Overall Survival with Ribociclib plus Letrozole in Advanced Breast Cancer

Radiosensitizing effects of CDK4/6 inhibitors in hormone receptor-positive and HER2-negative breast cancer mediated downregulation of DNA repair mechanism and NF-κB-signaling pathway

CDK4/6 inhibitors combined with endocrine therapy prolonged survival in hormone receptor (HR)-positive and HER2-negative advanced breast cancer. We investigated whether CDK4/6 inhibitors enhance radiosensitivity and their underlying mechanisms of this subtype of breast cancer. In vitro and in vivo experiments were conducted using two HR-positive and HER2-negative breast cancer cell lines (MCF-7 and T-47D), CDK4/6 inhibitors (ribociclib and palbociclib) and radiotherapy (RT) to assess the biological functions and mechanisms. The radiation-enhancing effect was assessed using clonogenic assays; γH2AX and 53BP1 levels were assessed by immunofluorescence to evaluate DNA damage. The levels of phospho (p)-ERK, c-Myc, and DNA-double strand break (DSB)-related molecules, p-DNA-PKcs, Rad51, and p-ATM, were assessed by western blotting. We used an NF-κB p65 transcription factor assay kit to evaluate NF-κB activity. We evaluated the antitumor effect of the combination of RT and ribociclib through the MCF-7 orthotopic xenograft model. The synergistic effects of combining RT with ribociclib and palbociclib pretreatment were demonstrated by clonogenic assay. CDK4/6 inhibitors synergistically increased the numbers of RT-induced γH2AX and 53BP1, downregulated the expression of p-DNA-PKcs, Rad51 and p-ATM activated by RT, and reduced RT-triggering p-ERK expression, NF-κB activation, and its down-streaming gene, c-Myc. Combined ribociclib and RT reduced the growth of MCF-7 cell xenograft tumors, and downregulated the immunohistochemical expression of p-ERK, p-NF-κB p65, and c-Myc compared to that in the control group. Combining CDK4/6 inhibitors enhanced radiosensitivity of HR-positive and HER2-negative breast cancer cells at least by reducing DNA-DSB repair and weakening the activation of ERK and NF-κB signaling by RT.

First- vs second-line CDK 4/6 inhibitor use for patients with hormone receptor positive, human epidermal growth-factor receptor-2 negative, metastatic breast cancer in the real world setting

PURPOSE

To compare CDK4/6 inhibitor (CDK4/6i) with endocrine therapy (ET) in the first- versus second-line setting for treatment of hormone receptor positive (HR+), HER2 negative, metastatic breast cancer (MBC) using real-world evidence.

METHODS

Patients with HR+, HER2 negative MBC, diagnosed between 2/3/2015 and 11/2/2021 and having ≥ 3 months follow-up were identified from the nationwide electronic health record-derived Flatiron Health de-identified database. Treatment cohorts included: (1) first-line ET with a CDK 4/6i (1st-line CDK4/6i) versus (2) first-line ET alone followed by second-line ET with a CDK4/6i (2nd-line CDK4/6i). Differences in baseline characteristics were tested using chi-square tests and two-sample t-tests. Time to third-line therapy, time to start of chemotherapy, and overall survival were compared using Kaplan-Maier method.

RESULTS

The analysis included 2771 patients (2170 1st-line CDK4/6i and 601 2nd-line CDK4/6i). Patients receiving 1st-line CDK4/6i were younger (75% vs 68% < 75 years old, p = 0.0001), less likely uninsured or not having insurance status documented (10% vs. 13%, p = 0.04), of better performance status (50% vs 43% with ECOG 0, p = 0.03), and more likely to have de novo MBC (36% vs. 24%, p < 0.001). Time to third-line therapy (49 vs 22 months, p < 0.001) and time to chemotherapy (68 vs 41 months, p < 0.001) were longer in those receiving first-line CDK4/6i. Overall survival (54 vs 49 months, p = 0.33) was similar between groups.

CONCLUSION

Use of CDK4/6i with first-, vs second-, line ET was associated with longer time to receipt of 3rd-line therapy and longer time to receipt of chemotherapy.

Trends in HR+ metastatic breast cancer survival before and after CDK4/6 inhibitor introduction in the United States: a SEER registry analysis of patients with HER2- and HER2+ metastatic breast cancer

PURPOSE

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have improved patient survival in hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) in clinical trials and real-world studies. However, investigations of survival gains in broader HR+/HER2- mBC populations using epidemiological approaches are limited.

METHODS

This retrospective study used SEER registry data to assess breast cancer-specific survival (BCSS) in patients diagnosed with HR+/HER2- de novo mBC from 2010 to 2019. Kaplan-Meier and Cox proportional hazards models were used to compare BCSS in patients diagnosed before (2010‒2013 with follow-up to 2014) and after (2015‒2018 with follow-up to 2019) the 2015 guideline recommendations for CDK4/6i use. A comparison was made to patients with HR+/HER2-positive (HER2+) de novo mBC, for which no major guideline changes occurred during 2015-2018.

RESULTS

Data from 11,467 women with HR+/HER2- mBC and 3260 women with HR+/HER2+ mBC were included. After baseline characteristic adjustment, patients with HR+/HER2- mBC diagnosed post-2015 (n = 6163), had an approximately 10% reduction in risk of BC-specific death compared with patients diagnosed pre-2015 (n = 5304; HR = 0.895, p < 0.0001). Conversely, no significant change was observed in HR+/HER2+ BCSS post-2015 (n = 1798) versus pre-2015 (n = 1462). Similar results were found in patients aged ≥ 65 years.

CONCLUSION

Using one of the largest US population-based longitudinal cancer databases, significant improvements in BCSS were noted in patients with HR+/HER2- mBC post-2015 versus pre-2015, potentially due to the introduction of CDK4/6i post-2015. No significant improvement in BCSS was observed in patients with HR+/HER2+ mBC post-2015 versus pre-2015, likely due to the availability of HER2-directed therapies in both time periods.

Clinical characterization, prognostic, and predictive values of HER2-low in patients with early breast cancer in the PALLAS trial (ABCSG-42/AFT-05/BIG-14-13/PrE0109)

BACKGROUND

Bidirectional crosstalk between HER2 and estrogen receptor (ER) pathways may influence outcomes and the efficacy of endocrine therapy (ET). Low HER2 expression levels (HER2-low) have emerged as a predictive biomarker in patients with breast cancer (BC).

METHODS

PALLAS is an open, international, phase 3 study evaluating the addition of palbociclib for 2 years to adjuvant ET in patients with stage II-III ER-positive/HER2-negative BC. To assess the impact of HER2 expression on patient outcomes in the phase III PALLAS trial, we analyzed (1) the association between rate of HER2-low with demographic and clinicopathological parameters, (2) the prognostic value of HER2-low status on invasive disease-free survival (iDFS), distant relapse-free survival (DRFS), and overall survival (OS) and (3) HER2 expression's value as a predictive biomarker of response to palbociclib. HER2-low was defined as HER2 immunohistochemistry (IHC) 1 + or IHC 2 + with negative in situ hybridization (ISH). All pathologic evaluation was performed locally. Prognostic and predictive power of HER2 were assessed with Cox models.

RESULTS

From the original PALLAS intention-to-treat population (N = 5753), 5304 patients (92.2%) were included in this analysis. Among these, 2254 patients (42.5%) were classified as having HER2 IHC 0 (HER2-0), and 3050 (57.5%) as having HER2-low disease (1838 with IHC 1 + and 1212 with IHC 2 +). Median follow-up was 59.8 months. HER2-low prevalence varied significantly across 21 participating countries (range 16.7% to 75.6%; p < 0.001) and was more frequent in patients enrolled in North America (63.1%) than in Europe (53.4%) or other regions (53.4%) (p < 0.001). HER2 status was not significantly associated with iDFS in a multivariable Cox model (hazard ratio 0.93, 95% confidence interval 0.81 - 1.06). No significant interaction was observed between treatment arm and HER2 status for iDFS (p = 0.43). Similar results were obtained for DRFS and OS.

CONCLUSIONS

In this large, prospective, global patient cohort, no differences were observed in clinical parameters, prognosis, or differential benefit from palbociclib between HER2-0 and HER2-low tumors. Significant geographic variability was observed in the prevalence of HER2-low status, suggesting a high degree of variation in pathologic assessment of HER2 expression without impact on outcomes.

Quality of life in women with early-stage and metastatic hormone receptor-positive, HER2-negative breast cancer receiving endocrine therapy

INTRODUCTION

Early discontinuation of endocrine therapy (ET) is higher among patients with early breast cancer (EBC) compared to patients with metastatic hormone receptor-positive (HR+) breast cancer (MBC). In our clinical experience the reasons for this may include a significant burden of ET side effects impacting quality of life (QOL) in patients with EBC. We hypothesized that QOL is lower in patients with HR + EBC compared to patients with HR + MBC on ET.

METHODS

We conducted a cross-sectional observational study to assess QOL utilizing FACT-ES & EORTC QLQ C30 tools among patients with EBC and MBC receiving ET across 5 Irish hospitals.

RESULTS

A total of 417 patients were enrolled-EBC (79% n = 331) and MBC 21% (n = 86). Using the FACT-ES, we found no difference in overall QOL by stage (139.2 vs 141, P  = .33). Patients with HR + MBC had a lower symptom burden from ET compared to HR + EBC (61.4 vs 54, P < .01). In adjusted multivariate linear regression models, there was no difference in QOL for patients with EBC and MBC receiving ET.

