A First-in-Human, Phase I, Multicenter, Open-Label, Dose-Escalation Study of PCA062: An Antibody-Drug Conjugate Targeting P-Cadherin, in Patients With Solid Tumors.

This first-in-human (FIH), phase I, multicenter, open-label study was conducted to characterize the safety, tolerability, pharmacokinetics, and preliminary efficacy, and to establish the MTD/recommended dose for expansion (RDE) of PCA062 in patients with solid tumors. Adult patients with any solid tumor type and having a documented P-cadherin-positive tumor were enrolled; exceptions to P-cadherin positivity requirement were head and neck squamous cell carcinomas (HNSCC) and esophageal squamous cell carcinoma (ESCC). Dose escalation was guided by an adaptive Bayesian logistic regression model with escalation with overdose control to determine the MTD/RDE. Forty-seven patients were treated at 10 different dose levels of PCA062, ranging from 0.4 to 5.0 mg/kg every 2 weeks administered as a 1-hour intravenous infusion. All enrolled patients discontinued the treatment; primary reason for discontinuation was progressive disease (78.7%). All 47 patients experienced at least one AE, of which 32 patients had a grade ≥3 AE and 37 patients experienced AEs suspected to be study drug related. The MTD of PCA062 was 3.6 mg/kg every 2 weeks and thrombocytopenia was reported as a DLT that was attributed to the known toxicities of the DM1 payload with no P-cadherin-related toxicities. Pharmacokinetics was proportional, and no patients developed antidrug antibodies, suggesting adequate exposure at the doses tested. One patient of 47 achieved a partial response and there was no correlation between tumor P-cadherin expression and clinical efficacy. Because of limited antitumor activity at the MTD level, Novartis has terminated clinical development of PCA062 (NCT02375958).

A Randomized Phase II Study of Anti-CSF1 Monoclonal Antibody Lacnotuzumab (MCS110) Combined with Gemcitabine and Carboplatin in Advanced Triple-Negative Breast Cancer.

PURPOSE: This phase II study determined the efficacy of lacnotuzumab added to gemcitabine plus carboplatin (gem-carbo) in patients with advanced triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Female patients with advanced TNBC, with high levels of tumor-associated macrophages not amenable to curative treatment by surgery or radiotherapy were enrolled. Lacnotuzumab was dosed at 10 mg/kg every 3 weeks, ± a dose on cycle 1, day 8. Gemcitabine (1,000 mg/m2) and carboplatin (dose in mg calculated by area under the curve [mg/mL/min] × (glomerular filtration rate [mL/min] + 25 [mL/min]) were dosed every 3 weeks. Treatment continued until unacceptable toxicity, disease progression, or discontinuation by physician/patient. RESULTS: Patients received lacnotuzumab + gem-carbo (n = 34) or gem-carbo (n = 15). Enrollment was halted due to recruitment challenges owing to rapid evolution of the therapeutic landscape; formal hypothesis testing of the primary endpoint was therefore not performed. Median progression-free survival was 5.6 months [90% confidence interval (CI), 4.47-8.64] in the lacnotuzumab + gem-carbo arm and 5.5 months (90% CI, 3.45-7.46) in the gem-carbo arm. Hematologic adverse events were common in both treatment arms; however, patients treated with lacnotuzumab experienced more frequent aspartate aminotransferase, alanine aminotransferase, and creatine kinase elevations. Pharmacokinetic results showed that free lacnotuzumab at 10 mg/kg exhibited a typical IgG pharmacokinetic profile and target engagement of circulating colony-stimulating factor 1 ligand. CONCLUSIONS: Despite successful target engagement and anticipated pharmacokinetic profile, lacnotuzumab + gem-carbo showed comparable antitumor activity to gem-carbo alone, with slightly poorer tolerability. However, the data presented in this article would be informative for future studies testing agents targeting the CSF1-CSF1 receptor pathway in TNBC.

Co-Targeting of MDM2 and CDK4/6 with Siremadlin and Ribociclib for the Treatment of Patients with Well-Differentiated or Dedifferentiated Liposarcoma: Results from a Proof-of-Concept, Phase Ib Study.

