Metastatic HER2 Research Articles

Double Anti-Her2 Blockade in Metastatic Breast Cancer: Experience of the Oncology Department of the Moulay Ismail Military Hospital in Meknes

Metastatic breast cancer is recognized as an incurable disease and whose management is palliative, but in recent years there has been an increase in the overall survival of patients with metastatic Her2 + breast cancer, this is thanks to the development new, particularly targeted therapies. Our study aims to assess the value of the double combination pertuzumab to the reference dual therapy (trastuzumab + chemotherapy) in patients with metastatic breast cancer and its impact on overall survival. This is a retrospective study spread over a period of 2 years (2018- 2019) carried out in the medical oncology department of the Moulay Ismail military hospital in Meknes.

Population Pharmacokinetic Analysis of Tucatinib in Healthy Participants and Patients with Breast Cancer or Colorectal Cancer.

Tucatinib is a highly selective, oral, reversible, human epidermal growth factor receptor 2 (HER2)-specific tyrosine kinase inhibitor. Tucatinib is approved at a 300-mg twice-daily dose in adults in combination with trastuzumab and capecitabine for advanced HER2-postitive (HER2+) unresectable or metastatic breast cancer and in combination with trastuzumab for RAS wild-type HER2+ unresectable or metastatic colorectal cancer. This study sought to characterize the pharmacokinetics (PK) and assess sources of PK variability of tucatinib in healthy volunteers and in patients with HER2+ metastatic breast or colorectal cancers. A population pharmacokinetic model was developed based on data from four healthy participant studies and three studies in patients with either HER2+ metastatic breast cancer or metastatic colorectal cancer using a nonlinear mixed-effects modeling approach. Clinically relevant covariates were evaluated to assess their impact on exposure, and overall model performance was evaluated by prediction-corrected visual predictive checks. A two-compartment pharmacokinetic model with linear elimination and first-order absorption preceded by a lag time adequately described tucatinib pharmacokinetic profiles in 151 healthy participants and 132 patients. Tumor type was identified as a significant covariate affecting tucatinib bioavailability and clearance, resulting in a 1.2-fold and 2.1-fold increase in tucatinib steady-state exposure (area under the concentration-time curve) in HER2+ metastatic colorectal cancer and HER2+ metastatic breast cancer, respectively, compared with healthy participants. No other covariates, including mild renal or hepatic impairment, had an impact on tucatinib pharmacokinetics. The impact of statistically significant covariates identified was not considered clinically meaningful. No tucatinib dose adjustments are required based on the covariates tested in the final population pharmacokinetic model. NCT03723395, NCT03914755, NCT03826602, NCT03043313, NCT01983501, NCT02025192.

Analytical and Clinical Validation of the Oncomine Dx Target Test to Assess HER2 Mutation Status in Tumor Tissue Samples From Patients With Non–Small Cell Lung Cancer Treated With Trastuzumab Deruxtecan in the DESTINY-Lung01 and DESTINY-Lung02 Studies

Context.— Trastuzumab deruxtecan (T-DXd), a human epidermal growth factor receptor 2 (HER2)–targeted therapy, has demonstrated durable anticancer activity in patients with advanced, metastatic HER2 (also known as ERBB2)–mutant (HER2m) non–small cell lung cancer (NSCLC) who have limited treatment options and poor prognosis. Objective.— To analytically validate and assess the clinical utility of the Oncomine Dx Target (ODxT) Test as a companion diagnostic to identify patients with HER2m NSCLC. Design.— Tumor samples from patients in DESTINY-Lung01 and DESTINY-Lung02 were retrospectively analyzed alongside commercially procured samples using the ODxT test and compared to the assays used for screening in these clinical trials. Results.— Positive percent agreement (PPA) and negative percent agreement (NPA) between the ODxT Test and TruSight Tumor 170 assay when testing DESTINY-Lung01 and commercially procured samples met prespecified thresholds (PPA and NPA ≥90%) for analytical accuracy (100% and 99.1%). The ODxT Test results were highly concordant with clinical trial assays (CTAs) used in DESTINY-Lung01 (PPA and NPA, 98.0% and 100%) and DESTINY-Lung02 (PPA and NPA, 96.7% and 100%) to identify activating HER2 mutations in tumor samples. Confirmed objective response rates were similar between patients with HER2m tumors identified by the ODxT Test and by CTAs in DESTINY-Lung01 (58.3% and 54.9%) and DESTINY-Lung02 (53.6% and 53.8%). Response duration was 12.0 and 9.3 months for patients identified by the ODxT Test and CTAs, respectively, in DESTINY-Lung01. Conclusions.— The ODxT Test detected HER2 mutations in NSCLC with high analytical and clinical accuracy and identified HER2m populations with response rates similar to populations identified by CTAs, supporting clinical utility of the ODxT Test to inform treatment decisions for HER2m NSCLC.