CONCLUSIONS

There was no significant difference in overall QOL for patients with EBC and MBC. However, patients with EBC experienced more endocrine symptoms. In adjusted multivariate linear regression models, the stage did not predict QOL. Our results suggest that endocrine symptoms are significant contributors to impaired QOL for patients with EBC but the role of other determinants of QOL (eg, stage) is less clear. Future work could include the development of stage-specific QOL tools and utilization of electronic patient-reported outcomes (ePROs) to identify and manage emergent toxicities.

The impact of previous therapy on overall-survival in registration clinical trials for 1st line metastatic breast cancer a systemic review

AIM

To explore the impact of previous treatment on the efficacy of investigational new drugs in registration trials for 1st line metastatic breast cancer (MBC).

METHODS

Thirteen US Food and Drug Administration (FDA) approved indications for 1st line MBC between 1/2000-12/2023 were identified and their supporting publications were searched in the ClinicalTrials.gov and Google Scholar. Where available, hazard ratios (HRs) and 95 % confidence intervals (CI) for overall-survival (OS) were pooled into meta-analysis and the difference in the magnitude of OS benefit between treatment naïve and previously treated patients was analyzed.

RESULTS

There was no difference in the magnitude of OS benefit between treatment-naïve and previously treated patients (HR=0.72 versus 0.80,p for difference=0.25). In indications for triple-negative BC, treatment-naïve patients had higher magnitude of OS benefit compared to previously treated patients (HR=0.53 versus 0.81,p=0.03). In indications for luminal disease, the magnitude of benefit was comparable between the subgroups.

CONCLUSIONS

In trials supporting 1st line therapy for TNBC the magnitude of benefit is significantly higher in treatment naïve compared to previously treated patients. Our findings may represent a previously unrecognized bias, potentially over-estimating the benefit of triple-negative BC new drugs.

Cost-effectiveness of CDK4/6 inhibitors in HR+/HER2- metastatic breast cancer: a systematic review and meta-analysis

BACKGROUND

Cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors have emerged as a significant advancement in the treatment of HR+/HER2- metastatic breast cancer (MBC). Despite the clinical efficacy of CDK 4/6 inhibitors in HR+/HER2- metastatic breast cancer, there remains a significant gap in understanding their cost-effectiveness, particularly regarding the long-term economic impact and the key drivers of costs, when used in combination with endocrine therapy. This study aims to systematically review and conduct a meta-analysis of cost-effectiveness studies evaluating CDK4/6 inhibitors in treatment of HR+/HER2- advanced breast cancer and identify key drivers of costs of CDK4/6 inhibitors in combination with endocrine therapy.

METHODS

A comprehensive search of PubMed and Embase was conducted to identify peer-reviewed studies from February 2015 to March 2022 reporting cost-effectiveness of CDK4/6 inhibitors in MBC treatment. Incremental net benefits (INBs) were estimated, and meta-analysis was conducted. This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

We identified 120 articles, of which 18 were eligible for systematic review and 16 for meta-analysis. None of the three CDK4/6 inhibitors had positive INB compared to endocrine/aromatase inhibitors therapy alone. The pooled INB was estimated at -$149,266.87 (95% Confidence Interval (CI) = -$196,961.54, -$101,572.20).

CONCLUSION

The combination of CDK4/6 inhibitors and letrozole/endocrine therapy for the treatment of postmenopausal patients with advanced HR+/HER2 - MBC was not cost-effective.

Precision therapeutics and emerging strategies for HR-positive metastatic breast cancer

Anti-oestrogen-based therapies, often combined with a CDK4/6 inhibitor, are the current standard-of-care first-line therapy for patients with advanced-stage hormone receptor-positive (HR+) breast cancer. Resistance to anti-oestrogen agents inevitably occurs, mediated by oestrogen receptor (ER)-dependent or ER-independent mechanisms that drive tumour progression. Emerging endocrine therapies include, but are not limited to, next-generation oral ER degraders and proteolysis targeting chimeras, which might be particularly effective in patients with ESR1-mutant breast cancer. Furthermore, cancers harbouring driver alterations in oncogenic signalling pathways, including AKT and PI3K, might be susceptible to novel combination strategies involving targeted inhibitors. Next-generation CDK2/4 inhibitors are an area of active clinical investigation, and efforts are ongoing to evaluate the role of sequential CDK inhibition. Approved and emerging antibody-drug conjugates exploiting novel target antigens have also demonstrated promising clinical activity. These novel agents, as well as further identification and characterization of predictive biomarkers, will hopefully continue to improve clinical outcomes, reduce the incidence of toxicities, and limit the extent of overtreatment in this population. In this Review, we describe the evolving treatment paradigm for patients with metastatic HR+ breast cancer in light of the growing armamentarium of drugs and biomarkers that will help to shape the future therapeutic landscape. These strategies are expected to involve tumour molecular profiling to enable the delivery of precision medicine.

Sacituzumab govitecan for hormone receptor-positive HER2-negative advanced breast cancer

INTRODUCTION

Initial treatment for hormone-receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer (ABC) typically involves endocrine therapy (ET) combined with different targeted agents. When hormonal therapies fail, until recently, the only option available was chemotherapy (ChT), presenting a significant therapeutic challenge. However, the recent introduction of antibody-drug conjugates (ADCs) has provided new treatment alternatives in this context. Sacituzumab govitecan (SG), a novel trophoblast cell-surface antigen 2 (Trop-2)-targeting ADC, has been evaluated following disease progression to ET and ChT in HR+/HER2- ABC.

AREAS COVERED

This review examines the latest clinical trials, including phase I/II and III studies and evaluates the impact of SG on HR+/HER2- ABC. The literature search focused on clinical outcomes, particularly regarding efficacy and safety, comparing them with traditional ChT.

EXPERT OPINION

SG has demonstrated to be an effective treatment for patients with HR+/HER2- ABC after progression to ET and cyclin-dependent kinase 4/6 inhibitors (CDKi) in any setting, and at least two ChT-containing regimens in the advanced setting. With a manageable toxicity profile, SG represents a significant advancement in the treatment landscape for this patient population. However, further research is essential to optimize its application and establish long-term benefits.

Questionnaire survey and analysis of drug clinical research implementation capabilities of breast cancer treatment departments in Chinese hospitals

BACKGROUND

Clinical research competence determines the quality of clinical research and the reliability of research findings. We aimed to explore the clinical research implementation capabilities of breast cancer treatment departments in China.

METHODS

This was a department-based cross-sectional study conducted in the form of electronic questionnaires on the Wenjuanxing platform from 7th August to 31st August 2023 among hospitals from the first batch of breast cancer standardized diagnosis and treatment quality control pilot centers in China.

RESULTS

A total of 127 questionnaires from 122 hospitals were ultimately included in the analysis. Medical personnel involved in the clinical research of 118 (92.9 %) departments received good clinical practice (GCP) training. The steps of the approval process from research initiation to completion lasted 2-4 weeks or longer. The majority of departments initiated or participated in 2 or fewer clinical research projects over the past year. Among the differences between different departments, the Department of Medical Oncology had a better qualification profile and process and greater number of initiated and participated clinical studies than did the Department of Surgical Oncology. For needs and problems, most of the departments were strongly willing to undertake clinical research and receive professional training; the most common problem in the process of conducting studies was patient recruitment.

CONCLUSIONS

Most departments generally exhibited complete capabilities for implementing clinical research. Improvements in implementation efficiency, quality of research and patient recruitment are still needed. Professional training and communication, as well as the recommendation of clinical research, are required in future development.

Neoadjuvant letrozole and palbociclib in patients with HR-positive/HER2-negative early breast cancer and Oncotype DX Recurrence Score ≥18: DxCARTES study

BACKGROUND

The effect of the addition of cyclin-dependent kinases 4 and 6 inhibitors to endocrine therapy in terms of molecular downstaging remains undetermined. Switching from a high-risk to a low risk Recurrence Score (RS) group could provide useful information to identify patients who might not require chemotherapy. The purpose of this study was to assess the biological and clinical activity of letrozole plus palbociclib as neoadjuvant treatment for patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with an initial Oncotype DX RS ≥18.

PATIENTS AND METHODS

Participants were women aged ≥18 years with HR-positive/HER2-negative, Ki67 ≥ 20%, stage II-IIIB early breast cancer with a baseline RS ≥18. Eligible patients with a pretreatment RS 18-25 (cohort A) and 26-100 (cohort B) received six 28-day cycles of letrozole (2.5 mg per day; plus goserelin if pre- or perimenopausal) plus palbociclib (125 mg per day; 3/1 schedule) before surgery. The primary endpoint for both cohorts was the proportion of patients who achieved an RS ≤25 at surgery or a pathological complete response (pCR).

RESULTS

A total of 67 patients were enrolled, among which 65 were assessable for the primary endpoint (32 patients in cohort A and 33 in cohort B). At surgery, 22 (68.8%) patients in cohort A and 18 (54.5%) patients in cohort B had an RS ≤25 or a pCR [only 1 (3.0%) patient in cohort B], meeting the primary endpoint in cohort B (P < 0.01), but not in cohort A (P = 0.98). No new safety signals were identified.

CONCLUSIONS

The efficacy of neoadjuvant treatment with letrozole plus palbociclib does not seem to depend on pretreatment RS for patients with RS ≥18. However, around half of patients with HR-positive/HER2-negative early breast cancer with an RS 26-100 at baseline achieved molecular downstaging with this regimen.