PURPOSE: Well-differentiated (WDLPS) and dedifferentiated (DDLPS) liposarcoma are characterized by co-amplification of the murine double minute-2 (MDM2) and cyclin-dependent kinase-4 (CDK4) oncogenes. Siremadlin, a p53-MDM2 inhibitor, was combined with ribociclib, a CDK4/6 inhibitor, in patients with locally advanced/metastatic WDLPS or DDLPS who had radiologically progressed on, or despite, prior systemic therapy. PATIENTS AND METHODS: In this proof-of-concept, phase Ib, dose-escalation study, patients received siremadlin and ribociclib across different regimens until unacceptable toxicity, disease progression, and/or treatment discontinuation: Regimen A [4-week cycle: siremadlin once daily (QD) and ribociclib QD (2 weeks on, 2 weeks off)], Regimen B [3-week cycle: siremadlin once every 3 weeks; ribociclib QD (2 weeks on, 1 week off)], and Regimen C [4-week cycle: siremadlin once every 4 weeks; ribociclib QD (2 weeks on, 2 weeks off)]. The primary objective was to determine the maximum tolerated dose (MTD) and/or recommended dose for expansion (RDE) of siremadlin plus ribociclib in one or more regimens. RESULTS: As of October 16, 2019 (last patient last visit), 74 patients had enrolled. Median duration of exposure was 13 (range, 1-174) weeks. Dose-limiting toxicities occurred in 10 patients, most of which were Grade 3/4 hematologic events. The RDE was siremadlin 120 mg every 3 weeks plus ribociclib 200 mg QD (Regimen B). Three patients achieved a partial response, and 38 achieved stable disease. One patient (Regimen C) died as a result of treatment-related hematotoxicity. CONCLUSIONS: Siremadlin plus ribociclib demonstrated manageable toxicity and early signs of antitumor activity in patients with advanced WDLPS or DDLPS.

M2-like macrophages induce colon cancer cell invasion via matrix metalloproteinases.

The inflammatory milieu plays an important role in colon cancer development and progression. Previously, we have shown that tumor-associated macrophages (TAMs), an important component of the tumor microenvironment, are enriched in tumors compared with normal tissue and confer a poorer prognosis. In the present study, we found that matrix metallopeptidase-9 (MMP-9), which degrades extracellular matrix proteins, was increased in biopsies from colon cancer patients and in mouse xenografts with SW480 cell-derived tumors. SW480 colon cancer cells exposed to M2-like macrophage-conditioned medium (M2-medium) exhibited increased MMP-9 mRNA, protein expression and gelatinase activity. A similar effect was obtained by the addition of tumor necrosis factor-α (TNFα) and leukotriene D4 (LTD4 ). MMP-9 expression and activity were reduced by a TNFα blocking antibody adalimumab and a cysteinyl leukotriene receptor 1 (CysLTR1, the receptor for LTD4 ) antagonist montelukast. M2-medium also induced changes in the epithelial-mesenchymal transition (EMT) markers E-cadherin, ß-catenin, vimentin, and snail in SW480 cells. We also found that both M2-medium and TNFα and LTD4 induced stabilization/nuclear translocation of ß-catenin. Furthermore, we also observed an elongated phenotype that may indicate increased invasiveness, as confirmed in a collagen I invasion assay. M2-medium increased the invasive ability, and a similar effect was also obtained by the addition of TNFα and LTD4 . The specific MMP inhibitor I or adalimumab and montelukast reduced the number of invasive cells. In conclusion, our findings show that M2-medium enriched in TNFα and LTD4 promote colon cancer cell invasion via MMP-9 expression and activation and the induction of EMT.

The inflammatory mediator leukotriene D4 induces subcellular ß-catenin translocation and migration of colon cancer cells.

