bims-cyhorp 2022-03-20 papers

Issue of 2022–03–20
seven papers selected by
Piotr Okupski,

Ann Transl Med. 2022 Feb;10(4): 233

Pharmacoeconomic evaluations of CDK4/6 inhibitors plus endocrine therapy for advanced hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) breast cancer: a systematic review.

Linhui Zhu, Mengmeng Wang, Xin Luo, Huan Li, Han Shan, Qiong Du, Qing Zhai.

Background: Hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) breast cancer is the most common molecular subtype of breast cancer in many countries, and endocrine therapy remains a mainstay in its treatment. Cyclin-dependent kinase (CDK) 4/6 inhibitors are a new class of targeted agents administered orally that are recommended being used in combination with endocrine therapy as first and second line treatments for advanced HR+/HER2- breast cancer. However, their high prices largely hinder using these drugs in real world settings. To offer a new basis for future research, we investigated the cost-effectiveness of combinations of CDK4/6 inhibitors with endocrine therapy in the treatment of advanced HR+/HER2- breast cancer.
Methods: We systematically searched several frequently used databases and identified economic evaluations published from February 2015 to April 2021. The systematic review was performed after retrieving the literatures and extracting data based on inclusion and exclusion criteria. The quality of each selected economic evaluation was assessed by the Consolidated Health Economic Evaluation Reporting Standards (CHEERS).
Results: The literature search yielded 161 articles, among which fourteen studies (15 articles) with CHEER scores ranging from 58.33% to 87.50% entered the final analysis. Markov models were used in most studies. Based on the currently available data, CDK4/6 inhibitors plus endocrine therapy were less cost-effective in first- or second-line treatment of patients with HR+/HER2- advanced breast cancer. However, ribociclib plus letrozole was more cost-effective than palbociclib plus letrozole in the first-line treatment of postmenopausal women. The economic impacts of CDK4/6 inhibitors plus endocrine therapy in non-postmenopausal patients or second-line therapy cannot be fully evaluated due to the limited number of studies. The three most common factors affecting economic outcomes were the prices of CDK4/6 inhibitors, hazard ratios for progression-free survival and overall survival, and health status utility values.
Discussion: CDK4/6 inhibitors plus endocrine therapy have shown significantly improved efficacy outcomes in HR+/HER2- metastatic breast cancer (mBC)/advancer breast cancer (ABC) first-line and second-line treatment for endocrine-sensitive and endocrine-resistant populations, while more potential fields including neoadjuvant and adjuvant settings are being identified to benefit a wider range of breast cancer patients. Meanwhile, risk of severe adverse events that more likely to happen in patients treated with CDK4/6 inhibitors can lead to reduced life quality and higher medical costs patients need to afford. The adverse drug reaction related cost in several economic burden studies were explored to be primarily driven by hospitalizations and outpatient, and assessment of cost associated with CDK4/6 inhibitors adverse events is worth further developing. Drug wastage costs were found higher in palbociclib regimen than ribociclib regimen due to different dosing patterns. Moreover, current economic evaluations showed that ribociclib plus letrozole had better economic benefits than palbociclib plus letrozole for first-line treatment of postmenopausal women with HR+/HER2- ABC.

Keywords: CDK4/6 inhibitors; breast cancer; pharmacoeconomic evaluation; systematic review

DOI: https://doi.org/10.21037/atm-21-5110

Clin Exp Med. 2022 Mar 19.

Cyclin-dependent kinase 4 and 6 inhibitors in combination with neoadjuvant endocrine therapy in estrogen receptor-positive early breast cancer: a systematic review and meta-analysis.

Yumei Guan, Guoshuang Shen, Qianqian Fang, Yuanfang Xin, Xingfa Huo, Jinming Li, Fuxing Zhao, Dengfeng Ren, Zhen Liu, Zitao Li, Jiuda Zhao.