Pharmacokinetics and pharmacogenomics of ribociclib in black patients with metastatic breast cancer the LEANORA study

Underrepresented populations' participation in clinical trials remains limited, and the potential impact of genomic variants on drug metabolism remains elusive. This study aimed to assess the pharmacokinetics (PK) and pharmacogenomics (PGx) of ribociclib in self-identified Black women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2) advanced breast cancer. LEANORA (NCT04657679) was a prospective, observational, multicenter cohort study involving 14 Black women. PK and PGx were evaluated using tandem mass spectrometry and PharmacoScan™ microarray (including CYP3A5*3, *6, and *7). CYP3A5 phenotypes varied among participants: 7 poor metabolizers (PM), 6 intermediate metabolizers (IM), and one normal metabolizer (NM). The area under the curve did not significantly differ between PMs (39,230 h*ng/mL) and IM/NMs (43,546 h*ng/mL; p = 0.38). The incidence of adverse events (AEs) was also similar. We found no association between CYP3A5 genotype and ribociclib exposure. Continued efforts are needed to include diverse populations in clinical trials to ensure equitable treatment outcomes.

Nanoemulsion-based transdermal delivery of third-generation steroidal and non-steroidal aromatase inhibitors in preclinical models

Aromatase inhibitors are effective in treating hormone receptor-positive breast cancer, particularly in postmenopausal women. However, the challenges of inconsistent dissolution, variable absorption and side effects with oral administration persist. To address these issues, transdermal delivery has emerged as a viable alternative. In our study, we have developed nanoemulsion-based transdermal creams containing third-generation aromatase inhibitors Exemestane (EXE) or Letrozole (LE) and evaluated their toxicity, anti-tumour effects and androgenic potency using preclinical models including Bama minipigs, DMBA-induced breast cancer rats and orchidectomized male rats. The results of our study are significant, suggesting that both creams effectively penetrated the skin, demonstrating an impressive anti-breast cancer effect. Importantly, EXE cream had no organ toxicity at the tested dose, providing a reassuring safety profile for its use. In contrast, LE cream displayed reversible toxicity from drug molecule itself in animals at the given dose, dissipating after 3 weeks of withdrawal and recovery. This study establishes a solid foundation for the safe clinical use of third-generation aromatase inhibitors. It highlights transdermal creams as a promising drug delivery carrier for administering them.

Acquired gene alterations in patients treated with ribociclib plus endocrine therapy or endocrine therapy alone using baseline and end-of-treatment circulating tumor DNA samples in the MONALEESA-2, -3, and -7 trials

BACKGROUND

A prior pooled analysis of the MONALEESA-2, -3, and -7 trials identified baseline markers predictive of sensitivity or resistance to ribociclib plus endocrine therapy (ET). We report the results of an analysis of paired baseline and end-of-treatment (EOT) circulating tumor DNA (ctDNA) samples across the MONALEESA trials.

PATIENTS AND METHODS

Paired baseline and EOT ctDNA samples from MONALEESA-2, -3, and -7 were sequenced using a targeted next-generation sequencing panel. Genes with an EOT alteration prevalence of >5% were included. A McNemar test was performed on paired samples and adjusted for multiple testing to control the false discovery rate. A Bayesian mixed-effects model was used to adjust for ctDNA fraction at both time points and for study differences.

RESULTS

The analysis included 523 paired samples. At EOT, 21 genes had a >5% alteration prevalence. A trend for higher ctDNA fraction at EOT vs baseline (P=0.08) was observed. Prevalence of alterations was higher at EOT vs baseline in RB1, SPEN, TPR, PCDH15, and FGFR2 in the ribociclib arm; PBRM1 in the placebo arm; and ESR1 in both arms. The mixed-effects model demonstrated that the same trends for increased prevalence of these alterations at EOT were observed after adjusting for ctDNA fraction and that the increased rate of RB1 and SPEN alterations at EOT were specific to ribociclib plus ET. Analysis of ESR1 indicated a similar increase at EOT in both arms. The most common acquired ESR1 mutations at EOT included Y537C/N/S/D, D538G, E380Q, and L536H/R/P/LC. The prevalence of PIK3CA hotspot mutations at baseline and EOT was similar.

CONCLUSIONS

This analysis identified acquired gene alterations in patients with HR+/HER2- advanced breast cancer treated with ribociclib plus ET or placebo plus ET. These data may support further studies on acquired resistance mechanisms and inform future systemic interventions in the post-CDK4/6 inhibitor setting.

Navigating Treatment Pathways in Metastatic Hormone Receptor-Positive, HER2-Negative Breast Cancer: Optimizing Second-Line Endocrine and Targeted Therapies

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Fighting Pancreatic Cancer with a Vaccine-Based Winning Combination: Hope or Reality?

Pancreatic adenocarcinoma (PDA) represents the fourth leading cause of cancer-related mortality in the USA. Only 20% of patients present surgically resectable and potentially curable tumors at diagnosis, while 80% are destined for poor survival and palliative chemotherapy. Accordingly, the advancement of innovative and effective therapeutic strategies represents a pivotal medical imperative. It has been demonstrated that targeting the immune system represents an effective approach against several solid tumors. The immunotherapy approach encompasses a range of strategies, including the administration of antibodies targeting checkpoint molecules (immune checkpoint inhibitors, ICIs) to disrupt tumor suppression mechanisms and active immunization approaches that aim to stimulate the host's immune system. While vaccines have proved effective against infectious agents, vaccines for cancer remain an unfulfilled promise. Vaccine-based therapy targeting tumor antigens has the potential to be a highly effective strategy for initiating and maintaining T cell recognition, enhancing the immune response, and ultimately promoting cancer treatment success. In this review, we examined the most recent clinical trials that employed diverse vaccine types to stimulate PDA patients' immune systems, either independently or in combination with chemotherapy, radiotherapy, ICIs, and monoclonal antibodies with the aim of ameliorating PDA patients' quality of life and extend their survival.

Dose reduction and discontinuation due to the combination of CDK4/6 inhibitors and endocrine drugs: a systematic review and meta-analysis

BACKGROUND

With the widespread use of CDK4/6 inhibitors, the number of discontinuations and reductions due to adverse events is increasing. Therefore, we examined the risk of dose reduction, discontinuation, and occurrence of serious adverse events and death due to adverse events when CDK4/6 inhibitors are combined with endocrine drugs.

METHODS

We searched English-language articles published up to February 10, 2024, using RR values (risk ratio) to indicate the risk of discontinuation, dose reduction, death, and the risk of serious adverse events.

RESULTS

When CDK4/6 inhibitors were used in combination with endocrine drugs, abemaciclib resulted in the highest risk of discontinuation, dose reduction, and serious adverse events. Ribociclib caused the highest risk of death.

CONCLUSION

When using CDK4/6 inhibitors in the clinical setting, a comprehensive evaluation should be performed to avoid dosage reductions and discontinuations and to choose the most appropriate treatment regimen.

Clinicopathological features, treatment patterns, and survival outcomes among Syrian patients with advanced breast cancer

Background

Advanced breast cancer (ABC) is a heterogeneous disease with varied prognoses, that is affected by many clinicopathological features. This study aimed to investigate the clinicopathological characteristics, first-line treatment (FLx), and prognostic impact of these features on survival among Syrian patients with ABC.

Materials and methods

This retrospective cohort study included patients with ABC. The association of clinicopathological factors with survival was assessed using Kaplan-Meier curves and the log-rank test, as well as the Cox proportional hazards regression model to calculate the hazard ratio (HaR).

Results

A total of 423 patients with ABC were included in the study, with a median age (range) of 47 years (23-82). 83% of metastases were metachronous. Most patients (91.8%) received chemotherapy as the FLx. The median progression-free survival (PFS) and overall survival (OS) of all the patients were 7 and 16 months, respectively. The median PFS was associated with four factors, which were time of metastasis (adjusted HaR=1.861, 95% CI 1.420-2.438, P<0.0001), performance status (PS) (adjusted HaR=1.456, 95% CI 1.049-2.021, P=0.025), ovarian metastasis (adjusted HaR=7.907, 95% CI 1.049-59.576, P=0.045), and FLx (adjusted HaR=2.536, 95% CI 1.581-4.068, P<0.0001). Similarly, the OS was associated with three factors, including hormone receptors (HRs) status (adjusted HaR=1.124, 95% CI 1.009-1.252, P=0.034), time of metastasis (adjusted HaR=2.099, 95% CI 1.588-2.775, P<0.0001), and PS (adjusted HaR=1.787, 95% CI 1.429-2.233, P<0.0001). In the HR-positive/human epidermal growth receptor 2 (HER2)-negative group, endocrine therapy was significantly associated with longer PFS compared with chemotherapy (15 vs 7 months, adjusted HaR=2.699, 95% CI 1.417-5.143, P=0.003). Furthermore, there was no difference in OS between the two treatment modalities (P=0.855).

Conclusions

ABC survival varies depending on the location of metastases. Good PS and synchronous stage 4 disease were independent prognostic factors for longer PFS and OS. In the HR-positive/HER2-negative group, PFS for endocrine therapy was significantly longer than chemotherapy, with no differences in OS. This study confirms that endocrine therapy is preferred as an FLx for ABC in the HR-positive/HER2-negative group.

Role of [18F]FDG PET/CT in patients with invasive breast carcinoma of no special type: Literature review and comparison between guidelines

PURPOSE

The recently released EANM/SNMMI guideline, endorsed by several important clinical and imaging societies in the field of breast cancer (BC) care (ACR, ESSO, ESTRO, EUSOBI/ESR, EUSOMA), emphasized the role of [18F]FDG PET/CT in management of patients with no special type (NST) BC. This review identifies and summarizes similarities, discrepancies and novelties of the EANM/SNMMI guideline compared to NCCN, ESMO and ABC recommendations.

