Oncology Roundup: Highlights From the ESMO Breast Cancer Virtual Congress

The ESMO Breast Cancer Virtual Congress 2021 took place last week, and this Oncology Roundup column highlights a few stories covered by OncLive^®.

ILD Prevention, Detection in Patients on Trastuzumab Deruxtecan for HER2+ Metastatic Breast Cancer

Early detection and optimal management are key in preventing high-grade interstitial lung disease (ILD), a treatment-related adverse effect (AE) of fam-trastuzumab deruxtecan-nxki in patients with HER2-positive metastatic breast cancer, according to retrospective data from a pooled analysis presented during the ESMO Breast Cancer Virtual Congress 2021.

As reported by OncLive^®, the study indicated that these patients do not experience cumulative toxicity, as the risk of all-grade ILD fell over time. Notably, toxicity management guidelines for ILD have been updated and implemented since December 2019, in an effort to lower the rates of high-grade ILD through early detection.

Since ILD was identified as an AE of interest in patients receiving trastuzumab deruxtecan, investigators sought to characterize ILD in heavily pretreated patients with metastatic breast cancer. The majority of the events examined took place before the guidelines were implemented; half of the ILD events leading to death were not treated with steroids, as per the guidelines, nor were 40% of the moderate to severe ILD cases.

The analysis is exploratory and hypothesis generating in nature, according to Charles A. Powell, MD, director of the Mount Sinai-National Jewish Health Respiratory Institute and professor of medicine, pulmonary, critical care, and sleep medicine at Mount Sinai. Phase 3 randomized, controlled trials of trastuzumab deruxtecan in breast cancer are ongoing.

Shorter Duration of Adjuvant Trastuzumab Shows Benefit in Select HER2+ Early Breast Cancer

Updated survival data from the phase 3 Short-HER trial confirm the promising long-term results from 9 weeks of adjuvant trastuzumab in patients with HER2-positive early breast cancer who have low and intermediate risk factors, according to OncLive®. That population makes up most patients seen in clinical practice.

After a median follow-up of 8.7 years, patients who received 1 year of trastuzumab had a 5-year disease-free survival (DFS) rate of 87.9% vs compared with 85.8% among those who received it for 9 weeks (HR, 1.09; 90% CI, 0.88-1.35). Moreover, patients had a 5-year overall survival (OS) rate of 95.1% in both arms (HR, 1.18; 90% CI, 0.86-1.62).

Early Study of Datopotamab Deruxtecan in TNBC Shows Promise

The differentiated TROP2-directed antibody-drug conjugate datopotamab deruxtecan (DS-1062a) has a promising antitumor action and a manageable safety profile in heavily pretreated patients with triple-negative breast cancer (TNBC), according to preliminary results from the TNBC cohort of the phase 1 TROPION-PanTumor01 trial.

Among 21 evaluable patients, the objective response rate with datopotamab deruxtecan was 43% (n = 9) per blinded independent central review (BICR); this included a confirmed complete response (CR)/partial response (PR) rate of 24%; 19% of patients also had a CR/PR that was pending confirmation. The disease control rate was 95% by BICR. Only 1 patient experienced disease progression, and no patients discontinued treatment due to AEs.

Read the full story here.