Κυριακή 3 Νοεμβρίου 2019

 Phase II study to evaluate the efficacy of Trastuzumab in combination with Capecitabine and Oxaliplatin in first-line treatment of HER2-positive advanced gastric cancer: HERXO trial
Phase II study to evaluate the efficacy of Trastuzumab in combination with Capecitabine.

Alternative dosing regimens for atezolizumab: right dose, wrong frequency

Abstract

The population pharmacokinetics of atezolizumab demonstrate that the trough concentrations are well above the putative target of 6 µg/ml. Thus, alternative dosing schedules are indeed of interest, focusing on reducing the frequency to allow greater patient convenience and reduced costs.

Dihydropyrimidine dehydrogenase in the metabolism of the anticancer drugs

Abstract

Cancer caused by fundamental defects in cell cycle regulation leads to uncontrolled growth of cells. In spite of the treatment with chemotherapeutic agents of varying nature, multiple resistance mechanisms are identified in cancer cells. Similarly, numerous variations, which decrease the metabolism of chemotherapeutics agents and thereby increasing the toxicity of anticancer drugs have been identified. 5-Fluorouracil (5-FU) is an anticancer drug widely used to treat many cancers in the human body. Its broad targeting range is based upon its capacity to act as a uracil analogue, thereby disrupting RNA and DNA synthesis. Dihydropyrimidine dehydrogenase (DPD) is an enzyme majorly involved in the metabolism of pyrimidines in the human body and has the same metabolising effect on 5-FU, a pyrimidine analogue. Multiple mutations in the DPD gene have been linked to 5-FU toxicity and inadequate dosages. DPD inhibitors have also been used to inhibit excessive degradation of 5-FU for meeting appropriate dosage requirements. This article focusses on the role of dihydropyrimidine dehydrogenase in the metabolism of the anticancer drug 5-FU and other associated drugs.

A phase I delayed-start, randomized and pharmacodynamic study of metformin and chemotherapy in patients with solid tumors

Abstract

Purpose

Metformin activates AMP-related pathways leading to inactivation of mammalian target of rapamycin (mTOR) and suppression of its downstream effectors, crucial for cancer growth. Epidemiologic studies showed a reduced incidence and improved survival in cancer patients. We conducted a prospective phase I study to assess the safety of metformin in combination with chemotherapy in patients with solid tumors.

Methods

We conducted a delayed-start randomized trial of non-diabetic patients in two stages. In Stage 1, we randomized patients to two arms: concurrent arm (metformin with chemo) vs. delayed arm (chemo alone). In Stage 2, patients in delayed arm were crossed over to receive metformin. Patients received metformin 500 mg twice daily with chemotherapy to define dose-limiting toxicities (DLTs) in both stages. Secondary endpoints assessed adverse events (AEs) and response rates. Translational correlates included effects of metformin on expression and phosphorylation of 5′ adenosine monophosphate-activated protein kinase (AMPK) by western blot in PBMCs.

Results

A total of 100 patients were enrolled (51 in delayed arm vs. 49 concurrent arm). Rate of DLTs in patients receiving metformin with chemotherapy was 6.1% vs. 7.8% in patients receiving chemotherapy alone. DLTs seen with addition of metformin included those associated with established chemo adverse events. No lactic acidosis or hypoglycemia occurred. Restaging showed stable disease in 46% at cessation of metformin. 28% of patients with measurable tumor markers showed improvement. AMPK phosphorylation showed a four- to sixfold increase in AMPK phosphorylation after metformin.

Conclusions

This is the largest phase I study of metformin combined with chemotherapy, which suggests that metformin can be given safely with chemotherapy, and offers a platform for future studies. Post-metformin increase in AMPK phosphorylation may potentially explain lack of disease progression in nearly half of our patients.

Funding

UL1 TR001064.

Clinical trial information

NCT01442870.

Upregulation of miR-519 enhances radiosensitivity of esophageal squamous cell carcinoma trough targeting PI3K/AKT/mTOR signaling pathway

Abstract

Purpose

MicroRNA-519 (miR-519) has been previously reported to function as a tumor suppressor in several types of malignancies. This study aimed to probe the biological role of miR-519 in esophageal squamous cell carcinoma (ESCC).

Methods

qRT-PCR was utilized to test the miR-519 expression level in ESCC tissues and cells. Clinical value of miR-519 was investigated by Kaplan–Meier method. Function assays were conducted to determine the role of miR-519 in radioresistance of ESCC cells. The miR-519-regulated pathways were determined by Kyoto Encyclopedia of Genes and Genomes pathway analysis.