METHODS

The EANM/SNMMI guideline was based on a systematic literature search and the AGREE tool. The level of evidence was determined according to NICE criteria, and 85 % agreement or higher was reached regarding each statement. Comparisons with NCCN, ESMO and ABC guidelines were examined for specific clinical scenarios in patients with early stage through advanced and metastatic BC.

RESULTS

Regarding initial staging of patients with NST BC, [18F]FDG PET/CT is the preferred modality in the EANM-SNMMI guideline, showing superiority as a single modality to a combination of contrast-enhanced CT of thorax-abdomen-pelvis plus bone scan in head-to-head comparisons and a randomized study. Its use is recommended in patients with clinical stage IIB or higher and may be useful in certain stage IIA cases of NST BC. In NCCN, ESMO, and ABC guidelines, [18F]FDG PET/CT is instead recommended as complementary to conventional imaging to solve inconclusive findings, although ESMO and ABC also suggest [18F]FDG PET/CT can replace conventional imaging for staging patients with high-risk and metastatic NST BC. During follow up, NCCN and ESMO only recommend diagnostic imaging if there is suspicion of recurrence. Similarly, EANM-SNMMI states that [18F]FDG PET/CT is useful to detect the site and extent of recurrence only when there is clinical or laboratory suspicion of recurrence, or when conventional imaging methods are equivocal. The EANM-SNMMI guideline is the first to emphasize a role of [18F]FDG PET/CT for assessing early metabolic response to primary systemic therapy, particularly for HER2+ BC and TNBC. In the metastatic setting, EANM-SNMMI state that [18F]FDG PET/CT may help evaluate bone metastases and determine early response to treatment, in agreement with guidelines from ESMO.

CONCLUSIONS

The recently released EANM/SNMMI guideline reinforces the role of [18F]FDG PET/CT in the management of patients with NST BC supported by extensive evidence of its utility in several clinical scenarios.

Cancer Patient-Derived Cell-Based Models: Applications and Challenges in Functional Precision Medicine

The field of oncology has witnessed remarkable progress in personalized cancer therapy. Functional precision medicine has emerged as a promising avenue for achieving superior treatment outcomes by integrating omics profiling and sensitivity testing of patient-derived cancer cells. This review paper provides an in-depth analysis of the evolution of cancer-directed drugs, resistance mechanisms, and the role of functional precision medicine platforms in revolutionizing individualized treatment strategies. Using two-dimensional (2D) and three-dimensional (3D) cell cultures, patient-derived xenograft (PDX) models, and advanced functional assays has significantly improved our understanding of tumor behavior and drug response. This progress will lead to identifying more effective treatments for more patients. Considering the limited eligibility of patients based on a genome-targeted approach for receiving targeted therapy, functional precision medicine provides unprecedented opportunities for customizing medical interventions according to individual patient traits and individual drug responses. This review delineates the current landscape, explores limitations, and presents future perspectives to inspire ongoing advancements in functional precision medicine for personalized cancer therapy.

Neoadjuvant Chemotherapy with Concurrent Letrozole for Estrogen Receptor-Positive and HER2-Negative Breast Cancer: An Open-Label, Single-Center, Nonrandomized Phase II Study (NeoCHAI)

The role of combining neoadjuvant endocrine therapy with conventional chemotherapy remains unclear; therefore, we conducted an open-label, single-center, nonrandomized phase II trial to assess the effect of this combination. Patients with previously untreated stage II or III HR-positive, HER2-negative breast cancer received concurrent letrozole 2.5 mg with standard neoadjuvant chemotherapy. The primary endpoint was pathologic complete response (pCR) at the time of surgery. We used Simon's minimax two-stage design; a pCR rate > 6% was necessary at the first stage to continue. Between November 2017 and November 2020, 53 women were enrolled in the first stage of the trial. Their median age was 49 years (range, 33-63), and 60% of them were premenopausal. Subsequently, 66% and 34% of patients with clinical stages II and III, respectively, were included; 93% had clinically node-positive disease. Two patients (4%) achieved pCR after neoadjuvant chemo-endocrine treatment, which did not satisfy the criteria for continuing to the second stage. The overall response rate was 83%. During the median follow-up of 53.7 months, the 3-year disease-free survival and overall survival rates were 87% and 98%, respectively. Neutropenia was the most common grade 3/4 adverse event (40%), but rarely led to febrile neutropenic episodes (4%). Myalgia (32%), nausea (19%), constipation (17%), heartburn (11%), oral mucositis (9%), and sensory neuropathy (9%) were frequently observed, but classified as grade 1 or 2. No deaths occurred during preoperative treatment. The addition of letrozole to standard neoadjuvant chemotherapy was safe and beneficial in terms of overall response rate, but did not provide a higher pCR rate in locally advanced HR-positive, HER2-negative breast cancer. Further research is needed to enhance neoadjuvant treatment strategies for this cancer subtype.

Dalpiciclib in combination with letrozole/anastrozole or fulvestrant in HR-positive and HER2-negative advanced breast cancer: results from a phase Ib study

Background

Dalpiciclib is a novel cyclin-dependent kinase 4/6 inhibitor which showed tolerability and preliminary efficacy as monotherapy for pretreated advanced breast cancer (BC).

Objectives

To further assess dalpiciclib with endocrine therapy (ET) in hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative BC.

Design

A multicenter, open-label, phase Ib trial.

Methods

Patients with locally recurrent or metastatic BC were enrolled in five cohorts. Patients without prior treatment for advanced disease (cohorts 1-2) were given dalpiciclib (125 or 150 mg) plus letrozole/anastrozole; patients who progressed after ET (cohorts 3-5) were given dalpiciclib (125, 150, or 175 mg) plus fulvestrant. Dalpiciclib was administered orally once daily in 3-weeks-on/1-week off schedule. The primary endpoint was safety.

Results

A total of 58 patients received dalpiciclib with letrozole/anastrozole and 46 received dalpiciclib with fulvestrant. No maximum tolerated dose of dalpiciclib was reached with letrozole/anastrozole or fulvestrant. Across all cohorts, 86.7%-93.8% of patients had a grade ⩾3 adverse event, with the most common being neutropenia (grade 3, 40.0% for dalpiciclib 175 mg and 61.8%-87.5% for lower doses; grade 4, 46.7% and 4.2%-20.6%, respectively) and leukopenia (grade 3, 80.0% for 175 mg and 33.3%-54.2% for lower doses; grade 4, 0% for all doses). At tested dose levels, steady-state areas under the concentration curve and peak concentration of dalpiciclib increased with dose when combined with letrozole/anastrozole and fulvestrant. Dalpiciclib at 150 mg was associated with a numerically higher objective response rate in both patients untreated for advanced disease (67.6%; 95% confidence interval (CI) 49.5-82.6) and patients progressing after ET (53.3%; 95% CI 26.6-78.7); as of July 30, 2022, the median progression-free survival with dalpiciclib 150 mg was 24.1 months (95% CI 16.9-46.0) with letrozole/anastrozole and 16.7 months (95% CI 1.9-24.1) with fulvestrant.

Conclusion

Dalpiciclib plus letrozole/anastrozole or fulvestrant showed an acceptable safety profile. The recommended phase III dose of dalpiciclib was 150 mg.

Trial registration

ClinicalTrials.gov identifier: NCT03481998.

QTc prolongation across CDK4/6 inhibitors: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Cyclin-dependent kinases (CDK) 4/6 inhibitors have significantly improved outcomes for patients with ER+/HER2- breast cancer. Nevertheless, they differ from each other in terms of chemical, biological, and pharmacological features, as well as toxicity profiles. We aim to determine whether QTc prolongation is caused by CDK4/6i in general or if it is associated with ribociclib only.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs) comparing the prevalence of QTc prolongation as an adverse event in HR+ breast cancer patients treated with CDK4/6i vs those without CDK4/6i. We pooled relative risk (RR) and mean difference (MD) with 95% confidence interval (CI) for the binary endpoint of QT prolongation.

RESULTS

We included 14 RCTs comprising 16 196 patients, of whom 8576 underwent therapy with CDK4/6i. An increased risk of QTc prolongation was associated with the use of CDK4/6i (RR = 2.35, 95% CI = 1.67 to 3.29, P < .001; I2 = 44%). Subgroup analyses revealed a significant increase in the QTc interval for the ribociclib and palbociclib cohorts. The ribociclib subgroup showed a relative risk of 3.12 (95% CI = 2.09 to 4.65, P < .001; I2 = 12%), whereas the palbociclib subgroup had a relative risk of 1.51 (95% CI = 1.05 to 2.15, P = .025; I2 = 0%).

CONCLUSION

Palbociclib was associated with QTc prolongation; however, the relative risk for any grade QTc was quantitively twice with ribociclib. Furthermore, grade 3 QTc prolongations were observed exclusively with ribociclib. These results are important for guiding clinical decision-making and provide reassurance regarding the overall safety profile of this drug class.

Real-world treatment patterns and outcomes in patients with HR+/HER2- metastatic breast cancer treated with chemotherapy in the United States

BACKGROUND

Until recently, treatment options for patients with hormone receptor-positive/human epidermal growth factor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) and resistance to endocrine therapy were limited to chemotherapy. This real-world study describes treatment patterns and outcomes in patients treated with chemotherapy in the United States before approval of antibody-drug conjugates.

PATIENTS AND METHODS

This retrospective, observational study included adults with HR+/HER2- mBC from the ConcertAI Patient360™ Breast Cancer dataset who initiated their first chemotherapy in the metastatic setting between January 2011 and June 2021. Treatment patterns were described; real-world overall survival, time to next treatment or death, and real-world progression-free survival were evaluated for all eligible patients and patients treated with subsequent chemotherapy. Index dates were the start date of each chemotherapy treatment.