The abnormal activation of the Wnt/ß-catenin pathway frequently occurs in colorectal cancer. The nuclear translocation of ß-catenin activates the transcription of target genes that promote cell proliferation, survival, and invasion. The pro-inflammatory mediator leukotriene D4 (LTD4) exerts its effects through the CysLT1 receptor. We previously reported an upregulation of CysLT1R in patients with colon cancer, suggesting the importance of leukotrienes in colon cancer. The aim of this study was to investigate the impact of LTD4 on Wnt/ß-catenin signaling and its effects on proliferation and migration of colon cancer cells. LTD4 stimulation led to an increase in ß-catenin expression, ß-catenin nuclear translocation and the subsequent transcription of MYC and CCND1. Furthermore, LTD4 significantly reduced the expression of E-cadherin and ß-catenin at the plasma membrane and increased the migration and proliferation of HCT116 colon cancer cells. The effects of LTD4 can be blocked by the inhibition of CysLT1R. Furthermore, LTD4 induced the inhibition of glycogen synthase kinase 3 (GSK)-3ß activity, indicating a crosstalk between the G-protein-coupled receptor CysLT1 and the Wnt/ß-catenin pathway. In conclusion, LTD4, which can be secreted from macrophages and leukocytes in the tumor microenvironment, induces ß-catenin translocation and the activation of ß-catenin target genes, resulting in the increased proliferation and migration of colon cancer cells.

The prognostic significance of Wnt-5a expression in primary breast cancer is extended to premenopausal women.

Wnt-5a protein expression in primary tumors from unselected breast cancer patients has revealed a tumor suppressive function of the protein. However, in vitro experiments on human breast cancer cells have reported contradictory results, indicating both a tumor suppressive and promoting functions of Wnt-5a. This could be due to various functions of Wnt-5a in different subgroups of patients. The unselected cohorts analyzed to date for Wnt-5a protein expression contained few premenopausal patients. The aim of the present investigation was to evaluate the prognostic significance of Wnt-5a protein expression in a cohort of premenopausal women with comprehensive data on biomarkers, molecular subtypes and long-term outcome. In a randomized trial of adjuvant tamoxifen versus no adjuvant treatment, 564 premenopausal primary breast cancer patients were included. The median follow-up time was 14 years. A tumor tissue array was constructed and 361 samples were evaluated for Wnt-5a reactivity by immunohistochemistry. The primary end-point was recurrence-free survival. Wnt-5a protein expression was reduced or lost in 146/361 of tumors and correlated to younger age, estrogen receptor (ER) negativity and triple-negative phenotype. Wnt-5a was a prognostic factor in the whole cohort (p = 0.003). In patients with ER-positive tumors, Wnt-5a was an independent positive prognostic marker (HR 0.51 95% CI: 0.33-0.78 p = 0.002) and HER2 a negative prognostic marker (HR 2.84 95% CI: 1.51-5.31, p = 0.001) in a Cox multivariate analysis adjusted for standard prognostic markers and tamoxifen treatment. In the ER-negative subset, Wnt-5a added no prognostic information. In a subgroup analysis, Wnt-5a was significantly associated with better prognosis in patients with Luminal A tumors (p = 0.04). Conclusively, our results suggest that loss of Wnt-5a is a valuable prognostic marker in premenopausal breast cancer patients in particular in patients with ER-positive tumors and out-performed conventional prognostic factors in this subset of patients.

Nuclear expression of glycogen synthase kinase-3ß and lack of membranous ß-catenin is correlated with poor survival in colon cancer.

Dysregulation of Wnt/ß-catenin signaling is a hallmark of colon cancer. Glycogen synthase kinase-3ß (GSK-3ß) can be a positive regulator of survival and proliferation of cultured colon cancer cell but its role in clinical colon cancer is unknown. Our objectives were to evaluate the role of GSK-3ß in colon cancer. A tumor tissue microarray of primary colon cancers and metastases was used to evaluate expression and subcellular localization of GSK-3ß and ß-catenin. In total, 85 primary colon cancer samples were evaluated by immunohistochemistry. Immunoreactivity was correlated to known markers of adverse prognosis. Overall survival was the primary end-point. We found nuclear accumulation of GSK-3ß in 39% (33/85) of evaluated tumors. Nuclear GSK-3ß was significantly associated with shorter overall survival (p = 0.008), larger tumor size (p = 0.015), distant metastasis (p = 0.029) and loss of membranous ß-catenin (p = 0.007). Loss of membranous ß-catenin occurred in 37% (30/82) of the tumors and was associated with poor survival (p = 0.016). The combination of nuclear GSK-3ß and lack of membrane ß-catenin occurred in a total of 26% of the studied tumors (21/61) and was significantly and independently associated with poor prognosis. Our results suggest that nuclear expression of GSK-3ß and loss of membrane ß-catenin identify a subset of colon carcinomas with worse prognosis.

