Managing the Risk of Lung Toxicity with Trastuzumab Deruxtecan (T-DXd): A Canadian Perspective

Meta-Analysis of Exposure-Adverse Event Relationships for Antibody-Drug Conjugates

Antibody-drug conjugates (ADCs) have become a vital class of therapeutics in oncology because of their ability to selectively deliver potent drug molecules to tumor cells. However, ADC-associated toxicities cause high failure rates in the clinic and hinder their full potential. Due to the complex structure and pharmacokinetics of ADCs, it is challenging to identify the drivers of their toxicities. Here, quantitative analysis was performed to correlate the incidence of clinical adverse events (AEs) with nine different commonly measured exposure parameters collected from study-level summary data. We considered ADC analytes for different classes of ADCs, to identify ADC analytes that are strongly associated with the AEs for ADCs. Published clinical exposure and safety data for any grade and grade ≥3 AEs from 40 publications across six ADCs and three payloads were collected and analyzed. Exposure-AE relationships were quantified using logit models, and the strength of the correlations and rank order were determined. The analysis suggests that deruxtecan ADC-related toxicities correlated most strongly with the exposure of the free payload; monomethyl auristatin E (MMAE) ADC-related toxicities correlated with the free MMAE area under the curve; and pyrrolobenzodiazepine ADC-related toxicities correlated with no specific analyte but the dose. These findings agree with the published literature and support the notion that AE profiles are often shared by ADCs that deliver the same cytotoxic payload. The exposure-AE relationships presented here, together with identification of the most informative ADC analytes, may facilitate more focused mechanistic studies on the drivers of clinical AEs and could support dosing decisions during clinical development of ADCs.

Updates in Drug-Related Pneumonitis Due to Targeted Oncologic Therapies

An increasing number of newer targeted oncologic therapies approved for clinical use can cause drug-related pneumonitis. Drug-related pneumonitis can be difficult to diagnose and requires a high index of suspicion. This review serves as an update to a prior review in this journal about pneumonitis with precision oncology therapies. In this review, we focus on the incidence, timing of onset, and imaging patterns of pneumonitis associated with a number of newly approved precision oncologic agents, with a particular focus on new antibody-drug conjugate therapies.

Diagnosis and Management of Drug-Induced Interstitial Lung Disease in the context of Anti-Cancer Therapy: a Multidisciplinary Viewpoint by Portuguese Experts

Drug-induced interstitial lung disease (DI-ILD) is a significant complication in patients undergoing treatment with certain anti-cancer therapies, with incidence rates rising, particularly with newer drugs such as trastuzumab-deruxtecan, which may impact their safe and effective use. Although the exact pathophysiological mechanisms remain unknown, and different drugs may induce lung damage through different pathways, the most recognized mechanisms are cytotoxic- and immune-mediated effects. Multidisciplinary teams play a crucial role in the diagnosis, management, and prevention of DI-ILD. Given the wide variability in the onset of DI-ILD, which may occur within the first few days of treatment or months after, patient education and clinician training are essential for early detection and improved outcomes. Moreover, the diagnostic confirmation requires the exclusion of alternative causes through clinical, imaging and bronchoscopy evaluation. Treatment strategies largely depend on the grade of severity of the clinical manifestations of DI-ILD, ranging from interruption or discontinuation of the offending drug to corticosteroid therapy and hospitalization for appropriate monitoring. Nonetheless, further research is needed to better understand the impact of emerging anti-cancer drugs on DI-ILD and to establish standardized management protocols.

Guidance for Canadian Breast Cancer Practice: National Consensus Recommendations for the Systemic Treatment of Patients with HER2+ Breast Cancer in Both the Early and Metastatic Setting

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is an aggressive subtype of breast cancer associated with a poor prognosis when sub-optimally treated. Recent advances include new and effective targeted therapies that have significantly improved outcomes for patients. Despite these advances, there are significant gaps across Canada, underscoring the need for evidence-based consensus guidance to inform treatment decisions. Addressing these gaps is crucial to ensuring that effective therapies are integrated into clinical practice, so as to improve the lives of patients affected by this aggressive form of breast cancer. The Research Excellence, Active Leadership (REAL) Canadian Breast Cancer Alliance is a standing nucleus committee of clinical-academic oncologists across Canada and Breast Cancer Canada, a patient organization. The mandate of this group is to provide evidence-based guidance on best practices in the management of patients with breast cancer. These consensus recommendations were developed using a modified Delphi process with up to three rounds of anonymous voting. Consensus was defined a priori as ≥75% of voters agreeing with the recommendation as written. There are 9 recommendations in the early setting; 7 recommendations in the metastatic setting; and 10 recommendations for patients with brain metastases.

Effectiveness of [67Cu]Cu-trastuzumab as a theranostic against HER2-positive breast cancer

PURPOSE

To evaluate the imaging and therapeutic properties (theranostic) of 67Cu-labeled anti-human epidermal growth factor receptor II (HER2) monoclonal antibody trastuzumab against HER2-positive breast cancer (BC).

