Safety, Pharmacokinetics, Pharmacodynamics, and Antitumor Activity from a Phase I Study of Simlukafusp Alfa (FAP-IL2v) in Advanced/Metastatic Solid Tumors.

PURPOSE: Simlukafusp alfa (FAP-IL2v), a tumor-targeted immunocytokine, comprising an interleukin-2 variant moiety with abolished CD25 binding fused to human immunoglobulin G1, is directed against fibroblast activation protein-α. This phase I, open-label, multicenter, dose-escalation and extension study (NCT02627274) evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of FAP-IL2v in patients with advanced/metastatic solid tumors. METHODS: Participants received FAP-IL2v intravenously once weekly. Dose escalation started at 5 mg; flat dosing (≤25 mg) and intra-participant up-titration regimens (15/20 mg, 20/25 mg, 20/20/35 mg, 20/35/35 mg) were evaluated. Primary objectives were dose-limiting toxicities (DLT), maximum tolerated dose (MTD), recommended expansion dose, and pharmacokinetics. RESULTS: Sixty-one participants were enrolled. DLTs included fatigue (flat dose 20 mg: n = 1), asthenia (25 mg: n = 1), drug-induced liver injury (up-titration regimen 20/25 mg: n = 1), transaminase increase (20/25 mg: n = 1), and pneumonia (20/35/35 mg: n = 1). Up-titration regimen 15/20 mg was the MTD and was selected as the recommended expansion dose. Increases in peripheral blood absolute immune cell counts were seen for all tested doses (natural killer cells, 13-fold; CD4+ T cells [including Tregs], 2-fold; CD8+ T cells, 3.5-fold), but without any percentage change in Tregs. Clinical activity was observed from 5 mg (objective response rate, 5.1% [n = 3]; disease control rate, 27.1% [n = 16]). Responses were durable (n = 3; 2.8 [censored], 6.3, and 43.4 months). CONCLUSIONS: FAP-IL2v had a manageable safety profile and showed initial signs of antitumor activity in advanced/metastatic solid tumors.

The ATR inhibitor ceralasertib potentiates cancer checkpoint immunotherapy by regulating the tumor microenvironment.

The Ataxia telangiectasia and Rad3-related (ATR) inhibitor ceralasertib in combination with the PD-L1 antibody durvalumab demonstrated encouraging clinical benefit in melanoma and lung cancer patients who progressed on immunotherapy. Here we show that modelling of intermittent ceralasertib treatment in mouse tumor models reveals CD8+ T-cell dependent antitumor activity, which is separate from the effects on tumor cells. Ceralasertib suppresses proliferating CD8+ T-cells on treatment which is rapidly reversed off-treatment. Ceralasertib causes up-regulation of type I interferon (IFNI) pathway in cancer patients and in tumor-bearing mice. IFNI is experimentally found to be a major mediator of antitumor activity of ceralasertib in combination with PD-L1 antibody. Improvement of T-cell function after ceralasertib treatment is linked to changes in myeloid cells in the tumor microenvironment. IFNI also promotes anti-proliferative effects of ceralasertib on tumor cells. Here, we report that broad immunomodulatory changes following intermittent ATR inhibition underpins the clinical therapeutic benefit and indicates its wider impact on antitumor immunity.

The CSF-1R inhibitor pexidartinib affects FLT3-dependent DC differentiation and may antagonize durvalumab effect in patients with advanced cancers.