Rapid morphological changes and loss of collagen following experimental acute colonic obstruction.

PURPOSE: Anastomosis of an acutely obstructed colon is associated with an increased risk of dehiscence. In experimental models, acute obstruction decreases collagen in the colonic wall, but the time course and propagation along the colon of the biochemical changes are unknown. Furthermore, there is a paucity of information on the correlation between these biochemical changes and histological features. METHODS: Forty male Sprague Dawley rats were subjected to partial obstruction by placing a silicone ring around the left colon 30 mm above the reflection. Obstruction was maintained for 0, 1, 2, 3 or 4 days. Samples from five different locations along the colon were analysed on circumference, tissue water content, collagen concentration and histomorphology. Neutrophil and macrophage infiltration was characterized immunohistochemically. RESULTS: The colonic circumference and water content increased (p < 0.001), while the collagen concentration decreased by 48 % (p < 0.01) proximal to the obstruction already after 1 day. The degree of dilation and collagen reduction did not change significantly over the subsequent 3 days of obstruction, whereas the water content normalized by day 3. Mucosal and submucosal oedema and the relative neutrophil infiltration were highest after 1 day in the colonic segment proximal to the stenosis while the macrophage population continued to increase to day 4. Muscular necrosis in addition to ganglionitis and neuritis in the nervous plexus increased with duration of obstruction. CONCLUSIONS: The pronounced and rapid changes of the composition of cells and the extracellular matrix of the colonic wall following acute obstruction may be of guidance for present surgical treatments and future pharmacological interventions.

Concordant and opposite roles of DNA-PK and the "facilitator of chromatin transcription" (FACT) in DNA repair, apoptosis and necrosis after cisplatin.

BACKGROUND: Platinum-containing chemotherapy produces specific DNA damage and is used to treat several human solid tumors. Tumors initially sensitive to platinum-based drugs frequently become resistant. Inhibition of DNA repair is a potential strategy to enhance cisplatin effectiveness. After cisplatin treatment, a balance between repair and apoptosis determines whether cancer cells proliferate or die. DNA-dependent protein kinase (DNA-PK) binds to DNA double strand breaks (DSBs) through its Ku subunits and initiates non-homologous end joining. Inhibition of DNA-PK sensitizes cancer cells to cisplatin killing. The goal of this study is to elucidate the mechanism underlying the effects of DNA-PK on cisplatin sensitivity. RESULTS: Silencing the expression of the catalytic subunit of DNA-PK (DNA-PKcs) increased sensitivity to cisplatin and decreased the appearance of γH2AX after cisplatin treatment. We purified DNA-PK by its Ku86 subunit and identified interactors by tandem mass spectrometry before and after cisplatin treatment. The structure specific recognition protein 1 (SSRP1), Spt16 and γH2AX appeared in the Ku86 complex 5 hours after cisplatin treatment. SSRP1 and Spt16 form the facilitator of chromatin transcription (FACT). The cisplatin-induced association of FACT with Ku86 and γH2AX was abrogated by DNase treatment. In living cells, SSRP1 and Ku86 were recruited at sites of DSBs induced by laser beams. Silencing SSRP1 expression increased sensitivity to cisplatin and decreased γH2AX appearance. However, while silencing SSRP1 in cisplatin-treated cells increased both apoptosis and necrosis, DNA-PKcs silencing, in contrast, favored necrosis over apoptosis. CONCLUSIONS: DNA-PK and FACT both play roles in DNA repair. Therefore both are putative targets for therapeutic inhibition. Since DNA-PK regulates apoptosis, silencing DNA-PKcs redirects cells treated with cisplatin toward necrosis. Silencing FACT however, allows both apoptosis and necrosis. Targeting DNA repair in cancer patients may have different therapeutic effects depending upon the roles played by factors targeted.