Ribociclib en mujeres pre/perimenopáusicas con el diagnóstico de cáncer de mama RH(+) HER2(-) metastásico sin crisis visceral, ECOG 0-1 y que no hayan recibido terapia endocrina antihormonal previamente / Ribociclib in pre/perimenopausal women with a diagnosis of RH(+) HER2(-) metastatic breast cancer without visceral crisis, ECOG 0-1 and who have not previously received antihormonal endocrine therapy

INTRODUCCIÓN: Cuadro clínico: El cáncer de mama es la primera causa de muerte por neoplasia maligna en mujeres. A nivel mundial, en el 2022, se produjeron 2.3 millones de casos nuevos y 666 103 muertes por cáncer de mama. En Latinoamérica, se estimó que la tasa estandarizada de incidencia es de 48.7 casos nuevos por cada 100 000 habitantes. Sobre la carga de enfermedad, los reportes nacionales informan que el cáncer de mama tiene una incidencia de 37.6 casos nuevos por cada 100 000 habitantes y produjo 39 139 años de vida saludables perdidos (AVISA) así como 9 049 años vividos por discapacidad (AVD). Según los subtipos moleculares, el más frecuente es el subtipo RH(+) y HER2(-), representando el 58.2% de casos. No se dispone de datos específicos epidemiológicos en el Perú para mujeres pre/perimenopáusicas con cáncer de mama RH (+) HER2(-) que han fallado a primera línea de terapia endocrina. Tecnología sanitária: El ribociclib es un inhibidor de la cinasa 4 dependiente de las ciclinas (CDK4) y la cinasa 6 dependiente de ciclinas (CDK6). Estas cinasas son proteínas que inducen el crecimiento tumoral. En Perú, el ribociclib cuenta con registro sanitario (N° EE10867), otorgado por la Dirección General de Medicamentos Insumos y Drogas (DIGEMID). Actualmente, ribociclib no forma parte del Petitorio Nacional Único de Medicamentos Esenciales (PNUME). Justificación de la evaluación: Este informe de ETS-EMC se realizó a solicitud de Comité Farmacoterapéutico (CFT) del Instituto Regional de Enfermedades Neoplásicas del Sur (IREN SUR) mediante Oficio N°475- 2023-GRA/GRS/GR-IREN-SUR, en e

Palbociclib en mujeres postmenopáusicas con cáncer de mama avanzado o metastásico; positivo para el receptor de hormonas (HR+); negativo para el receptor 2 de factor de crecimiento epidérmico humano (HER2-), y progresión de la enfermedad luego de tratamiento endocrino / Palbociclib in postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer and disease progression after endocrine therapy