Tumor-associated macrophages (TAMs) are a critical determinant of resistance to PD-1/PD-L1 blockade. This phase 1 study (MEDIPLEX, NCT02777710) investigated the safety and efficacy of pexidartinib, a CSF-1R-directed tyrosine kinase inhibitor (TKI), and durvalumab (anti-PD-L1) in patients with advanced colorectal and pancreatic carcinoma with the aim to enhance responses to PD-L1 blockade by eliminating CSF-1-dependent suppressive TAM. Forty-seven patients were enrolled. No unexpected toxicities were observed, one (2%) high microsatellite instability CRC patient had a partial response, and seven (15%) patients experienced stable disease as their best response. Increase of CSF-1 concentrations and decrease of CD14lowCD16high monocytes in peripheral blood mononuclear cells (PBMCs) confirmed CSF-1R engagement. Treatment decreased blood dendritic cell (DC) subsets and impaired IFN-λ/IL-29 production by type 1 conventional DCs in ex vivo TLR3-stimulated PBMCs. Pexidartinib also targets c-KIT and FLT3, both key growth factor receptors of DC development and maturation. In patients, FLT3-L concentrations increased with pexidartinib treatment, and AKT phosphorylation induced by FLT3-L ex vivo stimulation was abrogated by pexidartinib in human blood DC subsets. In addition, pexidartinib impaired the FLT3-L- but not GM-CSF-dependent generation of DC subsets from murine bone marrow (BM) progenitors in vitro and decreased DC frequency in BM and tumor-draining lymph node in vivo. Our results demonstrate that pexidartinib, through the inhibition of FLT3 signaling, has a deleterious effect on DC differentiation, which may explain the limited antitumor clinical activity observed in this study. This work suggests that inhibition of FLT3 should be considered when combining TKIs with immune checkpoint inhibitors.

Atezolizumab plus Magrolimab, Niraparib, or Tocilizumab versus Atezolizumab Monotherapy in Platinum-Refractory Metastatic Urothelial Carcinoma: A Phase Ib/II Open-Label, Multicenter, Randomized Umbrella Study (MORPHEUS Urothelial Carcinoma).

PURPOSE: The MORPHEUS platform was designed to identify early efficacy signals and evaluate the safety of novel immunotherapy combinations across cancer types. The phase Ib/II MORPHEUS-UC trial (NCT03869190) is evaluating atezolizumab plus magrolimab, niraparib, or tocilizumab in platinum-refractory locally advanced or metastatic urothelial carcinoma (mUC). Additional treatment combinations were evaluated and will be reported separately. PATIENTS AND METHODS: Patients had locally advanced or mUC that progressed during or following treatment with a platinum-containing regimen. The primary efficacy endpoint was investigator-assessed objective response rate (ORR). Key secondary endpoints included investigator-assessed progression-free survival (PFS) and overall survival (OS). Safety and exploratory biomarker analyses were also conducted. RESULTS: Seventy-six patients were randomized to receive either atezolizumab plus magrolimab (n = 16), atezolizumab plus niraparib (n = 15), atezolizumab plus tocilizumab (n = 15), or atezolizumab monotherapy (control; n = 30). No additive benefit in ORR, PFS, or OS was seen in the treatment arms versus the control. The best confirmed ORR was 26.7% with atezolizumab plus magrolimab, 6.7% with atezolizumab plus niraparib, 20.0% with atezolizumab plus tocilizumab, and 27.6% with atezolizumab monotherapy. Overall, the treatment combinations were tolerable, and adverse events were consistent with each agent's known safety profile. Trends were observed for shrinkage of programmed death-ligand 1-positive tumors (atezolizumab, atezolizumab plus magrolimab, atezolizumab plus tocilizumab), inflamed tumors, or tumors with high mutational burden (atezolizumab), and immune excluded tumors (atezolizumab plus magrolimab). CONCLUSIONS: The evaluated regimens in MORPHEUS-UC were tolerable. However, response rates for the combinations did not meet the criteria for further development in platinum-experienced locally advanced or mUC.

Sorafenib in Molecularly Selected Cancer Patients: Final Analysis of the MOST-Plus Sorafenib Cohort.

BACKGROUND: MOST-plus is a multicenter, randomized, open-label, adaptive Phase II trial evaluating the clinical benefit of targeted treatments matched to molecular alteration in advanced/metastatic solid tumors. Sorafenib was tested on patients with tumors harboring sorafenib-targeted genes. METHODS: The MOST-plus trial used a randomized discontinuation design. After 12 weeks of sorafenib (400 mg, po BID), patients with progressive disease discontinued study, patients with objective response were proposed to continue sorafenib, whereas patients with stable disease (SD) were randomly assigned (1:1) to the maintenance or interruption of treatment. The primary endpoint was RECIST version 1.1 progression-free rate at 16 weeks after randomization (PFR-16w). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. Statistical analyses used a sequential Bayesian approach with interim efficacy analyses. The enrolment could be stopped in the case of a 95% probability for the estimated PFR-16w to be higher in the maintenance than in the interruption arm (NCT02029001). RESULTS: 151 patients were included, of whom 35 had SD at 12 weeks of Sorafenib. For the 35 patients with SD on sorafenib, the PFR-16w was 65% [95% credibility interval 43.4-83.7] in the continuation arm and 25% [7.8-48.1] in the interruption arm. Median PFS and OS were improved in the maintenance versus the interruption arm (mPFS: 5.6 [95%CI 1.97-6.77] months versus 2.0 [95%CI 1.61-3.91] months (p = 0.0231) and mOS: 14.3 [95%CI 8.9-23.8] versus 8.0 months [95%CI 3.5-15.2] (p = 0.0857)). CONCLUSION: Sorafenib showed activity in progressive patients with solid tumors harboring somatic genomic alterations in sorafenib-targeted genes. Continuing sorafenib when SD is achieved improves PFR compared to interruption.

