Clinical benefit and safety profile of cross-line therapy with CDK4/6 inhibitors:a retrospective study of HR+/HER2–advanced breast cancer

Objective:CDK4/6 inhibitors(CDK4/6is)in combination with endocrine therapy have secured a central role in the treatment of hormone receptor(HR)-positive advanced breast cancer(ABC)and have transformed the therapeutic landscape.Cross-line CDK4/6i therapy in which another CDK4/6i is continued after progression on a prior CDK4/6i may still offer advantageous therapeutic effects.Cross-line CDK4/6i therapy is an area of active investigation in the ongoing pursuit to improve outcomes for patients with HR+/human epidermal growth factor receptor 2(HER2)–ABC.Methods:This retrospective study enrolled 82 patients with HR+/HER2–ABC who were treated with cross-line CDK4/6is(abemaciclib,palbociclib,ribociclib,and dalpiciclib)after progression with another CDK4/6i.The primary endpoint was progression-free survival(PFS)according to version 1.1 of the Response Evaluation Criteria in Solid Tumors.Secondary endpoints included toxicity,objective response rate,disease control rate,and overall survival.Adverse events(AEs)were graded according to version 5.0 of the Common Terminology Criteria for Adverse Events,as promulgated by the U.S.Department of Health and Human Services.Results:Eighty-two HR+/HER2–ABC patients who received cross-line CDK4/6i therapy from January 2022 to February 2024 were enrolled.The median age of the patients was 60 years.The median PFS of all patients was 7.6 months(95%CI,5.9-9.2).Cox regression analysis identified lung metastasis and a switch to endocrine therapy following prior CDK4/6i therapy as independent predictive factors for PFS.Notably,patients who previously received abemaciclib and switched to palbociclib upon disease progression had a median PFS of 10.7 months.The strategy of transitioning to chemotherapy after progression on a prior CDK4/6i,then to a subsequent CDK4/6i merits further investigation.Hematologic toxicity was the most common grade≥3 AEs.No instances of fatal safety events were observed.Conclusions:Cross-line CDK4/6i therapy is associated with significant clinical benefits and manageable safety profiles in patients with HR+/HER2–ABC,which underscores cross-line CDK4/6i therapy potential as an effective treatment strategy.

CDK4/6 inhibitors in the treatment of hormone receptor-positive, HER2-negative advanced breast cancer

Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no response to ET due to primary or acquired ET resistance.In this background,many agents have been studied to overcome ET resistance and of which the important agents are cyclin-dependent kinase 4/6(CDK4/6)inhibitors.The prognosis of advanced breast cancer has been improved by combing ET with CDK4/6 inhibitors.In this review,we mainly focused on the CDK4/6 inhibitors in the treatment of HR-positive,HER2-negative advanced breast cancer and discussed the action mechanisms of CDK4/6 inhibitors alone or combined with ET.We also summarized several molecular features that would predict response or resistance to CDK4/6 inhibitors.In addition,we put forward possible strategies to overcome CDK4/6 inhibitor resistance according to the latest research.

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world data from this center demonstrate a negative, non-statistically significant impact of PPi treatment on survival outcomes, in patients treated with Ci for HR+HER2-ABC.

A Systematic Review of Economic Evaluation of CDK4/6 Inhibitors in HR+/HER2-Advanced Breast Cancer

Objective To review the domestic and foreign economic studies on CDK4/6 inhibitors in first-line or second-line treatment of HR+/HER2-advanced breast cancer,and to analyze the main methodologies and research results.Methods Systematic literature review was used to search PubMed,EMBASE,Cochrane Library,CNKI,CBM,and Wanfang database.The incremental cost-effectiveness ratio was taken as the main outcome index,and all pharmacoeconomic evaluations with CDK4/6 inhibitors as intervention measures were included,such as Palbociclib,Ribociclib,and Abemaciclib.According to the Quality of Health Economic Studies Instrument,the quality of the included articles was evaluated,and then the included literature was analyzed.Results and Conclusion A total of 16 pharmacoeconomic evaluation studies were included,mainly from the perspective of national healthcare systems or third-party payers.Only 2 studies focused on second-line treatment,and the remaining treatment levels were first-line treatment.In terms of model structure,7 studies adopted the Markov model,6 studies adopted the PSM model,and 3 studies adopted the DES model.The basic analysis results showed that CDK4/6 inhibitor combined with endocrine regimen was not economical compared with endocrine alone regimen when the threshold was the conventional willingness to pay(WTP)value of each country.The uncertainty analysis included deterministic sensitivity analysis and probability sensitivity analysis.The included studies are all Cost-Utility Analysis with high-quality evaluation,which can provide evidence support for health-related decision-makers in decision-making.It can also provide methodological reference for the economic evaluation of other targeted drugs.