1425P Efficacy and safety of KN026 in combination with chemotherapy in patients (pts) with unresectable or metastatic HER2 positive gastric or gastroesophageal cancers (GC/GEJC) after first-line treatment with a trastuzumab-containing regimen

1425P Efficacy and safety of KN026 in combination with chemotherapy in patients (pts) with unresectable or metastatic HER2 positive gastric or gastroesophageal cancers (GC/GEJC) after first-line treatment with a trastuzumab-containing regimen

Long-term hepatobiliary disorder associated with trastuzumab emtansine pharmacovigilance study using the FDA Adverse Event Reporting System database

Trastuzumab emtansine (T-DM1) is widely utilized as a second-line and subsequent treatment for metastatic HER2+ breast cancer and has shown promise in early breast cancer treatment, particularly in adjuvant settings for residual disease after neoadjuvant chemotherapy. However, concerns have arisen regarding long-term hepatic adverse drug reactions (ADRs) not identified in clinical trials. We investigated potential safety signals of T-DM1 in hepatobiliary disorders and the time-to-onset of ADRs using the FDA Adverse Event Reporting System (FAERS) database. Suspected ADRs were extracted and divided into two groups: T-DM1 (N = 3387) and other drugs (N = 11,833,701). Potential signal for T-DM1 in hepatobiliary disorder were identified (reporting odds ratio [ROR] = 5.66, 95% confidence interval [CI] = 5.11–6.27; information component [IC] = 2.35, 95% Credibility Interval [Crl] = 2.18–2.51). A breast cancer indicated subgroup analysis (2519 T-DM1; 172,329 other drugs) also identified a potential safety signal (ROR = 3.28, 95% CI = 2.92–3.68; IC = 1.53, 95%CrI = 1.35–1.71). The median time-to-onset for T-DM1-associated hepatobiliary disorders was 41 days. For prolonged and chronic hepatobiliary disorders, median times were 322.5 and 301.5 days, respectively. These findings highlight the need for further research to inform clinical decisions on optimal T-DM1 treatment duration, balancing benefits with potential adverse reactions.

Safety and Efficacy of Trastuzumab Deruxtecan for Metastatic HER2+ and HER2-low Breast Cancer: An Updated Systematic Review and Meta-Analysis of Clinical Trials.

Trastuzumab deruxtecan (T-DXd) is a novel antibody-drug conjugate (ADC) promising in treating metastatic HER2+ and HER2-low breast cancer. This updated systematic review and meta-analysis, integrating data from the latest clinical trials, aimed to evaluate the safety and efficacy of T-DXd in this patient population. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A comprehensive search was conducted across PubMed, Scopus, and Web of Science up to January 2024, focusing on clinical trials that assessed T-DXd's efficacy and safety. Eligibility criteria were based on the PICOS framework, and selected studies underwent rigorous quality assessment and data extraction. The primary outcomes were progression-free survival (PFS), overall survival (OS), and the incidence of adverse events. A random-effects meta-analysis was performed to synthesize the data. Seven studies involving 2,201 patients met the inclusion criteria. The pooled analysis revealed that T-DXd significantly improved PFS (OR=0.37, 95% CI: 0.27-0.52), indicating a robust efficacy in slowing disease progression. However, treatment was associated with an increased risk of anemia (OR=2.10, 95% CI: 1.36-3.25), fatigue (OR=1.56, 95% CI: 1.21-2.02), nausea (OR=6.42, 95% CI: 4.37-9.42), vomiting (OR=6.21, 95% CI: 3.14-12.25), constipation (OR=2.26, 95% CI: 1.53-3.34), and notably, drug-related interstitial lung disease (OR=10.89, 95% CI: 3.81-31.12). The efficacy outcomes demonstrated significant heterogeneity, which was addressed through sensitivity analysis. T-DXd shows significant efficacy in treating metastatic HER2+ and HER2-low breast cancer, offering a valuable therapeutic option for patients with advanced disease. However, the treatment is associated with notable adverse events, including a heightened risk of ILD. These findings underscore the need for careful patient selection, monitoring, and management strategies to mitigate risks. Future research should focus on optimizing treatment protocols and exploring methods to enhance safety profiles.

18F-fluorodeoxyglucose positron emission tomography-computed tomography in the localization of the lesions in the osteogenic region of breast cancer bone metastases after therapy.

Accurate efficacy evaluation of bone metastases (BMs) from breast cancer (BC) is an intractable issue in clinical practice, for which solutions are urgently needed. This study aimed to investigate the utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) in the response evaluation of bone metastasis of BC. In total, 22 patients diagnosed with BC and BM were enrolled. These patients underwent repeated 18F-FDG PET/CT evaluations. The patients and each BM site were divided into two groups based on their response to treatment: progressive disease (PD) and nonprogressive disease (non-PD). We analyzed and compared the changes in PET and CT images, as well as the serum concentration of carcinoembryonic antigen (CEA), carbohydrate antigen 153 (CA153), alkaline phosphatase (ALP), and calcium (Ca) over the same time frame. The immunohistochemistry (IHC) of primary lesions between groups and between the primary focus and BM with high 18F-FDG uptake were compared and analyzed. Maximum standard uptake value (SUVmax) after therapy [area under the curve (AUC): 0.932] and Δ-value of SUVmax (AUC: 0.811) on 18F-FDG PET imaging proved significantly valuable for the efficacy of therapy outcomes related to BM lesions (P<0.05). In terms of overall evaluation of BM, age and human epidermal growth factor receptor 2 (HER2) expression were significantly lower in the PD group than in the non-PD group (P<0.05). There were marked differences in CEA after therapy, the changes of CEA, and CA153 (∆-value) between the groups (P<0.05). The SUVmax and Ca concentration after therapy and ∆-value of SUVmax, along with the levels of CA153, CEA, and ALP, were valuable indicators for evaluating the efficacy of individual BMs (P<0.05). IHC of BM in the PD group showed differences compared to primary lesions, with antigen Ki-67 being downregulated in metastatic lesions and HER2 being downregulated in a portion of BMs (2 of 6). Meanwhile, the expression of estrogen receptor (ER) and progesterone receptor (PR) remained relatively unchanged. 18F-FDG PET/CT confers precise assessment of the posttreatment efficacy pertaining to BM in BC. This modality facilitates the identification of poor effect lesions following extant therapies and localization for pathological assessment and may substantially contribute to evaluating therapeutic efficacy, refining treatment strategies, and predicting the disease trajectory of patients with BC and BM.

