Front-Line Bevacizumab plus Chemotherapy with or without Maintenance Therapy for Metastatic Breast Cancer: An Observational Study by the Hellenic Oncology Research Group.

Front-line bevacizumab (BEV) in combination with taxanes offers benefit in progression-free survival (PFS) in metastatic breast cancer (mBC). The medical records of mBC patients, treated with front-line BEV-based chemotherapy, were retrospectively reviewed in order to generate real life safety and efficacy data. Patients with human epidermal growth factor receptor 2 (HER2)-negative mBC treated with front-line BEV in combination with chemotherapy were eligible. Maintenance therapy with BEV and/or hormonal agents was at the physicians' discretion. Among the 387 included patients, the most common adverse events were anemia (61.9%, mainly grade 1), grade 3/4 neutropenia (16.5%), grade 1/2 fatigue (22.3%), and grade 1/2 neuropathy (19.6%). Dose reductions were required in 164 cycles (7.1%) and toxicity led to treatment discontinuation in 21 patients (5.4%). The median PFS and the median overall survival (OS) were 13.3 (95% CI: 11.7-14.8) and 32.3 months (95% CI: 27.7-36.9), respectively. Maintenance therapy, with hormonal agents (ET) and/or BEV, was associated with longer OS versus no maintenance therapy (47.2 versus 23.6 months; p < 0.001) in patients with hormone receptor (HR)-positive disease and BEV maintenance offered longer OS versus no maintenance in patients with HR-negative disease (52.8 versus 23.3; p = 0.023). These real-life data show that front-line BEV-based chemotherapy in HER2-negative mBC patients is an effective treatment with an acceptable toxicity profile. The potential benefit of maintenance treatment, especially ET, is important and warrants further research.

Efficacy of panitumumab in older patients with metastatic colorectal cancer: a retrospective analysis using the database of the Hellenic Oncology Research Group (HORG).

BACKGROUND: Although colorectal cancer (CRC) is a disease of the older patients, older patients are under-represented from randomized trials. Herein we conducted a retrospective analysis for the effect of panitumumab in the management of older patients (≥65 years) patients with metastatic CRC (mCRC) in the Hellenic Oncology Research Group's (HORG) database. METHODS: Τhe efficacy of panitumumab-based chemotherapy as front-line treatment in older patients with mCRC was assessed. RESULTS: In total, 110 older patients with KRAS exon 2 wild type tumors were treated with chemotherapy plus panitumumab. The median age was 74 years; 69.9% of the patients were male, with left-sided primary tumors (78.2%), ECOG Performance Status 0-1 (95.4%) and median number of metastatic sites 2. Sixty-two (Overall Response Rate-ORR: 56.4%; 95% CI: 48.8%-68.1%) achieved an objective response, while 21 (19.1%) had stable disease. Median Progression free survival (PFS) was 9.4 months (95% CI: 7.8-11.0 months) and median Overall survival (OS) 23.0 months (95% CI: 20.6-25.3 months). Additionally, a statistically significant difference in ORR (62.7% vs. 33.3%; p = .014), median PFS (12.9 vs. 5.7 months; p = .001) and median OS (31.6 vs. 16.7 months; p < .001) was observed in patients with left-sided compared to right-sided primary tumor. There was no treatment-related death. Grade 3-4 toxicities were neutropenia (8.9%) and diarrhea (14.5%) whereas skin rash grade 2 or 3 was recorded in 41.1% and 10.7%, respectively. CONCLUSIONS: The results of this retrospective study provide the evidence that combination chemotherapy plus panitumumab is active and well tolerated in older patients with mCRC.

Panitumumab in combination with modified docetaxel/cisplatin/5-fluorouracil as first-line treatment in gastric and gastroesophageal junction adenocarcinomas: a multicenter phase II study by the Hellenic Oncology Research Group.

BACKGROUND: A phase I/II study to define the maximum tolerated dose (MTD) of biweekly docetaxel/cisplatin/5-fluorouracil (DCF) plus panitumumab (P), its efficacy, and tolerability as first-line treatment in advanced gastroesophageal cancer. METHODS: In phase I part, patients with unresectable locally advanced or metastatic adenocarcinomas of the stomach or the gastroesophageal junction received cisplatin (40 mg/m2 on day 1), leucovorin (400 mg/m2 on day 1), 5-fluorouracil (400 mg/m2 bolus on day 1), 5-fluorouracil (1000 mg/m2/daycontinuous infusion on days 1-2), and escalated doses of docetaxel (on day 1) plus P (6 mg/kg on day 1) every 2 weeks. In phase II part, patients were treated with DCF/P at the MTD and the primary endpoint was response rate. The expected response rate was set at >40%. RESULTS: The MTD for docetaxel in the mDCF/P was defined at 40 mg/m2 and a total of 40 evaluable patients were enrolled in phase II study. One (2.5%) complete and 13 (32.5%) partial responses (overall response rate: 35%), as well as 16 (40%) disease stabilizations were documented. The median progression-free survival was 6.9 months (95% confidence interval [CI] 3.5-10.3) and the median overall survival was 11.3 months (95%CI 7.7-14.8). Grade 3-4 neutropenia occurred in 10 patients (25%) and febrile neutropenia in 2 (5%). Allergic reactions (grade 1-4) occurred in 9 patients (22.5%). There was 1 treatment-related death. CONCLUSIONS: mDCF/P combination was feasible, though associated with a poor toxicity profile. However, the study failed to meet its primary endpoint and was terminated prematurely due to futility.

Nab-paclitaxel as second-line treatment in advanced gastric cancer: a multicenter phase II study of the Hellenic Oncology Research Group.

