Her2-Positive Cancers and Antibody-Based Treatment: State of the Art and Future Developments

Attrition between lines of therapy and real-world outcomes of patients with HER2-positive metastatic breast cancer in Europe: a cohort study leveraging electronic medical records

PURPOSE

To characterize real-world attrition rates across first-line (1L) to third-line (3L) therapies in patients with HER2-positive (HER2 +) metastatic breast cancer (mBC) receiving routine care in seven hospital systems across Europe (France, Germany, Italy, Spain, and the UK).

METHODS

This retrospective, observational, multi-country, cohort study collected electronic medical record data from women aged ≥ 18 years diagnosed with HER2 + mBC from 2017-2021. The primary endpoint was attrition rate (the proportion of patients receiving a line of therapy [LOT] with no further evidence of subsequent LOTs). Key additional endpoints included treatment patterns, real-world time to treatment discontinuation (TTD), and time to next treatment (TTNT).

RESULTS

29.6% (95% confidence interval [CI] 25.0-34.6) and 34.2% (95% CI 27.5-41.5) of treated patients with HER2 + mBC had no further evidence of treatment beyond 1L and second-line (2L) therapy, respectively. Attrition was primarily owing to death, move to end-of-life palliative care, loss to follow up, and "other" reasons. Treatment patterns were generally aligned with clinical guidelines. Decreases in TTD (12.1 months [95% CI 10.4-14.5] for 1L, 8.9 months [95% CI 7.3-11.9] for 2L, 6.4 months [95% CI 5.2-8.9] for 3L) and TTNT (15.4 months [95% CI 13.6-20.6] for 1L, 13.5 months [95% CI 10.8-19.4] for 2L) were observed with each subsequent LOT.

CONCLUSION

Results unveil a large proportion of patients who do not benefit from state-of-the-art subsequent LOT, and suggest diminishing effectiveness with each subsequent LOT.

Trastuzumab deruxtecan in HER2-positive advanced breast cancer with or without brain metastases: a phase 3b/4 trial

Trastuzumab deruxtecan (T-DXd) intracranial activity has been observed in small or retrospective patient cohorts with human epidermal growth factor receptor 2-positive (HER2+) advanced/metastatic breast cancer (mBC) and stable or active (untreated/previously treated and progressing) brain metastases (BMs). The phase 3b/4 DESTINY-Breast12 study investigated T-DXd in patients with HER2+ mBC and is, to our knowledge, the largest prospective study of T-DXd in patients with BMs in this setting. Patients (stable/active BMs (n = 263) and no BMs (n = 241)) treated with one or more prior anti-HER2-based regimens received T-DXd (5.4 mg per kg). Primary endpoints were progression-free survival (PFS; BMs cohort) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (non-BMs cohort). Additional endpoints included central nervous system (CNS) PFS, ORR, time to second progression, CNS ORR (BMs cohort), incidence of new symptomatic CNS metastases (non-BMs cohort), time to progression, duration of response, overall survival and safety (both cohorts). No formal hypothesis testing was conducted for this single-arm, open-label study. In the BMs cohort, 12-month PFS was 61.6% (95% confidence interval (CI): 54.9-67.6), and 12-month CNS PFS was 58.9% (95% CI: 51.9-65.3). In the non-BMs cohort, ORR was 62.7% (95% CI: 56.5-68.8). Grade 3 or higher adverse events occurred in 51% (BMs cohort) and 49% (non-BMs cohort) of patients. Investigator-reported interstitial lung disease/pneumonitis occurred in 16% (grade ≥3: 3%) of patients with BMs and 13% (grade ≥3: 1%) of patients without BMs. These data show substantial and durable overall and intracranial activity for T-DXd, supporting its use in previously treated patients with HER2+ mBC irrespective of stable/active baseline BMs. ClinicalTrials.gov identifier: NCT04739761 .

Loss of TROP2 and epithelial cell adhesion molecule expression is linked to grade progression in pTa but unrelated to disease outcome in pT2-4 urothelial bladder carcinomas

Introduction

Trophoblast cell surface antigen 2 (TROP2; EpCAM2) is a transmembrane glycoprotein which is closely related to EpCAM (EpCAM; EpCAM1). Both proteins share partial overlapping functions in epithelial development and EpCAM expression but have not been comparatively analyzed together in bladder carcinomas. TROP2 constitutes the target for the antibody-drug conjugate Sacituzumab govitecan (SG; TrodelvyTM) which has been approved for treatment of metastatic urothelial carcinoma by the United States Food and Drug administration (FDA) irrespective of its TROP2 expression status.