Progress of CDK4/6 inhibitors in the treatment of malignant tumors

CDK4/6 inhibitor acts on cell cycle.It can be used alone or in combination to treat lung cancer,liver cancer,pancreatic cancer and other cancers by restoring normal cell cycle,triggering anti-tumor immunity and changing the microenvironment of tumors.It has a certain therapeutic effect,and has a certain inhibitory effect on the proliferation and development of malignant tumors.The combination of other antineoplastic drugs can effectively reduce the emergence of drug resistance and synergistically enhance the clinical efficacy.This article reviews the related research results of CDK4/6 inhibitors,as well as the literature,and summarizes the mechanism and clinical application of CDK4/6 inhibitors.Cyclin dependent kinase(CDK)is a group of serine/threonine protein kinases.The chemical action of CDK on serine/threonine protein is the key to driving cell cycle.The typical biological feature of cancer is cell cycle disorder.As the engine of cell cycle,CDK and its regulators play an important role in tumorigenesis and development.In modern times,cancer has gained a deeper understanding at the level of biomolecule.For cell receptors,more and more drugs are used for key genes.The new generation of CDK4/6 inhibitors cut into the cell cycle to treat malignant tumors,prevent cells from G1 phase to S phase.They have good clinical efficacy for ER+breast cancer patients.They are also used in clinical trials of lung cancer,melanoma and other malignant tumors to treat malignant tumors.Therapy provides a new way.

Beyond clinical trials:CDK4/6 inhibitor efficacy predictors and nomogram model from real‐world evidence in metastatic breast cancer

Background:CDK4/6 inhibitors(CDK4/6i)have shown promising results in the treatment of hormone receptor‐positive(HR+)metastatic breast cancer(MBC)when combined with endocrine therapy(ET).It is crucial to evaluate the actual effectiveness and safety of CDK4/6i in clinical practice,as well as to analyze the factors that can predict their outcomes.Methods:Patients with HR+MBC who received CDK4/6i‐based therapy between May 2016 and May 2023 at Hunan Cancer Hospital were evaluated for progression‐free survival(PFS).Adverse reactions were assessed based on the National Cancer Institute Common Toxicity Criteria(version 5.0).Results:This study included 344 patients,with a median PFS(mPFS)of 12.8 months(range:10.4–15.2 months).After adjustment,Cox multivariate regression analysis revealed that visceral metastasis(specifically liver and brain metastases),Eastern Cooperative Oncology Group Performance Status(ECOG PS)≥1,estrogen receptor≤80%,progesterone receptor≤10%,Ki‐67>30%,and treatment in later stages were significant factors associated with reduced PFS.Based on this,we created a prognostic nomogram and validated its performance,obtaining a C‐index of 0.714(95%confidence interval:0.640–0.787)as well as reliable calibration and clinical impact.The mPFS of CDK4/6i rechallenge was 7.7 months;for patients who initially discontinued CDK4/6i for reasons other than disease progression,CDK4/6i rechallenge still provided a mPFS of 11.4 months.The tolerability and safety of combining CDK4/6is with ET were manageable.Adverse events led to treatment discontinuation in 3.8%of patients.Neutropenia(29.1%),leukopenia(13.7%),and anemia(4.1%)were the primary grade 3/4 adverse reactions.Conclusions:This real‐world study highlights the ample efficacy and reasonable safety of combined CDK4/6i and ET in patients with HR+MBC.Individualized treatment decisions and ongoing safety monitoring are important to optimize the therapeutic benefit of CDK4/6i treatment.

