Sacituzumab Govitecan for Metastatic Triple-Negative Breast Cancer: Clinical Overview and Management of Potential Toxicities

Advances in targeted therapy for triple-negative breast cancer: a review of key antigens and recent advances

The most aggressive subtype of breast cancer is triple-negative breast cancer (TNBC), which affects about 10-15% of all breast cancer cases. TNBC is associated with a poor prognosis and drug resistance due to the lack of oestrogen, progesterone, and HER2 receptors. Developing targeted immunotherapy for TNBC was challenged by identifying TNBC-specific antigens that can be suitable targets for antibody and nanobody-based therapies. Evidence from cancer- targeted therapy demonstrates that treatment outcomes are more successful when the target antigen is either overexpressed in tumour tissue or exhibits tumour specificity. Several antigens have been overexpressed in TNBC, including programmed cell death protein 1 (PD-1), programmed death-ligand 1(PD-L1), mesothelin (MSLN), trophoblast cell-surface antigen 2 (Trop-2), tumour endothelial marker 8 (TEM8), etc. There have been investigations targeting these antigens with antibodies, nanobodies, small molecules, peptides, and miniproteins for targeted treatment of TNBC. Antibodies known as Aembrolizumab, Atezolizumab, and Sacituzumab Govitecan-hziy have been approved by the FDA, and many are under investigation. The present review discusses the antigens with high expression in TNBC, their role in cancer development and progression, and the targeted therapies like antibodies, recombinant proteins, and antibody-drug conjugates (ADC).

Adverse events and impact on quality of life of antibody-drug conjugates in the treatment of metastatic breast cancer: A systematic review and meta-analysis

BACKGROUND

Antibody-drug conjugates are novel effective therapies for metastatic breast cancer. Nevertheless, their toxicity profile can significantly affect patients' quality of life over time.

METHODS

This is a systematic review and meta-analysis of randomized controlled trials of antibody-drug conjugates currently approved for the treatment of metastatic breast cancer [trastuzumab-emtansine (T-DM1), trastuzumab deruxtecan (T-DXd) and sacituzumab-govitecan (SG)] versus standard therapy to evaluate the risk of adverse events, discontinuation rate due to toxicity, impact on quality of life according to EORTC QLQ-C30 scale and subdomains. Relative risks (RR) and hazard ratios (HR) with 95% CIs were calculated using random effects models.

RESULTS

Nine trials with a total of 5753 patients were included. The most common adverse events of any grade for T-DM1 included thrombocytopenia (RR 7.14, 95% CI 4.13-12.36) and increased alanine-transaminase (ALT) (RR 2.04, 95% CI 1.43-2.91), for T-DXd were nausea (RR 2.39, 95% CI 1.90-3.00) and anemia (RR 1.55, 95% CI 1.27-1.90), while for SG were neutropenia (RR 1.30, 95% CI 1.14-1.49), diarrhea (RR 3.62, 95% CI 2.97-4.42) and nausea (RR1.90, 95% CI 1.65-2.19). Severe adverse events such as interstitial lung disease and left ventricular dysfunction were peculiar of T-DXd. Antibody-drug conjugates significantly delayed clinical deterioration of global health status by EORTC QLQ-C30 (HR .71, 95% CI .59-.86), physical, emotional and social functioning, pain and fatigue symptoms.

CONCLUSIONS

This meta-analysis offers consolidated data on adverse events associated with antibody-drug conjugates and their effects on patients' quality of life, emphasizing differences based on the specific agent. These findings underscore the critical need for effective strategies to prevent, diagnose and manage these toxicities.

A Multicenter Real-Life Evaluation of Safety and Effectiveness of the Antibody-Drug Conjugate Sacituzumab Govitecan in Metastatic Triple-Negative Breast Cancer

OBJECTIVES

Randomized trials showed that the third-generation antibody-drug conjugate, sacituzumab govitecan (SG), is active against metastatic triple-negative breast cancer (mTNBC). Real-world data are relatively limited. This retrospective study reports the efficacy and safety of SG in a series of women with mTNBC in clinical practice.

METHODS

Eighty-four patients with widely pretreated, de novo, or metachronous mTNBC were treated with SG at the recommended dose of 10 mg/kg on days 1 and 8 every 3 weeks over a 3-hour intravenous infusion at 6 medical oncology units.

RESULTS

No complete response was observed. Overall, 29 patients (34%; 95% CI: 24.4%-44.7%) achieved a partial response with a median duration of 6 months (range: 5 to 14 mo). Twenty patients 24 (29%; 95% CI: 18.9%-38.2%) had stabilization of disease with a median duration of 7 months (4 to 13 mo), while 31 (37%; 95% CI: 26.6%-47.2%) progressed. The median progression-free survival was 5 months (range: 1 to 14 mo) and the median overall survival as 10 months (range: 1 to 18 mo). Twelve patients (22%) had metastatic deposits in CNS and had received radiotherapy.

CONCLUSIONS

The real-life data reported in this paper confirm the randomized trial results regarding efficacy and tolerability. The authors stressed the importance of the early identification of severe side effects in managing these patients.

[Translated article] Influence of the UGT1A1 gene polymorphism on treatment with sacituzumab govitecan. Narrative review

OBJECTIVE

Sacituzumab govitecan is an antineoplastic therapy composed of a monoclonal antibody directed to the Trop2 antigen, conjugated to SN-38, an active metabolite of irinotecan that inhibits topoisomerase I. It is indicated for the treatment of metastatic triple-negative breast cancer in patients who have received at least two prior lines of treatment, with at least one in the metastatic context. SN-38 is eliminated by glucuronidation mediated by uridine diphosphate-glucuronosyltransferase-1A1 (UGT1A1) enzymes, present in the liver. Mutations in the UGT1A1 gene decrease the expression of these enzymes, which increases the concentration of SN-38 and, consequently, increases the toxicity of the drug, especially in the form of neutropenia and diarrhea. This study aims to analyze the relationship between UGT1A1 gene polymorphisms and toxicity associated with treatment with sacituzumab govitecan, in addition to reviewing the usefulness of genetic screening prior to starting therapy.

METHODS

A non-systematic literature review was conducted on the impact of UGT1A1 gene polymorphisms on the safety of sacituzumab govitecan treatment in patients with triple-negative breast cancer. The search included primary and secondary literature sources and communications from oncology conferences.

RESULTS

Patients treated with sacituzumab govitecan with the UGT1A1*28/*28 mutated genotype are more likely to experience grade more than 3 hematologic adverse events: neutropenia (approximate incidence of 60% compared to 40% for 1/*1 and 1/*28 genotypes), febrile neutropenia (18% homozygotes vs. 5% heterozygotes and 3% wild-type), grade more than 3 anemia (15% vs. 6% and 4%, respectively); as well as grade more than 3 diarrhea (24% vs. 13% and 6%, respectively). Additionally, treatment discontinuation rates are higher in *28/*28 individuals (6% compared to 1% heterozygotes and 2% wild-type).

CONCLUSIONS

Patients homozygous for the UGT1A1*28 allele are at significantly increased risk of developing serious adverse events. Despite the clear relationship between UGT1A1 polymorphisms and sacituzumab-govitecan toxicity, the review suggests that there is insufficient consensus on the need for systematic genetic screening. However, the findings indicate that such screening could be useful for identifying patients at risk and personalizing sacituzumab govitecan therapy.

The Clinical Outcomes and Safety of Sacituzumab Govitecan in Heavily Pretreated Metastatic Triple-Negative and HR+/HER2- Breast Cancer: A Multicenter Observational Study from Turkey

Background/Objectives: Sacituzumab govitecan (SG) is an antibody-drug conjugate targeting Trop-2, approved for use in metastatic triple-negative breast cancer (mTNBC) and more recently in the hormone receptor-positive/HER2-negative (mHRPBC) subtype. While clinical trials have demonstrated its efficacy, real-world data-especially those involving both molecular subtypes-remain scarce. This multicenter, retrospective study aimed to evaluate real-world observational data describing the clinical outcomes, safety, and prognostic factors associated with SG treatment in patients with mTNBC or mHRPBC. Methods: A total of 68 patients treated with SG between 2022 and 2025 were included from multiple oncology centers in Turkey. Patients with mTNBC were required to have received at least one prior chemotherapy line, while mHRPBC patients had received at least two prior chemotherapy lines in addition to cyclin-dependent kinase 4 and 6 inhibitors (CDK 4/6) plus hormone therapy. The clinical outcomes-including the progression-free survival (PFS), overall survival (OS), and objective response rate (ORR)-were evaluated. Univariate and multivariate analyses were performed to identify factors influencing outcomes. Adverse events (AEs) were also documented and graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 5 (NCI-CTCAE v5.0). Results: The cohort included 35 (51.5%) mTNBC and 33 (48.5%) mHRPBC patients. The median PFS was 6.1 months, and the median OS was 12.5 months, with no significant differences between subtypes. The ORR was 52.9%, with a complete response observed in 10.3% of patients. A high Eastern Cooperative Oncology Group Performance Status (ECOG PS) and liver metastasis were independent predictors of poorer PFS and OS. Prior immunotherapy did not negatively impact SG's efficacy. SG was generally well tolerated; the most common AEs were alopecia, anemia, neutropenia, and diarrhea. Treatment discontinuation due to AEs was rare (2.9%). Conclusions: SG was associated with similar clinical outcomes and tolerability in both the mTNBC and mHRPBC subtypes. Although the real-world PFS and OS outcomes mirror those seen in clinical trials, the absence of a control group means that these findings should be interpreted descriptively rather than as confirmation of treatment efficacy. Importantly, this study provides one of the first real-world datasets evaluating SG in the mHRPBC subgroup, highlighting its potential role beyond clinical trials. These results support SG as a valuable therapeutic option in heavily pretreated patients, warranting further prospective and biomarker-driven studies.

