Efficacy and safety of tucidinostat in patients with advanced hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer: real-world insights

Background

Tucidinostat, which is a subtype-selective histone deacetylase inhibitor, has been approved in China for the treatment of hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). However, existing evidence mainly stemmed from randomized controlled trials, and might have limitations in representing the complexities of clinical practice and diverse patient populations. Therefore, there is a need to explore the efficacy and optimal therapeutic modality for tucidinostat in real-world clinical settings.

Methods

The objective of this real-world study was to analyze the clinical data of 47 patients with HR+/HER2- ABC who received tucidinostat treatment at West China Hospital, Sichuan University, between August 2020 and May 2023. The primary outcomes were progression-free survival (PFS) and clinical benefit rate [CBR; defined as partial response (PR) and stable disease (SD) for ≥6 months on clinical evaluation].

Results

A total of 47 patients were included, and the median follow-up time was 18.20 months. The median line of tucidinostat therapy was 3 (range, 1-9). In all, 52.17% patients were treated with tucidinostat plus fulvestrant, while 38.30% were treated with tucidinostat plus aromatase inhibitors. Notably, 10.64% of the patients with rapidly progressing visceral metastases received tucidinostat plus endocrine therapy as maintenance treatment after achieving disease control with chemotherapy. The median PFS was 4.43 months [95% confidence interval (CI), 2.77-10.53], and the median overall survival was 19.57 months (95% CI, 12.83-not reached). The 6-month CBR for the overall population was 41.86%. Patients undergoing maintenance therapy demonstrated a significantly longer PFS than did those who did not receive it as maintenance therapy (14.13 vs. 3.93 months; P=0.01). Univariate Cox regression analysis showed that use of tucidinostat in lines 1-2, use of tucidinostat plus fulvestrant, presence of one metastatic site, and lack of brain metastasis were favorable factors for PFS. Thrombocytopenia was the most frequently reported adverse event, with an incidence rate of 31.91% at all grades and 14.89% at grade ≥3. Four (8.51%) patients discontinued the treatment.

Conclusions

For patients with HR+/HER2- ABC, tucidinostat combination therapy offers certain survival benefits with controllable safety. Furthermore, compared with non-maintenance therapy, maintenance therapy after chemotherapy may have promising efficacy.

The effectiveness and safety of palbociclib and ribociclib in stage IV HR+/HER-2 negative breast cancer: a nationwide real world comparative retrospective cohort study

Introduction

Palbociclib and ribociclib are indicated in the first-line treatment of hormonal receptor-positive HER-2 negative (HR+/HER2- negative) advanced breast cancer. Although randomized-controlled trials (RCTs) proved their clinical efficacy, there are no observational studies yet to validate the clinical findings in the real-world. Therefore, this study aimed to evaluate and compare the clinical effectiveness and safety profiles of palbociclib and ribociclib in Qatar.

Materials and methods

A retrospective observational study was conducted on HR+/HER-2-negative stage-IV breast cancer patients receiving palbociclib or ribociclib in the state of Qatar. Clinical data were collected from the National Center for Cancer Care and Research (NCCCR) in Qatar using Cerner®. Primary outcomes were progression-free-survival (PFS) and overall-survival (OS) generated by Kaplan-Meier curves. Moreover, safety profiles of both two treatments were evaluated.

Results

The data from 108 patients were included in the final analysis. There was no statistically significant difference in PFS between the palbociclib and ribociclib groups; PFS was 17.85 versus 13.55 months, respectively(p> 0.05). Similarly, there was no statistically significant difference in OS between the two medications, 29.82 versus 31.72 months, respectively(p>0.05). Adverse events were similar between the two groups. Neutropenia was the most common side effect in the study population accounting for 59.3% of the patients.

Conclusions

Therefore, both treatments have similar efficacy and safety profiles. Further research on a larger-scale population and longer follow-up period is recommeneded.

Efficacy and safety of bevacizumab-containing therapy for refractory advanced breast cancer: a retrospective study

BACKGROUND

Advanced breast cancer (ABC) is difficult to treat due to the primary and acquired resistance, which is the main cause of rescue treatment failure. Thus, developing a new rescue treatment strategy for clinicians is a challenge. This study retrospectively collected the medical information of patients with refractory ABC who were treated with bevacizumab at our department to analyze the efficacy and safety of bevacizumab-containing therapy as a new treatment method for refractory ABC.

METHODS

The complete medical information of patients receiving bevacizumab treatment from November 2017 to November 2020 was collected, and patients' general medical history and disease characteristics were analyzed. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), time to failure (TTF), overall survival (OS), and safety were also analyzed using SPSS 20.0 statistical software.

RESULTS

The data of 68 women with refractory ABC who received bevacizumab-containing therapy were collected. The last follow-up examinations were performed on March 31, 2021. The ORR was 41.2% and the DCR was 88.2%. The median PFS, TTF, and OS were 6.0 months [95% confidence interval (CI): 3.4-8.6 months], 4.0 months (95% CI: 3.2-4.8 months), and 26.6 months (95% CI: 10.2-43.0 months), respectively. Treatment was discontinued in 2 patients due to chemo-related adverse reactions. The main adverse events related to bevacizumab were hypertension (7.4%) and bleeding (2 cases, 2.9%), both of which were grade 1. No specific adverse events causing the discontinuation of bevacizumab treatment were observed in the other patients.

CONCLUSIONS

Among patients with refractory ABC, bevacizumab-containing therapy is feasible and safe, and can be used as a new treatment strategy. However, the question of who can benefit the most from bevacizumab-containing therapy requires further exploration.

CDK4/6 Inhibitor Treatments in Patients with Hormone Receptor Positive, Her2 Negative Advanced Breast Cancer: Potential Molecular Mechanisms, Clinical Implications and Future Perspectives

Hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer is the most common breast cancer subtype, and endocrine therapy (ET) remains its therapeutic backbone. Although anti-estrogen therapies are usually effective initially, approximately 50% of HR+ patients develop resistance to ET within their lifetime, ultimately leading to disease recurrence and limited clinical benefit. The recent addition of cyclin-dependent kinase 4 (CDK4) and CDK6 inhibitors (palbociclib, ribociclib, abemaciclib) to ET have remarkably improved the outcome of patients with HR+ advanced breast cancer (ABC) compared with anti-estrogens alone, by targeting the cell-cycle machinery and overcoming some aspects of endocrine resistance. However, which patients are the better candidates for these drugs, which are the main characteristics for a better selection of patients or if there are predictive biomarkers of response, is still unknown. In this review we reported the mechanism of action of CDK4/6 inhibitors as well as their potential mechanism of resistance, their implications in clinical practice and the forthcoming strategies to enhance their efficacy in improving survival and quality of life of patients affected with HR+, HER2-, ABC.