) protect against autoimmunity. In type 1 diabetes (T1D), Tregs slow the progression of beta cell autoimmunity within pancreatic islets. Increasing the potency or frequency of Tregs can prevent diabetes, as evidenced by studies in the nonobese diabetic (NOD) mouse model for T1D. We report herein that a significant proportion of islets Tregs in NOD mice express Gata3 . The expression of Gata3 was correlated with the presence of IL-33, a cytokine known to induce and expand Gata3 + Tregs. Despite significantly increasing the frequency of Tregs in the pancreas, exogenous IL-33 was not protective. Based on these data, we hypothesized that Gata3 is deleterious to Treg function in autoimmune diabetes. To test this notion, we generated NOD mice with a Treg-specific deletion of Gata3 . We found that deleting Gata3 in Tregs strongly protected against diabetes. Disease protection was associated with a shift of islet Tregs toward a suppressive CXCR3 + Foxp3 + population. Our results suggest that islet Gata3 + Tregs are maladaptive and that this Treg subpopulation compromises the regulation of islet autoimmunity, contributing to diabetes onset.

Abstract Background Vascular endothelial growth factor (VEGF) was initially known as vascular permeability factor and identified as a driver of tumour angiogenesis. Recently, its role in supporting an immunosuppressive tumour microenvironment was demonstrated, and anti‐VEGF treatment combined with immune checkpoint blockade is currently investigated. Further, beta‐adrenergic signalling as a modifier of cancer hallmarks like immune response, angiogenesis and metastasis gained increased attention during past years. Methods Focusing on the aspect of immunosuppression in upregulated beta‐adrenergic signalling, we investigated predictive markers in patients with metastatic melanoma who received bevacizumab monotherapy, a specific VEGF‐A binding antibody. We explored the expression of beta‐2 adrenergic receptor (β2‐AR), interleukin 6‐receptor (IL6‐R), cyclooxygenase 2 (COX2) and VEGF‐A by immunohistochemistry in melanoma to assess the correlation between these proteins in melanoma cells and response to treatment. Results Strong β2‐AR expression in metastases was associated with clinical benefit of bevacizumab. Furthermore, expression of the latter was positively linked to expression of VEGF‐A and COX2. β2‐AR expression in melanoma metastasis appears to distinguish a subgroup of patients that might benefit from anti‐VEGF treatment. Conclusion Our results strengthen further exploration of anti‐VEGF therapy in combination with immune checkpoint blockade in clinical studies and the investigation of β2‐AR as predictive marker.

CD5 is constitutively expressed on all T cells and is a negative regulator of lymphocyte function. However, the full extent of CD5 function in immunity remains unclear. CD5 deficiency impacts thymic selection and extra-thymic regulatory T cell generation, yet CD5 knockout was reported to cause no immune pathology. Here we show that CD5 is a key modulator of gut immunity. We generated mice with inducible CD5 knockdown (KD) in the autoimmune-prone nonobese diabetic (NOD) background. CD5 deficiency caused T cell-dependent wasting disease driven by chronic gut immune dysregulation. CD5 inhibition also exacerbated acute experimental colitis. Mechanistically, loss of CD5 increased phospho-Stat3 levels, leading to elevated IL-17A secretion. Our data reveal a new facet of CD5 function in shaping the T cell cytokine profile.