METHODS

We conjugated trastuzumab with p-SCN-Bn-NOTA, 3p-C-NETA-NCS, or p-SCN-Bn-DOTA, and radiolabeled with [67Cu]CuCl2. Immunoconjugate internalization was evaluated in BT-474, JIMT-1 and MCF-7 BC cells. In vitro stability was studied in human serum (HS) and Phosphate Buffered Saline (PBS). Flow cytometry, radioligand binding and immunoreactive fraction assays were carried out. ImmunoSPECT imaging of [67Cu]Cu-NOTA-trastuzumab was done in mice bearing BT-474, JIMT-1 and MCF-7 xenografts. Pharmacokinetic was studied in healthy Balb/c mice while dosimetry was done in both healthy Balb/c and in athymic nude mice bearing JIMT-1 xenograft. The therapeutic effectiveness of [67Cu]Cu-NOTA-trastuzumab was evaluated in mice bearing BT-474 and JIMT-1 xenografts after a single intravenous (i.v.) injection of ~ 16.8 MBq.

RESULTS

Pure immunoconjugates and radioimmunoconjugates (> 95%) were obtained. Internalization was HER2 density-dependent with highest internalization observed with NOTA-trastuzumab. After 5 days, in vitro stabilities were 97 ± 1.7%, 31 ± 6.2%, and 28 ± 4% in HS, and 79 ± 3.5%, 94 ± 1.2%, and 86 ± 2.3% in PBS for [67Cu]Cu-NOTA-trastuzumab, [67Cu]Cu-3p-C-NETA-trastuzumab and [67Cu]Cu-DOTA-trastuzumab, respectively. [67Cu]Cu-NOTA-trastuzumab was chosen for further evaluation. BT-474 flow cytometry showed low KD, 8.2 ± 0.2 nM for trastuzumab vs 26.5 ± 1.6 nM for NOTA-trastuzumab. There were 2.9 NOTA molecules per trastuzumab molecule. Radioligand binding assay showed a low KD of 2.1 ± 0.4 nM and immunoreactive fraction of 69.3 ± 0.9. Highest uptake of [67Cu]Cu-NOTA-trastuzumab was observed in JIMT-1 (33.9 ± 5.5% IA/g) and BT-474 (33.1 ± 10.6% IA/g) xenograft at 120 h post injection (p.i.). Effectiveness of the radioimmunoconjugate was also expressed as percent tumor growth inhibition (%TGI). [67Cu]Cu-NOTA-trastuzumab was more effective than trastuzumab against BT-474 xenografts (78% vs 54% TGI after 28 days), and JIMT-1 xenografts (90% vs 23% TGI after 19 days). Mean survival of [67Cu]Cu-NOTA-trastuzumab, trastuzumab and saline treated groups were > 90, 77 and 72 days for BT-474 xenografts, while that of JIMT-1 were 78, 24, and 20 days, respectively.

CONCLUSION

[67Cu]Cu-NOTA-trastuzumab is a promising theranostic agent against HER2-positive BC.

The Canadian Breast Cancer Symposium 2023 Meeting Report

On 15-16 June 2023, healthcare professionals and breast cancer patients and advocates from across Canada met in Toronto, Ontario, for the 2023 Canadian Breast Cancer Symposium (CBSC.). The CBSC. is a national, multidisciplinary event that occurs every 2 years with the goal of developing a personalized approach to the management of breast cancer in Canada. Experts provided state-of-the-art information to help optimally manage breast cancer patients, including etiology, prevention, diagnosis, experimental biology, and therapy of breast cancer and premalignant breast disease. The symposium also had the objectives of increasing communication and collaboration among breast cancer healthcare providers nationwide and providing a comprehensive and real-life review of the many facets of breast cancer. The sessions covered the patient voice, the top breast cancer papers from different disciplines in 2022, artificial intelligence in breast cancer, systemic therapy updates, the management of central nervous system metastases, multidisciplinary management of ductal carcinoma in situ, special populations, optimization-based individual prognostic factors, toxicity management of novel therapeutics, survivorship, and updates in surgical oncology. The key takeaways of these sessions have been summarized in this conference report.

Successful dabrafenib and trametinib combination therapy in a patient with recurrent BRAFV600E-mutant non-small-cell lung cancer and coexisting radiation pneumonitis

There have been several reports of drug-induced lung injury caused by molecular-targeted agents. Additionally, medical history of interstitial lung disease and chest irradiation are established risk factors for the development and progression of drug-induced lung injury. Moreover, the presence of fibrosis on chest computed tomography before treatment is a predictive factor for the appearance of pneumonia induced by anticancer drugs. Accordingly, patients with a history of interstitial lung disease or pneumonitis were excluded from clinical trials of dabrafenib and trametinib combination therapy for patients with previously treated BRAF V600E-mutant metastatic non-small-cell lung cancer. This article presents a case of successful dabrafenib and trametinib combination therapy in a patient with BRAF V600E-mutant non-small-cell lung cancer who had a history of radiation pneumonitis and developed recurrence after conventional chemoradiotherapy.