From Intractable to Treatable: Milestones and Horizons in the Management of HER2+ Breast Cancer

The human epidermal growth factor receptor 2 (HER2) is a member of the epidermal growth factor receptor (EGFR) family that initiates various signalling pathways that control cell proliferation and tumourigenesis. Historically, approximately 15% of breast cancers have been characterized by overexpression or amplification of HER2, known as “HER2+” breast cancers. This subtype has been associated with an adverse prognosis, along with a high risk of recurrence and worse survival outcomes. However, with the discovery and subsequent development of HER2‑targeted therapies, the clinical course of HER2+ breast cancers has fundamentally changed. Optimizing therapeutic strategies using existing and emerging HER2-targeted therapies to build upon these advances remains a major priority for clinical development and treatment delivery. In 1998, the American Food and Drug Administration (FDA) and Health Canada approved trastuzumab, the first HER2-targeted therapy. Trastuzumab, a monoclonal antibody that binds to the HER2 receptor, has demonstrated clinical activity and improved outcomes in patients with metastatic HER2+ breast cancer when combined with chemotherapy. Following soon after, the first trial of adjuvant trastuzumab (HERA) demonstrated improvements in outcomes when combined with chemotherapy for early HER2+ breast cancer. More than 25 years after its first approval, trastuzumab retains a central role in the treatment of both early and advanced HER2+ breast cancer and has provided a backbone for both new therapeutic combinations (eg. with small molecule inhibitors of HER2) and new classes of therapeutic agents (antibody drug conjugates [ADC]). These successors of trastuzumab are currently redefining the HER2+ treatment landscape in both advanced and early breast cancer.

Abstract A013: NF1 loss is syntetic lethal with Trastuzumab emtansine

Abstract There is great interest in the identification of biomarkers to guide development of antibody-drug conjugates (ADC). Most research has focused on target expression, but key predictors of payload efficacy have not been indeitifed. NF1 is a tumor suppressor classically considered as an inhibitor of RAS signaling, and often mutated in metastatic HER2+ breast cancer (BC). We screened multiple approved drugs for differential sensitivityin CRISPR-engineeredf NF1 KO cells. HER2-targeted agents (small molecules or antibodies) were found to be less effective upon NF1 loss; surprisingly, we identified increased sensitivity to the approved ADC T-DM1, but not to Trastuzumab Deruxtecan (T-Dxd). We then elucidated the underlying molecular cause employing in vivo, in vitro and in vitro reductionist systems. To measure in vivo MT dynamics, we transiently transfected the MT end-binding protein EB3- GFP and reconstructed MT trajectories by live-cell imaging. Upon DM1 treatment, KO cells showed a highly significant reduction in MT speed, demonstrating a direct role for NF1 on MT dynamics in cells. In tubulin polymerization assays, recombinant NF1 greatly accelerated polymerization and completely rescued DM1-induced inhibition. NF1 induced significant MT bundling, a defining feature of many MT-associated proteins, which generates signal indistinguishable from true MT polymerization in turbidity assays. To follow the dynamics of individual microtubules, we applied Total Internal Reflection (TIRF) microscopy on glass-immobilized MTs. As expected, polymerization in the presence of NF1 led to a dose-dependent significant increase in MT dynamics (fraction of elongating MTs, elongation speed, catastrophe rate). Expectedly, DM1 led to significant reduction in the fraction of elongating MTs and speed, but these defects were completely or partially rescued by NF1. Importantly, DM1 did not only lead to MT shortening (as proposed by the current model), but also to clear and frequent MT fracturing, indicating that the drug is not only engaging MT ends but also intra-tubular binding sites. This is consistent with recent models of MT formation which incorporate the frequent presence of areas of discontinuity or damage induced by mechanical stress, exposing intratubular DM1 binding sites. Interestingly, adding NF1 to DM1-treated MTs generated areas of de novo intra-tubular tubulin insertion, coincident with damaged sites, suggesting an entirely novel role for NF1 in MT repair. In conclusion, we provide evidence for a model in which maytansinoids bind not only to soluble tubulin dimers and MT ends, but also to intratubular damaged sites. Thus, the number of binding sites in cells would be proportional to MT damage, suggesting a mechanism for differential efficacy across tumor types and a potential avenue for combinatorial drug development. These results prompt the use of NF1 as a biomarker to select patients for ADC treatment. Funding: FIEO fellowship 2023, AIRC (n25791), Italian MoH-Ricerca Corrente di Rete (ACCORD) 2022, Next Generation EU – PNRR M6C2 – PNRR-MAD-2022-12376934 Citation Format: Eleonora Messuti, Bruno Achutti Duso, Alessia Castiglioni, Giulia Tini, Emanuele Bonetti, Giuseppe Ciossani, Silvia Monzani, Daria Khuntsariya, Marcus Braun, Zdenek Lansky, Luigi Scietti, Luca Mazzarella. NF1 loss is syntetic lethal with Trastuzumab emtansine [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr A013.

