A phase I/II study of arfolitixorin and 5-fluorouracil in combination with oxaliplatin (plus or minus bevacizumab) or irinotecan in metastatic colorectal cancer.

BACKGROUND: 5-fluorouracil (5-FU) combined with a folate remains an essential treatment component for metastatic colorectal cancer (mCRC). Leucovorin is the folate most often used, but requires intracellular conversion to a reduced folate, and has high pharmacokinetic variability and limited bioavailability in patients with low folate pathway gene expression. Arfolitixorin is an immediately active form of folate, [6R]-5,10-methylenetetrahydrofolate ([6R]-MTHF), and may improve outcomes. PATIENTS AND METHODS: This open-label, multicenter, phase I/II study in patients with mCRC (NCT02244632) assessed the tolerability and efficacy of first- or second-line arfolitixorin (30, 60, 120, or 240 mg/m2 intravenous) with 5-FU alone, or in combination with oxaliplatin (plus or minus bevacizumab) or irinotecan, every 14 days. Safety, efficacy, and pharmacokinetics were assessed before and after four cycles (8 weeks) of treatment. RESULTS: In 105 treated patients, investigators reported 583 adverse events (AEs) in 86 patients (81.9%), and 256 AEs (43.9%) were potentially related to arfolitixorin and 5-FU. Dose adjustments were required in 16 patients (15.2%). At 8 weeks, 9 out of 57 patients assessed for efficacy achieved an objective response (15.8%), and all 9 achieved a partial response. Six of these nine patients had received arfolitixorin as a first-line treatment. A further 33 patients (57.9%) achieved stable disease. Pharmacokinetics were assessed in 35 patients. The average tmax was 10 min, and area under the plasma concentration-time curve from time 0 to 1 h increased linearly between 30 and 240 mg/m2. No accumulation was observed for [6R]-MTHF following repeated administration, and there were no major pharmacokinetic differences between cycle 1 and cycle 4 at any dose. CONCLUSIONS: Arfolitixorin is a well-tolerated moderator of 5-FU activity. It is suitable for further investigation in mCRC and has the potential to improve treatment outcomes in patients with low folate pathway gene expression. Arfolitixorin can easily be incorporated into current standard of care, requiring minimal changes to chemotherapy regimens.

Health-related quality of life in patients with advanced melanoma treated with ipilimumab: prognostic implications and changes during treatment.

BACKGROUND: We have previously reported that the safety and efficacy of ipilimumab in real-world patients with metastatic melanoma were comparable to clinical trials. Few studies have explored health-related quality of life (HRQL) in real-world populations receiving checkpoint inhibitors. This study reports HRQL in real-world patients receiving ipilimumab and assesses the prognostic value of patient-reported outcome measures. PATIENTS AND METHODS: Ipi4 (NCT02068196) was a prospective, multicentre, interventional phase IV trial. Real-world patients (N = 151) with metastatic melanoma were treated with ipilimumab 3 mg/kg intravenously as labelled. HRQL was assessed by the European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire at baseline and after 10-12 weeks. RESULTS: The European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire was completed by 93% (141/151 patients) at baseline, and by 82% at 10-12 weeks. Poor performance status and elevated C-reactive protein (CRP) were associated with worse baseline HRQL. Clinically relevant and statistically significant deteriorations in HRQL from baseline to weeks 10-12 were reported (P <0.05). Baseline physical functioning [hazard ratio (HR) 1.96, P = 0.016], role functioning (HR 2.15, P <0.001), fatigue (HR 1.60, P = 0.030), and appetite loss (HR 1.76, P = 0.012) were associated with poorer overall survival independent of performance status, lactate dehydrogenase (LDH), and CRP. We further developed a prognostic model, combining HRQL outcomes with performance status, LDH, and CRP. This model identified three groups with large and statistically significant differences in survival. CONCLUSIONS: Systemic inflammation is associated with impaired HRQL. During treatment with ipilimumab, HRQL deteriorated significantly. Combining HRQL outcomes with objective risk factors provided additional prognostic information that may aid clinical decision making.

Quality of life with encorafenib plus cetuximab with or without binimetinib treatment in patients with BRAF V600E-mutant metastatic colorectal cancer: patient-reported outcomes from BEACON CRC.

