Effect of Trastuzumab Deruxtecan on QT/QTc Interval and Pharmacokinetics in HER2-Positive or HER2-Low Metastatic/Unresectable Breast Cancer

Cardiac toxicity of HER-2 targeting antibody-drug conjugates: overview and clinical implications

Antibody-drug conjugates (ADCs) have recently emerged as a promising therapeutic option that combine the specificity of monoclonal antibodies and the cytotoxic effect of chemotherapy. With numerous ADCs approved and on the market, a particular concern of ADCs that target HER-2 has been their cardiac side effects, in view of the crucial role of HER-2 in cardiac development and physiology. While rarely toxic and generally safe, numerous publications have outlined the consistent association of trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) with the development of cardiac toxicity. Despite not being clinically relevant in most cases, cardiac baseline evaluation, monitoring and early detection of cardiac adverse events remain pivotal with HER-2 targeting ADCs. This review aims to summarize and better characterize the complete cardiac toxicity profile of HER-2 ADCs, with the goal of improving clinical understanding of this adverse event, leading to better recognition, monitoring and management.

Belantamab mafodotin concentration-QTc relationships in patients with relapsed or refractory multiple myeloma from the DREAMM-1 and -2 studies

AIMS

To evaluate relationships between plasma concentrations of belantamab mafodotin, total monoclonal antibody, and its payload and changes in electrocardiogram (ECG) parameters in patients with relapsed or refractory multiple myeloma from the DREAMM-1 and DREAMM-2 studies.

METHODS

Hysteresis plots and linear regression analyses of pharmacokinetic (PK) analyte (belantamab mafodotin, total monoclonal antibody, and cytotoxic cysteine-maleimidocaproyl monomethyl auristatin F payload) concentrations vs. time-matched ECG parameters (absolute/change from baseline in QT interval corrected for RR interval [QTc/ΔQTc] and QT interval corrected for heart rate by Fridericia's formula [QTcF/ΔQTcF]) were performed. Concentrations of PK analyte required for a 10-ms increase in QTc in DREAMM-2 were calculated via simulation, as was the probability of ΔQTc/ΔQTcF exceeding 10 ms for the expected Cmax of PK analyte concentrations associated with the doses (2.5 and 3.4 mg/kg) administered in DREAMM-2.

RESULTS

Time-matched PK and ECG data from 290 patients (DREAMM-1, n = 73; DREAMM-2, n = 217) were analysed. Hysteresis plots did not clearly indicate any concentration-related prolongation in QTc or QTcF; regression analyses indicated a very small rate of increase in ΔQTc and ΔQTcF with increasing concentrations of PK analytes. Calculated concentrations of PK analyte required for a 10-ms prolongation in QTc were higher than the maximum analyte concentrations observed following treatment with belantamab mafodotin in DREAMM-2; the probability that each dose would prolong ΔQTc and ΔQTcF by >10 ms was 0 and <0.25%, respectively.

CONCLUSION

This study of belantamab mafodotin and its payload did not provide evidence of QT prolongation in patients with relapsed or refractory multiple myeloma at clinically relevant doses.

Insights Into the Emerging Entity of HER2-Low Breast Cancer

Human epidermal growth factor receptor 2 (HER2)-low breast cancer (BC) is a subtype of BC that has been recently recognized as a separate clinical entity with distinct clinical and molecular characteristics. It is defined by a low level of HER2 protein expression, which distinguishes it from other more aggressive BC subtypes. Early studies suggest that it may have a more favorable prognosis than HER2-positive BC, as it is less likely to spread to other parts of the body and may be more responsive to standard BC treatments such as chemotherapy, radiation therapy, and hormone therapy. Given the relative new emergence of HER2-low BC, there is still much to be learned about this subtype; ongoing research is focused on identifying the underlying genetic mutations that contribute to HER2-low BC as well as developing targeted therapies that can improve outcomes for patients with this disease. This review is aimed at summarizing the current clinical knowledge on HER2-low BC, with the aim of creating a better understanding of this entity and paving the way for potential interventions and a new standard of care.