Distant antimetastatic effect of enterotropic colon cancer-derived α4ß7+CD8+ T cells.

Despite the high prognostic value of immune infiltrates in colorectal cancer (CRC), metastatic disease remains resistant to immunotherapy by immune checkpoint blockade (ICB). Here, we show, in metastatic CRC preclinical models, that orthotopically implanted primary colon tumors exert a colon-specific antimetastatic effect on distant hepatic lesions. Enterotropic α4ß7 integrin-expressing neoantigen-specific CD8 T cells were key components of the antimetastatic effect. Accordingly, the presence of concomitant colon tumors improved control of liver lesions by anti-PD-L1 proof-of-concept immunotherapy and generated protective immune memory, whereas partial depletion of α4ß7+ cells abrogated control of metastases. Last, in patients with metastatic CRC, response to ICB was associated with expression of α4ß7 integrin in metastases and with circulating α4ß7+ CD8 T cells. Our findings identify a systemic cancer immunosurveillance role for gut-primed tumor-specific α4ß7+ CD8 T cells.

In situ tumour arrays reveal early environmental control of cancer immunity.

The immune phenotype of a tumour is a key predictor of its response to immunotherapy1-4. Patients who respond to checkpoint blockade generally present with immune-inflamed5-7 tumours that are highly infiltrated by T cells. However, not all inflamed tumours respond to therapy, and even lower response rates occur among tumours that lack T cells (immune desert) or that spatially exclude T cells to the periphery of the tumour lesion (immune excluded)8. Despite the importance of these tumour immune phenotypes in patients, little is known about their development, heterogeneity or dynamics owing to the technical difficulty of tracking these features in situ. Here we introduce skin tumour array by microporation (STAMP)-a preclinical approach that combines high-throughput time-lapse imaging with next-generation sequencing of tumour arrays. Using STAMP, we followed the development of thousands of arrayed tumours in vivo to show that tumour immune phenotypes and outcomes vary between adjacent tumours and are controlled by local factors within the tumour microenvironment. Particularly, the recruitment of T cells by fibroblasts and monocytes into the tumour core was supportive of T cell cytotoxic activity and tumour rejection. Tumour immune phenotypes were dynamic over time and an early conversion to an immune-inflamed phenotype was predictive of spontaneous or therapy-induced tumour rejection. Thus, STAMP captures the dynamic relationships of the spatial, cellular and molecular components of tumour rejection and has the potential to translate therapeutic concepts into successful clinical strategies.

Nivolumab and Relatlimab in Patients With Advanced Melanoma That Had Progressed on Anti-Programmed Death-1/Programmed Death Ligand 1 Therapy: Results From the Phase I/IIa RELATIVITY-020 Trial.