The combination of cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors and endocrine treatment has benefited patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER + /HER2-) metastatic breast cancer; however, its effects in the neoadjuvant setting for ER + /HER2- early breast cancer (EBC) are unclear. Systematic searches were performed in PubMed, Embase, Cochrane Library, and major oncological meetings for trials of CDK4/6 inhibitors plus neoadjuvant endocrine treatment (NET) vs. NET/neoadjuvant chemotherapy (NACT) alone up to January 30, 2021. We assessed the efficacy of CDK4/6 inhibitors plus NET vs. NET/NACT alone in ER + /HER2- EBC. Six studies that included 803 patients treated with CDK4/6 inhibitors plus NET vs. NET/NACT alone were used. Compared with NET/NACT alone, CDK4/6 inhibitors plus NET increased the complete cell cycle arrest (CCCA) rate (OR, 9.00; 95% CI, 5.42-14.96; P < 0.001). Nonsignificant differences between CDK4/6 inhibitors and NET/NACT alone occurred in the preoperative endocrine prognostic index (PEPI)-0 rate (OR, 1.13; 95% CI, 0.59-2.18; P = 0.71), pathological complete response (pCR) rate (OR, 0.75; 95% CI, 0.13-4.29; P = 0.74), objective response rate (ORR) (OR, 0.70; 95% CI, 0.21-2.29; P = 0.55), and disease control rate (DCR) (OR, 1.16; 95% CI, 0.47-2.89; P = 0.74). CDK4/6 inhibitors plus NET indicated a high risk of neutropenia (OR, 56.43; 95% CI, 15.76-202.11; P < 0.001) as an adverse effect (AE) and elevated alanine aminotransferase (ALT) level (OR, 15.30; 95% CI, 2.02-115.98; P = 0.008) as grade 3/4 AEs. Compared with NET/NACT alone, CDK4/6 inhibitors plus NET increased CCCA rate in ER + /HER2- EBC patients. CDK4/6 inhibitors plus NET did not substantially improve the PEPI-0 rate, pCR rate, ORR, or DCR. The combination increased the risk of neutropenia and elevated ALT levels. In the neoadjuvant setting, addition of CDK4/6 inhibitors to NET may be an option for treating ER + /HER2- EBC.

Keywords: Breast cancer; Cyclin-dependent kinase 4/6 inhibitors; Endocrine therapy; Neoadjuvant

DOI: https://doi.org/10.1007/s10238-022-00814-3

Nat Rev Cancer. 2022 Mar 18.

Targeting CDK4 and CDK6 in cancer.

Shom Goel, Johann S Bergholz, Jean J Zhao.

Cyclin-dependent kinase 4 (CDK4) and CDK6 are critical mediators of cellular transition into S phase and are important for the initiation, growth and survival of many cancer types. Pharmacological inhibitors of CDK4/6 have rapidly become a new standard of care for patients with advanced hormone receptor-positive breast cancer. As expected, CDK4/6 inhibitors arrest sensitive tumour cells in the G1 phase of the cell cycle. However, the effects of CDK4/6 inhibition are far more wide-reaching. New insights into their mechanisms of action have triggered identification of new therapeutic opportunities, including the development of novel combination regimens, expanded application to a broader range of cancers and use as supportive care to ameliorate the toxic effects of other therapies. Exploring these new opportunities in the clinic is an urgent priority, which in many cases has not been adequately addressed. Here, we provide a framework for conceptualizing the activity of CDK4/6 inhibitors in cancer and explain how this framework might shape the future clinical development of these agents. We also discuss the biological underpinnings of CDK4/6 inhibitor resistance, an increasingly common challenge in clinical oncology.

DOI: https://doi.org/10.1038/s41568-022-00456-3

Cancer Manag Res. 2022 ;14 1033-1041

Thromboembolic Events in Patients with HER2-Negative, Hormone Receptor-Positive, Metastatic Breast Cancer Treated with Ribociclib Combined with Letrozole or Fulvestrant: A Real-World Data.

Hikmat Abdel-Razeq, Baha' Sharaf, Rama AlMasri, Rashid Abdel-Razeq, Faris Tamimi, Omar Khader, Osama Salama, Mahmoud Abunasser, Sarah Edaily, Hazem Abdulelah.

Purpose: Cyclin dependent kinase (CDK) 4/6 inhibitors (palbociclib, ribociclib and abemaciclib) modulate endocrine resistance and are integral treatment for patients with advanced hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Since their approval, CDK4/6 inhibitors are widely used in clinical practice. Thromboembolic events (TEE) were not a major issue in patients treated on clinical trials utilizing these agents. However, conflicting data started to emerge describing higher than expected rates of both arterial and venous thrombosis in patients treated with CDK4/6 inhibitors. In this study, we report our experience on TEE in patients treated with one of these agents (ribociclib) in real-world settings.
Patients and Methods: All consecutive patients with metastatic breast cancer (mBC) treated with ribociclib combined with letrozole or fulvestrant were retrospectively reviewed. All episodes of radiologically confirmed arterial or venous thrombosis were recorded. TEE was considered ribociclib-related if diagnosed while patients are on the drug, or within 4 weeks after the last dose.
Results: A total of 305 patients, median age (range), 49 (22-87) years were enrolled. All patients had metastatic disease, and most (n=241, 79.0%) were with visceral metastasis. Ribociclib was used for a median duration of 7 months (range: 1-45) and was used beyond the first-line setting in 110 (35.9%) patients. TEE were confirmed on 6 (1.97%) patients; 3 were pulmonary embolism, 2 cerebral venous sinus thrombosis (CVST), and one case of limb ischemia and all were symptomatic. Similar rates of TEE were noted prior to initiation, and after stopping ribociclib.
Conclusion: In real-world settings, breast cancer patients treated with ribociclib, combined with aromatase inhibitors or fulvestrant, may not be at higher risk for thromboembolic events. However, unusual sites of thrombosis, like CVST, may raise some concerns.