Assessment of trophoblast cell-surface antigen 2 (TROP2) and nectin-4 expression in choriocarcinoma

OBJECTIVES

Choriocarcinoma is associated with high mortality in multiply relapsed patients. Herein, we assessed immunohistochemistry (IHC) expression of TROP2 and nectin-4 in choriocarcinoma and other germ cell tumors (GCT), as antibody drug conjugates (ADCs) targeting these markers are entering the therapeutic landscape of many tumors.

METHODS

Archival cases of choriocarcinoma and controls (non-choriocarcinoma GCT) were evaluated for TROP2 and nectin-4 IHC, performed on whole-slide sections, and results were quantified using H-scores (range: 0-300) based on membranous staining.

RESULTS

The cohort included 20 primary GCT and 15 metastases from 34 patients. Of these, 18 specimens were choriocarcinoma (3 primary and 15 metastases), including six women with gestational choriocarcinoma. Median TROP2 and nectin-4 H-scores in choriocarcinomas were 22.5 and 60, respectively. For TROP2 and nectin-4, H-scores>200 were noted in 27.8% of patients, each. There was no correlation between serum beta-hCG levels measured within 2 weeks prior to specimen collection or peak serum beta-hCG levels and TROP2 or nectin-4 expression. The control group consisted of seminoma (n = 10); yolk sac tumor (n = 9), embryonal carcinoma (n = 10), postpubertal teratoma (n = 5), and spermatocytic tumor (n = 2). The median TROP2 H-scores for embryonal carcinoma, teratoma, and yolk sac tumor were 35, 30, and 15, respectively, and 0 for the remainder. The median nectin-4 H-score was 0 for all control group categories. Choriocarcinomas had a higher nectin-4 H-score compared to the control group (p < 0.001).

CONCLUSIONS

Given the high TROP2 and nectin-4 expression in a subset of choriocarcinoma, ADCs targeting these biomarkers may be a promising therapeutic approach for these tumors, pending additional validation.

Antibody-drug conjugates in elderly patients with breast cancer

Breast cancer remains a leading cause of cancer-related mortality worldwide, with elderly patients (aged >65 years) comprising a substantial portion of those affected. The treatment of breast cancer in this population is often complicated by frailty, comorbidities and polypharmacy. This review explores the application of antibody-drug conjugates (ADCs), such as trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG), in treating breast cancer among elderly populations. The underrepresentation of older patients in clinical trials complicates efficacy and safety assessments in this group. Current evidence indicates that ADCs are both effective and tolerable in elderly patients, demonstrating improved progression-free survival (PFS) and overall survival (OS) alongside a manageable safety profile. Data from several trials like the EMILIA, TH3RESA and DestinyBreast studies demonstrate that T-DM1 and T-DXd maintained benefit in PFS and OS for HER2-positive breast cancer in older patients, despite a slight increase in adverse events. The ASCENT and TROPiCS-02 trials further confirm that SG provides significant improvements in PFS and OS in elderly patients at the cost of an increase in some toxicity. Emerging ADCs, including datopotamab deruxtecan and ARX-788, show promise but lack extensive geriatric-specific data. While the ADCs offer encouraging results in terms of efficacy and safety, with appropriate dose adjustments, further research is needed to optimize their use in elderly patients with breast cancer.

Influence of the UGT1A1 gene polymorphism on treatment with sacituzumab govitecan. Narrative review

OBJECTIVE

Sacituzumab govitecan is an antineoplastic therapy composed of a monoclonal antibody directed to the Trop2 antigen, conjugated to SN-38, an active metabolite of irinotecan that inhibits topoisomerase I. It is indicated for the treatment of metastatic triple-negative breast cancer in patients who have received at least two prior lines of treatment, with at least one in the metastatic context. SN-38 is eliminated by glucuronidation mediated by uridine diphosphate-glucuronosyltransferase-1A1 (UGT1A1) enzymes, present in the liver. Mutations in the UGT1A1 gene decrease the expression of these enzymes, which increases the concentration of SN-38 and, consequently, increases the toxicity of the drug, especially in the form of neutropenia and diarrhea. This study aims to analyze the relationship between UGT1A1 gene polymorphisms and toxicity associated with treatment with sacituzumab govitecan, in addition to reviewing the usefulness of genetic screening prior to starting therapy.

METHODS

A non-systematic literature review was conducted on the impact of UGT1A1 gene polymorphisms on the safety of sacituzumab govitecan treatment in patients with triple-negative breast cancer. The search included primary and secondary literature sources and communications from oncology conferences.

RESULTS

Patients treated with sacituzumab govitecan with the UGT1A1*28/*28 mutated genotype are more likely to experience grade more than 3 hematologic adverse events: neutropenia (approximate incidence of 60% compared to 40% for 1/*1 and 1/*28 genotypes), febrile neutropenia (18% homozygotes vs. 5% heterozygotes and 3% wild-type), grade more than 3 anemia (15% vs. 6% and 4%, respectively); as well as grade more than 3 diarrhea (24% vs. 13% and 6%, respectively). Additionally, treatment discontinuation rates are higher in *28/*28 individuals (6% compared to 1% heterozygotes and 2% wild-type).

CONCLUSIONS

Patients homozygous for the UGT1A1*28 allele are at significantly increased risk of developing serious adverse events. Despite the clear relationship between UGT1A1 polymorphisms and sacituzumab-govitecan toxicity, the review suggests that there is insufficient consensus on the need for systematic genetic screening. However, the findings indicate that such screening could be useful for identifying patients at risk and personalizing sacituzumab govitecan therapy.

Toxicities and management strategies of emerging antibody-drug conjugates in breast cancer

Antibody-drug conjugates (ADCs) offer a promising therapeutic approach for various cancers, enhancing the therapeutic window while mitigating systemic adverse effects on healthy tissues. ADCs have achieved remarkable clinical success, particularly in treating breast cancer, becoming a standard therapy across all subtypes, including hormone receptor-positive, human epidermal growth factor receptor 2-positive, and triple-negative breast cancer. Although designed to selectively target antigens via monoclonal antibodies, ADCs can exhibit toxicity in normal tissues, often due to off-target effects of their cytotoxic payloads. Understanding and managing these toxicities according to established guidelines are crucial for enhancing ADC clinical efficacy, minimizing adverse events, and ultimately improving patient outcomes. This review comprehensively examines the toxicities of ADCs employed in breast cancer treatment and explores their management strategies. Furthermore, we investigate novel ADCs beyond trastuzumab deruxtecan and sacituzumab govitecan, evaluating their potential efficacy and corresponding safety profiles.

The real-world analysis of adverse events with azacitidine: a pharmacovigilance study based on the FAERS and WHO-VigiAccess databases

Background

Azacitidine is used to treat myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). It acts as a cytosine analog and DNA methyltransferase inhibitor, inducing DNA hypomethylation to reverse epigenetic modifications and restore normal gene expression. However, adverse events (AEs) associated with azacitidine are mainly reported in clinical trials, with limited real-world evidence. This study aims to assess the AE profile of azacitidine by utilizing data from the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) and WHO-VigiAccess databases.

Methods

We extracted adverse event (AE) reports related to azacitidine from the FAERS and WHO-VigiAccess databases, covering the period from the drug's market introduction to the third quarter of 2024. We used statistical methods including Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM) to analyze the association between azacitidine and documented AEs.

Results

The investigation unveiled 16,056 azacitidine-related adverse event (AE) reports from FAERS and 19,867 reports from WHO-VigiAccess. The median duration for the occurrence of these AEs during the observation period was 36 days, with an interquartile range (IQR) spanning from 11 to 126 days. Our statistical analysis identified 27 organ systems associated with AEs induced by azacitidine. Among these, the notable System Organ Classes (SOCs) that met four specific criteria included: infections and infestations, blood and lymphatic system disorders, and neoplasms benign, malignant, and unspecified (including cysts and polyps). Four algorithms identified 443 significant disproportionality preferred terms (PTs), including previously unreported AEs such as death, sepsis, septic shock, respiratory failure, cardiac failure, tumor lysis syndrome, bone marrow failure, interstitial lung disease, and pericarditis. Analysis from the WHO-VigiAccess database showed a ROR of 3.65 and a PRR of 3.30 for the SOC of infections and infestations.