INTRODUCCIÓN: Cuadro clínico: El cáncer de mama ocurre cuando existe un crecimiento desregulado de células en cualquier componente de la mama. La mayoría de cánceres de mama son de tipo invasivo, lo que significa que se extienden más allá de los ductos y glándulas a tejidos adyacentes y nódulos linfáticos. En Perú, en el año 2022 se reportaron 7,797 casos nuevos de cáncer de mama y 1,951 muertes en pacientes con cáncer de mama. Respecto a la carga de enfermedad por cáncer de mama en el Perú en el año 2019, por cada 1,000 habitantes, el cáncer de mama causó 39,139 años de vida saludable perdidos; 9,049 años de vida vividos con discapacidad y 30,091 años de vida perdidos por muerte prematura. Tecnología sanitária: El palbociclib, es un inhibidor de las cinasas dependientes de ciclina 4 (CDK4) y 6 (CDK6); controlando así la multiplicación celular. El fulvestrant es un antagonista competitivo de la unión de estrógenos al receptor de estrógenos; bloqueando así las acciones tróficas de los estrógenos. La dosis recomendada de la combinación palbociclib más fulvestrant (PAL + FUL) es 125 mg de palbociclib una vez al día durante 21 días consecutivos, seguidos de 7 días sin tratamiento, lo que completa el ciclo de 28 días; y 500 mg fulvestrant en los días 1, 15, 29, y luego una vez al mes. Justificación de la evaluación: Este documento técnico se realiza en base al envío de una solicitud del comité farmacoterapéutico (CFT) del Hospital Nacional Daniel Alcides Carrión, en el marco del numeral 13.5 del reglamento de la Ley Nacional de Cáncer y de la décimo sexta disposición complementaria final del reglamento de la Ley Nº 31336, Ley Nacional de Cáncer aprobado mediante Decreto Supremo Nº 004-2022-SA. OBJETIVOS: Identificar, evaluar y sintetizar la mejor evidencia disponible para informar los criterios de carga de enfermedad, efectos deseables, efectos indeseables, certeza de la evidencia, balance de efectos, nivel de innovación, equidad, recursos necesarios y costo-efectividad para la evaluación multicriterio de la tecnología sanitaria PAL+ FUL en mujeres postmenopáusicas con cáncer de mama avanzado o metastásico; positivo para el receptor de hormonas (HR+); negativo para el receptor 2 de factor de crecimiento epidérmico humano (HER2-), y progresión de la enfermedad luego de tratamiento endocrino. Reportar la valoración de los criterios y la recomendación efectuada por el Grupo de trabajo de la ETS-EMC respecto al uso de PAL + FUL en mujeres postmenopáusicas con cáncer de mama avanzado o metastásico; positivo para el receptor de hormonas (HR+); negativo para el receptor 2 de factor de crecimiento epidérmico humano (HER2-), y progresión de la enfermedad luego de tratamiento endocrino. METODOLOGÍA: Pregunta clínica y graduación de desenlaces: Se validó la pregunta clínica y graduó la importancia de los desenlaces incluidos con participación de profesionales de la institución solicitante y metodólogos a cargo de la presente ETS-EMC. Efectos deseables e indeseables (eficacia y seguridad): Se realizó una búsqueda bibliográfica en Medline (vía PubMed), The Cochrane Library (CENTRAL) y LILACS (Biblioteca virtual de Salud) desde la fecha de inserción de cada base de datos hasta el 24 de enero del 2024; la cual fue actualizada con fecha 16 de febrero de 2024. El proceso de selección de estudios fue desarrollado por un solo revisor y conducido en la plataforma electrónica Rayyan. Se evalúo el riesgo de sesgo mediante la herramienta Risk of Bias (RoB) de la colaboración Cochrane. La certeza de la evidencia fue evaluada mediante el enfoque Grading of Recommendations Assessment, Development and Evaluation (GRADE). Carga de enfermedad, necesidad clínica y equidade: Para estimar la carga de enfermedad, se revisó el Observatorio Global del Cáncer (GLOBOCAN), y el reporte epidemiológico del Centro Nacional de Epidemiología, Prevención y Control de Enfermedades (CDC) del Perú. Para evaluar la necesidad clínica, se revisó el Petitorio Nacional Único de Medicamentos Esenciales (PNUME) y la lista complementaria de medicamentos para el tratamiento de enfermedades neoplásicas. Para informar el impacto sobre la equidad en salud, se realizó una búsqueda de estudios realizados en América Latina publicados en Medline/PubMed hasta el 24 de enero del 2024; la cual fue actualizada con fecha 16 de febrero de 2024. Recursos necesarios (costos): Se desarrolló un estudio de costo de enfermedad desde la perspectiva del financiador incluyendo costos de procedimientos médicos, medicamentos e insumos. Se empleó un modelo estático con horizonte temporal de un año, con estimación de costos bottom-up y enfoque epidemiológico de prevalencia. Se definieron tres variantes clínicas de acuerdo a la pregunta PICO. Costo-efectividad: Se realizó una búsqueda en el repositorio de evaluaciones económicas de la Dirección General de