A phase 1b, multicenter, open-label study of valemetostat in combination with DXd antibody drug conjugates (ADCs), trastuzumab deruxtecan (T-DXd) or datopotamab deruxtecan (Dato-DXd), in patients with solid tumors.

TPS4180 Background: Valemetostat tosylate (valemetostat) is a novel, potent, and selective dual inhibitor of enhancer of zeste homolog (EZH) 2 and EZH1. Valemetostat 200 mg PO QD has demonstrated clinical efficacy and favorable tolerability in multiple hematologic malignancies. EZH2 controls gene expression, including the expression of genes involved in DNA damage response, like DNA/RNA helicase Schlafen 11 ( SLFN11). In response to DNA damage, SLFN11 binds to chromatin, causing a replication block and inducing apoptosis. Expression levels of SLFN11 indicate sensitivity to DNA-damaging agents (DDAs) in various solid tumors and are downregulated in chemotherapy-resistant tumor cells due to trimethylation of H3K27 at the SLFN11 gene locus. EZH2 inhibition by valemetostat is expected to upregulate SLFN11 and sensitize tumor cells to DDAs. Topoisomerase inhibition causes DNA strand breaks, which may synergize with valemetostat. This study will combine valemetostat with topoisomerase-I inhibitor ADCs, T-DXd or Dato-DXd, for the first time in patients (pts) with HER2-positive (HER2+) gastric cancer (GC) and non-squamous non-small-cell lung cancer (NSCLC), respectively. T-DXd is globally approved for the treatment of pts with locally advanced or metastatic HER2+ GC and other cancers, having received prior anti-HER2–based treatment. In the phase 3 TROPION-Lung01 trial, Dato-DXd significantly improved progression-free survival (PFS) vs standard chemotherapy in previously treated, locally advanced or metastatic NSCLC. Methods: This global, phase 1b, multicenter, two-part, open-label study is structured as a Master Protocol with independent sub-protocols defined by disease and treatment combination, including valemetostat + T-DXd in pts with 2L+ advanced or metastatic HER2+ GC or gastro-esophageal junction adenocarcinoma, and valemetostat + Dato-DXd in pts with 2L+ locally advanced, unresectable, or metastatic non-squamous NSCLC. Target enrollment is 70 pts per sub-protocol across 35 sites in US and Japan. Part 1 will determine the valemetostat recommended dose for expansion (RDE), combining escalating doses of valemetostat 50–200 mg PO QD with T-DXd at 5.4 mg/kg or 6.4 mg/kg (dose after first escalation) IV Q3W (GC protocol), or with fixed dose Dato-DXd 6.0 mg/kg IV Q3W (NSCLC protocol). Part 2 will evaluate the efficacy of valemetostat QD + Dato-DXd or T-DXd at the RDE. The main eligibility criteria for both protocols include at least 1 measurable lesion (per RECIST v1.1), an ECOG PS score of 0–1, and adequate organ function. Primary endpoints of this study are safety and tolerability of valemetostat in Part 1 and objective response rate in Part 2. Secondary endpoints include duration of response, PFS, overall survival and pharmacokinetics. Clinical trial information: NCT06244485 .

Trastuzumab and pertuzumab in combination with eribulin mesylate or a taxane as first-line chemotherapeutic treatment for HER2-positive, locally advanced or metastatic breast cancer: Results of a multicenter, randomized, non-inferiority phase 3 trial in Japan (JBCRG-M06/EMERALD).

1007 Background: Trastuzumab (H) + pertuzumab (P) + taxane is a current standard first-line therapy for recurrent or metastatic human epidermal growth factor 2–positive (HER2+) breast cancer (BC). However, taxane-induced toxicities, which reduce patient quality of life (QoL), necessitate development of less toxic but at least equally effective taxane alternatives. We investigated the non-inferiority of eribulin to taxane when used in combination with dual HER2 blockade (HP). Methods: The multicenter randomized open-label parallel-group phase 3 EMERALD trial (UMIN000027938, NCT03264547) was carried out to test the non-inferiority of eribulin + HP (study regimen) against docetaxel/paclitaxel + HP (control regimen) as first-line chemotherapeutic treatment in patients with locally advanced or metastatic HER2+ BC. The study design has been published (doi: 10.1186/s13063-020-04341-y). Patients were randomized (1:1) to receive, by intravenous infusion in a 21-day cycle, either (i) eribulin 1.4 mg/m2 on days 1 and 8, or (ii) a taxane (docetaxel 75 mg/m2 on day 1 or paclitaxel 80 mg/m2 on days 1, 8 and 15), each being administered in combination with HP on day 1. The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate, overall survival (OS), QoL and safety. Non-inferiority was tested using the Cox proportional hazards model to estimate hazard ratios (HRs) for PFS events. The upper limit of acceptance of non-inferiority HR margins (1.33 and 1.25) was tested in a stepwise manner. Results: Between August 2017 and June 2021, 446 patients (224 and 222 in the study and control groups, respectively) were enrolled: median age was 56.0 (29–70) years, 244 (54.7%) had ER-positive BC, 285 (63.9%) had visceral metastasis. While 247 patients (55.4%) had de novostage 4 disease, 199 (44.6%) underwent radical surgery and 138 (30.9%) received taxanes perioperatively. Both groups’ baseline characteristics were well balanced. Median PFS was 14.0 mos in the study group and 12.9 mos in the control group (HR, 0.96; 95% CI, 0.77–1.20), confirming non-inferiority of the study regimen. Median OS was 65.3 mos in the control group but has not been reached in the study group. Incidences of adverse drug reactions including grade ≥3 febrile neutropenia, edema and diarrhea were numerically lower in the study group than in the control group (4.9% vs 8.7%, 8.5% vs 42.2% and 36.6% vs 54.1%, respectively). Conclusions: This is the first study to show non-inferiority of eribulin to taxane when used in combination with dual HER2 blockade. As a less toxic but equally effective alternative to the taxane-containing regimen, eribulin combined with HP could be first-line treatment of locally advanced or metastatic HER2+ BC. Clinical trial information: UMIN000027938 , jRCTs021180027 .