Conclusion

This research not only confirms the widely acknowledged AEs linked to azacitidine but also uncovers several potentially new safety concerns noted in actual clinical practice. These results may offer important vigilance information for clinicians and pharmacists when addressing safety issues associated with azacitidine.

Preclinical evaluation of a novel antibody-drug conjugate OBI-992 for Cancer therapy

Trophoblast cell surface antigen 2 (TROP2), a transmembrane glycoprotein highly expressed in a variety of epithelial cancers, has been considered as a primary therapeutic target for the development of antibody-drug conjugates (ADCs). OBI-992, an investigational TROP2-targeted ADC, is composed of a novel TROP2 antibody (R4702) conjugated to the topoisomerase I (TOP1) inhibitor exatecan through a hydrophilic enzyme-cleavable linker. This study aimed to characterize R4702 and OBI-992 in vitro. TROP2-targeted antibodies sacituzumab and datopotamab were employed as the comparators for R4702. ADCs sacituzumab govitecan (SG) and datopotamab deruxtecan (Dato-DXd) were used as benchmarks for OBI-992. Results revealed that R4702 binds to an epitope that is distinct from sacituzumab and datopotamab. The cytotoxicity of the OBI-992, SG, and Dato-DXd against different cancer cells is comparable despite they have different internalization profile. Upregulation of breast cancer resistance protein (BCRP) was observed in SG-resistant and Dato-DXd-resistant cells, but not in OBI-992-resistant cells. In addition, significant downregulation of TROP2 expression was detected with Dato-DXd-resistant cells and only slightly downregulation with SG- and OBI-992-resistant cells was observed. Moreover, substantial enhancement of cytotoxicity and DNA damage was found in the combination of OBI-992 with a poly (ADP-ribose) polymerase (PARP) inhibitor (talazoparib). Taken together, the findings in this study support further clinical development of OBI-992.

Glycosylation profiling of triple-negative breast cancer: clinical and immune correlations and identification of LMAN1L as a biomarker and therapeutic target

Introduction

Breast cancer (BC) is the most prevalent malignant tumor in women, with triple-negative breast cancer (TNBC) showing the poorest prognosis among all subtypes. Glycosylation is increasingly recognized as a critical biomarker in the tumor microenvironment, particularly in BC. However, the glycosylation-related genes associated with TNBC have not yet been defined. Additionally, their characteristics and relationship with prognosis have not been deeply investigated.

Methods

Transcriptomic analyses were used to identify a glycosylation-related signature (GRS) associated with TNBC prognosis. A machine learning-based prediction model was constructed and validated across multiple independent datasets. The model's predictive capability was extended to evaluate the prognosis of TNBC individuals, tumor immune microenvironment and immunotherapy response. LMAN1L (Lectin, Mannose Binding 1 Like) was identified as a novel prognostic marker in TNBC, and its biological effects were validated through experimental assays.

Results

The GRS showed significant prognostic relevance for TNBC patients. The risk model effectively predicted molecular features, including immune cell infiltration and potential responses to immunotherapy. Experimental validation confirmed LMAN1L as a novel glycosylation-related prognostic gene, with low expression significantly inhibiting TNBC cell proliferation and migration.

Discussion

Our GRS risk model demonstrates robust predictive capability for TNBC prognosis and immunotherapy response. This model offers a promising strategy for personalized treatment and improved clinical outcomes in TNBC.

Targeting Refractory Triple-Negative Breast Cancer with Sacituzumab Govitecan: A New Era in Precision Medicine

Advanced triple-negative breast cancer (TNBC) has poorer outcomes due to its aggressive behavior and restricted therapeutic options. While therapies like checkpoint inhibitors and PARP inhibitors offer some benefits, chemotherapy remains ineffective beyond the first line of treatment. Antibody-drug conjugates (ADCs) like sacituzumab govitecan-hziy (SG) represent a significant advancement. SG combines SN-38, an irinotecan derivative, with a Trop-2-targeting antibody via a pH-sensitive linking moiety, achieving a good drug:antibody ratio. In a phase I-II study involving metastatic TNBC (mTNBC) individuals, SG achieved an overall response rate of 33.3% and a median response period of 7.7 months. The phase III ASCENT trial demonstrated SG's efficacy in relapsed or refractory TNBC, improving median progression-free survival and median overall survival compared to chemotherapy. Common side effects include neutropenia, nausea, and fatigue. This article highlights the clinical potential, pharmacokinetics, safety profile, and resistance mechanisms of SG along with key ongoing clinical trials, emphasizing its role in managing refractory mTNBC, especially in third-line therapy. The review also discusses current strategies for managing adverse reactions and sequencing ADC treatments in clinical practice, along with the predicted basis of resistance. The optimal sequencing of SG relative to other ADCs, such as trastuzumab deruxtecan or T-DXd, remains an evolving question, especially as newer agents with distinct mechanisms of action and safety profiles enter the field. Further research is essential to establish evidence-based strategies for sequencing SG and addressing disease progression post-ADC therapy.

Dermatologic toxicities of antibody-drug conjugates

Antibody-drug conjugates (ADCs) are a new and emerging category of oncologic treatments that combine the target specificity of a monoclonal antibody with a cytotoxic payload. These drugs are associated with unique cutaneous toxicities that vary across agents. Currently, there are eleven ADCs with regulatory approval for solid and liquid tumors and over 80 ADCs currently in clinical development, it is critical for dermatologists to recognize and appropriately mitigate the cutaneous toxicities associated with these therapies. This clinical review will summarize the novel mechanisms and indications of approved ADCs, discuss dermatologic toxicities demonstrated in clinical trials and postmarketing studies, and impart recognition and management guidance when encountering these reactions to help maintain patients safely and comfortably on their medications.

Mining and influencing factors analysis of sacituzumab govitecan adverse drug event based on FAERS database

OBJECTIVE

Utilizing the FAERS database, this study aims to analyze the ADE signals of sacituzumab govitecan to provide references for clinical safety.

METHODS

By searching the US FAERS database, we applied Reporting Odds Ratio (ROR) and Proportional Reporting Ratio (PRR) methods to analyze ADE reports for sacituzumab govitecan from Q2 2020 to Q4 2023, covering 15 quarters.

RESULTS

The total number of reports with sacituzumab govitecan as the first suspicion was 2854. A total of 139 signals involving 26 SOCs were obtained. The most reported were general disorders and administration site conditions (2,307 cases, 25.66%), followed by gastrointestinal disorders (1,125 cases, 12.52%), and investigations (810 cases, 9.01%). Frequent ADEs included sepsis and COVID-19 were not listed in the prescribing information. The signal strength analysis highlighted conditions like cholestasis and epilepsy not mentioned in the prescribing information. Furthermore, an analysis of influencing factors revealed differences in infections and infestations by gender and nationality (p < 0.05), and in gastrointestinal disorders and blood and lymphatic system disorders by gender, treatment duration, and nationality (p < 0.05).

CONCLUSIONS

Common ADEs generally correspond with the prescribing information. Clinicians should be vigilant regarding unlisted ADEs about sacituzumab govitecan, and close monitoring of laboratory indicators ensure patient medication safety.

Advances in Trop-2 targeted antibody-drug conjugates for breast cancer: mechanisms, clinical applications, and future directions

Breast cancer remains a leading cause of cancer-related deaths among women worldwide, highlighting the need for novel therapeutic strategies. Trophoblast cell surface antigen 2 (Trop-2), a type I transmembrane glycoprotein highly expressed in various solid tumors including all subtypes of breast cancer, has emerged as a promising target for cancer therapy. This review focuses on recent advancements in Trop-2-targeted antibody-drug conjugates (ADCs) for breast cancer treatment. We comprehensively analyzed the structure and mechanism of action of ADCs, as well as the role of Trop-2 in breast cancer progression and prognosis. Several Trop-2-targeted ADCs, such as Sacituzumab Govitecan (SG) and Datopotamab Deruxtecan (Dato-DXd), have demonstrated significant antitumor activity in clinical trials for both triple-negative breast cancer (TNBC) and hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer. We systematically reviewed the ongoing clinical studies of these ADCs, highlighting their efficacy and safety profiles. Furthermore, we explored the potential of combining Trop-2-targeted ADCs with other therapeutic modalities, including immunotherapy, targeted therapies, and small molecule inhibitors. Notably, Trop-2-targeted ADCs have shown promise in reprogramming the tumor microenvironment through multiple signaling pathways, potentially enhancing antitumor immunity. This review aims to provide new insights and research directions for the development of innovative breast cancer therapies, offering potential solutions to improve treatment outcomes and quality of life for breast cancer patients.