BACKGROUND: This study evaluated the safety and efficacy of nab-paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma. METHODS: Thirty-nine pretreated patients [33 with taxane-based regimens (docetaxel, cisplatin, and fluorouracil)] and 6 with combination of fluoropyrimidines plus cisplatin with locally advanced inoperable and metastatic gastric and gastroesophageal junction adenocarcinoma were treated with weekly nab-paclitaxel (150 mg/m2 d1, d8, d15 in cycles of 28 days). RESULTS: Partial response (PR) was documented in nine patients (23.1%; 95% confidence interval 10.1-37.2%), stable disease (SD) in 11 (28.2%) and disease progression in 18 (46.2%). The disease control rate (SD + PR + complete response) was 51.3%. Grade 3 and 4 neutropenia occurred in 10.2% and 5.1% of patients, respectively; grade 3 anemia in 5.1%; grade 3 neurotoxicity in 5.1%; and grade 2 pain in 5.1%. The median progression-free survival was 3.0 months (range 0.3-13.6) and the median overall survival 6.8 months (range 0.3-22). CONCLUSION: Nab-paclitaxel as second-line treatment in locally advanced inoperable or metastatic gastric and gastroesophageal junction carcinoma is an active chemotherapy regimen with a manageable toxicity profile and merits further evaluation.

Glutaredoxin-1 regulates TRAF6 activation and the IL-1 receptor/TLR4 signalling.

Glutaredoxin-1 (GRX-1) is a cytoplasmic enzyme that highly contributes to the antioxidant defense system. It catalyzes the reversible reduction of glutathione-protein mixed disulfides, a process called deglutathionylation. Here, we investigated the role of GRX-1 in the pathway triggered by interleukin-1/Toll-like receptor 4 (IL-1R/TLR4) by using RNA interference (RNAi) in HEK293 and HeLa cells. TNF receptor-associated factor 6 (TRAF6) is an intermediate signalling molecule involved in the signal transduction by members of the interleukin-1/Toll-like receptor (IL-1R/TLR) family. TRAF6 has an E3 ubiquitin ligase activity which depends on the integrity of an amino-terminal really interesting new gene (RING) finger motif. Upon receptor activation, TRAF6 undergoes K63-linked auto-polyubiquitination which mediates protein-protein interactions and signal propagation. Our data showed that IL-1R and TLR4-mediated NF-κB induction was severely reduced in GRX-1 knockdown cells. We found that the RING-finger motif of TRAF6 is S-glutathionylated under normal conditions. Moreover, upon IL-1 stimulation TRAF6 undergoes deglutathionylation catalyzed by GRX-1. The deglutathionylation of TRAF6 is essential for its auto-polyubiquitination and subsequent activation. Taken together, our findings reveal another signalling molecule affected by S-glutathionylation and uncover a crucial role for GRX-1 in the TRAF6-dependent activation of NF-κB by IL-1R/TLRs.

S-glutathionylation of IRF3 regulates IRF3-CBP interaction and activation of the IFN beta pathway.

Interferon regulatory factor 3 (IRF3) is an essential transcriptional regulator of the interferon genes. IRF3 is constitutively present in a latent conformation in the cell cytoplasm. In cells infected by Sendai virus, IRF3 becomes phosphorylated, homodimerizes, translocates to the nucleus, binds to target genes and activates transcription by interacting with CBP/p300 co-activators. In this study, we report that in non-infected cells IRF3 is post-translationally modified by S-glutathionylation. Upon viral-infection, it undergoes a deglutathionylation step that is controlled by the cytoplasmic enzyme glutaredoxin-1 (GRX-1). In virus-infected GRX-1 knockdown cells, phosphorylation, homodimerization and nuclear translocation of IRF3 were not affected, but the transcriptional activity of IRF3 and the expression of interferon-beta (IFNbeta), were severely reduced. We show that deglutathionylation of IRF3 is necessary for efficient interaction of IRF3 with CBP, an event essential for transcriptional activation of the interferon genes. Taken together, these findings reveal a crucial role for S-glutathionylation and GRX-1 in controlling the activation of IRF3 and IFNbeta gene expression.

Epstein-Barr virus latent membrane protein 1 activation of NF-kappaB through IRAK1 and TRAF6.

Epstein-Barr virus latent membrane protein 1 (LMP1) activation of NF-kappaB is critical for Epstein-Barr virus-infected B lymphocyte survival. LMP1 activates the IkappaB kinase complex and NF-kappaB through two cytoplasmic signaling domains that engage tumor necrosis factor receptor-associated factor (TRAF)1/2/3/5 or TRADD and RIP. We now use cells lacking expression of TRAF2, TRAF5, TRAF6, IKKalpha, IKKbeta, IKKgamma, TAB2, IL-1 receptor-associated kinase (IRAK)1, or IRAK4 to assess their roles in LMP1-mediated NF-kappaB activation. LMP1-induced RelA nuclear translocation was similar in IKKalpha knockout (KO) and WT murine embryo fibroblasts (MEFs) but substantially deficient in IKKbeta KO MEFs. NF-kappaB-dependent promoter responses were also substantially deficient in IKKbeta KO MEFs but were hyperactive in IKKalpha KO MEFs. More surprisingly, NF-kappaB responses were near normal in TRAF2 and TRAF5 double-KO MEFs, IKKgamma KO MEFs, TAB2 KO MEFs, and IRAK4 KO MEFs but were highly deficient in TRAF6 KO MEFs and IRAK1 KO HEK293 cells. Consistent with the importance of TRAF6, LMP1-induced NF-kappaB activation in HEK293 cells was inhibited by expression of dominant-negative TAB2 and Ubc13 alleles. These data extend a role for IKKalpha in IKKbeta regulation, identify an unusual IKKbeta-dependent and IKKgamma-independent NF-kappaB activation, and indicate that IRAK1 and TRAF6 are essential for LMP1-induced NF-kappaB activation.