Methods

To evaluate the potential clinical significance of subtle differences in TROP2 and EpCAM expression in urothelial bladder cancer, both proteins were analyzed by multiplex fluorescence immunohistochemistry in combination with a deep-learning based algorithm for automated cell detection on more than 2,700 urothelial bladder carcinomas in a tissue microarray (TMA) format.

Results

The staining pattern of TROP2 and EpCAM were highly similar. For both proteins, the staining intensity gradually decreased from pTa G2 low grade (TROP2: 68.8±36.1; EpCAM: 21.5±11.7) to pTa G2 high grade (64.6±38.0; 19.3±12.2) and pTa G3 (52.1±38.7; 16.0±13.0, p<0.001 each). In pT2-4 carcinomas, the average TROP2 and EpCAM staining intensity was intermediate (61.8±40.9; 18.3±12.3). For both proteins, this was significantly lower than in pTa G2 low grade (p<0.001 each) but also higher than in pTa G3 tumors (p=0.022 for TROP2, p=0.071 for EpCAM). Within pT2-4 carcinomas, the TROP2 and EpCAM staining level was unrelated to pT, grade, UICC-category, and overall or tumor-specific patient survival. The ratio TROP2/EpCAM was unrelated to malignant phenotype and patient prognosis.

Conclusion

Our data show that TROP2 and EpCAM expression is common and highly interrelated in urothelial neoplasms. Despite of a progressive loss of TROP2/EpCAM during tumor cell dedifferentiation in pTa tumors, the lack of associations with clinicopathological parameters in pT2-4 cancer argues against a major cancer driving role of both proteins for the progression of urothelial neoplasms.

Exploring the Role of Unconventional Post-Translational Modifications in Cancer Diagnostics and Therapy

Unconventional Post-Translational Modifications (PTMs) have gained increasing attention as crucial players in cancer development and progression. Understanding the role of unconventional PTMs in cancer has the potential to revolutionize cancer diagnosis, prognosis, and therapeutic interventions. These modifications, which include O-GlcNAcylation, glutathionylation, crotonylation, including hundreds of others, have been implicated in the dysregulation of critical cellular processes and signaling pathways in cancer cells. This review paper aims to provide a comprehensive analysis of unconventional PTMs in cancer as diagnostic markers and therapeutic targets. The paper includes reviewing the current knowledge on the functional significance of various conventional and unconventional PTMs in cancer biology. Furthermore, the paper highlights the advancements in analytical techniques, such as biochemical analyses, mass spectrometry and bioinformatic tools etc., that have enabled the detection and characterization of unconventional PTMs in cancer. These techniques have contributed to the identification of specific PTMs associated with cancer subtypes. The potential use of Unconventional PTMs as biomarkers will further help in better diagnosis and aid in discovering potent therapeutics. The knowledge about the role of Unconventional PTMs in a vast and rapidly expanding field will help in detection and targeted therapy of cancer.

Adoption and use of immunotherapy in breast cancer management in Africa: barriers and prospect - a narrative review

Breast cancer (BC) is the world's most frequently diagnosed cancer in women, with 7.8 million women diagnosed with BC in the past 5 years. BC has the highest incidence rate of all cancers in women worldwide (1.67 million), accounting for over 500 000 deaths annually. In Africa, BC accounts for 28% of all cancers and 20% of all cancer deaths in women. The African continent has recorded an alarming increase in incidence, with the highest mortality rate globally. Despite BC being a major health concern in Africa, there is limited access to adequate healthcare services to combat the growing need. Immunotherapy, a promising treatment approach that harnesses the immune system's power to fight cancer, has shown great potential in BC management. However, in the face of the growing body of evidence supporting its effectiveness, the adoption and use of immunotherapy in BC management in Africa remain limited. Hence, this review aimed to explore the barriers and prospects of immunotherapy adoption and use in BC management in Africa. A comprehensive search across various databases and sources using specific keywords related to immunotherapy and BC to achieve the study aim was conducted. The criteria for including data in the study were based on relevance and availability in English, with no publication year restrictions. The collected data underwent narrative analysis, supplemented by information from sources like country reports, newsletters, commentaries, policy briefs, and direct Google searches. By identifying the challenges and opportunities, this review provided insights into how healthcare providers, policymakers, and other stakeholders can work together to improve the availability and accessibility of immunotherapy to BC patients in Africa.

HER-2-Positive Tumors: A Continuously Evolving Field in Cancer Research

Almost 25 years ago, trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER2), was licensed for the treatment of patients with metastatic HER2-positive breast cancer in the United States of America (USA) [...].