LA-D-B1,a novel Abemaciclib derivative,exerts anti-breast cancer effects through CDK4/6

Background:Regulatory proteins involved in human cellular division and proliferation,cyclin-dependent kinases 4 and 6(CDK4/6)are overexpressed in numerous cancers,including triple-negative breast cancer(TNBC).TNBC is a common pathological subtype of breast cancer that is prone to recurrence and metastasis,and has a single treatment method.As one of the CDK4/6 inhibitors,abemaciclib can effectively inhibit the growth of breast tumors.In this study,we synthesized LA-D-B1,a derivative of Abemaciclib,and investigated its anti-tumor effects in breast cancer.Methods:Cellular viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Cell cloning and migration abilities were determined by colony formation assay and wound healing assay.Cell invasion abilities and adhesion were determined by cell invasion assay and cell adhesion assay.The impact of compound LA-D-B1 on cell proliferation and the cell cycle was analyzed through Western blotting,which quantified the levels of proteins associated with the cyclin-dependent kinase(CDK)4/6-cyclin D-Rb-E2F pathway.The in vivo anti-tumor activity of compound LA-D-B1 was investigated using a chick chorioallantoic membrane(CAM)model.Results:The study demonstrated that LA-D-B1 effectively suppressed breast cancer cell proliferation,induced apoptosis,and caused cell cycle arrest.Furthermore,LA-D-B1 reduced the expression of key proteins in the CDK4/6-cyclin D-Rb-E2F pathway,including CDK4,CDK6 and E2F1.The results also indicated significant antitumor activity of LA-D-B1 in a transplanted tumor model.Conclusion:In this study,LA-D-B1 demonstrated a potent anti-tumor effect by effectively suppressing cell proliferation and inhibiting cell cycle progression in breast cancer.These findings highlight the potential of LA-D-B1 as a valuable compound for enhancing therapeutic outcomes and controlling the progression of breast cancer.

CDK4/6抑制剂联合内分泌、靶向一线治疗HR+/HER2+晚期乳腺癌疗效分析

目前乳腺癌发病率位居女性恶性肿瘤第一位,且乳腺癌出现年轻化趋势,年轻乳腺癌患者,恶性程度高,进展迅速,预后相对较差。本文通过总结1例HR+/HER2+乳腺癌患者晚期一线应用CDK4/6抑制剂联合内分泌联合靶向治疗,并取得相对较好的临床疗效,生活质量得到极大改善,为更多年轻晚期乳腺癌患者的临床治疗提供新的治疗方案及思路。

CDK4/6抑制剂在HR^(+)晚期乳腺癌治疗中的耐药机制及进展后治疗策略

细胞周期蛋白依赖性激酶4/6(CDK4/6)抑制剂联合内分泌治疗已成为激素受体阳性(HR^(+))、人类表皮生长因子受体-2阴性(HER2^(-))乳腺癌患者的晚期一线及二线标准治疗方案。尽管CDK4/6抑制剂可实现有效的疾病控制,但对于晚期乳腺癌患者最终仍会因耐药出现疾病进展。目前CDK4/6抑制剂相关耐药机制尚不完全清楚,同时治疗失败后的最佳治疗策略仍是一个亟待解决的问题。本文就CDK4/6抑制剂的潜在耐药机制和后续治疗策略的最新研究进展做一综述。

Overexpressed Cyclin D1 and CDK4 proteins are responsible for the resistance to CDK4/6 inhibitor in breast cancer that can be reversed by PI3K/mTOR inhibitors

