Wenyan Chen

PURPOSE The global, phase 3, open-label, randomized TROPION-Breast01 study assessed the trophoblast cell surface antigen 2–directed antibody-drug conjugate datopotamab deruxtecan (Dato-DXd) versus investigator's choice of chemotherapy (ICC) in hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2–) breast cancer. METHODS Adult patients with inoperable/metastatic HR+/HER2‒ breast cancer, who had disease progression on endocrine therapy, for whom endocrine therapy was unsuitable, and had received one to two previous lines of chemotherapy in the inoperable/metastatic setting, were randomly assigned 1:1 to Dato-DXd (6 mg/kg once every 3 weeks) or ICC (eribulin/vinorelbine/capecitabine/gemcitabine). Dual primary end points were progression-free survival (PFS) by blinded independent central review (BICR) and overall survival (OS). RESULTS Patients were randomly assigned to Dato-DXd (n = 365) or ICC (n = 367). Dato-DXd significantly reduced the risk of progression or death versus ICC (PFS by BICR hazard ratio [HR], 0.63 [95% CI, 0.52 to 0.76]; P < .0001). Consistent PFS benefit was observed across subgroups. Although OS data were not mature, a trend favoring Dato-DXd was observed (HR, 0.84 [95% CI, 0.62 to 1.14]). The rate of grade ≥3 treatment-related adverse events (TRAEs) with Dato-DXd was lower than ICC (20.8% v 44.7%). The most common TRAEs (any grade; grade ≥3) were nausea (51.1%; 1.4%) and stomatitis (50%; 6.4%) with Dato-DXd and neutropenia (grouped term, 42.5%; 30.8%) with ICC. CONCLUSION Patients receiving Dato-DXd had statistically significant and clinically meaningful improvement in PFS and a favorable and manageable safety profile, compared with ICC. Results support Dato-DXd as a novel treatment option for patients with inoperable/metastatic HR+/HER2‒ breast cancer who have received one to two previous lines of chemotherapy in this setting.

In the global CAPItello-291 randomized phase 3 study (NCT04305496) in patients with hormone receptor-positive/HER2-negative advanced breast cancer and progression during/after aromatase inhibitor treatment, capivasertib-fulvestrant significantly improved progression-free survival (PFS) in the overall population and patients with PIK3CA/AKT1/PTEN-altered tumors versus placebo-fulvestrant. We assessed efficacy and safety of capivasertib-fulvestrant in a prespecified exploratory analysis of a Chinese cohort (n = 24) and extended study with the same protocol (n = 110). Clinically meaningful PFS benefit for capivasertib-fulvestrant was observed in the overall population (median PFS: 6.9 [capivasertib-fulvestrant] versus 2.8 [placebo-fulvestrant] months; hazard ratio 0.51, 95% CI 0.34-0.76), patients with PIK3CA/AKT1/PTEN-altered tumors (n = 46; 5.7 versus 1.9 months; hazard ratio 0.41, 95% CI 0.19-0.85) and PIK3CA/AKT1/PTEN-non-altered tumors (patients with confirmed next-generation sequencing results [n = 68]; 9.2 versus 2.7 months; hazard ratio 0.38; 95% CI 0.21-0.68). The most frequent adverse events (AEs) with capivasertib-fulvestrant were diarrhea (60.6% versus 11.3% with placebo-fulvestrant) and hyperglycemia (57.7% versus 17.7%). AEs leading to capivasertib-fulvestrant discontinuation were reported in 11.3% of patients versus 3.2% for placebo-fulvestrant. The benefit-risk profile of capivasertib-fulvestrant in the Chinese cohort was favorable; further exploration in patients with PIK3CA/AKT1/PTEN-non-altered tumors is warranted.