PURPOSE: Nivolumab and relatlimab activity in advanced melanoma with prior progression on anti-programmed death-1/programmed death ligand 1 (PD-(L)1)-containing regimens is under investigation. RELATIVITY-047 demonstrated significantly improved progression-free survival (PFS) for nivolumab and relatlimab over nivolumab in previously untreated advanced melanoma. METHODS: The phase I/IIa, open-label RELATIVITY-020 trial part D assessed efficacy and safety of nivolumab and relatlimab in advanced melanoma with progression during, or within 3 months of, 1 (D1) or ≥ 1 (D2) anti-PD-(L)1-containing regimens. Safety was a primary end point. Objective response rate (coprimary end point) and PFS by blinded independent central review (BICR) were assessed. RESULTS: Five hundred eighteen patients (D1 = 354; D2 = 164) received nivolumab and relatlimab. Among evaluable patients, the objective response rate by BICR was 12.0% (95% CI, 8.8 to 15.8) in D1 (n = 351) and 9.2% (95% CI, 5.2 to 14.7) in D2 (n = 163). Responses appeared to be enriched among patients with tumors expressing programmed death ligand 1 or lymphocyte activation gene 3; however, responses were observed regardless of programmed death ligand 1 and lymphocyte activation gene 3 expression (1%). The median duration of response was not reached (95% CI, 12.9 to not reached) in D1 and 12.8 months (95% CI, 6.9 to 12.9) in D2. The median PFS by BICR was 2.1 months (95% CI, 1.9 to 3.5) in D1 and 3.2 months (95% CI, 1.9 to 3.6) in D2; the 6-month PFS rate was 29.1% (95% CI, 24.2 to 34.1) and 27.7% (95% CI, 20.5 to 35.4), respectively. The grade 3-4 treatment-related adverse event incidence was 15.0% in D1 and 12.8% in D2. One case of grade 3 myocarditis and no treatment-related deaths occurred across part D. CONCLUSION: Nivolumab and relatlimab had a manageable safety profile and demonstrated durable clinical activity in a proportion of patients with heavily pretreated advanced melanoma with prior progression on anti-PD-(L)1-containing regimens.[Media: see text].

Genomic Instability and Protumoral Inflammation Are Associated with Primary Resistance to Anti-PD-1 + Antiangiogenesis in Malignant Pleural Mesothelioma.

Cancer immunotherapy combinations have recently been shown to improve the overall survival of advanced mesotheliomas, especially for patients responding to those treatments. We aimed to characterize the biological correlates of malignant pleural mesotheliomas' primary resistance to immunotherapy and antiangiogenics by testing the combination of pembrolizumab, an anti-PD-1 antibody, and nintedanib, a pan-antiangiogenic tyrosine kinase inhibitor, in the multicenter PEMBIB trial (NCT02856425). Thirty patients with advanced malignant pleural mesothelioma were treated and explored. Unexpectedly, we found that refractory patients were actively recruiting CD3+CD8+ cytotoxic T cells in their tumors through CXCL9 tumor release upon treatment. However, these patients displayed high levels of somatic copy-number alterations in their tumors that correlated with high blood and tumor levels of IL6 and CXCL8. Those proinflammatory cytokines resulted in higher tumor secretion of VEGF and tumor enrichment in regulatory T cells. Advanced mesothelioma should further benefit from stratified combination therapies adapted to their tumor biology. SIGNIFICANCE: Sequential explorations of fresh tumor biopsies demonstrated that mesothelioma resistance to anti-PD-1 + antiangiogenics is not due to a lack of tumor T-cell infiltration but rather due to adaptive immunosuppressive pathways by tumors, involving molecules (e.g., IL6, CXCL8, VEGF, and CTLA4) that are amenable to targeted therapies. This article is highlighted in the In This Issue feature, p. 799.

Circulating Exhausted PD-1+CD39+ Helper CD4 T Cells Are Tumor-Antigen-Specific and Predict Response to PD-1/PD-L1 Axis Blockade.

Tumor-infiltrating exhausted PD-1hiCD39+ tumor-antigen (Ag)-specific CD4 T cells contribute to the response to immune checkpoint blockade (ICB), but their circulating counterparts, which could represent accessible biomarkers, have not been assessed. Here, we analyzed circulating PD-1+CD39+ CD4 T cells and show that this population was present at higher proportions in cancer patients than in healthy individuals and was enriched in activated HLA-DR+ and ICOS+ and proliferating KI67+ cells, indicative of their involvement in ongoing immune responses. Among memory CD4 T cells, this population contained the lowest proportions of cells producing effector cytokines, suggesting they were exhausted. In patients with HPV-induced malignancies, the PD-1+CD39+ population contained high proportions of HPV Ag-specific T cells. In patients treated by ICB for HPV-induced tumors, the proportion of circulating PD-1+CD39+ CD4 T cells was predictive of the clinical response. Our results identify CD39 expression as a surrogate marker of circulating helper tumor-Ag-specific CD4 T cells.