BACKGROUND: In the BEACON CRC study (NCT02928224), encorafenib plus cetuximab with binimetinib {9.3 versus 5.9 months; hazard ratio (HR) [95% confidence interval (CI)]: 0.60 [0.47-0.75]} or without binimetinib [9.3 versus 5.9 months; HR (95% CI): 0.61 (0.48-0.77)] significantly improved overall survival (OS) compared with the previous standard of care (control) in patients with BRAF V600E metastatic colorectal cancer (mCRC). Quality of life (QoL) was a secondary endpoint, assessed using validated instruments. PATIENTS AND METHODS: BEACON CRC was a randomized, open-label, phase III study comparing encorafenib plus cetuximab with or without binimetinib and the investigator's choice of irinotecan plus cetuximab or FOLFIRI plus cetuximab (chemotherapy control) in patients with previously treated BRAF V600E mCRC. Patient-reported QoL assessments included the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC) and Functional Assessment of Cancer Therapy-Colorectal (FACT-C). The primary outcome for these tools was time to definitive 10% deterioration. RESULTS: Encorafenib plus cetuximab, both with and without binimetinib, was associated with longer median times to definitive 10% deterioration versus the control group in the EORTC Global Health Status scale [HR (95% CI): 0.65 (0.52-0.80) versus 0.61 (0.49-0.75), respectively] and the FACT-C functional well-being subscale [HR (95% CI): 0.62 (0.50-0.76) versus 0.58 (0.47-0.72), respectively]. Consistent results were observed across all subscales of the EORTC and FACT-C instruments. QoL was generally maintained during treatment for the global EORTC and FACT-C scales. CONCLUSIONS: In addition to improving OS, encorafenib plus cetuximab with or without binimetinib delays QoL decline in previously treated patients with BRAF V600E-mutant mCRC.

Total circulating cell-free DNA as a prognostic biomarker in metastatic colorectal cancer before first-line oxaliplatin-based chemotherapy.

BACKGROUND: Metastatic colorectal cancer (mCRC) is a heterogeneous disease where prognosis is dependent both on tumor biology and host factors. Total circulating cell-free DNA (cfDNA) has shown to harbor prognostic information in mCRC, although less is known about the biological correlates of cfDNA levels in this patient group. The primary objective was to evaluate the prognostic value of pretreatment cfDNA in patients receiving the first-line oxaliplatin-based chemotherapy for mCRC, by using a predefined upper limit of normal (ULN) from a cohort of presumed healthy individuals. The secondary objective was to model cfDNA levels as a function of predefined tumor and host factors. PATIENTS AND METHODS: This was a retrospective post hoc study based on a prospective multicenter phase III trial, the NORDIC-VII study. DNA was purified from 547 plasma samples and cfDNA quantified by a droplet digital PCR assay (B2M, PPIA) with controls for lymphocyte contamination. Main clinical end point was overall survival (OS). RESULTS: cfDNA was quantified in 493 patients, 54 were excluded mainly due to lymphocyte contamination. Median cfDNA level was 7673 alleles/ml (1050-1 645 000) for B2M and 5959 alleles/ml (555-854 167) for PPIA. High cfDNA levels were associated with impaired outcome; median OS of 16.6 months for levels above ULN and 25.9 months for levels below ULN (hazard ratio = 1.83, 95% confidence interval 1.51-2.21, P < 0.001). The result was confirmed in multivariate OS analysis adjusting for established clinicopathological characteristics. A linear regression model predicted cfDNA levels from sum of longest tumor diameters by RECIST, the presence of liver metastases and systemic inflammatory response as measured by interleukin 6 (F(6, 357) = 62.7, P < 0.001). CONCLUSION: cfDNA holds promise as a minimally invasive and clinically relevant prognostic biomarker in mCRC before initiating first-line oxaliplatin-based chemotherapy and may be a complex entity associated with tumor burden, liver metastases and systemic inflammatory response. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00145314.

Prognostic biomarkers for immunotherapy with ipilimumab in metastatic melanoma.