New Phenylspirodrimanes from the Sponge-Associated Fungus Stachybotrys chartarum MUT 3308

Two phenylspirodrimanes, never isolated before, stachybotrin J (1) and new stachybocin G (epi-stachybocin A) (2), along with the already reported stachybotrin I (3), stachybotrin H (4), stachybotrylactam (5), stachybotrylactam acetate (6), 2α-acetoxystachybotrylactam acetate (7), stachybotramide (8), chartarlactam B (9), and F1839-J (10) were isolated from the sponge-associated fungus Stachybotrys chartarum MUT 3308. Their structures were established based on extensive spectrometric (HRMS) and spectroscopic (1D and 2D NMR) analyses. Absolute configurations of the stereogenic centers of stachybotrin J (1), stachybocin G (2), and stachybotrin I (3), were determined by comparison of their experimental circular dichroism (CD) spectra with their time-dependent density functional theory (TD-DFT) circular dichroism (ECD) spectra. The putative structures of seventeen additional phenylspirodrimanes were proposed by analysis of their respective MS/MS spectra through a Feature-Based Molecular Networking approach. All the isolated compounds were evaluated for their cytotoxicity against five aggressive cancer cell lines (MP41, 786, 786R, CAL33, and CAL33RR), notably including two resistant human cancer cell lines (786R, CAL33RR), and compounds 5, 6, and 7 exhibited cytotoxicity with IC50 values in the range of 0.3−2.2 µM.

De-Escalated Neoadjuvant Trastuzumab-Emtansine With or Without Endocrine Therapy Versus Trastuzumab With Endocrine Therapy in HR+/HER2+ Early Breast Cancer: 5-Year Survival in the WSG-ADAPT-TP Trial

PURPOSE

Neoadjuvant chemotherapy is standard of care in human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (EBC), irrespective of the hormone receptor status. Trastuzumab-emtansine (T-DM1), antibody-drug conjugate, is highly effective in HER2+ EBC; however, no survival data are available for de-escalated antibody-drug conjugate-based neoadjuvant therapy without conventional chemotherapy.

PATIENTS AND METHODS

In the WSG-ADAPT-TP (ClinicalTrials.gov identifier: NCT01779206) phase II trial, 375 centrally reviewed patients with hormone receptor-positive (HR+)/HER2+ EBC (clinical stage I-III) were randomly assigned to 12 weeks of T-DM1 with or without endocrine therapy (ET) or trastuzumab + ET once every 3 weeks (ratio 1:1:1). Adjuvant chemotherapy (ACT) omission was allowed in patients with pathologic complete response (pCR). In this study, we report the secondary survival end points and biomarker analysis. Patients who received at least one dose of study treatment were analyzed. Survival was analyzed using the Kaplan-Meier method, two-sided log-rank statistics, and Cox regression models stratified for nodal and menopausal status. P values < .05 were considered statistically significant.

RESULTS

T-DM1, T-DM1 + ET, and trastuzumab + ET induced similar 5-year invasive disease-free survival (iDFS; 88.9%, 85.3%, 84.6%; P_log-rank = .608) and overall survival rates (97.2%, 96.4%, 96.3%; P_log-rank = .534). Patients with pCR versus non-pCR had improved 5-year iDFS rates (92.7% v 82.7%; hazard ratio, 0.40; 95% CI, 0.18 to 0.85). Among the 117 patients with pCR, 41 did not receive ACT; 5-year iDFS rates were similar in those with (93.0%; 95% CI, 84.0 to 97.0) and without ACT (92.1%; 95% CI, 77.5 to 97.4; P_log-rank = .848). Translational research revealed that tumors with PIK3CA wild type, high immune marker expression, and luminal-A tumors (by PAM50) had an excellent prognosis with de-escalated anti-HER2 therapy.

CONCLUSION

The WSG-ADAPT-TP trial demonstrated that pCR after 12 weeks of chemotherapy-free de-escalated neoadjuvant therapy was associated with excellent survival in HR+/HER2+ EBC without further ACT. Despite higher pCR rates for T-DM1 ± ET versus trastuzumab + ET, all trial arms had similar outcomes because of mandatory standard chemotherapy after non-pCR. WSG-ADAPT-TP demonstrated that such de-escalation trials in HER2+ EBC are feasible and safe for patients. Patient selection on the basis of biomarkers or molecular subtypes may increase the efficacy of systemic chemotherapy-free HER2-targeted approaches.