Anti-CSF-1R emactuzumab in combination with anti-PD-L1 atezolizumab in advanced solid tumor patients naïve or experienced for immune checkpoint blockade.

BACKGROUND: This phase 1b study (NCT02323191) evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of colony-stimulating factor-1 receptor-blocking monoclonal antibody (mAb) emactuzumab in combination with the programmed cell death-1 ligand (PD-L1)-blocking mAb atezolizumab in patients with advanced solid tumors naïve or experienced for immune checkpoint blockers (ICBs). METHODS: Emactuzumab (500-1350 mg flat) and atezolizumab (1200 mg flat) were administered intravenously every 3 weeks. Dose escalation of emactuzumab was conducted using the 3+3 design up to the maximum tolerated dose (MTD) or optimal biological dose (OBD). Extension cohorts to evaluate pharmacodynamics and clinical activity were conducted in metastatic ICB-naive urothelial bladder cancer (UBC) and ICB-pretreated melanoma (MEL), non-small cell lung cancer (NSCLC) and UBC patients. RESULTS: Overall, 221 patients were treated. No MTD was reached and the OBD was determined at 1000 mg of emactuzumab in combination with 1200 mg of atezolizumab. Grade ≥3 treatment-related adverse events occurred in 25 (11.3%) patients of which fatigue and rash were the most common (14 patients (6.3%) each). The confirmed objective response rate (ORR) was 9.8% for ICB-naïve UBC, 12.5% for ICB-experienced NSCLC, 8.3% for ICB-experienced UBC and 5.6% for ICB-experienced MEL patients, respectively. Tumor biopsy analyses demonstrated increased activated CD8 +tumor infiltrating T lymphocytes (TILs) associated with clinical benefit in ICB-naïve UBC patients and less tumor-associated macrophage (TAM) reduction in ICB-experienced compared with ICB-naïve patients. CONCLUSION: Emactuzumab in combination with atezolizumab demonstrated a manageable safety profile with increased fatigue and skin rash over usual atezolizumab monotherapy. A considerable ORR was particularly seen in ICB-experienced NSCLC patients. Increase ofCD8 +TILs under therapy appeared to be associated with persistence of a TAM subpopulation.

PD-1 Blockade in Solid Tumors with Defects in Polymerase Epsilon.

Missense mutations in the polymerase epsilon (POLE) gene have been reported to generate proofreading defects resulting in an ultramutated genome and to sensitize tumors to checkpoint blockade immunotherapy. However, many POLE-mutated tumors do not respond to such treatment. To better understand the link between POLE mutation variants and response to immunotherapy, we prospectively assessed the efficacy of nivolumab in a multicenter clinical trial in patients bearing advanced mismatch repair-proficient POLE-mutated solid tumors. We found that only tumors harboring selective POLE pathogenic mutations in the DNA binding or catalytic site of the exonuclease domain presented high mutational burden with a specific single-base substitution signature, high T-cell infiltrates, and a high response rate to anti-PD-1 monotherapy. This study illustrates how specific DNA repair defects sensitize to immunotherapy. POLE proofreading deficiency represents a novel agnostic biomarker for response to PD-1 checkpoint blockade therapy. SIGNIFICANCE: POLE proofreading deficiency leads to high tumor mutational burden with high tumor-infiltrating lymphocytes and predicts anti-PD-1 efficacy in mismatch repair-proficient tumors. Conversely, tumors harboring POLE mutations not affecting proofreading derived no benefit from PD-1 blockade. POLE proofreading deficiency is a new tissue-agnostic biomarker for cancer immunotherapy. This article is highlighted in the In This Issue feature, p. 1397.

Regorafenib-avelumab combination in patients with biliary tract cancer (REGOMUNE): a single-arm, open-label, phase II trial.