Medicamentos, Insumos y Drogas (DIGEMID), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA) y las páginas institucionales de organismos evaluadores de tecnología sanitaria de Colombia, Brasil, Argentina y Chile. Adicionalmente, se elaboró una estrategia de búsqueda en Medline/PubMed. La fecha de búsqueda fue el 24 de enero del 2024; la cual fue actualizada con fecha 16 de febrero de 2024. Elaboración de la recomendación clínica: Se convocó a un Grupo de trabajo conformado por representantes de la Red Oncológica Nacional (RON), la Dirección General de Aseguramiento e Intercambio Prestacional (DGAIN), el Fondo Intangible Solidario de Salud (FISAL), la Dirección General de Medicamentos, Insumos y Drogas (DIGEMID), y representantes de la institución solicitante (ie. Hospital Nacional Daniel Alcides Carrión). El equipo metodológico del Centro de Evaluación de Tecnología en Salud del Instituto Nacional de Salud (CETS/INS) presentó la evidencia para la evaluación de diez criterios: carga de enfermedad, necesidad clínica, efectos deseables (eficacia), efectos indeseables (seguridad), balance de efectos, certeza de evidencia, nivel de innovación, equidad, recursos necesarios y costo-efectividad. RESULTADOS: Pregunta clínica: La pregunta PICO formulada fue la siguiente, P: Mujeres postmenopáusicas con cáncer de mama avanzado o metastásico; positivo para el receptor de hormonas (HR+); negativo para el receptor 2 de factor de crecimiento epidérmico humano (HER2-), y progresión de la enfermedad luego de tratamiento endocrino; I: Palbociclib + fulvestrant.; C: Ribociclib + fulvestrant; O: Críticos: sobrevida global, calidad de vida, eventos adversos serios. Valoración de los criterios de decisión: Necesidad clínica: El grupo de trabajo concluyó que la población de pacientes descrita en la PICO cuenta con alternativas de tratamiento disponibles para el tratamiento; por lo tanto, no existe necesidad clínica. Efectos deseables e indeseables: Solo se identificó un estudio que cumplió con los criterios de elegibilidad (Rugo et al. 2021). La evidencia mostró que no había diferencia estadísticamente significativa entre PAL + FUL y RIB + FUL en términos de sobrevida global (diferencia en el riesgo de muerte de 3.8 muertes menos por cada 1000 personas; IC 95%: 20.4 muertes menos a 17.4 muertes más). Adicionalmente, la certeza de evidencia fue calificada como muy baja. No se identificaron estudios que comparen las tecnologías sanitarias PAL + FUL versus RIB + FUL en términos de calidad de vida e incidencia de eventos adversos serios en la población descrita en la PICO. Balance de efectos deseables e indeseables: En base a lo anterior, el grupo de trabajo concluyó por mayoría que el balance entre efectos deseables e indeseables no favorece a la intervención ni al comparador. Certeza global de la evidencia: Para valorar la certeza de la evidencia global se toma en cuenta la menor certeza de la evidencia de los desenlaces críticos, por ende, la certeza de la evidencia global fue considerada muy baja. Nivel de innovación: Se considera una tecnología sanitaria como innovadora si genera una mejora significativa en los desenlaces relevantes para la salud de los pacientes, en términos de mayor eficacia o seguridad en comparación con el mejor tratamiento disponible, basado en evidencia con certeza al menos moderada. La decisión del Grupo de trabajo fue considerar a PAL + FUL como una tecnología no innovadora debido a que la certeza de la evidencia para los desenlaces de beneficio fue muy baja. Equidad: No se encontró evidencia sobre el impacto que el uso de PAL + FUL podría tener sobre la equidad en salud. El grupo de trabajo tampoco identificó que el uso de PAL + FUL, en lugar de RIB + FUL, tuviese algún impacto sobre la equidad en salud. Por lo tanto, el grupo de trabajo concluyó que el tratamiento con PAL + FUL probablemente no tenga impacto en la equidad. Recursos necesarios (costos): El análisis de costos mostró que el uso de PAL + FUL en la población descrita en la PICO genera un incremento en los costos de entre 3.641.63 y 5.609.47 soles al año por cada paciente tratado según la variante clínica de presentación. Tomando en cuenta dicha información, el grupo de trabajo concluyó que el uso de PAL + FUL, en lugar de RIB + FUL genera costos y ahorros mínimos. RECOMENDACIÓN FORMULADA POR EL GRUPO DE TRABAJO: Considerando todo lo anteriormente expuesto, el grupo de trabajo formuló la siguiente recomendación clínica: En mujeres postmenopáusicas con cáncer de mama avanzado o metastásico; positivo para el receptor de hormonas; negativo para el receptor 2 de factor de crecimiento epidérmico humano, y progresión de la enfermedad luego de tratamiento endocrino, el grupo de trabajo no recomienda el uso de palbociclib más fulvestrant (recomendación en contra basada en una certeza global de la evidencia muy baja).