New therapies, including the anti-cytotoxic T lymphocyte antigen (CTLA)-4 antibody, ipilimumab, is approved for metastatic melanoma. Prognostic biomarkers need to be identified, because the treatment has serious side effects. Serum samples were obtained before and during treatment from 56 patients with metastatic or unresectable malignant melanoma, receiving treatment with ipilimumab in a national Phase IV study (NCT0268196). Expression of a panel of 17 inflammatory-related markers reflecting different pathways including extracellular matrix remodeling and fibrosis, vascular inflammation and monocyte/macrophage activation were measured at baseline and the second and/or third course of treatment with ipilimumab. Six candidate proteins [endostatin, osteoprotegerin (OPG), C-reactive protein (CRP), pulmonary and activation-regulated chemokine (PARC), growth differentiation factor 15 (GDF15) and galectin-3 binding-protein (Gal3BP)] were persistently higher in non-survivors. In particular, high Gal3BP and endostatin levels were also independently associated with poor 2-year survival after adjusting for lactate dehydrogenase, M-stage and number of organs affected. A 1 standard deviation increase in endostatin gave 1·74 times [95% confidence interval (CI) = 1·10-2·78, P = 0·019] and for Gal3BP 1·52 times (95% CI = 1·01-2·29, P = 0·047) higher risk of death in the adjusted model. Endostatin and Gal3BP may represent prognostic biomarkers for patients on ipilimumab treatment in metastatic melanoma and should be further evaluated. Owing to the non-placebo design, we could only relate our findings to prognosis during ipilimumab treatment.

Differential effects of epidermal growth factor (EGF) receptor ligands on receptor binding, downstream signalling pathways and DNA synthesis in hepatocytes.

Hepatocytes are responsive to mitogenic effects of several ligands acting via EGFR. Studying primary cultures of rat hepatocytes, we found that, as compared to EGF, HB-EGF had a markedly higher affinity of the EGFR, while AR and TGFα had lower affinity. HB-EGF was also more potent compared to the other growth factors regarding phosphorylation of EGFR, Shc, ERK1/2 and Akt. All ligands induced phosphorylation of ErbB2, indicating receptor heterodimerization. TGFα, despite having much lower receptor affinity, was about equally potent and efficacious as HB-EGF as a stimulator of DNA synthesis. In contrast, EGF had relatively high affinity but markedly lower efficacy in stimulation of DNA synthesis. The results suggest that amplifying and/or inhibitory mechanisms may modulate the mitogenic responses downstream of the initial signalling steps, and that this may affect the effects of the EGFR ligands differentially.

Impaired nuclear accumulation and shortened phosphorylation of ERK after growth factor stimulation in cultured hepatocytes from rats exposed to 2-acetylaminofluorene.

The hepatic carcinogen 2-acetylaminofluorene (AAF) exerts its effect as a tumor promoter by mitoinhibition of normal hepatocytes. Initiated cells proliferate selectively and develop into preneoplastic foci and subsequently into carcinomas. To study whether some of the mitoinhibitory effects of AAF could be attributed to an influence on intracellular signal transduction, growth factor signaling was studied in cultured hepatocytes from rats fed AAF for 7 d. Activation through the epidermal growth factor receptor (EGFR) was used to probe possible changes in downstream mitogenic signaling mechanisms. The proliferative response to epidermal growth factor (EGF), measured as proliferating cell nuclear antigen expression and thymidine incorporation, was almost completely inhibited in hepatocytes exposed to AAF. Neither EGFR protein levels nor EGF binding was notably altered in AAF-exposed hepatocytes as opposed to normal hepatocytes. The initial tyrosine phosphorylation of EGFR and downstream activation of Sos, Raf-1, and extracellular signal-regulated protein kinase (ERK) were similar in AAF-treated and control hepatocytes. Even though ERK phosphorylation was unaffected, a remarkable (80%) reduction of ERK nuclear accumulation was observed in AAF-exposed hepatocytes immediately after mitogen stimulation. EGFR tyrosine phosphorylation and downstream signaling lasted 6 h in control cells versus 2 h in AAF-exposed hepatocytes. We previously demonstrated that AAF inhibits the growth factor-dependent induction of cyclin D1 and arrests hepatocyte cell-cycle progression before the p21/CIP1-controlled DNA-damage check point. The present data indicate that the DNA-damaging carcinogen AAF induces growth inhibition by a distinct inhibition of ERK nuclear accumulation after mitogen stimulation. Inhibition of intracellular signal transduction may represent a novel mechanism of growth arrest. Mol. Carcinog. 28:84-96, 2000.