Purpose: Breast cancer is the most common type of cancer and the leading cause of cancer-related death in women worldwide. In this study, we aimed to construct an inflammatory response-related gene model for predicting the immune status and prognosis of breast cancer patients. Methods: We obtained the inflammatory response-related genes from the Molecular Signatures Database. Furthermore, we used univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO) regression analysis, and multivariate Cox regression to construct an inflammatory response-related gene signature (IRGS) model based on dataset obtained from The Cancer Genome Atlas (TCGA). Patients were consequently categorized into high-risk and low-risk groups. Kaplan-Meier analysis was used to compare the overall survival (OS) of high-risk and low-risk groups. Following that, we validated the model using a dataset (GSE96058) acquired from Gene Expression Omnibus (GEO) database. Univariate and multivariate Cox analyses were used to determine the independent prognostic value of the IRGS in the TCGA and GSE96058 cohorts. A nomogram was constructed to predict the OS in the TCGA cohort. Further, we used Gene Set Enrichment Analysis (GSEA), CIBERSORT, and single-sample Gene Set Enrichment Analysis (ssGSEA) to evaluate the associations of IRGS with immune-associated pathways and immune infiltration. Finally, the relationship between the expression of the signature genes and drug sensitivity was conducted using Pearson correlation analysis. Results: We established an IRGS to stratify breast cancer patients into the low-risk and high-risk groups. In both the training and validation sets, patients in the high-risk group had significantly shorter OS than those in the low-risk group. The risk score was significantly correlated with the clinical characteristics and could be used as a tool to predict the prognosis of breast cancer. Moreover, we found that the IRGS risk score was an independent predictor of OS in breast cancer patients, and a nomogram model based on IRGS risk score and other clinical factors could effectively predict the prognosis of breast cancer patients. Furthermore, the IRGS risk score was correlated with immune characteristics and was inversely associated with the abundance of immune cell infiltration. Patients with a low IRGS risk score had higher expression levels of immune checkpoint genes, suggesting that IRGS can be used as a potential indicator for immunotherapy. Finally, we found that the expression levels of prognostic genes were significantly correlated with tumor cell sensitivity to chemotherapeutic drugs. Conclusion: Overall, these findings suggest that the IRGS can be used to predict the prognosis and immune status of breast cancer patients and provide new therapeutic targets for the treatment of these patients.

1046 Background: In the front-line setting, our previous work demonstrated an impressive median progression-free survival (PFS) of 11.3 months with 66.7% response rate, and concluded a recommended phase 2 dose of pyrotinib 320mg/d, dalpiciclib (SHR6390, a novel CDK4/6i) 125mg/d, and letrozole 2.5mg/d for HR+/HER2+ MBC patients (pts) (Xichun Hu, FRONT ONCOL 2022). Results and biomarkers analysis from phase II dose expansion study are presented. Methods: ER+/HER2+ MBC Pts eligible for first- or second-line treatment were enrolled to receive dalpiciclib combined with pyrotinib and ET (letrozole or fulvestrant determined by physician’s choice). The primary endpoint was objective response rate (ORR). For biomarkers analysis, 68 Ga-HER2 affibody, pre-treatment tissue-derived DNA and circulating tumor DNA (ctDNA) were assessed by PET/CT, and next-generation sequencing (NGS), respectively. Results: As of January 19, 2023, 48 pts were enrolled. 17 pts (35.4%) were treatment naïve, and 31 pts (64.6%) had received prior trastuzumab. The ORR was 68.1% (32/47) and disease control rate was 100% (47/47). In trastuzumab-naïve and trastuzumab-pretreated patients, ORR was 81.3% (13/16) and 61.3% (19/31), respectively. PFS and OS data were not mature by cut-off date. No new safety signals were observed. The most frequent treatment-related adverse events were neutropenia (95.8%; G3:60.4%, G4:6.3%), leukopenia (91.7%; G3:45.8%), diarrhea (87.5%; G3:2.1%), anemia (79.2%; G3:4.2%), oral mucositis (68.8%, G3:2.1%) and platelet count decreased (41.7%; G3:2.1%, G4:2.1%). The heterogeneity of 68 Ga-HER2 affibody uptake was observed among patients, both at baseline (N=16，median SUV max 7.5, range, 2.3-34.9) and after 2 cycles of therapy (N=12，median SUV max 4.0, range, 0-14.9). All patients with a decline in 68 Ga-HER2 affibody uptake (N=8) achieved partial response, while the uptake in non-responders was elevated (N=2). NGS was conducted to detect somatic and germline mutations in baseline tissue (n=10) and ctDNA (n=10) samples. Two patients with BRCA mutation (one had somatic BRCA1/ 2 mutation and another with germline BRCA2 mutation) had no tumor response. Conclusions: The chemotherapy-sparing regimens showed significant anti-tumor activity for ER+/HER2+ MBC pts in the front-line setting. The 68 Ga-HER2 affibody PET/CT may be a potential predictive biomarker of therapy response. Additional analysis including correlation of biomarkers with long-term outcomes is underway. Clinical trial information: NCT03772353 .