Incidence of HER2-targeted antibody-drug conjugates-related cardiac events: a meta-analysis

Background: Human epidermal growth factor receptor 2 (HER2)-targeted antibody-drug conjugate (ADC) has emerged as a hotspot for research and brought breakthroughs in the treatment of breast cancer and other solid tumors. While the occurrence of cardiac events (CEs) has yet not been systematically reported. Methods: The prospective clinical trials of marketed HER2-targeted ADCs were systematically searched in PubMed, Embase, Cochrane Library, and ClinicalTrials.gov from inception to May 2023. Two investigators independently extracted data with priority given to ClinicalTrials.gov, followed by peer-reviewed articles. Stata 15.0 software was used to perform the meta-analysis. The effect statistics were estimated as pooled incidence with 95% confidence intervals (CI). The primary objectives were to assess the incidence of all-grade and ≥3 /serious grades CEs related to HER2-targeted ADC. Our study strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and has been registered on PROSPERO (NO. CRD42023440448). Results: After conducting a comprehensive literature search, initially 7000 relevant studies were identified, and eventually a total of 47 trials involving 10594 patients were included for analysis. The pooled incidence of all-grade and ≥3/serious grades CEs respectively were 4.7% [95% CI, 3.7-5.8%] and 0.6% (95% CI, 0.5-0.8%). The pooled incidence of CEs leading to dosage discontinuation was 0.8% (95% CI, 0.4-1.3%). Subgroup analysis revealed a significantly higher incidence of all-grade CEs in T-DXd treatment compared to T-DM1 treatment (7.7% versus 3.6%; p=0.017), as well as in phase I/II trials compared to phase III trials (6.9% versus 3.2%; p=0.002) and combination therapy compared to monotherapy (7.6% versus 3.9%; p=0.013). The electrocardiogram QT corrected interval prolonged was identified as the CE with the highest pooled incidence, occurring at a rate of 5.9% (95% CI, 3.3-8.5%). Conclusions: The incidence of CEs associated with HER2-targeted ADC is relatively low. However, it is crucial to enhance surveillance measures, particularly for T-DXd treatment and combination therapy.

Incidence of interstitial lung disease and cardiotoxicity with trastuzumab deruxtecan in breast cancer patients: a systematic review and single-arm meta-analysis

BACKGROUND

Trastuzumab deruxtecan (T-DXd) has been shown to benefit progression-free survival and overall survival in patients with metastatic breast cancer (mBC) after progression on ≥1 human epidermal growth factor receptor 2 (HER2)-targeted therapies. However, interstitial lung disease (ILD) and cardiotoxicity are the most significant toxicities associated with T-DXd. Therefore, we conducted a systematic review and meta-analysis to assess the incidence and severity of these toxicities in mBC patients treated with T-DXd.

MATERIALS AND METHODS

We searched PubMed, Cochrane, and Scopus databases, and conferences websites for randomized clinical trials and nonrandomized studies of intervention including HER2-low or HER2-positive mBC patients who received at least one dose of T-DXd. Statistical analysis was carried out using R software.

RESULTS

We included 15 studies comprising 1970 patients with a mean follow-up of 13.3 months. Median age ranged from 53 to 59 years, 61.9% were non-Asian, and 67.4% had hormone receptor-positive mBC. In a pooled analysis, the incidence of ILD was 11.7% [222 patients; 95% confidence interval (CI) 9.1% to 15.0%]. Patients receiving T-DXd dose of 6.4 mg/kg developed a significantly higher rate of ILD (22.7%) compared to those receiving a dose of 5.4 mg/kg (9.3%) (P < 0.01). Most cases of ILD (80.2%; 174/217 patients) were mild (grade 1 or 2). Grade 3 or 4 ILD was reported in 29 patients (13.4%), and grade 5 in 14 patients (6.4%). The incidence of decreased left ventricular ejection fraction (LVEF) was 1.95% (95% CI 0.65% to 3.73%), and the QT interval (QTi) prolongation was 7.77% (95% CI 2.74% to 20.11%). Most patients were asymptomatic, but four had LV dysfunction and heart failure (0.26%).

CONCLUSIONS

In this meta-analysis of 1970 patients with mBC, treatment with T-DXd was associated with a 11.7% incidence of ILD, 7.7% incidence of prolonged QTi, and 1.9% incidence of reduced LVEF. Early detection and management of T-DXd-related toxicity by a multidisciplinary team may ultimately improve patient outcomes.