Ribociclib en mujeres post menopaúsicas o varones con el diagnóstico de cáncer de mama receptor hormonal positivo (+), HER2 negativo (-), en contexto de segunda línea / Ribociclib in postmenopausal women or men diagnosed with hormone receptor positive (+), HER2 negative (-) breast cancer, in the second-line setting

INTRODUCCIÓN: Cuadro clínico: El cáncer de mama ocurre cuando existe un crecimiento desregulado de células en cualquier componentede la mama. La mayoría de los cánceres de mama son de tipo invasivo, lo que significa que se extiendenmás allá de los ductos y glándulas a tejidos adyacentes y nódulos linfáticos. En Perú, en el año 2022 sereportaron 7,797 casos nuevos de cáncer de mama y 1,951 muertes en pacientes con cáncer de mama. Respecto a la carga de enfermedad por cáncer de mama en el Perú en el año 2019, por cada 1,000 habitantes, el cáncer de mama causó 39,139 años de vida saludable perdidos; 9,049 años de vida vividoscon discapacidad y 30,091 años de vida perdidos por muerte prematura. Tecnología sanitária: El ribociclib, también conocido como Kisqali ®, es un inhibidor de las cinasas dependientes de ciclina 4 (CDK4) y 6 (CDK6); controlando así la multiplicación celular. El fulvestrant es un antagonista competitivo de la unión de estrógenos al receptor de estrógenos; bloqueando así las acciones tróficas delos estrógenos. La dosis recomendada de ribociclib + fulvestrant es: es 600 mg de ribociclib (tres comprimidos recubiertos de 200 mg) una vez al día durante 21 días consecutivos, seguidos de 7 días sin tratamiento para completar un ciclo de 28 días. Cuando fulvestrant se administra con ribocic

CDK4/6 inhibitors for hormone receptor-positive/human epidermal growth factor receptor 2 negative advanced breast cancer: A rapid health technology assessment.

OBJECT: Based on the best available evidence, rapid health technology was used to assess 4 CDK4/6 inhibitors approved for marketing in China. This assessment aims to provide a reference basis for the selection of drugs by medical institutions in China and to promote the rational use of drugs in the clinic. METHODS: Depending on the Rapid Guidelines for Drug Evaluation and Selection in Chinese Medical Institutions (the Second Edition), a percentage quantitative scoring approach was used to objectively score the pharmacological properties, efficacy, safety, economy, and other attributes of CDK4/6 inhibitors. RESULTS: The composite score rankings were, in descending order, 78.09 points for abemaciclib, 78.04 points for palbociclib, 72.15 points for dalpiciclib, and 69.24 points for ribociclib by integrating the result of the 5 dimensions. CONCLUSION: Until the clinical studies, guideline recommendations, prices, and many other aspects of this assessment are updated, abemaciclib and palbociclib, which have the top 2 scores, can be used as a priority recommendation for Chinese medical institutions to select CDK4/6 inhibitors and optimize the use of the drug catalog based on the scoring results of this assessment.

Overall survival associated with CDK4/6 inhibitors in patients with HR+/HER2- metastatic breast cancer in the United States: A SEER-Medicare population-based study.

BACKGROUND: Evidence on overall survival (OS) with cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors is generally limited to data from clinical trials or a few observational studies with limited generalizability to Medicare population. The aim of this study was to determine OS benefits associated with CDK4/6 inhibitors in older Medicare patients with hormone receptor (HR)-positive and human epidermal growth factor receptor-2 overexpressing (HER2-) metastatic breast cancer (MBC). METHODS: In a retrospective cohort design, female patients aged ≥65 years with diagnosis of HR+/HER2- MBC from 2015 to 2017 who initiated first-line systemic therapy within 12 months of MBC diagnosis were selected from the Survey Epidemiology and End Results-Medicare database. The effect of treatment type (endocrine therapy [ET]+CDK4/6 inhibitor vs. ET alone) on OS was analyzed using Kaplan-Meier methods and multivariable Cox regression models. Adjusted hazard ratio (aHR) and 95% CIs were estimated. RESULTS: A total of 630 eligible patients were identified (169 patients treated with ET+CDK4/6 inhibitor and 461 patients treated with ET alone). In the Kaplan-Meier analysis, OS rate at 3 years after first-line treatment initiation was 73.0% for ET+CDK4/6 inhibitor versus 49.1% for ET alone (log-rank p < .0001). In Cox regression analysis, first-line ET+CDK4/6 inhibitor therapy was associated with 41% lower rate of mortality versus ET alone (aHR, 0.590; 95% CI, 0.423-0.823). CONCLUSIONS: The findings of this real-world study demonstrate significant OS benefit associated with ET+CDK4/6 inhibitor therapy over ET alone in an older Medicare population of patients with HR+/HER2- MBC, largely consistent with the evidence from clinical trials.