Ipilimumab was the first treatment that improved survival in advanced melanoma. Efficacy and toxicity in a real-world setting may differ from clinical trials, due to more liberal eligibility criteria and less intensive monitoring. Moreover, high costs and lack of biomarkers have raised cost-benefit concerns about ipilimumab in national healthcare systems and limited its use. Here, we report the prospective, interventional study, Ipi4 (NCT02068196), which aimed to investigate the toxicity and efficacy of ipilimumab in a real-world population with advanced melanoma. This national, multicentre, phase IV trial included 151 patients. Patients received ipilimumab 3 mg/kg intravenously and were followed for at least 5 years or until death. Treatment interruption or cessation occurred in 38%, most frequently due to disease progression (19%). Treatment-associated grade 3 to 4 toxicity was observed in 28% of patients, and immune-related toxicity in 56%. The overall response rate was 9%. Median overall survival was 12.1 months (95% CI: 8.3-15.9); and progression-free survival 2.7 months (95% CI: 2.6-2.8). After 5 years, 20% of patients were alive. In a landmark analysis from 6 months, improved survival was associated with objective response (HR 0.16, P = .001) and stable disease (HR 0.49, P = .005) compared to progressive disease. Poor performance status, elevated lactate dehydrogenase and C-reactive protein were identified as biomarkers. This prospective trial represents the longest reported follow-up of a real-world melanoma population treated with ipilimumab. Results indicate safety and efficacy comparable to phase III trials and suggest that the use of ipilimumab can be based on current cost-benefit estimates.

Type 1 diabetes (T1D) is characterized by pancreatic islet infiltration by autoreactive immune cells and a nearly complete loss of β cells1. Restoration of insulin-producing β cells coupled with immunomodulation to suppress the autoimmune attack has emerged as a potential approach to counter T1D2–4. Here we report that enhancing β-cell mass early in life, in two models of female non-obese diabetic (NOD) mice, results in immunomodulation of T cells, reduced islet infiltration and lower β-cell apoptosis, which together protect them from developing T1D. The animals displayed altered β-cell antigens; islet transplantation studies showed prolonged graft survival in the NOD-liver-specific insulin receptor knockout (LIRKO) model. Adoptive transfer of splenocytes from NOD-LIRKO mice prevented development of diabetes in prediabetic NOD mice. A substantial increase in the splenic CD4+CD25+Foxp3+ regulatory T cell (Treg) population was observed to underlie the protected phenotype since Treg-cell depletion rendered NOD-LIRKO mice diabetic. An increase in Treg cells coupled with activation of transforming growth factor-β/SMAD family member 3 signalling pathway in pathogenic T cells favoured reduced ability to kill β cells. These data support a previously unidentified observation that initiating β-cell proliferation, alone, before islet infiltration by immune cells alters the identity of β cells, decreases pathological self-reactivity of effector T cells and increases Treg cells to prevent the progression of T1D. Type 1 diabetes (T1D) involves immune-mediated destruction of pancreatic β cells. Here, the authors show that inducing β-cell replication before immune cell infiltration of the pancreas alters β-cell antigen expression and prevents T1D disease progression in female NOD mice in a regulatory-T-cell-dependent manner.

Angiogenesis is important for the progression of cutaneous melanoma. Here, we analyzed the prognostic impact of the angiogenic factor urokinase plasminogen activator resecptor (uPAR), vascular proliferation index (VPI) and tumor necrosis as a measure of hypoxia in a patient series of nodular melanomas (n = 255) and matched loco-regional metastases (n = 78). Expression of uPAR was determined by immunohistochemistry and VPI was assessed by dual immunohistochemistry using Factor-VIII/Ki67 staining. Necrosis was recorded based on HE-slides. As novel findings, high uPAR expression and high VPI were associated with each other, and with increased tumor thickness, presence of tumor necrosis, tumor ulceration, increased mitotic count and reduced cancer specific survival in primary melanoma. In matched cases, VPI was decreased in metastases, whereas the frequency of necrosis was increased. Our findings demonstrate for the first time the impact on melanoma specific survival of uPAR expression and VPI in primary tumors, and of increased necrosis as an indicator of tumor hypoxia in loco-regional metastases. These findings support the importance of tumor angiogenesis in melanoma aggressiveness, and suggest uPAR as an indicator of vascular proliferation and a potential biomarker in melanoma.