Antibody-drug conjugates: A review of cutaneous adverse effects

Antibody-drug conjugates (ADCs) are an emerging class of anticancer agents that combine targeting antibodies with potent cytotoxic agents. Their molecular configuration allows for increased therapeutic efficacy and reduced adverse-effect profiles compared to monoclonal antibodies or cytotoxic chemotherapy alone. ADCs cause off-target toxicities through several mechanisms, including premature deconjugation of the cytotoxic agent in the serum and the presence of the targeted antigen on normal tissues. Given cutaneous adverse events comprise 31.3% of all-grade adverse events in clinical trials involving ADCs, dermatologists are increasingly called upon to manage the cutaneous toxicities caused by these drugs. In this review, we summarize known cutaneous toxicities of the ADCs that have been approved for use by the US Food and Drug Administration to date. Dermatologists can play a key role in recognizing cutaneous reactions associated with ADCs, contributing to guidelines for their management, and aiding during clinical trials to generate detailed morphologic and histopathologic descriptions of cutaneous toxicities caused by ADCs.

Efficacy of Sacituzumab Govitecan in Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: A Comprehensive Systematic Review and Meta-analysis

OBJECTIVES

Breast cancer is the most diagnosed cancer in women, with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) being the predominant subtype. Sacituzumab govitecan (SG), a novel antibody-drug conjugate, has emerged as a promising treatment for metastatic HR+/HER2- breast cancer. This systematic review and meta-analysis aimed to evaluate its efficacy and safety.

METHODS

Adhering to "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" guidelines, a comprehensive search was conducted in PubMed, Scopus, and Cochrane databases up to December 2023. We included clinical trials and observational studies evaluating SG in patients with HR+/HER2- advanced breast cancer. The primary outcome was progression-free survival (PFS). In contrast, the secondary outcomes included overall survival, objective response rate, clinical benefit rate, duration of response (DOR), and adverse event profiles. Review Manager (Version 5.4) was used for the statistical analysis.

RESULTS

Nine studies met the inclusion criteria for systematic review; 2 were suitable for meta-analysis. The pooled analysis showed a hazard ratio of 0.53 (95% CI: 0.34-0.83; P = 0.005; I2 = 86%) for PFSl and a hazard ratio of 0.63 (95% CI: 0.36-1.11; P = 0.11; I2 = 92%) for overall survival. The pooled analysis of the duration of response showed significant results with a standard mean difference = 0.22 (95% CI: 0.03-0.42; P = 0.02; I2 = 61%).

CONCLUSION

SG demonstrates significant benefit in PFS and duration of response in patients of HR+/HER2- advanced breast cancer.

Sacituzumab Govitecan in Triple Negative Breast Cancer: A Systematic Review of Clinical Trials

BACKGROUND/OBJECTIVES

Triple-negative breast cancer is difficult to treat due to the absence of hormone receptors and Her2neu. Sacituzumab govitecan is a new therapeutic approach that uses an antibody directed against the Trop-2 antigen present in solid epithelial tumors, linked to the active metabolite SN-38, similar to irinotecan, to specifically target cancer cells while minimizing damage to healthy cells. The objective of the present review was to evaluate the efficacy and safety of sacituzumab govitecan as a single treatment in patients with triple-negative breast cancer and to compare its results with the standard conventional chemotherapy regimen currently used in this disease.

METHODS

A systematic review of randomized clinical trials of sacituzumab govitecan was performed. The search was performed in Medline (PubMed), Web of Science, and Cochrane from September 2022 to January 2024.

RESULTS

Thirty-eight articles are included and evaluated according to inclusion and exclusion criteria corresponding to the two most relevant clinical trials, including specific analyses of cohorts and subgroup study arms within these trials. Data from more recent clinical trials are also reviewed.

CONCLUSIONS

The efficacy results showed a significantly greater clinical benefit with sacituzumab govitecan compared to standard chemotherapy in patients with triple-negative breast cancer. This drug will become a treatment of substantial impact in future treatment guidelines for this type of cancer.

Cost-effectiveness of Sacituzumab Govitecan versus Single-agent Chemotherapy for Patients with Metastatic Triple-Negative Breast Cancer in China

INTRODUCTION

Patients with metastatic triple-negative breast cancer (mTNBC) have poor prognosis and survival outcomes. Sacituzumab govitecan was newly approved into Chinese market for mTNBC. However, whether its price matches the survival benefit still needs exploring. Here, this study aimed to evaluate the cost-effectiveness of sacituzumab govitecan versus chemotherapy in patients with mTNBC from the perspective of Chinese healthcare system.

METHODS

A partitioned survival model consisting of three discrete health states was constructed to assess the cost-effectiveness of sacituzumab govitecan versus single-agent chemotherapy. The key clinical data in the model were from the ASCENT trial. Costs and utility inputs were collected from published literatures. Life-years gained, quality adjusted life-years (QALYs), incremental cost-effectiveness ratio (ICER), incremental net health benefits, and incremental net monetary benefits were calculated between 2 treatment strategies. One-way and probabilistic sensitivity analyses were conducted to account for uncertainty and verify model robustness. Subgroup and cost-threshold analysis were also performed.

RESULTS

Sacituzumab govitecan provided an additional 0.25 QALYs and an incremental cost of $ 81,778.61 compared with chemotherapy, which was associated with an ICER of $ 323,603.84/QALY. One-way sensitivity analysis revealed that the model was most sensitive to the cost of sacituzumab govitecan, weight, and utility of progression-free survival. The probabilistic sensitivity analysis indicated that the probability of sacituzumab govitecan being cost-effective was 0%. Considering a willingness-to-pay (WTP) of 3 times GDP, the maximum cost of sacituzumab govitecan that would make it cost-effective was $155.65 per unit (180 mg).

CONCLUSIONS

Sacituzumab govitecan was not cost-effective for patients with mTNBC compared with chemotherapy at the commonly adopted WTP threshold of 3 times GDP per capita per QALY in China.

Triple-Negative Breast Cancer: Molecular Particularities Still a Challenge

Worldwide, breast cancer (BC) is one of the most common cancers in women and is responsible for the highest number of cancer-related deaths among women, with a special clinical behavior and therapy response. Triple-negative breast cancer (TNBC) is seen as a highly invasive BC, characterized by a short survival, higher mortality, recurrence, and metastasis when it is compared to the other BC subtypes. The molecular subtyping of TNBC based on mRNA expression levels does not accurately reflect protein expression levels, which impacts targeted therapy effectiveness and prognostic predictions. Most TNBC cases exhibit a high frequency of homologous recombination (HR) DNA repair deficiency (HRD) signatures and are associated with a complex genomic profile. Biomarker research in TNBC includes investigating genetic mutations, gene expression patterns, immune system-related markers, and other factors that can provide valuable information for diagnosis, treatment selection, and patient outcomes. Additionally, these biomarkers are often crucial in the development of personalized and precision medicine approaches, where treatments are customized to each patient's unique characteristics. This ongoing research is essential for improving the management and outcomes of TNBC, which is a challenging and heterogeneous form of breast cancer. The findings of this research have practical implications for refining treatment strategies, particularly in selecting appropriate systemic therapies and integrating traditional treatment modalities like surgery and radiotherapy into comprehensive care plans for TNBC patients.

Trop2-targeted therapy in breast cancer

Human trophoblastic cell surface antigen 2 (Trop2) is a glycoprotein, a cellular marker of trophoblastic and stem cells, and a calcium signaling transducer involved in several signaling pathways, leading to the proliferation, invasion, and metastasis of tumors. It is expressed at a low level in normal epithelial cells, but at a high level in many tumors, making it an ideal target for cancer therapy. According to previous literature, Trop2 is broadly expressed in all breast cancer subtypes, especially in triple negative breast cancer (TNBC). Several clinical trials have demonstrated the effectiveness of Trop2-targeted therapy in breast cancer. Sacituzumab govitecan (SG) is a Trop2-targeted antibody-drug conjugate (ADC) that has been approved for the treatment of metastatic TNBC and hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer. This article reviews the structure and function of Trop2, several major Trop2-targeted ADCs, other appealing novel Trop2-targeted agents and relevant clinical trials to provide a landscape of how Trop2-targeted treatments will develop in the future.

Recent Advances in Targeted Cancer Therapy: Are PDCs the Next Generation of ADCs?

Antibody-drug conjugates (ADCs) comprise antibodies, cytotoxic payloads, and linkers, which can integrate the advantages of antibodies and small molecule drugs to achieve targeted cancer treatment. However, ADCs also have some shortcomings, such as non-negligible drug resistance, a low therapeutic index, and payload-related toxicity. Many studies have focused on changing the composition of ADCs, and some have even further extended the concept and types of targeted conjugated drugs by replacing the targeted antibodies in ADCs with peptides, revolutionarily introducing peptide-drug conjugates (PDCs). This Perspective summarizes the current research status of ADCs and PDCs and highlights the structural innovations of ADC components. In particular, PDCs are regarded as the next generation of potential targeted drugs after ADCs, and the current challenges of PDCs are analyzed. Our aim is to offer fresh insights for the efficient design and expedited development of innovative targeted conjugated drugs.