Triple combination treatment of trastuzumab, chemotherapy and immune checkpoint inhibitor in HER2 positive unresectable, locally advanced, metastatic gastric and esophageal adenocarcinoma: A systematic review and meta-analysis.

e16071 Background: The current standard of care for unresectable, locally advanced or metastatic HER2 positive gastric, esophageal and gastroesophageal junction adenocarcinomas is the combination of the anti HER 2 antibody trastuzumab and cytotoxic chemotherapy. In recent years, the addition of immune checkpoint inhibitors to this combination has been studied to determine if it can improve clinical outcomes for this disease. This systematic review and meta-analysis evaluated high-quality data from clinical trials to determine the role and efficacy of this triple combination treatment. Methods: A systematic search of English-language articles on PubMed, Cochrane and Google scholar was done to identify randomized trials (RCTs) investigating the use of triple combination treatment of anti-Her 2 antibody, chemotherapy and immune checkpoint inhibitor in the treatment of unresectable, locally advanced, or metastatic HER2 overexpression positive gastric, esophageal and gastroesophageal junction adenocarcinoma. Quality of the studies was assessed using the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2). Inverse variance was the statistical method used with random effects as the analysis model in the production of the Forest plot and calculation of risk ratio (RR) at 95% confidence intervals (CI). Results: Four (4) RCTs (N = 866) were included for quality assessment and data extraction. Two (2) of these RCTs (N = 80) were single arm studies which both showed favorable outcomes in terms of objective response rate and progression free survival. The two (2) other RCTS (N = 786), each had two arms (triple regimen versus comparator) and were used in the meta-analysis. Risk of bias was low and heterogeneity was low (I2 below 50%). Pooled results showed that in patients given triple combination regimen, there is statistically significant improvement in progression free survival (RR 1.55 95% CI 1.20-2.00, p 0.0007). There is also an increase in overall response rate in favor of the triple combination regimen, albeit not statistically significant (RR 1.31 95% CI 0.99-1.74, p = 0.06). Conclusions: The addition of an immune checkpoint inhibitor to the current standard of care of anti Her 2 antibody and chemotherapy provides meaningful results in terms of tumor response and progression free survival in Her 2 positive locally advanced or metastatic gastric and esophageal adenocarcinomas. More robust trials, and data on overall survival supporting the use of this triple regimen may help re-shape the current standard of care for this disease.

Pooled analysis on characteristics of nausea and vomiting in patients receiving trastuzumab deruxtecan (T-DXd) in clinical studies.

12118 Background: The efficacy and safety profile of T-DXd has been established in patients (pts) with various tumor types, and nausea and vomiting are the most common treatment-emergent adverse events (TEAEs). T-DXd study protocols were refined over time to recommend prophylaxis (eg, neurokinin or serotonin receptor antagonists and/or steroids) before T-DXd treatment, in line with antiemetic and institutional guidelines. We conducted a pooled, post hoc analysis capturing safety information across tumor types; we report results on nausea and vomiting. While this analysis was not designed to assess antiemetic effectiveness, it reveals the incidence of nausea and vomiting in clinical trials of T-DXd 5.4 mg/kg in more detail across a large dataset. Methods: 1449 pts treated with ≥1 dose of 5.4 mg/kg T-DXd (every 3 wks) were included from 7 phase 1-3 clinical trials in metastatic HER2+ and HER2-low breast cancer, HER2+ gastric cancer, and HER2-mutant non–small cell lung cancer (DESTINY-Breast01, -Breast02, -Breast03, -Breast04, -Lung01, -Lung02, and the first-in-human phase 1 study J101 in multiple tumor types; study enrollment starting 2015-2021). Regardless of antiemetic use (including prophylaxis), the incidence, severity, time to onset, and duration of nausea and vomiting TEAEs were assessed along with event outcomes. Results: Of 1449 pts receiving T-DXd 5.4 mg/kg (median [range] number of 3-wk treatment cycles: 13 [1-60]), 74.6% (n=1081) experienced nausea, and 41.6% (n=603) reported vomiting. Most pts had grade 1/2 nausea (41.2%/27.6%) and/or vomiting (26.2%/12.8%). Grade 3 TEAEs of nausea were reported in 5.8% of pts, with grade ≥3 TEAEs of vomiting observed in 2.6% of pts. By the data cutoff for each trial, 66.9% of pts with nausea and 87.6% with vomiting had their symptoms resolve. Most pts who experienced nausea and vomiting did so during the initial 21 days (cycle 1; n=879 [81.3%] and 336 [55.7%], respectively; 35.8% of all pts received antiemetic prophylaxis at cycle 1); both TEAEs declined notably in subsequent cycles. Rates of drug discontinuation, dose reduction, and drug interruption due to nausea and vomiting were generally low (Table). Conclusions: Most nausea and vomiting events were reported during the first 3 wks of treatment and resolved. Appropriate prophylaxis of nausea and vomiting is a key management strategy and allows pts to benefit from longer treatment durations with T-DXd. Ongoing studies are exploring the implementation and impact of prophylaxis for T-DXd–related emesis. Clinical trial information: NCT03248492 , NCT03523585 , NCT03529110 , NCT03734029 , NCT03505710 , NCT04644237 , NCT02564900 . [Table: see text]