DNA vaccines against autoimmune type 1 diabetes (T1D) contain a nonpredictable risk to induce autoreactive T cell responses rather than a protective immunity. Little is known if (and how) antigen expression and processing requirements favor the induction of autoreactive or protective immune responses by DNA immunization. Here, we analyzed whether structural properties of preproinsulin (ppins) variants and/or subcellular targeting of ppins designer antigens influence the priming of effector CD8(+) T cell responses by DNA immunization. Primarily, we used H-2(b) RIP-B7.1 tg mice, expressing the co-stimulator molecule B7.1 in beta cells, to identify antigens that induce or fail to induce autoreactive ppins-specific (K-b/A(12-21) and/or K-b/B22-29) CD8(+) T cell responses. Female NOD mice, expressing the diabetes-susceptible H-2(g7) haplotype, were used to test ppins variants for their potential to suppress spontaneous diabetes development. We showed that ppins antigens excluded from expression in the endoplasmic reticulum (ER) did not induce CD8(+) T cells or autoimmune diabetes in RIP-B7.1 tg mice, but efficiently suppressed spontaneous diabetes development in NOD mice as well as ppins-induced CD8(+) T cell-mediated autoimmune diabetes in PD-L1(-/-) mice. The induction of a ppins-specific therapeutic immunity in mice has practical implications for the design of immune therapies against T1D in individuals expressing different major histocompatibility complex (MHC) I and II molecules.

Bevacizumab is included in an increasing number of clinical trials. To find biomarkers to predict and monitor treatment response, cancer and angiogenesis relevant mutations in tumour and circulating tumour DNA (ctDNA) were investigated in 26 metastatic melanoma patients treated with bevacizumab. Patients with >1% BRAF/NRAS ctDNA at treatment start had significantly decreased progression free survival (PFS) and overall survival (OS) (PFS: p = 0.019, median 54 vs 774 days, OS: p = 0.026, median 209 vs 1064 days). Patients with >1% BRAF/NRAS ctDNA during treatment showed similar results (PFS: p = 0.002, OS: p = 0.003). ≤1% BRAF/NRAS ctDNA and normal lactate dehydrogenase (LDH) levels both significantly predicted increased response to treatment, but BRAF/NRAS ctDNA was better at predicting response compared to LDH at treatment start (OR 16.94, p = 0.032 vs OR 4.57, p = 0.190), and at predicting PFS (HR 6.76, p = 0.002) and OS (HR 6.78, p = 0.002) during therapy. ctDNA BRAF p.V600D/E/K and NRAS p.G12V/p.Q61K/L/R were better biomarkers for response prediction than TERT promoter mutations (OR 1.50, p = 0.657). Next generation sequencing showed that all patients with ≥2 mutations in angiogenesis-relevant genes had progressive disease, but did not reveal other biomarkers identifying responders. To conclude, ctDNA and LDH are useful biomarkers for both monitoring and predicting response to bevacizumab.

Genome-wide association studies have implicated more than 50 genomic regions in type 1 diabetes (T1D). A T1D region at chromosome 16p13.13 includes the candidate genes CLEC16A and DEXI. Conclusive evidence as to which gene is causal for the disease association of this region is missing. We previously reported that Clec16a deficiency modified immune reactivity and protected against autoimmunity in the nonobese diabetic (NOD) mouse model for T1D. However, the diabetes-associated SNPs at 16p13.13 were described to also impact on DEXI expression and others have argued that DEXI is the causal gene in this disease locus. To help resolve whether DEXI affects disease, we generated Dexi knockout (KO) NOD mice. We found that Dexi deficiency had no effect on the frequency of diabetes. To test for possible interactions between Dexi and Clec16a, we intercrossed Dexi KO and Clec16a knockdown (KD) NOD mice. Dexi KO did not modify the disease protection afforded by Clec16a KD. We conclude that Dexi plays no role in autoimmune diabetes in the NOD model. Our data provide strongly suggestive evidence that CLEC16A, not DEXI, is causal for the T1D association of variants in the 16p13.13 region.