CDK4/6 inhibitors are the standard treatment in advanced HR+/HER2-breast cancer patients.Nevertheless,the resistance to CDK4/6 inhibitors is inevitable and the strategies to overcome resistance are of great interest.Here,we show that the palbociclibresistant breast cancer cells expressed significantly higher levels of Cyclin D1 and CDK4 proteins because of upregulated protein synthesis.Silencing Cyclin D1 or CDK4 led to cell cycle arrest while silencing Cyclin E1 or CDK2 restored the sensitivity to palbociclib.Furthermore,PI3K/mTOR pathway was hyper-activated in palbociclib-resistant cells,leading to more phosphorylated 4E-BP1 and higher levels of Cyclin D1 and CDK4 translation.Targeting PI3K/mTOR pathway with a specific PI3Kαinhibitor(BYL719)or an mTOR inhibitor(everolimus)reduced the protein levels of Cyclin D1 and CDK4,and restored the sensitivity to palbociclib.The tumor samples expressed significantly higher levels of Cyclin D1,CDK4,p-AKT and p-4E-BP1 after progression on palbociclib treatment.In conclusion,our findings suggest that overexpressed Cyclin D1 and CDK4 proteins lead to the resistance to CDK4/6 inhibitor and PI3K/mTOR inhibitors are able to restore the sensitivity to CDK4/6 inhibitors,which provides the biomarker and rationale for the combinational use of CDK4/6 inhibitors and PI3K/mTOR inhibitors after CDK4/6 inhibitor resistance in breast cancer.

FSIP1 enhances the therapeutic sensitivity to CDK4/6 inhibitors in triple-negative breast cancer patients by activating the Nanog pathway

CDK4/6 inhibitors are routinely recommended agents for the treatment of advanced HR+HER2-breast cancer.However,their therapeutic effectiveness in triple-negative breast cancer(TNBC)remains controversial.Here,we observed that the expression level of fibrous sheath interacting protein 1(FSIP1)could predict the treatment response of TNBC to CDK4/6 inhibitors.High FSIP1 expression level was related to a poor prognosis in TNBC,which was associated with the ability of FSIP1 to promote tumor cell proliferation.FSIP1 downregulation led to slowed tumor growth and reduced lung metastasis in TNBC.FSIP1knockout caused cell cycle arrest at the G0/G1 phase and reduced treatment sensitivity to CDK4/6 inhibitors by inactivating the Nanog/CCND1/CDK4/6 pathway.FSIP1 could form a complex with Nanog,protecting it from ubiquitination and degradation,which may facilitate the rapid cell cycle transition from G0/G1 to S phase and exhibit enhanced sensitivity to CDK4/6 inhibitors.Our findings suggest that TNBC patients with high FSIP1 expression levels may be suitable candidates for CDK4/6 inhibitor treatment.

CDK4/6抑制剂联合芳香化酶抑制剂类药物用于HR^(+)/HER2^(-)晚期乳腺癌一线治疗的临床综合评价

目的 比较CDK4/6抑制剂哌柏西利、瑞博西利、阿贝西利联合芳香化酶抑制剂(AI)类药物一线治疗HR^(+)/HER2^(-)晚期乳腺癌的临床综合价值,以期为临床用药实践提供参考。方法根据《抗肿瘤药品临床综合评价技术指南(2022年版试行)》构建CDK4/6抑制剂联合AI类药物用于HR^(+)/HER2^(-)晚期乳腺癌一线治疗的临床综合评价指标体系,并通过网状meta分析、专家咨询等方法进行各维度的临床综合评价。结果 在安全性方面,哌柏西利、瑞博西利和阿贝西利联合AI的总体不良反应发生率相似,但阿贝西利联合AI的3级以上不良反应发生率最低。在有效性方面,三种治疗方案在无进展生存期和总生存期方面彼此间差异无统计学意义。在经济性方面,阿贝西利的治疗所需费用略低于哌柏西利。在创新性方面,阿贝西利的用药方式和作用靶点更多样,哌柏西利的专利价值最低但可促进技术国产化。在适宜性方面,阿贝西利适应证和医保目录涵盖范围更广,但哌柏西利的药品剂型更多样,瑞博西利适宜性相对较差。在可及性方面,阿贝西利的可获得性和可负担性均优于哌柏西利,瑞博西利尚未在中国上市,可及性最低。结论 综合来看,阿贝西利在6个维度均表现良好,其临床综合价值高于哌柏西利和瑞博西利。建议临床应用时结合患者基本情况选择适当的药物。