Tucatinib-trastuzumab-capecitabine for treatment of leptomeningeal metastasis in HER2+ breast cancer: TBCRC049 phase 2 study results.

2018 Background: Treatment options for patients with leptomeningeal metastasis (LM) are limited and prognosis is poor. Tucatinib is a potent, highly selective HER2-targeted tyrosine kinase inhibitor. The combination of tucatinib-trastuzumab-capecitabine is approved for patients with metastatic HER2+ breast cancer, with or without brain metastases, who have received ≥ 1 prior HER2-based regimens in the metastatic setting. Patients with LM were excluded from HER2CLIMB (NCT02614794). The aim of this study was to determine the benefit of this regimen in patients with HER2+ breast cancer and LM. We previously reported preliminary efficacy data, with a median OS of 10 months and a median time to CNS progression of 6.9 months. Here, we present additional data on LM objective response, provider-rated neurologic clinical exam, and patient-reported outcomes (PRO). Methods: TBCRC049 (NCT03501979) is an investigator-initiated phase 2 study evaluating a tucatinib-trastuzumab-capecitabine regimen in adults with HER2+ breast cancer and newly diagnosed LM. Eligible patients had a Karnofsky performance status &gt; 50 and untreated LM (defined as positive CSF cytology and/or radiographic evidence of LM plus clinical signs/symptoms). In 21-day cycles, patients received PO tucatinib, PO capecitabine, and IV trastuzumab. The primary endpoint was OS. LM objective response was assessed using a composite of neuroaxis imaging, neurologic clinical exam, and CSF cytology, derived from RANO-LM. The clinical exam incorporated the NANO scoring tool and symptom evaluation using MDASI-BT. Up to 4 provider-rated baseline target neuro deficits were monitored. An imaging scorecard was used. PROs were assessed using the LASA and MDASI-BT tools. Results: Enrollment was planned for 30 patients but closed at 17 patients following FDA approval of tucatinib (April 2020). All patients (median age 53 years) had MRI evidence of LM, 15 (88%) were symptomatic, and 8 (47%) had abnormal CSF cytology. At data cutoff (7/20/21), 5 (38%) of 13 response-eligible patients achieved LM objective response per the composite criteria at first response assessment, and all 13 (100%) achieved clinical benefit (SD, PR, or CR). Notably, 7 (58%) of 12 evaluable patients with target neurologic deficits at baseline experienced improvement of deficits. All 17 completed ≥ 75% of LASA and MDASI-BT PRO questionnaires at pre-specified timepoints. The mean improvement in LASA score was 13.5, indicating improved QOL and the mean improvement in MDASI-BT score was 32, indicating improved symptom burden. Conclusions: This is the first prospective evidence of clinically meaningful benefit including objective responses, symptom improvement, and quality of life, along with extended survival, with a systemic regimen for LM from HER2+ BC. These data support the trend toward using systemic therapy as an initial approach in CNS metastases. Clinical trial information: NCT03501979 .

A single-arm, multicenter, phase II study of utidelone in advanced solid tumors: Efficacy data from screening and the expansion cohort assessing utidelone plus sintilimab and oxaliplatin for advanced gastric cancer.

e16055 Background: Treatment regimens for many advanced solid tumors are limited and alternative options are needed.Utidelone is approved for the treatment of advanced breast cancer in China. NCT04911907 is a single-arm, multicenter, phase II study to assess the efficacy and safety of utidelone in advanced cancer. Stage I of the trial, completed in October 2023, included patients (pts) with pretreated advanced solid tumors. Based on the stage I data, a stage II expansion cohort (USO-G) investigated utidelone plus sintilimab and oxaliplatin as first-line therapy for advanced gastric cancer (GC). Here, we report efficacy and safety data from stage I and stage II for interim analysis. Methods: Eligible pts aged 18–70 years with pretreated advanced solid tumors were enrolled in stage I and received utidelone monotherapy (35 mg/m2/day iv on days 1–5 every 21 days). In stage II, eligible pts with metastatic and/or unresectable HER2 negative GC received utidelone (30mg/m2/day iv on days 1–5 every 21 days) plus sintilimab (200 mg iv Q3W) and oxaliplatin (130 mg/m2/day Q3W for up to 6 cycles), until disease progression or unacceptable toxicity. Results: From March 18th 2021 to October 13th 2022, 79 pts were enrolled into 7 tumor cohorts and 54 pts were evaluable for efficacy. The best overall responses were 1 CR, 3 PRs and 3 SDs in 10 esophageal cancer pts, 3 PRs and 5 SDs in 15 GC pts, 1 PR and 3 SDs in 10 ovarian cancer pts, SD for all 4 cholangiocarcinoma pts, 3 SDs in 4 cervical cancer pts, 2 SDs in 3 pancreatic cancer pts and a PR in 1 neuroectodermal tumor patient. Grade 3/4 TRAEs occurred in 27.8% of pts in stage I, and included anemia (13.9%), peripheral neuropathy (11.4%) and neutropenia (7.6%). No treatment-related deaths occurred. Gastric cancer was chosen as the expansion cohort indication. As of February 1st 2024, 14 eligible pts with GC with a median age of 57 years (range, 41–69) were enrolled. The median follow-up was 5.5 months (range, 1.0–9.7) and the longest duration of response was 8.0 months. A total of 8 PRs and 3 SDs were achieved in the 11 pts evaluable for efficacy, and 6 pts including the 3 with SD were still receiving treatment. Grade 3/4 TRAEs occurred in 28.6% of pts including diarrhea (14.3%), fatigue (14.3%), neutropenia (14.3%), and vomiting (7.1%). Other AEs were all Grade 1 or 2, with no treatment-related deaths. Conclusions: Utidelone monotherapy showed antitumor activity and manageable toxicity in pts with advanced solid tumors. Utidelone plus sintilimab and oxaliplatin demonstrated promising efficacy and an acceptable safety profile as first-line treatment for pts with GC. Stage II of the USO-G study is still actively enrolling; further data will be provided at the time of presentation. Clinical trial information: NCT04911907 .