The incidence of malignant melanoma is rising worldwide and survival for metastatic disease is still poor. Recently, new treatment options have become available. Still, predictive biomarkers are needed to optimise treatment for this patient group. In this study, we investigated the predictive value of 60 angiogenic factors in patients with metastatic melanoma treated with the anti-vascular endothelial growth factor A antibody bevacizumab. Thirty-five patients were included in a clinical phase II trial and baseline serum samples were analysed by multiplex protein array. High-serum concentration of Activin A was significantly associated with objective response (OR) to treatment (p = 0.014). Candidate proteins that indicated a borderline association with treatment response were further investigated by immunohistochemistry. Strong expression of Activin A, interleukin-1 beta, and urokinase-type plasminogen activator receptor in metastases was significantly associated with OR (p = 0.011, p = 0.003, and p = 0.007, respectively), as well as with markers of activated angiogenesis, such as higher number of proliferating vessels and the presence of glomeruloid microvascular proliferations. Our findings indicate that these proteins may be potential predictive markers for treatment with bevacizumab monotherapy.

Type 1 diabetes (T1D) results from the autoimmune destruction of pancreatic beta cells and is partly caused by deficiencies in the Foxp3 + regulatory T cell (Treg) compartment. Conversely, therapies that increase Treg function can prevent autoimmune diabetes in animal models. The majority of Tregs develop in the thymus (tTregs), but a proportion of Foxp3 + Tregs is generated in the periphery (pTregs) from Foxp3 - CD4 + T cell precursors. Whether pTregs play a distinct role in T1D has not yet been explored. We report here that pTregs are a key modifier of disease in the nonobesed diabetic (NOD) mouse model for T1D. We generated NOD mice deficient for the Foxp3 enhancer CNS1 involved in pTreg induction. We show that CNS1 knockout decreased the frequency of pTregs and increased the risk of diabetes. Our results show that pTregs fulfill an important non-redundant function in the prevention of beta cell autoimmunity that causes T1D.

Abstract Background Upregulation of the receptor tyrosine kinase Axl has been linked with both a reduced response to immune checkpoint blockade as well as the development of therapy resistance to BRAF directed therapies in melanoma. Bemcentinib is a first-in-class orally bioavailable selective inhibitor of Axl which is currently being explored in several phase II clinical trials. BGBIL006 (NCT02872259) is an open label phase Ib/II trial designed to explore whether combinations with bemcentinib improves ORR and duration of response compared to standard of care therapies in patient (pts) with metastatic melanoma (MM). Trial design Patients are randomized 2:1 to receive D/T or pembro +/- bemcentinib, respectively, based on mutation status and tumour load. BRAF positive pts are allowed to switch D/T with pembrolizumab and vice versa upon progression. Tumour responses are assessed per investigator using RECIST v1.1. Plasma protein biomarker levels are measured using the DiscoveryMap v3.3 panel (Myriad RBM) in pts pre-dose and at C2D1. In June 2019, a formal interim analysis of clinical safety and efficacy data will be performed when at least 20 randomised patients have completed up to 12 cycles of treatment. Currently, 50 pts (92 planned) have been enrolled in the trial. Tolerability of the bemcentinib RP2D (200 mg daily) in combination with either D/T or pembro, and AE profiles for either therapeutic approach alone will be reported. Protein biomarkers candidates predictive of pt benefit following treatment and pre/post treatment changes of soluble proteins will be presented. Preliminary efficacy outcome data and safety data from the first formal preplanned interim analysis will be presented together with the recommendations from the Data Monitoring Committee. Clinical trial identification NCT02872259. Legal entity responsible for the study The authors. Funding Research Council Norway. Disclosure O. Straume: Travel / Accommodation / Expenses: BerGenBio. J.B. Lorens: Shareholder / Stockholder / Stock options: BerGenBio ASA. G. Gausdal: Full / Part-time employment: BerGenBio ASA. All other authors have declared no conflicts of interest.