CDK4/6抑制剂联合非甾体芳香化酶抑制剂治疗晚期乳腺癌有效性和安全性的Meta分析

目的 系统评价细胞周期蛋白依赖性激酶(cyclin dependent kinase, CDK)4/6抑制剂联合非甾体芳香化酶抑制剂治疗晚期乳腺癌的有效性与安全性。方法 计算机检索Pubmed、Cochrane图书馆、EMbase、中国知网、万方数据库和维普数据库,以收集CDK4/6抑制剂联合非甾体芳香化酶抑制剂治疗晚期乳腺癌的相关文献,检索时限均从建库至2023年02月01日。由2位研究者背对背筛选文献、提取数据并进行偏倚风险评估后,使用Rev Man 5.3软件进行Meta分析。结果 纳入Meta分析的文献有8篇,共2 706例患者。Meta分析结果显示,与安慰剂联合非甾体芳香化酶抑制剂治疗相比,CDK4/6抑制剂联合非甾体芳香化酶抑制剂治疗可延长晚期乳腺癌患者无进展生存期(RR=0.58,95%CI:0.51~0.64,P<0.001)、提高客观缓解率(RR=1.34,95%CI:1.20~1.48,P<0.001)和临床获益率(RR=1.11,95%CI:1.06~1.16,P<0.001)。在安全性方面,CDK4/6抑制剂联合非甾体芳香化酶抑制剂治疗患者的3~4级不良反应发生率较高(RR=2.63,95%CI:2.17~3.19,P<0.001)。其中,试验组白细胞减少、嗜中性粒细胞减少、贫血、乏力、呕吐及腹泻等不良反应发生率高于对照组(P<0.05);2组便秘和头疼的发生率差异无统计学意义(P>0.05)。结论 CDK4/6抑制剂联合非甾体芳香化酶抑制剂治疗可延长晚期乳腺癌患者的无进展生存期、提高客观缓解率和临床获益率,但该方案可能导致3~4级不良反应发生率升高。

CDK4/6抑制剂阿贝西利联合顺铂对人胃癌细胞生物学行为的影响

目的:探讨CDK4和CDK6(CDK4/6)抑制剂阿贝西利与顺铂联合作用对人胃癌细胞生物学行为的影响。方法:利用生物信息学网站UALCAN在线分析TCGA数据库,获取人胃癌组织与正常胃组织中CDK4/6基因表达情况;培养人胃癌细胞SGC-7901,采用Western blot检测细胞中CDK4/6蛋白的表达。利用细胞增殖实验检测顺铂和阿贝西利单独作用24 h的半数抑制浓度,然后将细胞分为空白对照组、0.5μg/mL顺铂组、10μmol/L阿贝西利组、10μmol/L阿贝西利和0.5μg/mL顺铂联合组,分别作用24、48、72 h后采用CCK-8法、流式细胞术、划痕实验、Transwell实验检测各组中SGC-7901细胞的增殖、凋亡、迁移和侵袭情况。结果:生物信息学分析表明CDK4/6蛋白在人胃癌组织中的表达显著高于正常胃组织(P<0.05)。Western blot实验显示,与对照组相比,人胃癌细胞SGC-7901中CDK4/6蛋白的表达水平均显著升高(P<0.05)。CCK-8实验结果显示最接近IC50值的顺铂浓度为0.5μg/mL,阿贝西利浓度为10μmol/L,故后续选择此浓度进行试验。与空白对照组、顺铂组、阿贝西利单独组相比,阿贝西利联合顺铂组的细胞增殖抑制率明显增强且具有时间依赖性(r=0.949,P<0.01),细胞凋亡率亦显著升高(P<0.01),迁移和侵袭能力均显著减弱(P<0.01)。结论:CDK4/6在人胃癌组织和细胞中的表达均显著升高,CDK4/6抑制剂阿贝西利联合顺铂显示出协同作用,可显著抑制人胃癌细胞的增殖、迁移和侵袭,并促进其凋亡。

Endocrine therapy in metastatic breast cancer-more than just CDK4/6 inhibitors

Advanced hormone receptor-positive breast cancer is one of the women’s most common malignant diseases and remains incurable despite recent therapeutic innovations.The dependence of hormone receptor-positive breast cancer on hormonal growth signals offers the possibility of inhibiting this signaling pathway using anti-hormonal therapy.Nevertheless,the development of resistance to antitumoral drugs remains a challenge.Molecularly-targeted substances significantly improve survival rates and(as in the case of cyclin-dependent kinase 4 and 6 inhibitors)are widely used in clinical practice and enhance endocrine therapy’s efficacy.Agents such as everolimus,alpelisib,and capivasertib target the phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin pathway,which is a promising approach to overcoming endocrine resistance.Novel therapies are being studied in numerous trials,and some already show significant benefits in survival rates.The development of new therapies to avert endocrine resistance is an urgent challenge in modern medicine.The following review will examine some promising therapeutic approaches.