Results

Low expression level of miR-519 was closely correlated with the poor prognosis for overall survival of ESCC patients or patients who received radiotherapy. Functional assays indicated that upregulation of miR-519 made ESCC cells more sensitive to γ-ray radiation and facilitated ESCC cell apoptosis triggered by irradiation treatment via regulating DNA response. Ectopic expression of miR-519 decreased the level of p-AKT and p-mTOR, thus inactivating PI3K/AKT/mTOR signaling pathway after irradiation.

Conclusion

These observations elucidated that upregulated miR-519 is closely correlated with the radiosensitivity of ESCC cells, which may contribute to finding a new promising target for improving the efficiency of radiotherapy in patients with ESCC.

Phase I trial of belinostat in combination with 13-cis-retinoic acid in advanced solid tumor malignancies: a California Cancer Consortium NCI/CTEP sponsored trial

Abstract

Purpose

The reported maximum tolerated dose (MTD) of single-agent belinostat is 1000 mg/m2 given days 1–5, every 21 days. Pre-clinical evidence suggests histone deacetylase inhibitors enhance retinoic acid signaling in a variety of solid tumors. We conducted a phase I study of belinostat combined with 50–100 mg/m2/day 13-cis-retinoic acid (13-cRA) in patients with advanced solid tumors.

Methods

Belinostat was administered days 1–5 and 13-cRA days 1–14, every 21 days. Dose-limiting toxicity (DLT) was defined as cycle 1 hematologic toxicity grade ≥ 3 not resolving to grade ≤ 1 within 1 week or non-hematologic toxicity grade ≥ 3 (except controlled nausea and vomiting and transient liver function abnormalities) attributable to belinostat.

Results

Among 51 patients, two DLTs were observed: grade 3 hypersensitivity with dizziness and hypoxia at 1700 mg/m2/day belinostat with 100 mg/m2/day 13-cRA, and grade 3 allergic reaction at 2000 mg/m2/day belinostat with 100 mg/m2/day 13-cRA. The MTD was not reached. Pharmacokinetics of belinostat may be non-linear at high doses. Ten patients had stable disease, including one with neuroendocrine pancreatic cancer for 56 cycles, one with breast cancer for 12 cycles, and one with lung cancer for 8 cycles. Partial responses included a patient with keratinizing squamous cell carcinoma of the tonsils, and a patient with lung cancer.

Conclusions

The combination of belinostat 2000 mg/m2 days 1–5 and 13-cRA 100 mg/m2 days 1–14, every 21 days, was well-tolerated and an MTD was not reached despite doubling the established single-agent MTD of belinostat.

Prevalence of the DPYD variant (Y186C) in Brazilian individuals of African ancestry

Abstract

Purpose

The presence of deleterious variants of dihydropyrimidine-dehydrogenase gene (DPYD) is associated with 5-Fluorouracil toxicity. Most of the data are based on findings in Caucasian populations. The variant Y186C (rs115232898) is found almost exclusively in African populations and is related to low DPD function. Its prevalence may vary among African subpopulations and in African Americans. There is no information in other populations. Brazil has the biggest African population outside Africa. We studied for the first time the frequency of this mutation in African Brazilians.

Methods

We amplified exon 6 of DPYD extracted from genomic DNA of 79 healthy volunteers of genetically defined African ancestry from Southeast Brazil and 36 self-reported African descendants from Northeast Brazil in order to determine the prevalence of the variant Y186C in Brazilians of African ancestry.

Results

The variant Y186C was found in heterozygosity in two samples from Southeast (2.53%) and one from Northeast (2.77%) Brazil. Overall, the prevalence of this mutation in the 115 African Brazilians was 2.6%.

Conclusions

The variant Y186C is prevalent among Brazilians of African ancestry and should be taken in account in targeted genotyping for fluoropyrimidine risk variants.

Dasatinib attenuates overexpression of Src signaling induced by the combination treatment of veliparib plus carboplatin in triple-negative breast cancer

Abstract

Purpose

Triple-negative breast cancer (TNBC) has a poor prognosis because of limited treatment options. The combination of a poly ADP ribose polymerase (PARP) inhibitor with a DNA-damaging agent has shown promise in treating TNBC; however, not all patients respond to this combination. The Src protein kinase modulates multiple cancer cell properties and plays a key role in tumorigenic processes. However, Src inhibitors as single agents have shown limited effects in solid tumors. Here, we examined the antitumor effects of the Src inhibitor dasatinib, the PARP inhibitor veliparib, and the DNA-damaging agent carboplatin in TNBC models to try and identify the combination with the most clinical potential.

Methods

Dasatinib, veliparib and carboplatin were tested in TNBC cells in vitro and in xenograft tumors in vivo.