Abstract Background. MAPK inhibitors and immune checkpoint inhibitors are major breakthroughs in metastatic melanoma showing high response rates and durable responses. To further improve patient outcome, and to overcome treatment resistance, combination strategies have been suggested. We have initiated a phase Ib/II randomized clinical trial with the selective AXL inhibitor BGB324 (IC50=14 nM R428 Bergen Bio AS) with or without immune check point inhibition (pembrolizumab) or MAPK inhibitors (dabrafenib+trametinib) (NCT02872259). Upregulation of the AXL kinase has been associated with reduced response to anti-PD-1 therapy. The drug resistant low MITF/ high AXL melanoma signature has been associated with an immune suppressive micro-environment. AXL is a key negative feedback regulator of the innate immune response and attenuates macrophage, dendritic and natural killer (NK) cell activity. Hence, AXL signaling contributes to both tumor intrinsic and microenvironmental immune suppression mechanisms. Further we have recently shown that BGB324 sensitizes the highly metastatic K1736 murine melanoma tumors to anti-PD-1 treatment. This provides a rationale for targeting AXL to enhance the anti-cancer immune response. AXL dependent cell plasticity signaling pathways confer resistance to inhibitors of BRAF/MEK. Melanomas display either a high E-cadherin/high MITF-M expression on the one hand, or high N-cadherin/high AXL expression on the other. The low MITF/high AXL phenotype is linked to drug-resistance in mutant BRAF and NRAS melanoma cell lines. Interestingly, AXL-mediated resistance to BRAF and MEK targeting agents could be predicted by levels of soluble AXL receptor in patient blood samples and prevented by coadministration of BGB324, Methods. This is a Phase Ib/II, multicentre, open label, parallel group study in patients with metastatic melanoma. Part 1 is a dose selection phase in up to 12 patients to evaluate the safety of BGB324 when administered in combination with dabrafenib+trametinib and to determine the BGB324 dose to be administered in the combination in Part 2 and Part 3. Part 2 is an open label, multiple arm, randomised treatment phase evaluating efficacy and safety of pembrolizumab and dabrafenib+trametinib in combination with BGB324 as first line treatment in 80 patients with advanced melanoma compared to pembrolizumab or dabrafenib/trametinib alone. Patients will be stratified according to BRAF status and tumor load to receive pembrolizumab or dabrafenib+trametinib with or without BGB324, randomised in a 2:1 ratio. Part 3 is an open label, multiple arm, non-randomised treatment phase evaluating efficacy and safety of pembrolizumab and dabrafenib/trametinib in combination with BGB324 or alone, as second line treatment in patients continuing from Part 1 or Part 2. Co-primary endpoints are safety and response rates according to RECIST 1.1. Enrollment began in January 2017. Citation Format: Oddbjorn Straume, Cornelia Schuster, James Lorens, Bjørn Tore Gjertsen. A Phase Ib/II randomised open label study of BGB324 in combination with pembrolizumab or dabrafenib/trametinib compared to pembrolizumab or dabrafenib/trametinib alone, in patients with advanced non-resectable (Stage IIIc) or metastatic (Stage IV) melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT056. doi:10.1158/1538-7445.AM2017-CT056

The aim of this study was to identify potential predictive biomarkers in 35 patients with metastatic melanoma treated with anti-angiogenic bevacizumab monotherapy in a clinical phase II study. The immunohistochemical expression of various angiogenic factors in tissues from primary melanomas and metastases as well as their concentration in blood samples were examined. Strong expression of Heat Shock Protein 27 (HSP27) in metastases correlated significantly with complete or partial response to bevacizumab (p = 0.044). Furthermore, clinical benefit, i.e., complete or partial response or stable disease for at least 6 months, was more frequent in patients with strong expression of HSP27 in primary tumors (p = 0.046). Tissue expression of vascular endothelial growth factor (VEGF-A), its splicing variant VEGF165b or basic fibroblast growth factor (bFGF) did not correlate with response, and the concentration of HSP27, VEGF-A or bFGF measured in blood samples before treatment did not show predictive value. Further, microvessel density, proliferating microvessel density and presence of glomeruloid microvascular proliferations were assessed in sections of primary tumors and metastases. Microvessel density in primary melanomas was significantly higher in patients with clinical benefit than in non-responders (p = 0.042). In conclusion, our findings suggest that strong HSP27 expression in melanoma metastases predicts response to bevacizumab treatment.