The Evolving Paradigm of Antibody-Drug Conjugates Targeting the ErbB/HER Family of Receptor Tyrosine Kinases

Current therapies targeting the human epidermal growth factor receptor (HER) family, including monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs), are limited by drug resistance and systemic toxicities. Antibody-drug conjugates (ADCs) are one of the most rapidly expanding classes of anti-cancer therapeutics with 13 presently approved by the FDA. Importantly, ADCs represent a promising therapeutic option with the potential to overcome traditional HER-targeted therapy resistance by delivering highly potent cytotoxins specifically to HER-overexpressing cancer cells and exerting both mAb- and payload-mediated antitumor efficacy. The clinical utility of HER-targeted ADCs is exemplified by the immense success of HER2-targeted ADCs including trastuzumab emtansine and trastuzumab deruxtecan. Still, strategies to improve upon existing HER2-targeted ADCs as well as the development of ADCs against other HER family members, particularly EGFR and HER3, are of great interest. To date, no HER4-targeting ADCs have been reported. In this review, we extensively detail clinical-stage EGFR-, HER2-, and HER3-targeting monospecific ADCs as well as novel clinical and pre-clinical bispecific ADCs (bsADCs) directed against this receptor family. We close by discussing nascent trends in the development of HER-targeting ADCs, including novel ADC payloads and HER ligand-targeted ADCs.

[Treatment-related adverse events associated with antibody drug conjugate in breast cancer]

Therapeutic options for breast cancer have recently been enriched by new antibody-drug conjugates (ADC), which are now being utilized across all known molecular subtypes. ADCs represent a groundbreaking class of therapies that combine a cytotoxic agent with a monoclonal antibody via a combination molecule (linker). The primary objective is to selectively deliver chemotherapy to cells expressing the target antigen, thereby enhancing the therapeutic index. Trastuzumab-emtansine marked the pioneering use of this approach for HER2-overexpressed breast cancer. More recently, trastuzumab-deruxtecan and sacituzumab-govitecan have demonstrated efficacy in progression-free survival and overall survival in HER2-overexpressed and HER2-low breast cancer for the former, and HER2-non-overexpressed (including HER-low) for the latter. Numerous other ADCs are currently under development in breast cancer. While ADCs were initially designed to widen the therapeutic index and mitigate toxicities, managing ADC-related adverse events in the clinical setting remains a challenge. This review article aims to provide an overview of the toxicity profiles of these drugs already in current clinical practice or under development, drawing from results observed in various studies.

Antibody-Drug Conjugates: A promising breakthrough in cancer therapy

Antibody-drug conjugates (ADCs) provide effective cancer treatment through the selective delivery of cytotoxic payloads to the cancer cells. They offer unparalleled precision and specificity in directing drugs to cancer cells while minimizing off-target effects. Despite several advantages, there is a requirement for innovations in the molecular design of ADC owing to drug resistance, cancer heterogeneity along the adverse effects of treatment. The review critically analyses ADC function mechanisms, unraveling the intricate interplay between antibodies, linkers, and payloads in facilitating targeted drug delivery to cancer cells. The article also highlights notable advancements in antibody engineering, which aid in creating highly selective and potent ADCs. Additionally, the review details significant progress in clinical ADC development with an in-depth examination of pivotal trials and approved formulations. Antibody Drug Conjugates (ADCs) are a ground-breaking approach to targeted drug delivery, especially in cancer treatment. They offer unparalleled precision and specificity in directing drugs to cancer cells while minimizing off-target effects. This review provides a comprehensive examination of the current state of ADC development, covering their design, mechanisms of action, and clinical applications. The article emphasizes the need for greater precision in drug delivery and explains why ADCs are necessary.

The patient perspective on dose optimization for anticancer treatments: A new era of cancer drug dosing-Challenging the "more is better" dogma

The Patient-Centered Dosing Initiative, a patient-led effort advocating for a paradigm shift in determining cancer drug dosing strategies, pioneers a departure from traditional oncology drug dosing practices. Historically, oncology drug dosing relies on identifying the maximum tolerated dose through phase 1 dose escalation methodology, favoring higher dosing for greater efficacy, often leading to higher toxicity. However, this approach is not universally applicable, especially for newer treatments like targeted therapies and immunotherapies. Patient-Centered Dosing Initiative challenges this "more is better" ethos, particularly as metastatic breast cancer patients themselves, as they not only seek longevity but also a high quality of life since most metastatic breast cancer patients stay on treatment for the rest of their lives. Surveying 1221 metastatic breast cancer patients and 119 oncologists revealed an evident need for flexible dosing strategies, advocating personalized care discussions based on patient attributes. The survey results also demonstrated an openness toward flexible dosing and a willingness from both patients and clinicians to discuss dosing as part of their care. Patient-centered dosing emphasizes dialogue between clinicians and patients, delving into treatment efficacy-toxicity trade-offs. Similarly, clinical trial advocacy for multiple dosing regimens encourages adaptive strategies, moving away from strict adherence to maximum tolerated dose, supported by recent research in optimizing drug dosages. Recognizing the efficacy-effectiveness gap between clinical trials and real-world practice, Patient-Centered Dosing Initiative underscores the necessity for patient-centered dosing strategies. A focus on individual patient attributes aligns with initiatives like Project Optimus and Project Renewal, aiming to optimize drug dosages for improved treatment outcomes at both the pre- and post-approval phases. Patient-Centered Dosing Initiative's efforts extend to patient education, providing tools to initiate dosage-related conversations with physicians. In addition, it emphasizes physician-patient dialogues and post-marketing studies as essential in determining optimal dosing and refining drug regimens. A dose-finding paradigm prioritizing drug safety, tolerability, and efficacy benefits all stakeholders, reducing emergency care needs and missed treatments for patients, aligning with oncologists' and patients' shared goals. Importantly, it represents a win-win scenario across healthcare sectors. In summary, the Patient-Centered Dosing Initiative drives transformative changes in cancer drug dosing, emphasizing patient well-being and personalized care, aiming to enhance treatment outcomes and optimize oncology drug delivery.

Myasthenia Gravis-Like Syndrome Resulting From Immune Checkpoint Inhibitors in a Patient With Urothelial Carcinoma

The widespread use of immune checkpoint inhibitors (ICIs) for the treatment of various types of cancer has led to increasing reports of associated adverse effects. The use of the ipilimumab/nivolumab/sacituzumab combination is currently under study in patients with metastatic urothelial carcinoma, given their potential synergism for immunogenic cell death. Information regarding the toxicity spectrum of this combination is lacking. Here, we describe a patient with urothelial carcinoma who had a severe multisystem autoimmune-like toxicity and myasthenia gravis-like syndrome in response to the ipilimumab/nivolumab/sacituzumab combination therapy. We also briefly describe the literature regarding the association between combined immunotherapy use and systemic and neurological autoimmunity.

Emerging Toxicities of Antibody-Drug Conjugates for Breast Cancer: Clinical Prioritization of Adverse Events from the FDA Adverse Event Reporting System

BACKGROUND

Antibody-drug conjugates (ADCs) are gaining widespread use in the treatment of breast cancer, although toxicity remains an underexplored issue in the real-world clinical setting. Individual case safety reports collected in large pharmacovigilance databases can advance our knowledge on their safety profile in routine clinical practice.

OBJECTIVE

We prioritized adverse events (AEs) reported with ADCs approved for breast cancer using the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

We assessed clinical priority of AEs reported in FAERS (February 2013-March 2022) for trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd), and sacituzumab govitecan (SG) by attributing a score to each AE disproportionally reported with ADCs. Four criteria were assessed: clinical relevance, reporting rate, reported case fatality rate, and stability of disproportionality signals (consistency of the reporting odds ratio across multiple analyses using three different comparators).

RESULTS

We retained 6589 reports (77.4% referring to T-DM1 as suspect), and 572 AEs generated a disproportionality signal in at least one analysis. The majority of these AEs (62%) were classified as moderate clinical priorities (e.g., interstitial lung disease with T-DXd, thrombocytopenia, peripheral neuropathy with T-DM1, febrile neutropenia, and large intestine perforation with SG). Three AEs emerged as high clinical priorities (6 points): septic shock and neutropenic colitis with SG (N = 8 and 13, with median onset 13 and 10 days, respectively), without co-reported immunosuppressive agents; and pulmonary embolism with T-DM1 (N = 31, median onset 109 days, 52% with reported metastasis).