BACKGROUND: Regorafenib has shown substantial clinical activity in patients with advanced biliary tract cancers (BTCs). Preclinical data suggested that this drug modulates antitumour immunity and is synergistic with immune checkpoint inhibition. PATIENTS AND METHODS: This is a single-arm, multicentric phase II trial. Regorafenib was given 3 weeks/4, 160 mg quaque die (once a day) (QD); avelumab 10 mg/kg IV was given every two weeks, beginning at C1D15 until progression or unacceptable toxicity. The primary end-point was the confirmed objective response rate under treatment, as per Response Evaluation Criteria in Solid Tumours 1.1. The secondary end-points included the following: 1-year non-progression rate; progression-free survival (PFS) and overall survival; safety and biomarkers studies performed on sequential tumour samples obtained at baseline and at cycle 2 day 1. RESULTS: Thirty-four patients were enrolled in four centres. Twenty-nine patients were assessable for efficacy after central radiological review. The best response was partial response for four patients (13.8%), stable disease for 11 patients (37.9%) and progressive disease for 14 patients (48.3%). The median PFS and overall survival were 2.5 months (95% confidence interval [CI] [1.9-5.5]) and 11.9 months (95%CI [6.2-NA]) respectively. The most common grade 3 or 4 clinical adverse events related to treatment were hypertension (17.6%), fatigue (14.7%) and maculopapular rash (11.8%). High baseline levels of programmed cell death ligand 1 and of indoleamine 2, 3-dioxygénase expression were associated with improved outcomes. CONCLUSIONS: Regorafenib combined with avelumab has antitumour activity in a subset of heavily pretreated biliary tract cancer population. Further investigations are needed in patients selected based on tumour microenvironment features. CLINICAL TRIAL REGISTRATION: NCT03475953.

Exploratory window-of-opportunity trial to investigate the tumor pharmacokinetics/pharmacodynamics of the IAP antagonist Debio 1143 in patients with head and neck cancer.

Inhibitor of apoptosis proteins (IAPs) regulate apoptosis and modulate NF-κB signaling thereby driving expression of genes involved in immune/inflammatory responses. The orally available IAP antagonist Debio 1143 has potential to enhance tumor response to chemoradiotherapy and/or immunotherapy. Patients with pre-operative squamous cell carcinomas of the head and neck (SCCHN) received: Debio 1143 monotherapy (200 mg/day [D]1-15 +/- 2); Debio 1143 (200 mg/day D1-15 +/- 2) plus cisplatin (40 mg/m2 D 1 and 8); cisplatin alone (40 mg/m2 D 1 and 8; EudraCT: 2014-004655-31). Pharmacokinetic/pharmacodynamic effects were assessed in plasma and resected tumors. Primary end point; effect of Debio 1143 on cellular IAP-1 (cIAP-1). Levels of cIAP-1/-2, X-linked inhibitor of apoptosis protein (XIAP), tumor infiltrating lymphocytes (TILs), including CD8+ T cells, programmed cell death protein 1 (PD-1), PD-ligand 1 (PD-L1), and gene expression were also analyzed. Twenty-three of 26 patients completed treatment. In the Debio 1143 monotherapy cohort (n = 13), mean tumor concentrations of Debio 1143 were 18-fold (maximum 55.2-fold) greater than in plasma, exceeding the half-maximal inhibitory concentration for cIAPs and XIAP by 100 to 1000-fold, with significant engagement/degradation of cIAP-1 (p < 0.05). Overall, levels of CD8+ TILs, PD-1, and PD-L1 positive immune cells increased significantly (p < 0.05) following Debio 1143 treatment. Changes were observed in the expression of genes related to NF-κB signaling. Treatments were well-tolerated. Debio 1143 penetrated SCCHN tumors, engaged cIAP-1, and induced immune inflammatory changes in the tumor microenvironment. Based on the mode of action demonstrated here and in previous studies, these data support future combinations of Debio 1143 with immune-checkpoint agents.

Macrophage depletion induces edema through release of matrix-degrading proteases and proteoglycan deposition.

Colony-stimulating factor 1 receptor (CSF1R) blockade abates tumor-associated macrophage (TAM) infiltrates and provides marked clinical benefits in diffuse-type tenosynovial giant cell tumors. However, facial edema is a common adverse event associated with TAM elimination in patients. In this study, we examined molecular and cellular events associated with edema formation in mice and human patients with cancer treated with a CSF1R blocking antibody. Extended antibody treatment of mice caused marked body weight gain, an indicator of enhanced body fluid retention. This was associated with an increase of extracellular matrix-remodeling metalloproteinases (MMPs), namely MMP2 and MMP3, and enhanced deposition of hyaluronan (HA) and proteoglycans, leading to skin thickening. Discontinuation of anti-CSF1R treatment or blockade of MMP activity restored unaltered body weight and normal skin morphology in the mice. In patients, edema developed at doses well below the established optimal biological dose for emactuzumab, a CSF1R dimerization inhibitor. Patients who developed edema in response to emactuzumab had elevated HA in peripheral blood. Our findings indicate that an early increase of peripheral HA can serve as a pharmacodynamic marker for edema development and suggest potential interventions based on MMP inhibition for relieving periorbital edema in patients treated with CSF1R inhibitors.