RESULTS

Among 1545 eligible patients, 76% were white, 12% had Eastern Cooperative Oncology Group performance status ≥2, 38% had de novo mBC, and median age was 61 years (range, 52-69 years). Within the index period, capecitabine was used the most as the first chemotherapy agent and decreased in later treatments, while the use of eribulin increased between first and fourth chemotherapies. Median (95% confidence interval) real-world overall survival was 23.3 months (21.3-25.4 months) from start of first chemotherapy, time to next treatment or death was 6.5 months (5.9-7.1 months), and real-world progression-free survival was 6.9 months (6.4-7.6 months); median times from second, third, and fourth chemotherapies decreased with each additional chemotherapy treatment.

CONCLUSIONS

This real-world study demonstrates that for patients with HR+/HER2- mBC, chemotherapy provides relatively limited survival benefit which decreases with each additional chemotherapy line, and highlights the need for improved treatment options.

Mechanisms of sensitivity and resistance to CDK4/CDK6 inhibitors in hormone receptor-positive breast cancer treatment

Cell cycle dysregulation is a hallmark of cancer that promotes eccessive cell division. Cyclin-dependent kinase 4 (CDK4) and cyclin-dependent kinase 6 (CDK6) are key molecules in the G1-to-S phase cell cycle transition and are crucial for the onset, survival, and progression of breast cancer (BC). Small-molecule CDK4/CDK6 inhibitors (CDK4/6i) block phosphorylation of tumor suppressor Rb and thus restrain susceptible BC cells in G1 phase. Three CDK4/6i are approved for the first-line treatment of patients with advanced/metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) BC in combination with endocrine therapy (ET). Though this has improved the clinical outcomes for survival of BC patients, there is no established standard next-line treatment to tackle drug resistance. Recent studies suggest that CDK4/6i can modulate other distinct effects in both BC and breast stromal compartments, which may provide new insights into aspects of their clinical activity. This review describes the biochemistry of the CDK4/6-Rb-E2F pathway in HR+ BC, then discusses how CDK4/6i can trigger other effects in BC/breast stromal compartments, and finally outlines the mechanisms of CDK4/6i resistance that have emerged in recent preclinical studies and clinical cohorts, emphasizing the impact of these findings on novel therapeutic opportunities in BC.

Metronomic chemotherapy using capecitabine and cyclophosphamide in metastatic breast cancer - efficacy, tolerability and quality of life results from the phase II METRO trial

BACKGROUND

Chemotherapy is commonly used in metastatic breast cancer (MBC) to prolong life and improve quality of life (QoL). The optimal dosing and sequencing beyond the second line of treatment are unknown and pose a risk of overtreatment. Continuous low oral doses of metronomic chemotherapy using capecitabine 500 mg three times daily and cyclophosphamide 50 mg once daily (MCT-CX) may be an effective and tolerable treatment option for patients with MBC.

METHODS

In this open-label, single-arm single-centre phase II trial patients with MBC received MCT-CX until disease progression or unacceptable toxicity. The primary endpoint was the clinical benefit rate (CBR), defined as the proportion of participants with a best overall response of complete (CR) or partial response (PR) at any time, or stable disease (SD) for ≥24 weeks according to radiological evaluation. Toxicity was assessed according to the Common Toxicity Criteria v 4.0. QoL was assessed with the EORTC-30 questionnaire.

RESULTS

In total, 40 patients were included. Most participants (72 %) presented with visceral disease and received MCT-CX beyond the second line (58 %). The CBR was 45 % (8 PR and 10 SD ≥ 24 weeks). Toxicities were low grade with hand-foot syndrome being the most common. There was no significant change in QoL over the first 24 weeks.

CONCLUSION

MCT-CX is a plausible treatment option in far advanced breast cancer, with almost half of trial participants responding to treatment without QoL impairments.

Palbociclib: Randomized Studies and Real-world Evidence as the Basis for Therapeutic Planning in Metastatic Breast Cancer

Endocrine-based combination therapy with an inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6 inhibitors) is currently the first-line therapy of choice for patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-), locally advanced or metastatic breast cancer (mBC). The efficacy and safety of the treatment with palbociclib, the first CDK4/6 inhibitor approved for this indication, have been confirmed in large randomized controlled clinical trials (RCTs) with strictly defined patient cohorts. Since then, many relevant questions about CDK4/6 inhibition with palbociclib for mBC have been investigated in RCTs and real-world studies. Based on this evidence, palbociclib is widely used in clinical practice since many years because of its efficacy and good tolerability. The aim of this review is to summarize findings from RCTs and RWE considering clinically relevant aspects such as safety, tolerability, quality of life and efficacy with a focus on specific questions and patient characteristics. A critical discussion and review of the overall evidence for endocrine-based therapy with the CDK4/6 inhibitor palbociclib can contribute to support therapy decisions in daily clinical practice.

The role of locoregional surgery in de novo stage IV breast cancer: A meta-analysis of randomized controlled trials

BACKGROUND

We performed an updated meta-analysis to explore the value of locoregional surgery in de novo stage IV breast cancer patients.

METHODS

A literature search was conducted to identify randomized controlled trials comparing primary tumor resection with systemic therapy in de novo stage IV breast cancer. The hazard ratio (HR) of overall survival (OS), local relapse-free survival (LRFS), and distant relapse-free survival (DRFS) were estimated and pooled.

RESULTS

Six studies were eligible, including a total of 1368 patients. Both OS (HR = 0.86; 95 %CI: 0.77-0.96; p = 0.01; I2 = 45 %) and LRFS (HR = 0.35; 95 %CI: 0.20-0.62; p = 0.0003; I2 = 83 %) were significantly improved with locoregional surgery compared with systemic therapy alone. There was no significant difference in terms of DRFS (HR = 0.96; 95 %CI: 0.41-2.22; p = 0.92; I2 = 86 %). The OS benefit was more pronounced in hormone receptor-positive patients (HR = 0.79; p = 0.003) and HER2-negative patients (HR = 0.80; p = 0.003).

CONCLUSIONS

This study demonstrated that locoregional surgery conferred significant OS and LRFS benefits in de novo stage IV breast cancer patients and may serve as an alternative choice for selected patients.

Current and Novel Treatment Options in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer

Metastatic breast cancer (mBC) remains an incurable disease, and most patients will experience disease progression during their treatment course. Although endocrine therapy remains the mainstay of treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative mBC, significant progress has been and continues to be made in the treatment of this BC subtype. The discovery of molecular markers, mutations in key cellular pathways, and genomic signatures have led to the development of novel and targeted agents, such as antibody-drug conjugates, oral selective estrogen receptor downregulators, and inhibitors of the PI3K/AKT/mTOR pathway. This has resulted in significant improvements in the survival and quality of life of patients. With the increasing number of treatment options for patients, appropriate drug sequencing remains a challenge. Treatment discussions should involve patient-physician shared decision making, with consideration of genomic data, previous lines of therapy, side effect profiles, and clinical trial enrollment.

Effect of Cyclin-Dependent Kinase 4/6 Inhibitors on Circulating Cells in Patients with Metastatic Breast Cancer

The combination of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) with endocrine therapy (ET) is the standard-of-care for estrogen receptor (ER)-positive, HER2-negative (ER+/HER2- advanced/metastatic breast cancer (mBC). However, the impact of CDK4/6i on circulating immune cells and circulating tumor cells (CTCs) in patients receiving CDK4/6i and ET (CDK4/6i+ET) remains poorly understood. This was a prospective cohort study including 44 patients with ER+/HER2- mBC treated with CDK4/6i+ET in either first or second line. Peripheral blood samples were collected before (baseline) and 3 months (t2) after therapy. Immune cell's subsets were quantified by flow cytometry, and microfluidic-captured CTCs were counted and classified according to the expression of cytokeratin and/or vimentin. Patients were categorized according to response as responders (progression-free survival [PFS] ≥ 6.0 months; 79.1%) and non-responders (PFS < 6.0 months; 20.9%). CDK4/6i+ET resulted in significant changes in the hematological parameters, including decreased hemoglobin levels and increased mean corpuscular volume, as well as reductions in neutrophil, eosinophil, and basophil counts. Specific immune cell subsets, such as early-stage myeloid-derived suppressor cells, central memory CD4+ T cells, and Vδ2+ T cells expressing NKG2D, decreased 3 months after CDK4/6i+ET. Additionally, correlations between the presence of CTCs and immune cell populations were observed, highlighting the interplay between immune dysfunction and tumor dissemination. This study provides insights into the immunomodulatory effects of CDK4/6i+ET, underscoring the importance of considering immune dynamics in the management of ER+/HER2- mBC.

Profiling the Cardiovascular Toxicities of CDK4/6 Inhibitors: A Real-World Pharmacovigilance Study

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors are approved for the treatment of human epidermal growth factor receptor 2 (HER-2)-negative, hormone receptor-positive breast cancer. The cardiovascular toxicity of CDK4/6 inhibitors is not well understood. This study aims to profile the cardiac events associated with CDK4/6 inhibitors. Reports from 2015Q1 to 2024Q1 were obtained from the FDA Adverse Event Reporting System (FAERS). Reports identifying palbociclib, ribociclib, and abemaciclib as the primary suspect were examined for cardiovascular toxicity, including hypertension, cardiac failure, cardiomyopathy, arrhythmia, myocardial infarction, and myocarditis. Signal detection was performed using the proportional reporting ratio (PRR), reporting odds ratio (ROR), and information component (IC). A total of 69,139 reports were analyzed. The median time to adverse events was 69 days (interquartile range [IQR], 18-260 days). Of these, 2065 reports documented cardiac adverse events. Ribociclib and QT prolongation were re-confirmed as a signal (PRR 8.43, ROR 8.65, IC025 2.86). Hypertension and cardiac failure were the most frequently reported cardiovascular toxicities. This study demonstrates that the use of CDK4/6 inhibitors is associated with cardiovascular adverse events, such as heart failure and hypertension. Further research is needed to understand the mechanisms and risk factors contributing to the cardiovascular toxicity of CDK4/6 inhibitors.