Efficacy and safety of trastuzumab deruxtecan in the treatment of HER2-low/positive advanced breast cancer: a single-arm meta-analysis

Background: Clinical trials have shown that the use of trastuzumab deruxtecan (DS-8201) alone is expected to provide novel therapeutic options for HER2-low/positive patients. Nevertheless, there are some variations in the efficacy of trial results, with potential risks at the safety level. Most DS-8201 trials in HER2 advanced breast cancer (ABC) have been conducted in the form of small-sample nonrandomized controlled studies, resulting in a lack of validated indicators to evaluate the efficacy and safety of DS-8201. Thus, this meta-analysis aimed to pool the results of various trials of DS-8201 alone to explore the efficacy and safety of DS-8201 in patients with HER2-low/positive advanced breast cancer. Methods: Relevant studies were searched in seven databases, including Embase, PubMed, Web of Science, Cochrane Library, CNKI, VIP database and WanFang data, to collect single-arm studies on DS-8201 for HER2-low/positive ABC. MINORS was adopted for quality assessment and STATA 16.0 for data analysis. Results: Ten studies involving 1,108 patients were included in this meta-analysis. As for the tumor response rate, the pooled ORR and DCR of all studies reached 57% (95% CI: 47%-67%) and 92% (95% CI: 89%-96%) respectively, and the pooled ORRs of the HER2-low expression group and the HER2-positive expression group were 46% (95% CI: 35%-56%) and 64% (95% CI: 54%-74%). Only the low expression group achieved median survival time, with a pooled median PFS and median OS of 9.24 (95% CI: 7.54-10.94) months and 23.87 (95% CI: 21.56-26.17) months, respectively. The most common treatment-related adverse events from DS-8201 were nausea (all grades: 62%; ≥ grade III: 5%), fatigue (all grade: 44%; ≥ grade III: 6%), and alopecia (all grades: 38%; ≥ grade III: 0.5%). Drug-related interstitial lung disease or pneumonitis occurred in 13% of the 1,108 patients, with only a 1% incidence of AE ≥ grade III. Conclusion: The present study suggests that DS-8201 is effective and safe in the treatment of ABC with low or positive HER2 expression, providing additional relevant information for its clinical application. However, further strengthening of the pairs is needed, as well as more clinical studies to support individualized treatment. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023390316.

Final results of DESTINY-CRC01 investigating trastuzumab deruxtecan in patients with HER2-expressing metastatic colorectal cancer

DESTINY-CRC01 (NCT03384940) was a multicenter, open-label, phase 2 trial assessing the efficacy and safety of trastuzumab deruxtecan (T-DXd) in patients with HER2-expressing metastatic colorectal cancer (mCRC) that progressed after ≥2 prior regimens; results of the primary analysis are published. Patients received T-DXd 6.4 mg/kg every 3 weeks and were assigned to either: cohort A (HER2-positive, immunohistochemistry [IHC] 3+ or IHC 2+/in situ hybridization [ISH]+), cohort B (IHC 2+/ISH-), or cohort C (IHC 1+). Primary endpoint was objective response rate (ORR) by independent central review in cohort A. Secondary endpoints included ORR (cohorts B and C), duration of response, disease control rate, progression-free survival, overall survival, pharmacokinetics, and safety of T-DXd. 86 patients were enrolled (53 in cohort A, 15 in cohort B, and 18 in cohort C). Results of the primary analysis are published, reporting an ORR of 45.3% in cohort A. Here, we report the final results. No responses occurred in cohorts B or C. Median progression-free survival, overall survival, and duration of response were 6.9, 15.5, and 7.0 months, respectively. Overall serum exposure (cycle 1) of T-DXd, total anti-HER2 antibody, and DXd were similar regardless of HER2 status. Most common grade ≥3 treatment-emergent adverse events were decreased neutrophil count and anemia. Adjudicated drug-related interstitial lung disease/pneumonitis occurred in 8 patients (9.3%). These findings support the continued exploration of T-DXd in HER2-positive mCRC.