Predictive Potential of RNA Polymerase B (II) Subunit 1 (RPB1) Cytoplasmic Aggregation for Neoadjuvant Chemotherapy Failure

We aimed to investigate the contribution of co-translational protein aggregation to the chemotherapy resistance of tumor cells. Increased co-translational protein aggregation reflects altered translation regulation that may have the potential to buffer transcription under genotoxic stress. As an indicator for such an event, we followed the cytoplasmic aggregation of RPB1, the aggregation-prone largest subunit of RNA polymerase II, in biopsy samples taken from patients with invasive carcinoma of no special type. RPB1 frequently aggregates co-translationally in the absence of proper HSP90 chaperone function or in ribosome mutant cells as revealed formerly in yeast. We found that cytoplasmic foci of RPB1 occur in larger sizes in tumors that showed no regression after therapy. Based on these results, we propose that monitoring the cytoplasmic aggregation of RPB1 may be suitable for determining-from biopsy samples taken before treatment-the effectiveness of neoadjuvant chemotherapy.

BC-Monitor: Towards a Routinely Accessible Circulating Tumor DNA-Based Tool for Real-Time Monitoring Breast Cancer Progression and Treatment Effectiveness

Circulating tumor DNA (ctDNA) is increasingly employed in the screening, follow-up, and monitoring of the continuously evolving tumor; however, most ctDNA assays validated for clinical use cannot maintain the right balance between sensitivity, coverage, sample requirements, time, and cost. Here, we report our BC-monitor, a simple, well-balanced ctDNA diagnostic approach using a gene panel significant in breast cancer and an optimized multiplex PCR-based NGS protocol capable of identifying allele variant frequencies below 1% in cell-free plasma DNA. We monitored a cohort of 45 breast cancer patients prospectively enrolled into our study receiving neoadjuvant chemotherapy or endocrine therapy or palliative therapy for metastatic diseases. Their tumor mutation status was examined in the archived tumor samples and plasma samples collected before and continuously during therapy. Traceable mutations of the used 38-plex NGS assay were found in approximately two-thirds of the patients. Importantly, we detected new pathogenic variants in follow-up plasma samples that were not detected in the primary tumor and baseline plasma samples. We proved that the BC-monitor can pre-indicate disease progression four-six months earlier than conventional methods. Our study highlights the need for well-designed ctDNA monitoring during treatment and follow-up, integrated into a real-time treatment assessment, which could provide information on the active tumor DNA released into the blood.

RGB-02 (biosimilar pegfilgrastim) in the treatment of chemotherapy-induced neutropenia

Pegfilgrastim is widely used for the prevention of chemotherapy-induced neutropenia. The development and use of biosimilar agents help to rationalize healthcare expenditure and improve access to modern therapies to all who need them. This review focuses on pegfilgrastims with important role in oncology supportive care. RGB-02 (Gedeon Richter) is a proposed biosimilar to pegylated granulocyte-colony stimulating factor (Neulasta^®, Amgen) with sustained release properties. The clinical analyses in three randomized clinical studies provided comparative data between RGB-02 and Neulasta, in a Phase III study patients receiving docetaxel-doxorubicin chemotherapy treatment equivalence was found. No difference was detected in any safety measure including immunogenicity; treatment switch, from the reference product to RGB-02 proved safe. Long-acting pegylated filgrastim RGB-02 has successfully accomplished various steps of biosimilar development.

Capecitabine in Combination with Docetaxel in First Line in HER2-Negative Metastatic Breast Cancer: an Observational Study

Due to the limited experience with capecitabine plus docetaxel (XT) combination in the first-line treatment of metastatic breast cancer in Hungary, the main objective of the study was to analyze the effectiveness and tolerability of XT therapy. A prospective, open-label, non-randomized, single-arm, multicenter, observational study was designed. All female patients were eligible whose metastatic breast cancer could be treated with the XT protocol according to the summary of product characteristics of the drugs. The median progression free survival was 9.9 ± 3.0 months. Time to treatment failure was 4.6 ± 5.1 months on average. The overall response rate was 28.9 %, the clinical benefit rate was 73.3 %. The treatment was discontinued in 35.6 % of patients due to disease progression and in 20.0 % due to adverse events (AE). 33 patients with a total of 73 AEs have been reported, and 13 of them had serious adverse events (SAE). The efficacy and the safety profile of XT chemotherapy proven in the study are consistent with the results demonstrated in randomized trials. First-line XT chemotherapy effectively improves the PFS in metastatic breast cancer.