Results

Surprisingly, treatment with the combination of veliparib plus carboplatin led to an increase in Src phosphorylation. Importantly, dasatinib attenuated Src overexpression induced by veliparib plus carboplatin and further inhibited the downstream signaling of Src. In xenograft models, the triple combination of dasatinib with veliparib plus carboplatin showed greater tumor growth inhibitory effects compared with single agents or double combinations. No systemic toxicity was observed in mice treated with the triple combination.

Conclusions

This study emphasizes the merit of evaluating the triple combination therapy, dasatinib with veliparib plus carboplatin, in TNBC clinical trials.

BATF2 inhibits chemotherapy resistance by suppressing AP-1 in vincristine-resistant gastric cancer cells

Abstract

Purpose

Chemotherapy remains the primary treatment used to improve overall survival and quality of life for patients with gastric cancer (GC); however, multidrug resistance is a major reason underlying failure of chemotherapy. Drug resistance (DR) can arise because of molecular changes inhibiting drug–target interactions; for example, overexpression of drug efflux pumps, such as P-gp, mediated by the activation of AP-1. BATF2 is a suppressor of AP-1; therefore, this study aimed to determine how BATF2 interacts with AP-1to inhibit DR in GC cells.

Methods

Expression of BATF2 in drug-responsive and non-responsive GC tumor tissues was evaluated by quantitative PCR and western blotting. Further, expression levels of BATF2- and AP-1-related genes were confirmed in vincristine-resistant SGC7901/VCR cells treated with cisplatin or 5-fluorouracil. A BATF2 overexpression system was established in SGC7901/VCR cells, and then AP-1 also overexpressed in the cells with upregulated BATF2 levels. Further, an AP-1 knockdown system was generated in SGC7901/VCR cells. MTT and flow cytometry assays were performed in the BATF2/AP-1 overexpression system, to evaluate cell proliferation, cell cycle effects, and apoptosis, and the expression of various proteins was detected by western blotting in AP-1/BATF2 overexpression cells. Finally, the effects of BATF2 overexpression in an in vivo nude mouse GC model were evaluated.

Results

We found that BATF2 was overexpressed in tissues from patients with non-responsive GC and the VCR resistance cell line, SGC7901/VCR, while levels of c-Fos and c-Jun were reduced in the SGC7901/VCR cell line. BATF2 overexpression suppressed levels of AP-1 and P-gp. Further, our data demonstrate that cell proliferation is suppressed, and the cell cycle and apoptosis are induced in SGC7901/VCR cells overexpressing both AP-1 and BATF2. Overexpression of AP-1 restored levels of genes downstream of AP-1 in BATF2 overexpressing cells. Compared with controls, tumor growth of SGC7901/VCR cells in nude mice was suppressed in the BATF2 overexpression group.

Conclusion

AP-1 down-regulation by BATF2 overexpression or AP-1 knockdown can inhibit DR in GC cells. These findings suggest that BATF2 inhibits DR in SGC7901/VCR GC cells by down-regulating AP-1 expression.

Phase 1 study of veliparib (ABT-888), a poly (ADP-ribose) polymerase inhibitor, with carboplatin and paclitaxel in advanced solid malignancies

Abstract

Purpose

Veliparib is an oral inhibitor of poly (ADP-ribose) polymerase (PARP)-1 and -2. PARP-1 expression may be increased in cancer, and this increase confers resistance to cytotoxic agents. We aimed to determine the recommended phase 2 dose (RP2D), maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and pharmacokinetics (PK) of veliparib combined with paclitaxel and carboplatin.

Methods

Eligibility criteria included patients with advanced solid tumors treated with ≤ 3 prior regimens. Paclitaxel and carboplatin were administered on day 3 of a 21-day cycle. Veliparib was given PO BID days 1–7, except for cycle 1 in the first 46 patients to serve as control for toxicity and PK. A standard “3 + 3” design started veliparib at 10 mg BID, paclitaxel at 150 mg/m2, and carboplatin AUC 6. The pharmacokinetic (PK) disposition of veliparib, paclitaxel, and carboplatin was determined by LC–MS/MS and AAS during cycles 1 and 2.

Results

Seventy-three patients were enrolled. Toxicities were as expected with carboplatin/paclitaxel chemotherapy, including neutropenia, thrombocytopenia, and peripheral neuropathy. DLTs were seen in two of seven evaluable patients at the maximum administered dose (MAD): veliparib 120 mg BID, paclitaxel 200 mg/m2, and carboplatin AUC 6 (febrile neutropenia, hyponatremia). The MTD and RP2D were determined to be veliparib 100 mg BID, paclitaxel 200 mg/m2, and carboplatin AUC 6. Median number of cycles of the three-agent combination was 4 (1–16). We observed 22 partial and 5 complete responses. Veliparib did not affect paclitaxel or carboplatin PK disposition.

Conclusion

Veliparib, paclitaxel, and carboplatin were well tolerated and demonstrated promising antitumor activity.

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