CONCLUSION

The heterogeneous spectrum of post-marketing toxicities for ADCs used in breast cancer, as emerging from the FAERS, is largely in line with preapproval evidence. Although causality cannot be proved, we call for increased awareness by oncologists on potential serious unexpected reactions, including early onset of septic shock and neutropenic colitis with SG, and late emergence of pulmonary embolism with T-DM1.

Cutting-edge approaches for targeted drug delivery in breast cancer: beyond conventional therapies

Breast cancer is a global health challenge with staggering statistics underscoring its pervasive impact. The burden of this disease is measured in terms of its prevalence and the challenges it poses to healthcare systems, necessitating a closer look at its epidemiology and impact. Current breast cancer treatments, including surgery, chemotherapy, radiation therapy, and targeted therapies, have made significant strides in improving patient outcomes. However, they are not without limitations, often leading to adverse effects and the development of drug resistance. This comprehensive review delves into the complex landscape of breast cancer, including its incidence, current treatment modalities, and the inherent limitations of existing therapeutic approaches. It also sheds light on the promising role of nanotechnology, encompassing both inorganic and organic nanoparticles equipped with the ability to selectively deliver therapeutic agents to tumor sites, in the battle against breast cancer. The review also addresses the emerging therapies, their associated challenges, and the future prospects of targeted drug delivery in breast cancer management.

Cardiovascular complications of ribociclib in breast cancer patients

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have unprecedentedly advanced hormone-dependent breast cancer treatment paradigm. In the metastatic setting, ribociclib has consistently demonstrated survival benefit in pre-, peri-, and postmenopausal patients, conjugating efficacy with health-related quality of life preservation. Accordingly, the emergence of cardiac and/or vascular adverse events related to this novel targeted agent is gaining significant interest. This narrative review provides an overview of the incidence and spectrum of cardiovascular toxicity, in both clinical trial framework and real-world evidence. The potential pathogenetic mechanism, along with the available diagnostic parameters including biomarkers, and proper management, are also summarized.

Sacituzumab Govitecan for the treatment of advanced triple negative breast cancer patients: a multi-center real-world analysis

Objective

The objective of this multicenter, observational, retrospective analysis was to evaluate the safety and efficacy of sacituzumab govitecan in metastatic triple-negative breast cancer (mTNBC) patients managed according to common clinical practice in Italy.

Methods

Data were retrieved by 7 sites. Triple-negative BC was defined by the lack of expression of estrogen receptor (ER <1%), progesterone receptor (PgR <1%) and human-epidermal growth factor receptor-2 (HER2 0, 1+, 2+ ISH-not amplified) according to standard ASCO-CAP criteria. Demographic and clinical characteristics were collected. Premedication, dose modifications and treatment schedule were based on the approved label of the product. Adverse events (AEs) were assessed according to NCI-CTCAE v5.0.

Results

Fifty-seven eligible patients who received sacituzumab govitecan for mTNBC were included. Median age was 53 years (range 25-75). Approximately 70% of patients had an initial diagnosis of TNBC. Median time from the diagnosis of metastatic BC to start of sacituzumab govitecan was 17 months (range 0-97) and median number of previous therapies was 3 (range 1-7). The most common sites of metastasis were lymph nodes (63.1% of patients), lung (57.9%), bone (50.8%) and liver (38.6%). Eight (14.0%) patients had a disease-free interval ≤12 months. A total of 32 (56.1%) deaths were observed and the median overall survival (OS) was 12.43 months (95% CI, 7.97 months-not reached). At a median follow-up of 10.6 months, 45 patients (78.9%) had progression and the median progression-free survival (PFS) was 4.9 months (95% CI, 3.7-7.1 months). Partial tumour response was observed in 19 patients (33.3%), stable disease in 16 (28.1%) and disease progression in 22 patients (38.6%). The most common treatment-related AEs were anemia (66.6% of patients), alopecia (66.6%), neutropenia (59.6%), nausea (42.1%) and diarrhea (38.6%). Neutropenia was the most common serious treatment-related AE: 21.0% and 8.7% of patients experienced grade 3 or 4 neutropenia, respectively. Twenty-two patients (38.6%) reduced the dose and 5.3% permanently discontinued treatment.

Conclusion

The results of this real-world analysis showed that both safety and efficacy of sacituzumab govitecan in mTNBC patients are consistent with that previously reported in regulatory trials. The use of premedication and supportive measures was associated with a satisfactory toxicity profile.

Response-guided neoadjuvant sacituzumab govitecan for localized triple-negative breast cancer: results from the NeoSTAR trial

BACKGROUND

Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results.

PATIENTS AND METHODS

Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician.

RESULTS

From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%.

CONCLUSIONS

In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.

Efficacy of anlotinib in Chinese patients with metastatic breast cancer: A retrospective observational study

Anlotinib, a multitarget tyrosine kinase inhibitor, can inhibit tumour angiogenesis proliferation, metastasis, promote vascular normalization, increase T cell and NK cell activity and infiltration, remodel tumour microenvironment and synergistic immune enhancement. Our study aimes to evaluate the efficacy of anlotinib in the treatment of advanced metastatic breast cancer (MBC) after multiple lines of therapy. Patients included were treated with anlotinib for advanced MBC in the Affiliated Cancer Hospital of Zhengzhou University from 1 January 2019 to 30 June 2023. The objective remission rate, disease-free progression survival and adverse reactions were analysed. We compared and analysed the efficacy of anlotinib in the treatment of advanced metastatic breast cancer, which showed that ORR was 23.6% and DCR was 69.1%. The DCR of monotherapy was 66.7% and that of combination therapy was 69.6% in MBC patients. The combination therapy, combined with chemotherapy had the best effect (79.3%), combined with immunotherapy came second. In addition, the DCR (88.9%) was higher in MBC patients having received prior antiangiogenic therapy. According to the Kaplan-Meier (K-M) survival estimate analysis, the mPFS was 4.17 months (95% CI, 1.758-6.582 months) in Her-2 positive MBC patients, and 7.83 months (95% CI, 2.416-9.104) in Her-2 negative MBC patients. The mPFS was 5.76 months (95% CI, 3.231-8.298 m) in HR positive MBC patients, 7.83 months (95% CI, 3.182-12.478 m) in TNBC patients. Fatigue (20.0%), hypertension (21.8%) and liver dysfunction (18.2%) were common adverse reactions, followed by bone marrow suppression (16.4%), anorexia (14.5%), hypothyroidism (14.5%) and diarrhoea (14.5%). Altogether, Anlotinib monotherapy or combination therapy provides a viable third (or above)-line therapeutic strategy in patients with metastatic breast cancer. The adverse reactions of anlotinib are well tolerated and controllable.

Breaking barriers in triple negative breast cancer (TNBC) - Unleashing the power of antibody-drug conjugates (ADCs)

Antibody-drug conjugates (ADCs) represent a novel class of molecules composed of a recombinant monoclonal antibody targeted to a specific cell surface antigen, conjugated to a cytotoxic agent through a cleavable or non-cleavable synthetic linker. The rationale behind the development of ADCs is to overcome the limitations of conventional chemotherapy, such as the narrow therapeutic window and the emergence of resistance mechanisms. ADCs had already revolutionized the treatment algorithm of HER2-positive breast cancer. Currently, emergent non-HER2 targeted ADCs are gaining momentum, with special focus on triple-negative disease therapeutic landscape. Sacituzumab govitecan (SG) is an ADC consisting of a humanized monoclonal antibody hRS7 targeting trophoblast cell surface antigen 2 (Trop2), linked to the topoisomerase I inhibitor SN-38 by a hydrolysable linker. It currently stands as the only non-HER2 targeted ADC that already received approval for the treatment of unresectable locally advanced or metastatic triple negative breast cancer (TNBC) in patients who had received two or more prior systemic therapies, with at least one for advanced disease. The purpose of these review is to analyze the available evidence regarding ADCs in TNBC, alongside with providing an overview on the ongoing and future research horizons in this field.

New strategies for the management of triple-negative breast cancer

PURPOSE OF REVIEW

This review highlights important changes in our understanding of triple-negative breast cancer. It highlights important novel approaches in treatment and reviews predicts potential challenges facing the treatment of triple-negative breast cancer.

RECENT FINDINGS

There is a clear shift away from chemotherapy-centric approaches to the treatment of breast cancer, and instead, a move towards incorporating immune checkpoint inhibitors, antibody-drug conjugates, and other targeted therapies. There is a focus on understanding biomarkers and leveraging novel targets in drug development.

SUMMARY

It is now standard of care to use neoadjuvant combination immunotherapy-chemotherapy in patients with Stage 1 and 2 breast cancers. Chemo-immunotherapy combinations when appropriate biomarkers are present (PD-L1) are standard first-line therapy in metastatic triple-negative breast cancer. Antibody-drug conjugates are now a mainstay in the treatment of this disease. These findings have shifted the treatment paradigm of the treatment of triple-negative breast cancer.