Radiotherapy in the Era of Immunotherapy With a Focus on Non-Small-Cell Lung Cancer: Time to Revisit Ancient Dogmas?

Radiation-induced immune effects have been extensively deciphered over the last few years, leading to the concept of the dual immune effect of radiotherapy with both immunostimulatory and immunosuppressive effects. This explains why radiotherapy alone is not able to drive a strong anti-tumor immune response in most cases, hence underlining the rationale for combining both radiotherapy and immunotherapy. This association has generated considerable interest and hundreds of trials are currently ongoing to assess such an association in oncology. However, while some trials have provided unprecedented results or shown much promise, many hopes have been dashed. Questions remain, therefore, as to how to optimize the combination of these treatment modalities. This narrative review aims at revisiting the old, well-established concepts of radiotherapy relating to dose, fractionation, target volumes and organs at risk in the era of immunotherapy. We then propose potential innovative approaches to be further assessed when considering a radio-immunotherapy association, especially in the field of non-small-cell lung cancer (NSCLC). We finally propose a framework to optimize the association, with pragmatic approaches depending on the stage of the disease.

The Activity of Crizotinib in Chemo-Refractory MET-Amplified Esophageal and Gastric Adenocarcinomas: Results from the AcSé-Crizotinib Program.

BACKGROUND: The AcSé-crizotinib program provides extensive screening of crizotinib-targeted genomic alteration in several malignancies. We here report the results in patients with esogastric MET-amplified adenocarcinomas. OBJECTIVE: The objective of the study was to evaluate the efficacy and tolerability of crizotinib in patients with pretreated esogastric MET-amplified adenocarcinoma who have no alternative treatment options. PATIENTS AND METHODS: MET expression was evaluated by fluorescence in situ hybridization in tumor samples with immunohistochemistry scores ≥ 2+. Patients with chemo-refractory tumors showing ≥ 6 MET copies were eligible for crizotinib 250 mg twice daily. The primary efficacy outcome was the objective response rate after two cycles of crizotinib. RESULTS: MET was prospectively analyzed in 570 esogastric adenocarcinomas. Amplifications were found in 35/570 adenocarcinomas (29/523 gastric and 6/47 esophageal). Nine patients were treated with crizotinib. The objective response rate after two cycles was 33.3% (95% CI 7.5-70), the best overall response rate was 55.6% (95% CI 21.2-86.3), with median progression-free survival of 3.2 months (95% CI 1.0-5.4), and overall survival of 8.1 months (95% CI 1.7-24.6). Safety was consistent with that previously reported for crizotinib. CONCLUSIONS: Large-scale screening for MET-amplified esogastric adenocarcinomas is feasible. MET amplification was observed in 5.5% of gastric and 12.8% of esophageal adenocarcinomas. Crizotinib shows encouraging results in selected patients. Thus, c-MET inhibition for MET-amplified tumors deserves further evaluation. TRIAL REGISTRATION NUMBER: NCT02034981. DATE OF REGISTRATION: 14 January 2014.

VOTRAGE study: Phase I dose-escalation study of pazopanib in unfit older patients.