EGF-induced activation of Stat1, Stat3, and Stat5b is unrelated to the stimulation of DNA synthesis in cultured hepatocytes.

Transcription factors of the STAT family have been implicated in regulation of cell proliferation. EGF activates several STAT proteins in liver. We have studied the relationship between STAT activation and the growth-stimulatory effect of EGF in rat hepatocytes, assessing specific DNA-binding activity of STAT proteins in electrophoretic mobility-shift and supershift assays. In freshly isolated hepatocytes, EGF activated Stat1, Stat3, and, particularly, Stat5b. However, the ability of EGF to produce this activation was rapidly attenuated when the cells were cultured, while the activation by IFN-gamma (Stat1) and IL-6 (Stat3) was sustained. Hepatocytes cultured for 24-48 h are highly sensitive to the stimulatory effect of EGF on S phase entry. In these cells EGF did not detectably activate Stat1, Stat3, or Stat5b but markedly stimulated MAP kinase (Erk1/2). Thus, although EGF has the ability to activate several STAT proteins, this did not seem to be part of the mitogenic mechanisms used by the EGF receptor in hepatocytes.

Endocytosed epidermal growth factor (EGF) receptors contribute to the EGF-mediated growth arrest in A431 cells by inducing a sustained increase in p21/CIP1.

We investigated the ability of endocytosed activated epidermal growth factor receptors (EGFR) to induce expression of the cyclin-interacting protein p21/CIP1 in A431 cells. Transforming growth factor alpha (TGFalpha) and EGF both induced tyrosine phosphorylation, induction of p21/CIP1, and thereby inhibition of DNA synthesis. TGFalpha is released from the EGFR when the TGFalpha-EGFR complex encounters low pH upon endocytosis. Consistently, we found more rapid dephosphorylation of the EGFR and less induction of p21/CIP1 by TGFalpha than by EGF. This difference was abolished upon neutralizing endosomal pH by the carboxylic ionophore monensin or the proton ATPase inhibitor bafilomycin A1. When surface-bound TGFalpha was removed by acid stripping and endosomal pH was neutralized with bafilomycin A1, TGFalpha stimulated EGFR tyrosine phosphorylation, induced p21/CIP1, and inhibited DNA synthesis. This strongly suggests that p21/CIP1 can be induced by endocytosed, activated EGFR and that endocytosed EGFR can affect cell growth.

Response to transforming growth factor alpha (TGFalpha) and epidermal growth factor (EGF) in hepatocytes: lower EGF receptor affinity of TGFalpha is associated with more sustained activation of p42/p44 mitogen-activated protein kinase and greater efficacy in stimulation of DNA synthesis.

The epidermal growth factor (EGF) receptor mediates the effects of both EGF and transforming growth factor alpha (TGFalpha). Recent data suggested that EGF acts as a partial agonist/antagonist in hepatocytes, TGFalpha exerting a larger maximal stimulation of DNA synthesis than EGF. To further study the mechanisms involved in mediating the different effects of EGF and TGFalpha, we have examined receptor binding of the two growth factors and their action on the p42/p44 mitogen-activated protein (MAP) kinase activity in hepatocytes. Single-ligand concentration curves and competition experiments showed that the binding affinity to a common population of surface binding sites was about 20-fold lower for TGFalpha than for EGF. MAP kinase activity responded to EGF and TGFalpha with different kinetics. While the two agents produced almost identical acute (5 min) stimulation (peak about fivefold), TGFalpha produced a more sustained MAP kinase activity than EGF. The difference between EGF and TGFalpha was still detectable 24 h after growth factor addition. The results show that in hepatocytes a lower receptor affinity of TGFalpha, as compared to EGF, is associated with a more sustained activation of the MAP kinase and a greater efficacy in the stimulation of DNA synthesis. This suggests that differential interaction of these two agents with the EGF receptor results in differences in the downstream events elicited at a given level of receptor occupancy. The data also are compatible with a role of a prolonged MAP kinase activity in the mitogenic effects of EGF and TGFalpha.