Advances in the study of marketed antibody-drug Conjugates (ADCs) for the treatment of breast cancer

Breast cancer continues to have a high incidence rate among female malignancies. Despite significant advancements in treatment modalities, the heterogeneous nature of breast cancer and its resistance to various therapeutic approaches pose considerable challenges. Antibody-drug conjugates (ADCs) effectively merge the specificity of antibodies with the cytotoxicity of chemotherapeutic agents, offering a novel strategy for precision treatment of breast cancer. Notably, trastuzumab emtansine (T-DM1) has provided a new therapeutic option for HER2-positive breast cancer patients globally, especially those resistant to conventional treatments. The development of trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) has further broadened the applicability of ADCs in breast cancer therapy, presenting new hopes for patients with low HER2 expression and triple-negative breast cancer. However, the application of ADCs presents certain challenges. For instance, their treatment may lead to adverse reactions such as interstitial lung disease, thrombocytopenia, and diarrhea. Moreover, prolonged treatment could result in ADCs resistance, complicating the therapeutic process. Economically, the high costs of ADCs might hinder their accessibility in low-income regions. This article reviews the structure, mechanism of action, and clinical trials of commercially available ADCs for breast cancer treatment, with a focus on the clinical trials of the three drugs, aiming to provide insights for clinical applications and future research.

Research Progress of SN38 Drug Delivery System in Cancer Treatment

The active metabolite of irinotecan (CPT-11), 7-ethyl-10-hydroxycamptothecin (SN38), is 100-1000 times more active than CPT-11 and has shown inhibitory effects on a range of cancer cells, including those from the rectal, small cell lung, breast, esophageal, uterine, and ovarian malignancies. Despite SN38's potent anticancer properties, its hydrophobicity and pH instability have caused substantial side effects and anticancer activity loss, which make it difficult to use in clinical settings. To solve the above problems, the construction of SN38-based drug delivery systems is one of the most feasible methods to improve drug solubility, enhance drug stability, increase drug targeting ability, improve drug bioavailability, enhance therapeutic efficacy and reduce adverse drug reactions. Therefore, based on the targeting mechanism of drug delivery systems, this paper reviews SN38 drug delivery systems, including polymeric micelles, liposomal nanoparticles, polymeric nanoparticles, protein nanoparticles, conjugated drug delivery systems targeted by aptamers and ligands, antibody-drug couplings, magnetic targeting, photosensitive targeting, redox-sensitive and multi-stimulus-responsive drug delivery systems, and co-loaded drug delivery systems. The focus of this review is on nanocarrier-based SN38 drug delivery systems. We hope to provide a reference for the clinical translation and application of novel SN38 medications.

Early Real-World Treatment Patterns and Clinical Outcomes in Patients with Metastatic Breast Cancer Treated with Eribulin After Prior Immuno-Oncology or Antibody-Drug Conjugate Therapy

Introduction

Eribulin was approved by the FDA in 2010 for the treatment of metastatic breast cancer (MBC) in the United States (US). More recently, several immuno-oncology (IO) and antibody-drug conjugate (ADC) regimens have been approved for MBC. We assessed the treatment patterns and clinical outcomes in MBC patients treated with eribulin following treatment with an IO or ADC in US clinical practice.

Materials and Methods

In a retrospective patient medical chart review study, patients with MBC, aged ≥18 years, who initiated eribulin therapy between March 1, 2019, and September 30, 2020, treated with either prior IO or ADC in the metastatic setting were included. Patient demographics, treatment characteristics, and clinical outcomes were analyzed descriptively. Real-world progression-free survival (rwPFS) and overall survival (OS) were estimated using Kaplan-Meier analyses.

Results

In the study population (N=143), median age at eribulin initiation was 62 years; 64% were Caucasian, and 67% had triple-negative MBC (TNBC). Eribulin therapy was used in the second to fifth line of therapy in the metastatic setting; median treatment duration was 7.2 months. The overall response rate for eribulin was 59.4%. Median rwPFS and OS from eribulin initiation were 21.4 months (95% CI, 12.9-not estimable [NE]) and 24.2 months (95% CI, 17.5-NE), respectively. In patients with TNBC, median rwPFS and OS from eribulin initiation were 12.0 months (95% CI, 8.8-NE) and 18.3 months (95% CI, 14.9-NE), respectively.

Conclusion

These real-world data provide evidence for the clinical effectiveness outcomes of eribulin treatment among MBC patients previously treated with an IO or ADC.

Post-marketing safety surveillance of sacituzumab govitecan: an observational, pharmacovigilance study leveraging FAERS database

Background and objective: Sacituzumab govitecan (SG), the first antibody-drug conjugate targeting human trophoblast cell-surface antigen 2 (Trop-2), has been approved by the Food and Drug Administration (FDA) for the treatment of advanced or metastatic breast cancer and urothelial cancer. However, there is currently a dearth of information regarding the safety profiles of SG in a large sample cohort. The objective of the present study is to investigate SG-related adverse events (AEs) in real-world settings leveraging the FDA Adverse Event Reporting System (FAERS) database to guide the safety management of clinical medication. Methods: The FAERS database was retrospectively queried to extract reports associated with SG from April 2020 to March 2023. To identify and evaluate potential AEs in patients receiving SG, various disproportionality analyses such as reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN), and the multi-item gamma Poisson shrinker (MGPS) were employed. Results: Overall, 2069 reports of SG as the "primary suspect" were identified. Noteworthy, SG was significantly associated with an increased risk of blood lymphatic system disorders (ROR, 7.18; 95% CI, 6.58-7.84) and hepatobiliary disorders (ROR, 2.68; 95% CI, 2.17-3.30) at the System Organ Class (SOC) level. Meanwhile, 61 significant disproportionality preferred terms (PTs) simultaneously complied with all four algorithms were adopted. Therein, anemia, thrombocytopenia, neutropenia, leukopenia, diarrhea, asthenia, alopecia, and electrolyte imbalance were consistent with the common AEs described in the clinical trials and specification of SG. Furthermore, unexpected significant AEs include colitis (ROR, 12.09; 95% CI, 9.1-16.08), heart rate increased (ROR, 5.11; 95% CI, 3.84-6.79), sepsis (ROR, 4.77; 95% CI, 3.59-6.34), cholestasis (ROR, 6.28; 95% CI, 3.48-11.36), blood bilirubin increased (ROR, 4.65; 95% CI, 2.42-8.94) and meningitis (ROR, 7.23; 95% CI, 2.71-19.29) were also be detected. The median time to onset of SG-related AEs was 14 [interquartile range (IQR), 7-52] days, with the majority occurring within the initial month of SG treatment. Conclusion: Our study validates the commonly known AEs and also found some potentially emerging safety issues related to SG in real-world clinical practice, which could provide valuable vigilance evidence for clinicians and pharmacists to manage the safety issues of SG.

Functional Analysis of Viable Circulating Tumor Cells from Triple-Negative Breast Cancer Patients Using TetherChip Technology

Metastasis, rather than the growth of the primary tumor, accounts for approximately 90% of breast cancer patient deaths. Microtentacles (McTNs) formation represents an important mechanism of metastasis. Triple-negative breast cancer (TNBC) is the most aggressive subtype with limited targeted therapies. The present study aimed to isolate viable circulating tumor cells (CTCs) and functionally analyze them in response to drug treatment. CTCs from 20 TNBC patients were isolated and maintained in culture for 5 days. Biomarker expression was identified by immunofluorescence staining and VyCap analysis. Vinorelbine-induced apoptosis was evaluated based on the detection of M30-positive cells. Our findings revealed that the CTC absolute number significantly increased using TetherChips analysis compared to the number of CTCs in patients' cytospins (p = 0.006) providing enough tumor cells for drug evaluation. Vinorelbine treatment (1 h) on live CTCs led to a significant induction of apoptosis (p = 0.010). It also caused a significant reduction in Detyrosinated α-tubulin (GLU), programmed death ligand (PD-L1)-expressing CTCs (p < 0.001), and disruption of McTNs. In conclusion, this pilot study offers a useful protocol using TetherChip technology for functional analysis and evaluation of drug efficacy in live CTCs, providing important information for targeting metastatic dissemination at a patient-individualized level.

Defining the Emergence of New Immunotherapy Approaches in Breast Cancer: Role of Myeloid-Derived Suppressor Cells

Breast cancer (BC) continues to be the most diagnosed tumor in women and a very heterogeneous disease both inter- and intratumoral, mainly given by the variety of molecular profiles with different biological and clinical characteristics. Despite the advancements in early detection and therapeutic strategies, the survival rate is low in patients who develop metastatic disease. Therefore, it is mandatory to explore new approaches to achieve better responses. In this regard, immunotherapy arose as a promising alternative to conventional treatments due to its ability to modulate the immune system, which may play a dual role in this disease since the relationship between the immune system and BC cells depends on several factors: the tumor histology and size, as well as the involvement of lymph nodes, immune cells, and molecules that are part of the tumor microenvironment. Particularly, myeloid-derived suppressor cell (MDSC) expansion is one of the major immunosuppressive mechanisms used by breast tumors since it has been associated with worse clinical stage, metastatic burden, and poor efficacy of immunotherapies. This review focuses on the new immunotherapies in BC in the last five years. Additionally, the role of MDSC as a therapeutic target in breast cancer will be described.

