Clinical application and progression of monoclonal antibodies targeting HER2 extracellular domain Ⅳ in breast cancer / 中国药房

Human epidermal growth factor receptor 2 （HER2）-positive breast cancer is aggressive and prone to metastasis，and the applications of HER2 agents have improved the prognosis of patients with HER2-positive breast cancer. Among the marketed HER2 agents，macromolecular monoclonal antibodies that target the extracellular domain Ⅳ of HER2 were the cornerstone drugs of HER2-positive breast cancer，including trastuzumab，inetetamab，and margetuximab. Trastuzumab is available for the full-line treatment of breast cancer with sufficient proof of evidence-based medicine，sufficient practical experience and controllable safety. Inetetamab and trastuzumab have similar efficacy and controllable safety in HER2-positive metastatic breast cancer and neoadjuvant/ adjuvant therapy. Margetuximab focuses on patients carrying the CD16A-158F allele，and is an option of posterior line treatment for advanced breast cancer. It is necessary to select the most suitable drugs clinically according to the specific condition of the patient.

Effects of adjuvant trastuzumab on long-term survival of T1N0M0 stage human epidermal growth factor receptor 2 positive breast cancer: a real-world study / 中华肿瘤杂志

Objective: To investigate the prognosis impact of adjuvant trastuzumab treatment on human epidermal growth factor receptor 2 (HER-2) positive early breast cancer patients. Methods: A retrospective study was conducted, HER-2-positive T1N0M0 stage breast cancer patients who underwent surgery in the Affiliated Tumor Hospital of Xinjiang Medical University from January 2010 to December 2019 were divided into treatment group and control group according to whether they were treated with trastuzumab or not. Propensity score matching (PSM) was used to balance the confounding bias caused by differences in baseline characteristics between the two groups. Cox proportional hazards model was used to analyze the risk factors affecting disease-free survival (DFS). The Kaplan-Meier method was used to estimate the 3- and 5-year DFS and overall survival (OS) rates of the two groups before and after PSM. Results: There were 291 patients with HER-2 positive T1N0M0 stage breast cancer, including 21 cases in T1a (7.2%), 61 cases in T1b (21.0%), and 209 cases in T1c (71.8%). Before PSM, there were 132 cases in the treatment group and 159 cases in the control group, the 5-year DFS rate was 88.5%, and the 5-year OS rate was 91.5%. After PSM, there were 103 cases in the treatment group and 103 cases in the control group, the 5-year DFS rate was 86.0%, and the 5-year OS rate was 88.5%. Before PSM, there were significant differences in tumor size, histological grade, vascular invasion, Ki-67 index, postoperative chemotherapy or not and radiotherapy between the treatment group and the control group (P<0.05). After PSM, there were no significant difference in clinicopathological features between the treatment group and the control group (P>0.05). Multivariate analysis showed that histological grade (HR=2.927, 95 CI: 1.476, 5.805; P=0.002), vascular invasion (HR=3.410, 95 CI: 1.170, 9.940; P=0.025), menstrual status (HR=3.692, 95 CI: 1.021, 13.344, P=0.046), and chemotherapy (HR=0.238, 95 CI: 0.079, 0.720; P=0.011) were independent factors affecting DFS. After PSM, the 5-year DFS rate of the treatment group was 89.2%, while that of the control group was 83.5%(P=0.237). The 5-year OS rate of the treatment group was 96.1%, while that of the control group was 84.7%(P=0.036). Conclusion: Postoperative targeted therapy with trastuzumab can reduce the risk of recurrence and metastasis in patients with HER-2-positive T1N0M0 stage breast cancer.

Visual analysis of tyrosine kinase inhibitors in HER2 positive breast cancer / 中国药房

OBJECTIVE To analyze the research status， hotspot and development trend of tyrosine kinase inhibitors （TKIs） in the treatment of human epidermal growth factor receptor 2 （HER2） positive breast cancer. METHODS The literature related to TKIs in the treatment of HER2 positive breast cancer were searched from the Web of Science core collection database； the author， country/region， institution， subject field， journal and keywords was visualized by CiteSpace 6.1.R3 software. RESULTS A total of 732 pieces of literature were included， and the number of literature published showed an increasing trend year by year. The number of literature published in the United States was the largest （center degree 0.10）， and the number of literature published in China ranked second （center degree 0.05）. The most published and cited authors were Crown from St. Vincent’s University Hospital in Australia and Slamon from University of California， Los Angeles in the United States； the institution with the highest number of literature was the University of Texas MD Anderson Cancer Center， and the journal with the highest number of literature was the Journal of Clinical Oncology. The research mainly focused on five aspects： HER2 positive breast cancer treatment drugs， TKIs receptor， TKIs mechanism of action， HER2 positive breast cancer brain metastasis， and TKIs clinical trials. The main frontier areas and development trends were the combination of TKIs with other drugs or therapies to enhance targeting and reduce toxic side effects. CONCLUSIONS The study of TKIs in the treatment of HER2 positive breast cancer has attracted the attention of scholars at home and abroad. Chinese scholars and research teams need to strengthen cooperation and communication in the future， and cooperation with other countries should be strengthened in terms of the efficacy and safety of TKIs alone and combined with other drugs in the treatment of HER2 positive breast cancer.