CDK4/6抑制剂联合氟维司群二线治疗Luminal型晚期乳腺癌的Meta分析

目的:对CDK4/6抑制剂联合氟维司群二线治疗Luminal型乳腺癌进行有效性及安全性评价。方法:根据检索式从Embase、PubMed、Web of Science、中国知网、万方医学网和维普网等数据库中网络检索与CDK4/6抑制剂联合氟维司群治疗Luminal型内分泌耐药乳腺癌有关的随机对照试验并进行筛选,使用Stata17.0和RevMan5.4软件对纳入的RCT进行评价及Meta分析。结果:纳入8篇文献,共5项RCT,纳入研究对象2466例。Meta分析结果显示,CDK4/6抑制剂联合氟维司群与单纯应用氟维司群相比可延长患者的无进展生存期[HR=0.51,95%CI(0.46,0.56),P<0.00001]及总生存期[HR=0.73,95%CI(0.65,0.83),P<0.00001],两组间差异具有统计学意义(P<0.05)。然而CDK4/6抑制剂联合氟维司群治疗时更容易造成中性粒细胞减少、白细胞计数下降、贫血、血小板下降及疲乏等不良反应,两组间差异具有统计学意义(P<0.05)。结论:与氟维司群加安慰剂相比,CDK4/6抑制剂联合氟维司群显著延长Luminal型乳腺癌患者的PFS和OS。用药过程中常见的不良反应是血液系统的中性粒细胞减少、白细胞计数下降、贫血、血小板下降及疲乏等,且3级及以上不良反应发生率可控,在临床治疗上获益较大。

Liquid biopsies to predict CDK4/6 inhibitor efficacy and resistance in breast cancer

Cyclin-dependent kinase 4 and 6(CDK4/6)inhibitors combined with endocrine therapy have transformed the treatment of estrogen receptor-positive(ER+)and human epidermal growth factor receptor 2 negative(HER2-)metastatic breast cancer.However,some patients do not respond to this treatment,and patients inevitably develop resistance,such that novel biomarkers are needed to predict primary resistance,monitor treatment response for acquired resistance,and personalize treatment strategies.Circumventing the spatial and temporal limitations of tissue biopsy,newly developed liquid biopsy approaches have the potential to uncover biomarkers that can predict CDK4/6 inhibitor efficacy and resistance in breast cancer patients through a simple blood test.Studies on circulating tumor DNA(ctDNA)-based liquid biopsy biomarkers of CDK4/6 inhibitor resistance have focused primarily on genomic alterations and have failed thus far to identify clear and clinically validated predictive biomarkers,but emerging epigenetic ctDNA methodologies hold promise for further discovery.The present review outlines recent advances and future directions in ctDNA-based biomarkers of CDK4/6 inhibitor treatment response.

CDK4/6抑制剂敏感性及耐药性生物标志物的研究进展

根据世界卫生组织国际癌症研究机构数据显示,2020年全球总计新增1930万癌症病例,女性乳腺癌已超过肺癌,成为最常见的癌症,新增病例达230万。其中激素受体阳性(HR+)乳腺癌占据了主要比例,传统治疗方式为内分泌治疗(ET),然而ET治疗产生耐药性是不可避免的。直至2015年全球首个选择性CDK4/6抑制剂哌柏西利获得批准上市,CDK4/6抑制剂与ET的联合作用才得以克服对ET的耐药性,显著改善患者的生存时间和生活质量,使得晚期HR+乳腺癌的治疗发生了革命性变化。然而,由于固有性和获得性耐药的存在,仍有部分患者对CDK4/6抑制剂治疗无反应或治疗后不久产生耐药。受限于对药物耐药机制的了解有限,无法预测患者用药的疗效及耐药性。因此,迫切需要可靠的预测性生物标志物来指导患者用药的选择和新型药物组合的研发。本文就目前有关CDK4/6抑制剂的预测性生物标志物的最新进展进行综述。