Neurologic complications of breast cancer

Breast cancer is a heterogeneous disease with unique neurologic complications that can arise from central nervous system (CNS) involvement or secondary to treatments themselves. As progress is made, with more targeted therapies and combinations available, particularly in the realm of human epidermal growth factor receptor 2 (HER2)-positive disease, the role of these new agents in patients with CNS disease is gradually evolving, although intracranial efficacy itself is lagging. At the same time, both systemic and local standard therapies pose clinical challenges regarding neurologic complications, such as peripheral neuropathy and cognitive changes. The development of new agents, such as immunotherapy, and new strategies, such as incorporating systemic therapies into local therapy, unveil new presentations of neurological complications.

Identifying biomarkers of differential chemotherapy response in TNBC patient-derived xenografts with a CTD/WGCNA approach

Although systemic chemotherapy remains the standard of care for TNBC, even combination chemotherapy is often ineffective. The identification of biomarkers for differential chemotherapy response would allow for the selection of responsive patients, thus maximizing efficacy and minimizing toxicities. Here, we leverage TNBC PDXs to identify biomarkers of response. To demonstrate their ability to function as a preclinical cohort, PDXs were characterized using DNA sequencing, transcriptomics, and proteomics to show consistency with clinical samples. We then developed a network-based approach (CTD/WGCNA) to identify biomarkers of response to carboplatin (MSI1, TMSB15A, ARHGDIB, GGT1, SV2A, SEC14L2, SERPINI1, ADAMTS20, DGKQ) and docetaxel (c, MAGED4, CERS1, ST8SIA2, KIF24, PARPBP). CTD/WGCNA multigene biomarkers are predictive in PDX datasets (RNAseq and Affymetrix) for both taxane- (docetaxel or paclitaxel) and platinum-based (carboplatin or cisplatin) response, thereby demonstrating cross-expression platform and cross-drug class robustness. These biomarkers were also predictive in clinical datasets, thus demonstrating translational potential.

Health-related quality of life in the phase III ASCENT trial of sacituzumab govitecan versus standard chemotherapy in metastatic triple-negative breast cancer

BACKGROUND

The antibody-drug conjugate sacituzumab govitecan (SG) prolongs progression-free survival and overall survival in patients with refractory/relapsed metastatic triple-negative breast cancer (mTNBC). Here, we investigated its effect on health-related quality of life (HRQoL).

METHODS

This analysis was based on the open-label phase III ASCENT trial (NCT02574455). Adults with refractory/relapsed mTNBC who had received ≥2 prior systemic therapies (≥1 in the metastatic setting) were randomised 1:1 to SG or treatment of physician's choice (TPC; capecitabine, eribulin, vinorelbine, or gemcitabine). HRQoL was assessed on day 1 of each treatment cycle using the EORTC QLQ-C30. Score changes from baseline were analysed using linear mixed-effect models for repeated measures. Stratified Cox regressions evaluated time to first clinically meaningful change of HRQoL.

RESULTS

The analysis population comprised 236 patients randomised to SG and 183 to TPC. For global health status (GHS)/QoL, physical functioning, fatigue, and pain, changes from baseline were superior for SG versus TPC. Compared with TPC, SG was inferior regarding changes from baseline for nausea/vomiting and diarrhoea but non-inferior for other QLQ-C30 domains. Median time to first clinically meaningful worsening was longer for SG than for TPC for physical functioning (22.1 versus 12.1 weeks, P < 0.001), role functioning (11.4 versus 7.1 weeks, P < 0.001), fatigue (7.7 versus 6.0 weeks, P < 0.05), and pain (21.6 versus 9.9 weeks, P < 0.001).

CONCLUSIONS

SG was generally associated with greater improvements and delayed worsening of HRQoL scores compared with TPC. This supports the favourable profile of SG as an mTNBC treatment.

Targeted Therapy for Locally Advanced or Metastatic Urothelial Cancer (mUC): Therapeutic Potential of Sacituzumab Govitecan

Urothelial carcinoma is the second most frequent genitourinary malignancy. Despite the poor prognosis, new treatment options have emerged and have expanded the therapeutic landscape for the disease. Although major improvements have been achieved, many patients experience rapid disease progression and low responses in subsequent lines of therapy. Sacituzumab govitecan is an ADC that targets Trop-2, which is highly expressed in urothelial cancers. Promising results in early clinical trials have led to further drug development which confirmed encouraging efficacy. Sacituzumab govitecan has been given accelerated approval in 2021 for patients with locally advanced and metastatic urothelial cancer who previously received a platinum containing chemotherapy and either a programmed death receptor-1 or programmed death ligand inhibitor. The results are promising, with encouraging efficacy and safety, however responses are not universal. There is a growing comprehension of mechanisms of resistance and predictive biomarkers that are crucial to improving outcomes. In this review, we summarize the current knowledge on antibody-drug conjugates and the clinical findings that led to the approval of Sacituzumab govitecan and discuss the therapeutic potential of new combinations, mechanisms of resistance and predictive biomarkers.

Patient-centered dosing: oncologists' perspectives about treatment-related side effects and individualized dosing for patients with metastatic breast cancer (MBC)

PURPOSE

Although metastatic breast cancer (MBC) is treatable, it is not curable and most patients remain on treatment indefinitely. While oncologists commonly prescribe the recommended starting dose (RSD) from the FDA-approved label, patient tolerance may differ from that seen in clinical trials. We report on a survey of medical oncologists' perspectives about treatment-related toxicity and willingness to discuss flexible dosing with patients.

METHODS

We disseminated a confidential survey via social media/email in Spring 2021. Eligible respondents needed to be US-based medical oncologists with experience treating patients with MBC.

RESULTS

Of 131 responses, 119 were eligible. Physicians estimated that 47% of their patients reported distressing treatment-related side effects; of these, 15% visited the Emergency Room/hospital and 37% missed treatment. 74% (n = 87) of doctors reported improvement of patient symptoms after dose reduction. 87% (n = 104) indicated that they had ever, if appropriate, initiated treatment at lower doses. Most (85%, n = 101) respondents did not believe that the RSD is always more effective than a lower dose and 97% (n = 115) were willing to discuss individualized dosing with patients.

CONCLUSION

Treatment-related side effects are prevalent among patients with MBC, resulting in missed treatments and acute care visits. To help patients tolerate treatment, oncologists may decrease initial and/or subsequent doses. The majority of oncologists reject the premise that a higher dose is always superior and are willing to discuss individualized dosing with patients. Given potential improvements regarding quality of life and clinical care, dose modifications should be part of routine shared decision-making between patients and oncologists.

Trop-2 as a Therapeutic Target in Breast Cancer

The emergence of Trop-2 as a therapeutic target has given rise to new treatment paradigms for the treatment of patients with advanced and metastatic breast cancer. Trop-2 is most highly expressed in triple negative breast cancer (TNBC), but the receptor is found across all breast cancer subtypes. With sacituzumab govitecan, the first FDA-approved, Trop-2 inhibitor, providing a survival benefit in patients with both metastatic TNBC and hormone receptor positive breast cancer, additional Trop-2 directed therapies are under investigation. Ongoing studies of combination regimens with immunotherapy, PARP inhibitors, and other targeted agents aim to further harness the effect of Trop-2 inhibition. Current investigations are also underway in the neoadjuvant and adjuvant setting to evaluate the therapeutic benefit of Trop-2 inhibition in patients with early stage disease. This review highlights the significant impact the discovery Trop-2 has had on our patients with heavily pretreated breast cancer, for whom few treatment options exist, and the future direction of novel Trop-2 targeted therapies.

Allyl phenyl selenides as H2O2 acceptors to develop ROS-responsive theranostic prodrugs

Reactive oxygen species (ROS)-responsive prodrugs have received significant attention due to their capacity to target tumors to relieve the side effects caused by chemotherapy. Herein, a series of novel H₂O₂-activated theranostic prodrugs (CPTSe1-CPTSe7) were developed containing allyl phenyl selenide moieties as H₂O₂ acceptors. Compared with conventional boronate ester-based prodrug CPT-B, CPTSe1 was more stable in human plasma and showed a more complete release of camptothecin (CPT) in H₂O₂ inducing experiment. The selectively activated fluorescence signals of CPTSe1 in tumor cells make it useful for real-time monitoring of CPT release and H₂O₂ detection. Furthermore, excellent selectivity of CPTSe1 was achieved for tumor cells over normal cells. Our results provide a new platform for the development of H₂O₂-responsive theranostic prodrugs.