Keywords: CDK4/6 inhibitors; fulvestrant; letrozole; patient stratification; prediction; thrombosis

DOI: https://doi.org/10.2147/CMAR.S353584

Ann Transl Med. 2022 Jan;10(2): 117

Chemotherapy modulates CDK4/6 inhibitors resistance in metastatic breast cancer by Rb1 mutations: a case report and literature review.

Lu Gao, Xiabo Shen, Libin He, Jiayi Wu, Yiyuan Liu, Xiaojia Wang, Xiying Shao.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) plays a major role in breast cancer therapeutics acting through preventing the cell cycle from G1 to the S phase. Recently, Endocrine therapy combined with CDK4/6i represented a major milestone in hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer treatment. However, the resistance of CDK4/6i is clinically common, and the mechanism remains to be clarified. Retinoblastoma (Rb) is a negative regulator of cell cycle. It inhibits cell cycle transition by binding to E2F transcription factors, and prevent cells division in this way. Rb is regulated by phosphorylation. The CDK4/6i have been shown to affect cancer by blocking phosphorylation of Rb. In addition, decreasing estrogen signal has been confirmed to reduce cyclin D-CDK4/6 complexing. Currently, FCN-437c is a new CDK4/6i that is in clinical trials. Here, we present the case of an HR-positive and HER2-negative patient whose disease continued to rapidly progress after receiving FCN-437c. To determine why, we did a series of examinations and found that her Rb1 had mutated after using CDK4/6i. To our surprise, the Rb1 mutations recovered after treatment with eribulin, and CDK4/6i was shown to exert a renewed effect. In this way, a hypothesis was made that eribulin may influence the pathway of cyclin D- CDK4/6- Rb- E2F by effecting in Rb. This case provides new insights into strategies for CDK4/6i therapy resistance options and shows the significance of next-generation sequencing in the clinic.

Keywords: CDK4/6 inhibitors resistance (CDK4/6i resistance); Retinoblastoma (Rb); case report; metastatic breast cancer (MBC); next-generation sequencing

DOI: https://doi.org/10.21037/atm-22-52

Jpn J Clin Oncol. 2022 Mar 16. pii: hyac022. [Epub ahead of print]

Factors associated with overall survival after recurrence in patients with ER-positive/HER2-negative postmenopausal breast cancer: an ad hoc analysis of the JBCRG-C06 Safari study.

BACKGROUND: The Safari study (UMIN000015168) was a retrospective, multicenter study in which 1072 consecutive cases of estrogen receptor-positive advanced breast cancer treated using 500 mg fulvestrant were registered. We previously reported the relationship between the patient factors and overall survival after the diagnosis using the same cases and the same factors for the analysis of time to treatment failure in patients with estrogen receptor-positive advanced breast cancer. The current study is an ad hoc analysis that focused on the relationship between the patient factors and overall survival after recurrence by adding factors generally associated with overall survival after recurrence.
METHODS: The overall survival after recurrence in patients with estrogen receptor-positive human epidermal growth factor receptor 2 negative recurrent breast cancer was analyzed via univariate and multivariate analyses with a Cox proportional hazards model.
RESULTS: A total of 598 cases were used for the analysis of overall survival after recurrence. Multivariate analysis revealed that favorable overall survival (median, 6.4 years) was significantly correlated with long time from recurrence to fulvestrant use (≥3 years), low nuclear or histological grade (G3 vs. G1), long time to treatment failure of initial palliative endocrine therapy (≥12 months) and long time to initial palliative chemotherapy (≥2 years).
CONCLUSION: The results of this study indicate that sequential endocrine monotherapy may be a useful treatment option for patients with estrogen receptor-positive/human epidermal growth factor receptor 2 negative recurrent breast cancer who have been successfully treated with initial long-term palliative endocrine therapy.

Keywords: antineoplastic agents; breast cancer; hormones; overall survival; post-menopause

DOI: https://doi.org/10.1093/jjco/hyac022