CDK4/6抑制剂一线治疗HR+/HER2-晚期乳腺癌的快速卫生技术评估

目的对细胞周期依赖性激酶4/6(CDK4/6)抑制剂一线治疗激素受体阳性(HR+)及人表皮生长因子受体2阴性(HER2-)晚期乳腺癌的有效性、安全性和经济性进行快速卫生技术评估,为临床和决策者提供参考。方法计算机检索PubMed、Cochrane Library、Embase、CNKI、WanFang Data、VIP数据库和卫生技术评估(health technology assessment,HTA)机构官方网站,搜集CDK4/6抑制剂治疗HR+/HER2-晚期乳腺癌的文献及报告,检索时限均从建库至2023年12月31日。由2名研究者独立筛选文献、提取资料并评价纳入研究的质量,对结果进行定性描述与分析。结果共纳入33篇文献,包括系统评价/Meta分析9篇、经济学研究15篇及HTA报告9篇。有效性方面,与单纯内分泌治疗相比,CDK4/6抑制剂联合内分泌治疗可显著改善患者的无疾病进展生存期(PFS)和总生存期(OS)(P<0.05),但哌柏西利、阿贝西利和瑞波西利3种CDK4/6抑制剂间的疗效差异无统计学意义(P>0.05)。安全性方面,与单纯内分泌治疗相比,CDK4/6抑制剂联合内分泌治疗的患者不良反应发生率更高(P<0.05);不同CDK4/6抑制剂间不良反应发生率有差异,哌柏西利血液学不良反应发生率更高(P<0.05),阿贝西利更易导致腹泻等胃肠道不良反应(P<0.05)。药物经济学研究中,由于不同国家的医疗成本、分析角度、意愿支付阈值、研究时间等不同,研究结果差异性较大。结论CDK4/6抑制剂在一线治疗HR+/HER2-晚期乳腺癌患者中疗效类似,但安全性和经济性等方面存在一定差异。

SENEX-mediated CDK4/6 inhibition promotes senescence and confers apoptosis resistance in B-cell non-Hodgkin lymphoma

Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a crucial mechanism contributing to tumor drug resistance.Here,we analyzed SENEX/Rho GTPase Activating Protein 18(ARHGAP18)expression and prognostic significance in doxorubicin-induced B-NHL-TIS model and r/r B-NHL patients,investigating its target in B-NHL cell senescence and the effect of combining specific inhibitors on apoptosis resistance in B-NHL-TIS cells.Methods:Raji cells were transfected with the human SENEX shRNA recombinant lentiviral vector(Sh-SENEX)and the empty vector negative(NC)to construct a stable transfection cell line with knockdown of SENEX.Effect of SENEX-silencing on B-NHL-TIS formation,cell function and cell cycle-related pathways was analyzed.Using doxorubicin(DOX)-inducible senescent B-NHL cells combined with the specific cyclin dependent kinase 4/6(CDK4/6)inhibitor Palbociclib to observe that blocking CDK4/6 effects on TIS formation.SENEX expression of 21 B-NHL patients and 8 healthy controls were analyzed by qRT-PCR,and the correlation between its expression and clinical indicators were evaluated.Results:The downregulation of SENEX expression promotes G1-S phase transition and apoptosis while inhibiting cell proliferation,collectively suppressing the formation of TIS in B-NHL.Blockade of CDK4/6 promotes the DOX-induced G1 phase arrest to enhance TIS formation in B-NHL cells which can reverse the regulatory effect of silencing SENEX on B-NHL cell cycle regulation and senescence.The expression levels of SENEX were notably elevated in B-NHL patients compared to healthy controls,and Elevated expression levels of SENEX were associated with poor prognosis of B-NHL patients.Conclusions:SENEX enhances apoptosis resistance in B-NHL by inhibiting CDK4/6,thereby preventing G1-S phase transition and promoting TIS formation.