Advances in Personalized Oncology

Advances in next-generation sequencing (NGS) have catalyzed a paradigm shift in cancer treatment, steering the focus from conventional, organ-specific protocols to precision medicine. Emerging targeted therapies offer a cutting-edge approach to cancer treatment, while companion diagnostics play an essential role in aligning therapeutic choices with specific molecular changes identified through NGS. Despite these advances, interpreting the clinical implications of a rapidly expanding catalog of genetic mutations remains a challenge. The selection of therapies in the presence of multiple mutations requires careful clinical judgment, supported by quality-centric genomic testing that emphasizes actionable mutations. Molecular tumor boards can play an increasing role in assimilating genomic data into clinical trials, thereby refining personalized treatment approaches and improving patient outcomes.

Comparative effectiveness analysis of survival with first-line palbociclib or ribociclib plus AI in HR + /HER2- advanced breast cancer (CEPRA study): preliminary analysis of real-world data from Thailand

BACKGROUND

The current standard first-line treatment for hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR + /HER2 -) advanced breast cancer (ABC) is a combination of aromatase inhibitor (AI) plus CDK4/6 inhibitors (CDK4/6i). Direct comparison trials of different CDK4/6i are scarce. This real-world study compared the effectiveness of first-line AI plus ribociclib versus palbociclib.

METHODS

This multicenter retrospective cohort study, conducted in six cancer centers in Thailand, enrolled patients with HR + /HER2 - ABC treated with first-line AI, and either ribociclib or palbociclib. Propensity score matching (PSM) was performed. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), time to chemotherapy (TTC), and adverse events.

RESULTS

Of the 250 patients enrolled, 134 patients with ribociclib and 49 patients with palbociclib were captured after PSM. Baseline characteristics were well-balanced between groups. Median PFS in patients receiving ribociclib and palbociclib were 27.9 and 31.8 months, respectively (hazard ratio: 0.87; 0.55-1.37). The median OS in the AI + ribociclib arm was 48.7 months compared to 59.1 months in the AI + palbociclib arm (hazard ratio: 0.55; 0.29-1.05). The median TTC in the AI + palbociclib group was 56 months, but not reached in the AI + ribociclib group (p = 0.42). The ORR of AI + ribociclib and AI + palbociclib were comparable (40.5% vs. 53.6%, p = 0.29). Patients receiving palbociclib demonstrated a higher proportion of neutropenia compared to those receiving ribociclib, despite a similar dose reduction rate (p = 0.28). Hepatitis rate was similar between the ribociclib (21%) and palbociclib groups (22%). Additionally, a low incidence of QT prolongation was observed in both the ribociclib (5%) and palbociclib groups (4%).

CONCLUSION

This preliminary analysis of a real-world study demonstrated the comparable effectiveness of ribociclib and palbociclib with AI as an initial therapy for HR + /HER2 - ABC. No statistically significant difference in PFS, OS, and TTC was found in patients treated with AI combined with palbociclib or ribociclib. Longer follow-up and further prospective randomized head-to-head studies are warranted.

Enhancing breast cancer treatment through pharmacogenomics: A narrative review

Pharmacogenomics has become integral to personalised medicine in breast cancer, utilising genetic insights to customize treatment strategies and enhance patient outcomes. Understanding how genetic variations influence drug metabolism, response, and toxicity is crucial for guiding treatment selection and dosing regimens. Genetic polymorphisms in drug-metabolizing enzymes and transporters significantly impact pharmacokinetic variability, influencing the efficacy and safety of chemotherapy agents and targeted therapies. Biomarkers associated with the hormone receptor status of breast cancer and mutations serve as key determinants of treatment response, aiding in the selection of therapies. Despite substantial progress in understanding the pharmacogenomic landscape of breast cancer, efforts to identify novel genetic markers and refine treatment optimisation strategies are required. Genome-wide association studies and advanced sequencing technologies hold promise for uncovering genetic determinants of drug response variability and elucidating complex pharmacogenomic interactions. The future of pharmacogenomics in breast cancer lies in real-time treatment monitoring, the discovery of additional predictive markers, and the seamless integration of pharmacogenomic data into clinical decision-making processes. However, translating pharmacogenomic discoveries into routine clinical practice requires collaborative efforts among stakeholders to address implementation challenges and ensure equitable access to genetic testing. By embracing pharmacogenomics, clinicians can tailor treatment approaches to individual patients, maximizing therapeutic benefits while minimizing adverse effects. This review discusses the integration of pharmacogenomics in breast cancer treatment, highlighting the significance of understanding genetic influences on treatment response and toxicity, and the potential of advanced technologies in refining treatment strategies.

Pharmacokinetics and Pharmacogenomics of Ribociclib in Black Patients with Metastatic Breast Cancer: The LEANORA study

Underrepresented populations' participation in clinical trials remains limited, and the potential impact of genomic variants on drug metabolism remains elusive. This study aimed to assess the pharmacokinetics (PK) and pharmacogenomics (PGx) of ribociclib in self-identified Black women with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2) advanced breast cancer. LEANORA (NCT04657679) was a prospective, observational, multicenter cohort study involving 14 Black women. PK and PGx were evaluated using tandem mass spectrometry and PharmacoScan™ microarray (including CYP3A5*3 , *6 , and *7 ). CYP3A5 phenotypes varied among participants: 7 poor metabolizers (PM), 6 intermediate metabolizers (IM), and one normal metabolizer (NM). The area-under-the-curve did not significantly differ between PMs (39,230 hr*ng/mL) and IM/NMs (43,546 hr*ng/mL; p = 0.38). The incidence of adverse events (AEs) was also similar. We found no association between CYP3A5 genotype and ribociclib exposure. Continued efforts are needed to include diverse populations in clinical trials to ensure equitable treatment outcomes.

Real-world experience with CDK4/6 inhibitors in hormone receptor-positive metastatic and recurrent breast cancer: findings from an Asian population

PURPOSE

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) combined with endocrine therapy have demonstrated significant clinical benefits in progression-free and overall survival. This study investigates the outcomes associated with two kinds of CDK4/6i in patients with hormone receptor (HR)-positive metastatic and relapsed breast cancer to inform real-world evidence of treatment strategies.

METHODS

This retrospective study included 340 Taiwanese patients with HR-positive advanced breast cancer from the Taipei Veterans General Hospital, between 2018 and 2023. We analyzed patient characteristics, treatment strategies and outcomes associated with two CDK4/6i. The efficacy of patients who experienced economic burden and interrupted CDK4/6i treatment after 2 years of National Health Insurance (NHI) reimbursement was also investigated.

RESULTS

Patients receiving ribociclib and palbociclib showed no significant differences in age, histology, body mass index(BMI), or pathologic status. The distribution of disease status and endocrine therapy partners was comparable between the two groups. Dose reduction was similar, while patients with palbociclib tended to discontinue CDK4/6i usage, and those with ribociclib tended to switch to the other CDK4/6i or endocrine partners. There was no significant difference in progression-free survival (PFS) between the two CDK4/6i in the first-line setting. Adverse prognostic factors were increasing HER2 IHC score, higher Ki-67 levels, visceral and liver metastasis, prior chemotherapy, and endocrine therapy resistance, while higher BMI, bone-only metastasis, and letrozole treatment were associated with a lower risk of progression. The limited follow-up time in our study was insufficient to assess the outcomes of patients treated with interrupted CDK4/6i for up to two years under the NHI reimbursement policy.

CONCLUSION

Treatment outcomes between the two types of CDK4/6i did not differ significantly, indicating the safety and efficacy of CDK4/6i for the Asian population. Ribociclib and palbociclib showed similar efficacy in PFS in the real-world setting.

The Clinical Features and Outcomes of Pseudocirrhosis in Breast Cancer

Pseudocirrhosis is a diffuse nodularity of the liver that radiologically mimics cirrhosis but is a distinct pathological process. It is seen almost exclusively in patients with liver metastases and may represent a response to systemic treatment. Data on the risk factors for pseudocirrhosis and outcomes are limited. In total, 170 patients with a diagnosis of breast cancer and pseudocirrhosis in a 10-year period were identified and retrospectively analysed. Data were collected on baseline patient characteristics, treatments received, and outcomes. Median time between diagnosis of liver metastases and diagnosis of pseudocirrhosis was 17.1 months (range, 0-149 months). In total, 89.4% of patients received chemotherapy between their diagnosis of breast cancer liver metastases and their diagnosis of pseudocirrhosis, most commonly a taxane (74.7%) or capecitabine (67.1%), and the median treatment lines received was 3. Median OS from first diagnosis of pseudocirrhosis was 7.6 months (95% CI: 6.1-9.6 months) and was longer in patients with HER2+ disease at 16.7 months (95% CI: 6.4-32.9 months), which was statistically significant. In our study, pseudocirrhosis occurred in the presence of liver metastases and was associated with a poor prognosis. HER2+ patients with pseudocirrhosis had a better prognosis than other subtypes, but we did not identify other significant predictors of survival. Chemotherapy was not a prerequisite for pseudocirrhosis development, although the majority of patients had received at least one line of chemotherapy before pseudocirrhosis was diagnosed.