Efficacy and safety of oral lapatinib in HER2 positive metastatic breast cancer / 肿瘤

Objective: To determine the effectiveness and safety of lapatinib for patients with human epidermal growth factor receptor-2 (HER2) positive metastatic breast cancer. Methods: In this retrospective study, 40 patients with HER2 positive metastatic breast cancer (MBC) received lapatinib-based regimen. The clinical records and follow-up information were collected and analyzed. Results: Forty patients with HER2 positive MBC were enrolled in this study, and 90.0% (36/40) of the patients had received trastuzumab-based regimen during the recurrent/metastatic period, the median interval of trastuzumab treatment was 12.0 months (95% confidence interval: 10.5-13.5 months) (range: 2.0-54.0 months); 5.0% (2/40) of the patients had received adjuvant trastuzumab, but the disease-free survival (DFS) was two years or less; 5.0% (2/40) of the patients had never received trastuzumab, but the brain was the first metastatic organ. Of 40 patients, 31 (77.5%) received lapatinib combined with chemotherapy, 6 (15.0%) combined with endocrine therapy, and 3 (7.5%) combined with trastuzumab. The objective response to lapatinib-based therapy was evaluable in all patients. Ten (25.0%) patients achieved partial response (PR), 21 (52.5%) patients had stable disease (SD), 9 (22.5%) had progressive disease (PR), and no one achieved complete response (CR). The objective response rate (ORR) (CR+PR) was 25.0%, and the clinical benefit rate (CBR) (CR+PR+SD≥ 6 months) was 50.0%. The median progression-free survival (PFS) was 6.0 months (95% confidence interval: 4.6-7.5 months) (range: 1.0-20.0 months). The main toxicities related to lapatinib were grade 1-2 diarrhea in 8 patients (20.0%), and grade 1-2 rash in 6 patients (15.0%). Conclusion: Lapatinib-based therapy is an effective treatment for patients with HER2 positive metastatic breast cancer after prior exposure to trastuzumab.

An economic evaluation of trastuzumab as adjuvant treatment of early HER2-positive breast cancer patients in Colombia / Evaluación económica del trastuzumab como tratamiento adyuvante en cáncer de mama HER2- positivo en Colombia

Objective: Trastuzumab (Herceptin®), a recombinant, humanized, monoclonal antibody targeting HER2 is well established as an effective treatment for HER2-positive breast cancer. Evidence from developed countries showed that trastuzumab was cost-effective; but there are few evidences in developing countries. This study assesses the cost-effectiveness of adjuvant trastuzumab treatment in Colombia. Methods: A Markov health-state transition model was built to estimate clinical and economic outcomes in HER2-positive breast cancer with or without 12 months trastuzumab adjuvant chemotherapy over a lifetime perspective with annual transition cycles. The model incorporated five health states (diseasefree, local recurrence, distant recurrence, cardiac failure, and death). Baseline event rates and 3-year hazard ratio (HR=0.51, IC 95% 0.44-0.59; p<0.0001) were derived from 4-year follow up of the N9831 and NSABP B-31 trial. Costs and utility weights were obtained from the literature and were discounted by 5% annually. Results: The model showed that the utilization of adjuvant trastuzumab treatment in early breast cancer can prolong 0.80 quality-adjusted life-years (QALY), compared with standard chemotherapy, an incremental cost-effectiveness ratio (ICER) of US$ 71,491 per QALY gained. Conclusion: The results suggest that 1-year adjuvant Trastuzumab treatment is not cost-effective in Colombia, using the definition of WHO cost-effectiveness threshold of 3 times GDP per capita.

Introducción. El trastuzumab es un anticuerpo monoclonal de reconocida efectividad para el tratamiento en mujeres con cáncer de mama positivo para HER2. Sin embargo, la mayoría de estudios de costo-efectividad se han llevado a cabo en países desarrollados. Objetivo. Determinar el costo-efectividad del tratamiento adyuvante con trastuzumab en mujeres con cáncer de mama HER2+ en Colombia. Materiales y métodos. Se construyó un modelo de Markov, con ciclos de transición anuales y desde la perspectiva del pagador, para estimar los resultados clínicos y económicos derivados de la administración de trastuzumab en mujeres con HER2 positivo. El modelo incorpora cinco estados de transición: libre de enfermedad, recurrencia local, metástasis, falla cardiaca y muerte. La tasa de eventos y la razón de tazas instantáneas (0,51; IC 95% 0,44-0,59; p<0,0001) se derivaron del reporte a cuatro años de los ensayos clínicos controlados N9831 y NSABP B-31. Los costos y las utilidades se estimados a partir de la literatura científica, utilizando una tasa de descuento del 5 % anual. Resultados. El modelo revela que la utilización de trastuzumab como tratamiento adyuvante prolonga la expectativa de vida ajustada por calidad en 0,8 años, en comparación con la quimioterapia sin trastuzumab; a una razón de costo efectividad incremental (sic.) de US$ 71.491 por año de vida ganado ajustado por calidad de vida. Conclusión. El tratamiento con trastuzumab durante un año no es costo-efectivo en Colombia, utilizando la definición de costo-efectividad de la OMS de menos de dos a tres veces el PIB per cápita por año de vida ganado ajustado por calidad de vida.