BACKGROUND: Pazopanib is a tyrosine kinase inhibitor given at the approved dose of 800 mg orally once daily (OD), but often requiring individual dose adjustment due to toxicity. Limited data is available to guide prescription in older patients especially the unfit according to geriatric assessment. PATIENTS AND METHODS: VOTRAGE is a 3 + 3 dose-escalation, open-label phase I trial of continuous OD oral administration of pazopanib to evaluate safety, PK and PD data in unfit older patients with advanced solid tumors. The primary objective was to determine the maximum tolerated dose (MTD). PK data were compared with those obtained in younger adult patients in a population PK analysis. RESULTS: Eighteen patients with a median age of 82.5 years (range 75-91) were included in three dosing cohorts (400, 600, and 800 mg daily). Three dose-limiting toxicities (DLT) were observed in five patients at 800 mg and one DLT at 600 mg in six evaluable patients. MTD was defined as level 2 dose (600 mg). Individual oral clearance was not correlated with age. A relationship was observed between the occurrence of DLT and pazopanib plasma exposure. Decreased oral bioavailability of pazopanib when given with proton-pump inhibitors was confirmed in this group of patients. CONCLUSION: We recommend performing geriatric assessment in patients older than 75 and starting pazopanib at 600 mg per day in unfit older patients. Therapeutic drug monitoring appears very helpful in this population.

Regorafenib-Avelumab Combination in Patients with Microsatellite Stable Colorectal Cancer (REGOMUNE): A Single-arm, Open-label, Phase II Trial.

PURPOSE: Regorafenib is synergistic with immune checkpoint inhibition in colorectal cancer preclinical models. PATIENTS AND METHODS: This was a single-arm, multicentric phase II trial. Regorafenib was given 3 weeks on/1 week off, 160 mg every day; avelumab 10 mg/kg i.v. was given every 2 weeks, beginning at cycle 1, day 15 until progression or unacceptable toxicity. The primary endpoint was the confirmed objective response rate under treatment, as per RECIST 1.1. The secondary endpoints included a 1-year nonprogression rate, progression-free survival (PFS), and overall survival (OS), safety and biomarkers studies performed on sequential tumor samples obtained at baseline and at cycle 2 day 1. RESULTS: Forty-eight patients were enrolled in four centers. Forty-three were assessable for efficacy after central radiological review. Best response was stable disease for 23 patients (53.5%) and progressive disease for 17 patients (39.5%). The median PFS and OS were 3.6 months [95% confidence interval (CI), 1.8-5.4] and 10.8 months (95% CI, 5.9-NA), respectively. The most common grade 3 or 4 adverse events were palmar-plantar erythrodysesthesia syndrome (n = 14, 30%), hypertension (n = 11, 23%), and diarrhea (n = 6, 13%). High baseline infiltration by tumor-associated macrophages was significantly associated with adverse PFS (1.8 vs. 3.7 months; P = 0.002) and OS (3.7 months vs. not reached; P = 0.002). Increased tumor infiltration by CD8+ T cells at cycle 2, day 1 as compared with baseline was significantly associated with better outcome. CONCLUSIONS: The combination of regorafenib + avelumab mobilizes antitumor immunity in a subset of patients with microsatellite stable colorectal cancer. Computational pathology through quantification of immune cell infiltration may improve patient selection for further studies investigating this approach.

PD-1 blockade restores helper activity of tumor-infiltrating, exhausted PD-1hiCD39+ CD4 T cells.

Tumor antigen-specific CD4 T cells accumulate at tumor sites, evoking their involvement in antitumor effector functions in situ. Contrary to CD8 cytotoxic T lymphocyte exhaustion, that of CD4 T cells remains poorly appreciated. Here, using phenotypic, transcriptomic, and functional approaches, we characterized CD4 T cell exhaustion in patients with head and neck, cervical, and ovarian cancer. We identified a CD4 tumor-infiltrating lymphocyte (TIL) population, defined by high PD-1 and CD39 expression, which contained high proportions of cytokine-producing cells, although the quantity of cytokines produced by these cells was low, evoking an exhausted state. Terminal exhaustion of CD4 TILs was instated regardless of TIM-3 expression, suggesting divergence with CD8 T cell exhaustion. scRNA-Seq and further phenotypic analyses uncovered similarities with the CD8 T cell exhaustion program. In particular, PD-1hiCD39+ CD4 TILs expressed the exhaustion transcription factor TOX and the chemokine CXCL13 and were tumor antigen specific. In vitro, PD-1 blockade enhanced CD4 TIL activation, as evidenced by increased CD154 expression and cytokine secretion, leading to improved dendritic cell maturation and consequently higher tumor-specific CD8 T cell proliferation. Our data identify exhausted CD4 TILs as players in responsiveness to immune checkpoint blockade.