Genomic alterations associated with resistance and circulating tumor DNA dynamics for early detection of progression on CDK4/6 inhibitor in advanced breast cancer

Combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy significantly improves outcome for patients with estrogen receptor-positive (ER+) metastatic breast cancer, but drug resistance and thus disease progression inevitably occur. Herein, we aimed to identify genomic alterations associated with combined CDK4/6i and endocrine therapy resistance, and follow the levels of specific mutations in longitudinal circulating tumor DNA (ctDNA) for early detection of progression. From a cohort of 86 patients with ER+ metastatic breast cancer we performed whole exome sequencing or targeted sequencing of paired tumor (N = 8) or blood samples (N = 5) obtained before initiation of combined CDK4/6i and endocrine therapy and at disease progression. Mutations in oncogenic genes at progression were rare, while amplifications of growth-regulating genes were more frequent. The most frequently acquired alterations observed were PIK3CA and TP53 mutations and PDK1 amplification. Longitudinal ctDNA dynamics of mutant PIK3CA or private mutations revealed increased mutation levels at progression in 8 of 10 patients (80%). Impressively, rising levels of PIK3CA-mutated ctDNA were detected 4-17 months before imaging. Our data add to the growing evidence supporting longitudinal ctDNA analysis for real-time monitoring of CDK4/6i response and early detection of progression in advanced breast cancer. Further, our analysis suggests that amplification of growth-related genes may contribute to combined CDK4/6i and endocrine therapy resistance.

Confirming the efficacy and safety of CDK4/6 inhibitors in the first-line treatment of HR+ advanced breast cancer: a systematic review and meta-analysis

Objective: Cyclin-dependent kinase (CDK) 4 and 6 inhibitors (abemaciclib, palbociclib and ribociclib) have been recommended in the first-line treatment of hormone receptor-positive (HR+) breast cancer in China. Our study aims to evaluate the efficacy and safety of CDK4/6 inhibitors by processing survival data using fractional polynomial modeling methods. Methods: Phase II or III randomized controlled trials in treatment-naive HR + patients with advanced breast cancer were systematically searched through the preset search strategy. The fractional polynomial (FP) model was used to relax the proportional hazard assumption and obtain time-varying hazard ratio (HR). Progression-free life years (PFLYs) and life years (LYs) were calculated from the area under curve (AUC) of the predicted progression-free survival (PFS) and overall survival (OS) curves to evaluate the long-term efficacy benefit. Odds ratio (OR) of grade≥3 adverse events were analyzed for safety outcomes. Results: 6 randomized controlled trials with 2,638 patients were included. The first-order FP model (p = -1) and the first-order FP model (p = 1) were used to calculate the time-varying HR of PFS and OS, respectively. Extrapolating to 240 months, abemaciclib obtained a PFS benefit of 3.059 PFLYs and 6.275 LYs by calculating the AUC of the PFS and OS curves. Palbociclib obtained 2.302 PFLYs and 6.351 LYs. Ribociclib obtained 2.636 PFLYs and 6.543 LYs. In terms of safety, the use of CDK4/6 inhibitors resulted in a higher risk of adverse events (OR = 9.84, 95% CI: 8.13-11.95), especially for palbociclib (OR = 14.04, 95% CI: 10.52-18.90). Conclusion: The use of CDK4/6 inhibitors in treatment-naive patients with HR + advanced breast cancer significantly improves survival, but also increases the risk of adverse events. Abemaciclib and ribociclib may be the best options for prolonging PFS and OS in treatment-naïve patients, respectively.

6th and 7th International consensus guidelines for the management of advanced breast cancer (ABC guidelines 6 and 7)

This manuscript describes the Advanced Breast Cancer (ABC) international consensus guidelines updated at the last two ABC international consensus conferences (ABC 6 in 2021, virtual, and ABC 7 in 2023, in Lisbon, Portugal), organized by the ABC Global Alliance. It provides the main recommendations on how to best manage patients with advanced breast cancer (inoperable locally advanced or metastatic), of all breast cancer subtypes, as well as palliative and supportive care. These guidelines are based on available evidence or on expert opinion when a higher level of evidence is lacking. Each guideline is accompanied by the level of evidence (LoE), grade of recommendation (GoR) and percentage of consensus reached at the consensus conferences. Updated diagnostic and treatment algorithms are also provided. The guidelines represent the best management options for patients living with ABC globally, assuming accessibility to all available therapies. Their adaptation (i.e. resource-stratified guidelines) is often needed in settings where access to care is limited.

Everolimus plus endocrine therapy beyond CDK4/6 inhibitors progression for HR+ /HER2- advanced breast cancer: a real-world evidence cohort

PURPOSE

Everolimus in combination with endocrine therapy (ET) was formerly approved as 2nd-line therapy in HR(+)/HER2(-) advanced breast cancer (aBC) patients (pts) progressing during or after a non-steroidal aromatase inhibitor (NSAI). Since this approval, the treatment landscape of aBC has changed dramatically, particularly with the arrival of CDK 4-6 inhibitors. Endocrine monotherapy after progression to CDK4/6 inhibitors has shown a limited progression-free survival (PFS), below 3 months. Evidence of the efficacy of everolimus plus ET after CDK4/6 inhibitors is scarce.

METHODS

A retrospective observational study of patients with aBC treated with everolimus and ET beyond CDK4/6-i progression compiled from February 2015 to December 2022 in 4 Spanish hospitals was performed. Clinical and demographic data were collected from medical records. The main objective was to estimate the median progression-free survival (mPFS). Everolimus adverse events (AE) were registered. Quantitative variables were summarized with medians; qualitative variables with proportions and the Kaplan-Meier method were used for survival estimates.

RESULTS

One hundred sixty-one patients received everolimus plus ET (exemestane: 96, fulvestrant: 54, tamoxifen: 10, unknown: 1) after progressing on a CDK4/6 inhibitor. The median follow-up time was 15 months (interquartile range: 1-56 months). The median age at diagnosis was 49 years (range: 35-90 years). The estimated mPFS was 6.0 months (95%CI 5.3-7.8 months). PFS was longer in patients with previous CDK4/6 inhibitor therapy lasting for > 18 months (8.7 months, 95%CI 6.6-11.3 months), in patients w/o visceral metastases (8.0 months, 95%CI 5.8-10.5 months), and chemotherapy-naïve in the metastatic setting (7.2 months, 95%CI 5.9-8.4 months).

CONCLUSION

This retrospective analysis cohort of everolimus plus ET in mBC patients previously treated with a CDK4/6 inhibitor suggests a longer estimated mPFS when compared with the mPFS with ET monotherapy obtained from current randomized clinical data. Everolimus plus ET may be considered as a valid control arm in novel clinical trial designs.

Abemaciclib plus a nonsteroidal aromatase inhibitor as initial therapy for HR+, HER2- advanced breast cancer: final overall survival results of MONARCH 3

BACKGROUND

In MONARCH 2, the addition of abemaciclib to fulvestrant significantly improved both progression-free survival (PFS) and overall survival (OS) in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) with disease progression on prior endocrine therapy. In MONARCH 3, the addition of abemaciclib to a nonsteroidal aromatase inhibitor (NSAI) as initial therapy for HR+, HER2- ABC significantly improved PFS. Here, we present the prespecified final OS results for MONARCH 3.

PATIENTS AND METHODS

MONARCH 3 is a randomized, double-blind, phase III study of abemaciclib plus NSAI (anastrozole or letrozole) versus placebo plus NSAI in postmenopausal women with HR+, HER2- ABC without prior systemic therapy in the advanced setting. The primary objective was investigator-assessed PFS; OS was a gated secondary endpoint, and chemotherapy-free survival was an exploratory endpoint.

RESULTS

A total of 493 women were randomized 2 : 1 to receive abemaciclib plus NSAI (n = 328) or placebo plus NSAI (n = 165). After a median follow-up of 8.1 years, there were 198 OS events (60.4%) in the abemaciclib arm and 116 (70.3%) in the placebo arm (hazard ratio, 0.804; 95% confidence interval 0.637-1.015; P = 0.0664, non-significant). Median OS was 66.8 versus 53.7 months for abemaciclib versus placebo. In the subgroup with visceral disease, there were 113 OS events (65.3%) in the abemaciclib arm and 65 (72.2%) in the placebo arm (hazard ratio, 0.758; 95% confidence interval 0.558-1.030; P = 0.0757, non-significant). Median OS was 63.7 months versus 48.8 months for abemaciclib versus placebo. The previously demonstrated PFS benefit was sustained, and chemotherapy-free survival numerically improved with the addition of abemaciclib. No new safety signals were observed.

CONCLUSIONS

Abemaciclib combined with an NSAI resulted in clinically meaningful improvement in median OS (intent-to-treat population: 13.1 months; subgroup with visceral disease: 14.9 months) in patients with HR+ HER2- ABC; however, statistical significance was not reached.

Randomized Phase III Study of Amcenestrant Plus Palbociclib Versus Letrozole Plus Palbociclib in Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Primary Results From AMEERA-5

PURPOSE

AMEERA-5 investigated amcenestrant (oral selective estrogen receptor [ER] degrader) plus palbociclib versus letrozole plus palbociclib as first-line treatment for ER-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced/metastatic breast cancer (aBC).