Clinicopathological characteristics and outcomes of patients with HER2-low breast cancer: 6-year ambispective cohort study from India.

e23260 Background: Patients with low HER2-positive breast cancers are treated like those who are entirely HER2-negative. The DESTINY-Breast trials have proven Trastuzumab deruxtecan's benefit in the low HER2 subset. In Literature, limited data is available regarding the characteristics and outcomes of patients with low HER2 positivity from India. This study is done to address this research gap. Methods: This was an ambispective cohort study where we analysed the patients with carcinoma breast who were treated at our institute in the last 6 years. Out of 1845 patients, 243 were identified to have low HER2 expression. Patients were classified as Low HER2 positive if they had HER2 1+ or 2+ by IHC and negative by FISH. The clinical and pathological characteristics, progression-free survival (PFS) and overall survival (OS) of HER2 low subset, Estrogen Receptor (ER) positive and negative HER2 low cohorts and Metastatic (MBC) HER2 low patients were analysed separately. Results: A total of 243 patients were analysed. Of which 157 had HER2 2+ and 86 had 1+ expression. 240 were females. 79.8% were ER+ and 20.2% were ER negative among the total patients. 76.7% and 81.5% were ER+ in HER2 1+ and 2+ cohorts respectively. 78.2% were non-metastatic and 21.8% had MBC. 34.6% were treated with Neoadjuvant chemotherapy (NACT) and 42.4% with adjuvant chemotherapy (CT). 4.5% of patients treated with NACT attained PCR. 53.1% had T2, 16.8% had T4 disease. Most of the patients had N0 (35.4%) and N1(37%) disease. The OS of all low HER2+ patients were 4.97 years 95%CI(4.72-5.22). The OS in HER1+ and 2+ cohorts were 4.08 years and 5.04 years respectively. The PFS in low HER2+ patients was 5.01 years 95%CI(4.74-5.27) and 4.29 years and 4.89 years in HER2 1+ and 2+ cohorts. In the ER+ and negative cohorts, 31.4% of ER+ were treated with NACT and 45.4% of ER+ patients were treated with adjuvant CT. Most of ER+ low HER2 patients were of T2 stage (53.6%, p = 0.037). 36.6% were N0 and 34% were N1. 14.4% of ER+ low HER2 were MBC and 16.3% ER negative low HER2 were MBC. The OS of ER+ lowHER2+ cohort was 4.44 years and ER- HER2+ cohort was 4.43 years. Patients with MBC had a larger tumour size and nodal positivity (T4 43.4%, N1 37.8%,p = 0.001). The PFS and OS in MBC were 3.42 and 3.07 years compared to 5.29 years and 5.37 years in non-metastatic patients. Patients who were treated with NACT had an OS and PFS of 4.24 and 4.20 years and those who were treated with adjuvant CT had an OS of 5.39 years. Conclusions: The data on low HER2-positive patients is scarce in the Indian population. The low HER2+ patients had a PFS of 4.97 years and an OS of 5.01 years. Most of the patients had a T2 and N1 disease. The research gap low HER2+ subset is significant, especially considering the recent approval of trastuzumab deruxtican in India. With ongoing trials in MBC and non-metastatic settings, the benefit from this newer option may become clearer, particularly in ER+ low HER2 subset.

A phase 1 study of liposomal irinotecan in patients with advanced breast cancer.