Epidermal growth factor behaves as a partial agonist in hepatocytes: effects on DNA synthesis in primary culture and competition with transforming growth factor alpha.

The structurally related mitogens epidermal growth factor (EGF) and transforming growth factor (alpha (TGFalpha) are believed to exert all their effects via the same receptor. We have compared the effects of EGF and TGFalpha, and examined their interaction, on DNA synthesis in cultured rat hepatocytes. The potency of the two agents was similar, or slightly higher for EGF, but TGFalpha stimulated the DNA synthesis more efficiently, producing at high levels a rate of S phase entry that clearly exceeded (two to threefold) that obtained with maximally effective concentrations of EGF. While the hepatocytes became more sensitive both to TGFalpha and EGF when addition of the agents was postponed until late in the prereplicative period, TGFalpha exhibited higher efficacy than EGF both at early and late exposure. When EGF and TGFalpha were added together at 24 h, TGFalpha further enhanced the DNA synthesis in the presence of a saturating concentration (5 nM) of EGF, while EGF dose-dependently reduced the DNA synthesis in the presence of a high concentration (10 nM) of TGFalpha. The results show a lower efficacy of EGF than of TGFalpha, and, therefore, EGF displays the characteristics of a partial agonist in its EGF receptor-mediated growth stimulation in hepatocytes.

Elevated glucose concentrations inhibit DNA synthesis and expression of c-myc in cultured hepatocytes.

Glucose depressed DNA synthesis in rat hepatocytes in primary culture. As compared to controls cultured with 5.6 mM glucose, maximal (> or = 75%) inhibition was obtained at 20-30 mM, and half-maximal effect at 10-15 mM. Comparison of D- and L-glucose showed that the effect was specific for the D-form. Maximal inhibition required the presence of glucose during the first 24 hours of culture. The expression of the c-myc gene was reduced when the hepatocytes were cultured in the presence of elevated glucose. The responses to epidermal growth factor, insulin and vasopressin, in terms of percentual stimulation of DNA synthesis, were qualitatively similar at 5.6 and 16.8 mM glucose, while glucagon stimulated more strongly when the glucose concentration was increased; glucagon at concentrations > or = 1 nM reversed the inhibition by glucose. 8-Br-cAMP mimicked the effect of glucagon. These results suggest that an increase in the level of glucose depresses hepatocyte DNA synthesis. The effect is associated with lowered expression of the c-myc gene and is counteracted by cAMP.

Dual effects of glucagon and cyclic AMP on DNA synthesis in cultured rat hepatocytes: stimulatory regulation in early G1 and inhibition shortly before the S phase entry.

Although several lines of evidence implicate cyclic AMP in the humoral control of liver growth, its precise role is still not clear. To explore further the role of cyclic AMP in hepatocyte proliferation, we have examined the effects of glucagon and other cyclic AMP-elevating agents on the DNA synthesis in primary cultures of adult rat hepatocytes, with particular focus on the temporal aspects. The cells were cultured in a serum-free, defined medium and treated with epidermal growth factor (EGF), insulin, and dexamethasone. Exposure of the hepatocytes to low concentrations (10 pM-1 nM) of glucagon in the early stages of culturing (usually within 6 h from plating) enhanced the initial rate of S phase entry without affecting the lag time from the plating to the onset of DNA synthesis, whereas higher concentrations inhibited it. In contrast, glucagon addition at later stages (24-45 h after plating) produced only the inhibition. Thus, if glucagon was added at a time when there was a continuous EGF/insulin-induced recruitment of cells to S phase, the rate of G1-S transition was markedly decreased within 1-3 h. This inhibitory effect occurred at low glucagon concentrations (ID50 less than 1 nM) and was mimicked by cholera toxin, forskolin, isobutyl methylxanthine, and 8-bromo cyclic AMP. The results indicate that cyclic AMP has dual effects on hepatocyte proliferation with a stimulatory modulation early in the prereplicative period (G0 or early G1), and a marked inhibition exerted immediately before the transition from G1 to S phase.