MATERIALS AND METHODS

In AMEERA-5 (ClinicalTrials.gov identifier: NCT04478266), a double-blind, double-dummy, international phase III trial, adult pre-/post-menopausal women and men without previous systemic therapy for ER+/HER2- aBC were randomly assigned 1:1 to amcenestrant 200 mg once daily + standard palbociclib dosage (125 mg once daily, 21 days on/7 days off) or letrozole 2.5 mg once daily + standard palbociclib dosage, stratified by de novo metastatic disease, postmenopausal women, and visceral metastasis. The primary end point was progression-free survival (PFS), compared using a stratified log-rank test with one-sided type I error rate of 2.5%. Secondary end points included overall survival (key secondary), pharmacokinetics, and safety.

RESULTS

Between October 14, 2020, and December 2, 2021, 1,068 patients were randomly assigned to amcenestrant + palbociclib (N = 534) or letrozole + palbociclib (N = 534). At the interim analysis (median follow-up 8.4 months), the stratified hazard ratio for PFS was 1.209 (95% CI, 0.939 to 1.557; one-sided P value = .9304); therefore, the study was stopped for futility. The 6-month PFS rate was 82.7% (95% CI, 79.0 to 85.8) with amcenestrant + palbociclib versus 86.9% (95% CI, 83.5 to 89.6) with letrozole + palbociclib. In the amcenestrant + palbociclib versus letrozole + palbociclib groups, treatment-emergent adverse events (any grade) occurred in 85.6% versus 85.4% of patients and grade ≥3 events in 46.3% versus 60.8%, respectively.

CONCLUSION

The AMEERA-5 study was discontinued on the basis of the recommendation of the data monitoring committee at the interim futility analysis. No new safety signals were identified.

Initial ribociclib plus endocrine therapy for HR+/HER2- advanced breast cancer in pre- and postmenopausal Chinese women: Primary results from a phase 2 randomized study

Background

The MONALEESA‐7 and ‐2 phase 3 randomized trials demonstrated a statistically significant progression‐free survival (PFS) and overall survival (OS) benefit with initial ribociclib + endocrine therapy (ET) versus placebo + ET in pre‐ and postmenopausal patients with hormone receptor–positive (HR+)/human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (ABC), respectively. Similar trends were observed in Asian subgroup analyses. This phase 2 bridging study of initial ET + ribociclib enrolled pre‐ and postmenopausal patients with HR+/HER2– ABC from China and was conducted to demonstrate consistency of PFS results in a Chinese population relative to the global MONALEESA‐7 and ‐2 studies.

Methods

Patients were randomized (1:1) to ET (nonsteroidal aromatase inhibitor + goserelin for premenopausal patients; letrozole for postmenopausal patients) + either ribociclib or placebo. The primary endpoint was investigator‐assessed PFS.

Results

As of April 25, 2022, the median follow‐up was 34.7 months in both cohorts. In the premenopausal cohort, median PFS was 27.6 months in the ribociclib arm (n = 79) versus 14.7 months in the placebo arm (n = 77) (hazard ratio 0.67 [95% CI: 0.45, 1.01]). In the postmenopausal cohort, median PFS was not reached in the ribociclib arm versus 18.5 months in the placebo arm (n = 77 in each arm) (hazard ratio 0.40 [95% CI: 0.26, 0.62]). Data also suggested improvements in secondary efficacy endpoints, although OS data were not mature. The safety profile in this population was consistent with that in global studies.

Conclusions

These data demonstrate a favorable benefit–risk profile for ribociclib + ET in Chinese patients.

The NEOLETRIB trial: neoadjuvant treatment with Letrozole and Ribociclib in ER-positive, HER2-negative breast cancer

Chemotherapy is used as neoadjuvant therapy for all subgroups of breast cancer, including ER-positive, and HER2-negative cases. However, studies have suggested that using aromatase inhibitors combined with CDK4/6-inhibitors might be an appropriate alternative in selected patients. Thus, the NEOLETRIB trial evaluates the response of ER-positive, HER2-negative luminal A/B breast cancer to the combination of letrozole and ribociclib in the neoadjuvant setting. Comprehensive molecular biology procedures, including sequential single-cell RNA-sequencing of tumor biopsies, are performed during 6 months of treatment with extensive biobanking of blood samples, tumor biopsies and gut microbiome specimens. Our findings will hopefully contribute to an improved selection of patients who may benefit from this drug combination and give new insights into the intra-tumoral changes during this treatment.Trial registration number: NCT05163106 (ClinicalTrials.gov).

The impact of human epidermal growth factor receptor-2 (low) status on the efficacy of first line cyclin-dependent kinase 4/6 inhibitors in advanced breast cancer

The fact that the human epidermal growth factor receptor 2 (HER2)-low group, historically classified as HER2 negative in breast cancer histology, benefited from HER2-targeted treatments similarly to the HER2-positive group indicates that this group has a distinct histology from the HER2-0 group. The effectiveness of cyclin-dependent kinase 4/6 inhibitors, which are the standard first-line treatment for hormone receptor-positive, HER2-negative advanced breast cancer, in this newly defined histological subgroup remains a topic of debate. In our study, we examined the impact of HER2 status on the efficacy of CDK4/6 inhibitors. Our study is a retrospective, multicenter, real-world data analysis. One hundred sixty patients were included in the study. The relationship between HER2 status and other clinical-pathological features, as well as progression-free survival, was examined. Median follow-up was 20.33 ± 0.98 months. The mPFS could not be reached. All patients exhibited positive estrogen receptor expression. Among the patients, 111 (69.4%) were categorized as HER2-0, and 49 (30.6%) as HER2-low. The 24-month progression-free survival rates were similar between HER2-0 and HER2-low patients (60.6% vs 65.3%, hormone receptor: 1.18, CI: 0.67-2.20, P = .554). We established that the mPFS achieved with cyclin-dependent kinase 4/6 inhibitors as a first-line therapy for patients with advanced breast cancer is unaffected by HER2 status.

Supervised, structured and individualized exercise in metastatic breast cancer: a randomized controlled trial

Physical exercise both during and after curative cancer treatment has been shown to reduce side effects. Evidence in the metastatic cancer setting is scarce, and interventions that improve health-related quality of life (HRQOL) are much needed for patients with metastatic breast cancer (MBC). The multinational randomized controlled PREFERABLE-EFFECT trial assessed the effects of exercise on fatigue and HRQOL in patients with MBC. In total, 357 patients with MBC and a life expectancy of ≥6 months but without unstable bone metastases were recruited at eight study centers across five European countries and Australia. Participants were randomly assigned (1:1) to usual care (control group, n = 179) or a 9-month supervised exercise program (exercise group, n = 178). Intervention effects on physical fatigue (European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-FA12 scale) and HRQOL (EORTC QLQ-C30 summary score) were determined by comparing the change from baseline to 3, 6 (primary timepoint) and 9 months between groups using mixed models for repeated measures, adjusted for baseline values of the outcome, line of treatment (first or second versus third or higher) and study center. Exercise resulted in significant positive effects on both primary outcomes. Physical fatigue was significantly lower (-5.3 (95% confidence interval (CI), -10.0 to -0.6), Bonferroni-Holm-adjusted P = 0.027; Cohen's effect size, 0.22) and HRQOL significantly higher (4.8 (95% CI, 2.2-7.4), Bonferroni-Holm-adjusted P = 0.0003; effect size, 0.33) in the exercise group than in the control group at 6 months. Two serious adverse events occurred (that is, fractures), but both were not related to bone metastases. These results demonstrate that supervised exercise has positive effects on physical fatigue and HRQOL in patients with MBC and should be recommended as part of supportive care.ClinicalTrials.gov Identifier: NCT04120298 .

Comparative cost-effectiveness analysis of CDK4/6 inhibitors in the first-line treatment of HR-positive and HER2-negative advanced breast cancer: a Markov's model-based evaluation

Introduction

CDK4/6 inhibitors are the first-line treatment for HR+/HER2- advanced breast cancer. Despite their clinical benefit, they can increase healthcare expenditure. To date, there is no thorough comparison among the three approved CDK4/6 inhibitors in terms of their cost-effectiveness.

Objective

To investigate and compare the cost-effectiveness of CDK4/6 inhibitors in combination with letrozole as a first-line treatment for advanced breast cancer with hormonal-receptor-positivity and HER-2-negativity versus one another and versus letrozole monotherapy.

Methods

A 10-year within-cycle-corrected Markov's model was employed from the healthcare payer perspective. Costs were obtained from the National Center for Cancer Care and Research (NCCCR) in Qatar. Utilities and transition probabilities were calculated from published landmark trials of PALOMA-2, MONALEESA-2, MONARCH-3, PO25, and other relevant literature. Costs, measured in Qatari Riyal (QAR), and effectiveness, measured in quality-adjusted-life-years (QALYs), were incremented and the incremental cost-effectiveness ratio (ICER) was compared to a willingness-to-pay threshold (WTP) of 1.5 Qatari GDP (448,758 QAR). A deterministic sensitivity analysis was implemented to account for uncertainties.

Results

Ribociclib was the most effective option, generating 4.420 QALYs, followed by palbociclib (4.406 QALYs), abemaciclib (4.220 QALYs), then letrozole monotherapy (2.093 QALYs). As for cost-effectiveness, ribociclib dominated palbociclib. However, it was not cost-effective compared to abemaciclib (ICER=1,588,545 QAR/QALY). Ribociclib remained dominant over palbociclib with all uncertainties. The base-case conclusion of ribociclib versus abemaciclib remained robust over all uncertainties.

Conclusion

From the healthcare payer perspective in Qatar, ribociclib is the most effective CDK4/6 inhibitor. It was dominant over palbociclib in terms of cost-effectiveness; however, it was not cost-effective compared to abemaciclib at current prices.