1080 Background: Liposomal irinotecan (HE072) is a liposomal formulation that encapsulates irinotecan in a lipid bilayer vesicle, and as a generic drug, had been approved in China, recently, in patients with pancreatic cancer after gemcitabine treatment. Advanced triple negative breast cancer (TNBC) has very poor prognosis and limited treatment choices. Here we present results of breast cancer treated with HE072 in patients with highly pre-treated metastatic TNBC and HER2 negative breast cancer brain metastasis (BCBM). Methods: HE072-CSP-002 was a phase 1 study, consisting of two parts, dose escalation and expansion part (part 1) and expansion cohort part (part 2). In part 1, standard 3+3 design was used to investigate up to three dose levels of HE072 (50 mg/m2, 70 mg/m2 and 90 mg/m2), up to 6-9 additional subjects may be enrolled for dose expansion. In part 2, patients were enrolled in two cohorts (TNBC cohort and BCBM cohort), and received HE072 70 mg/m2 every two weeks (Q2W). The primary endpoints were the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D), and the incidence and severity of treatment emergent adverse events (TEAEs). Secondary endpoints included progression free survival (PFS), objective response rate (ORR), overall survival (OS). Results: As of June 5th, 2023, 119 patients were enrolled, including 101 patients with TNBC and 18 patients with HER2 negative BCBM (part 1: n=27; part 2: n=92). In the part 1, one dose-limiting toxicity (grade 3 nausea and grade 3 vomiting) was observed at 70 mg/m2 dose level, and MTD was not reached. A total of 115 patients (96.6%) had at least one TEAEs of any grade, and 55 patients (46.2%) had ≥grade 3 TEAEs. The most common ≥grade 3 TEAEs related to HE072 included neutropenia (21.0%), leukopenia (18.5%), diarrhea (10.1%), anemia (9.2%) and hypokalemia (8.4%). Eighty-three (82.2%) of the 101 patients with TNBC were evaluable for response. After a median follow-up of 10.1 months (range 8.8-10.8), 22 patients (26.5%, 95%CI 17.4-37.3) achieved overall response, which were all partial response and 58 patients (69.9%, 95%CI 58.8-79.5) achieved disease control. The median PFS and OS were 4.8 months (95%CI 3.9-5.8) and 14.1 months (95%CI 11.2-not reached), respectively. 12(66.7%) of the 18 patients with HER2 negative BCBM were evaluable for response. 1 patient (8.3%, 95%CI 0.2, 38.5) achieved overall response, which is partial response and 8 patients (66.7%, 95%CI 34.9, 90.1) achieved disease control. The median PFS was 5.6 months (95%CI 1.4~ not reached), 12-month OS rate was 55.5%. Conclusions: HE072 exhibited excellent antitumor activity in heavily pre-treated patients with TNBC and HER2 negative BCBM with acceptable safety profiles. 70 mg/m2 Q2W was determined as the RP2D. Further clinical trials are under plan. Clinical trial information: NCT04728035 .

Safety and efficacy of trastuzumab deruxtecan for metastatic HER2+ and HER2-low breast cancer: An updated systematic review and meta-analysis of clinical trials.

Safety and efficacy of trastuzumab deruxtecan for metastatic HER2+ and HER2-low breast cancer: An updated systematic review and meta-analysis of clinical trials.

Circulating immune protein biomarkers of early response and resistance in patients with metastatic HER-2–negative esophagogastric cancer (mEGC) treated with pembrolizumab and chemotherapy.

Circulating immune protein biomarkers of early response and resistance in patients with metastatic HER-2–negative esophagogastric cancer (mEGC) treated with pembrolizumab and chemotherapy.

Trastuzumab-emtansine versus other anti-HER2 regimens in early or unresectable or metastatic HER-2 positive breast cancer: systematic review and network meta-analysis.

Motivation for the study. Treatment options for HER2-positive breast cancer were evaluated, focusing on the efficacy and safety of trastuzumab-emtansine (T-DM1) compared to other anti-HER2 therapies. Main findings. Trastuzumab-deruxtecan (T-DXd) and PyroCap emerged as promising alternatives, showing substantial improvements in progression-free survival for locally advanced or metastatic breast cancer. T-DM1 showed superior efficacy to the other treatments. Implications. Our findings could inform healthcare decision-making processes to optimize strategies for HER2-positive breast cancer, and potentially improve health outcomes and quality of life. We aimed to study the efficacy and safety of trastuzumab-emtansine (T-DM1) versus other anti-HER2 therapies in HER2+ breast cancer (BC). We performed a network meta-analysis (NMA) of randomized controlled trials (RCTs). Our study focused on patients undergoing treatment for unresectable locally advanced breast cancer (LABC) or metastatic breast cancer (mBC), which included regimens involving trastuzumab and taxanes. Additionally, we considered cases within the first 6 months of treatment for HER2+ early breast cancer (EBC). A total of 23 RCTs and 41 reports were included in our analysis. LABC and mBC showed no statistically significant difference in any of the comparisons of T-DM1 versus the other anti-HER2+ therapies. When assessing progression-free survival (PFS), trastuzumab-deruxtecan (T-DXd) and PyroCap demonstrated greater efficacy compared to other treatments (Hazard Ratio [HR]: 3.57; 95% confidence interval [CI]: 2.75-4.63 and HR: 1.82; 95% CI: 1.35-2.44; respectively), while T-DM1 alone exhibited superior effectiveness compared to LapCap (HR: 0.65; 95% CI: 0.55-0.77), TrasCap (HR: 0.65; 95% CI: 0.46-0.91), LapCapCitu (HR: 0.60; 95% CI: 0.33-1.10), Nera (HR: 0.55; 95% CI: 0.39-0.77), and Cap (HR: 0.37; 95% CI: 0.28-0.49). NMA allows a ranking based on the comparative efficacy and safety among the interventions available. Although superior to other schemes, T-DM1 showed a lower efficacy performance in PFS and overall response rate and a trend towards worse overall survival than T-DXd.