Real world incidence and management of adverse events in patients with HR+, HER2- metastatic breast cancer receiving CDK4 and 6 inhibitors in a United States community setting.

OBJECTIVE: To examine the real-world incidence and management of select adverse events (AEs) among female patients with hormone receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC), receiving a cyclin-dependent kinase 4 and 6 (CDK4 and 6) inhibitor (palbociclib, abemaciclib, or ribociclib). METHODS: This retrospective study analyzed data from the US Oncology Network iKnowMed electronic health record database for 396 patients with an initial MBC diagnosis on/after 1 January 2014 and receipt of first CDK4 and 6 regimen between 1 January 2017 and 31 December 2018. In this descriptive study, the proportion of patients who experienced select AEs and associated dose modifications or discontinuations were reported. The occurrence of select healthcare resource utilization categories was also reported. RESULTS: Median follow-up time was 451, 262, and 355 days for patients in the palbociclib, abemaciclib, and ribociclib cohorts, respectively. The most common AEs were neutropenia (palbociclib, 44.8%; abemaciclib, 10.6%; ribociclib, 36.3%), diarrhea (palbociclib, 8.0%; abemaciclib, 43.0%; ribociclib, 8.8%), and fatigue (palbociclib, 12.9%; abemaciclib, 17.6%; ribociclib, 16.5%). AEs resulted in a treatment hold among 91 (23.0%), a dose reduction among 86 (21.7%), and permanent discontinuation among 48 (12.1%) patients overall. CONCLUSIONS: This real-world study provides insight into the occurrence of AEs which varied by CDK4 and 6 inhibitor. Compared to clinical trials, frequencies of AEs were numerically lower but dose reductions due to AEs were numerically higher. It is possible these differences reflect proactive management of AEs on the part of clinicians to help patients remain on therapy.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4 and 6 inhibitors) have changed the landscape for the treatment of metastatic breast cancer (MBC) among patients who are hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2−). An understanding of the real-world management of adverse events (AEs) will help optimize treatment strategies. Here, data from the US Oncology Network electronic health record database for 396 HR+, HER2−, MBC patients receiving a CDK4 and 6 inhibitor were examined to describe the proportion of patients who experienced select AEs and the associated outcomes of these AEs. Compared to clinical trials, frequencies of AEs were numerically lower but dose reductions due to AEs were numerically higher. It is possible that these differences reflect a proactive management of AEs on the part of clinicians to help patients remain on therapy.

Thrombotic events in patients using cyclin dependent kinase 4/6 inhibitors, analysis of existing ambulatory risk assessment models and the potential influences of tumor specific risk factors.

Cyclin dependent kinase 4 of 6 inhibitors (CDKi) are key therapeutics in the treatment of advanced breast cancer and have recently been approved in small cell lung cancer for the prevention of myelosuppression. Thrombotic events have emerged as a significant treatment related adverse event in up to 5% of patients in clinical trials and has been reported at higher rates, up to 10%, in real world analysis. The prothrombotic mechanisms of CDKis, however, remain unknown. Cancer specific risk assessment models exist to identify who may be at highest risk of thrombosis and who could potentially benefit from prophylactic anticoagulation. However, these models may not be accurate in patients taking CDKis and may not fully capture recently identified thrombotic risk factors such as tumor specific somatic mutations. In the following manuscript, we summarize the literature on thrombotic events with CDKis in clinical trials and real-world settings, review the existing thrombosis risk assessment models for ambulatory cancer patients, and discuss the literature on tumor mutations and role in cancer associated thrombosis.

Real-world clinical outcome and toxicity data and economic aspects in patients with advanced breast cancer treated with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy: the experience of the Hellenic Cooperative Oncology Group.

BACKGROUND: We evaluated real-world clinical outcomes and toxicity data and assessed treatment-related costs in patients with advanced breast cancer who received treatment with cyclin-dependent kinase inhibitors (CDKi). PATIENTS AND METHODS: We conducted a prospective-retrospective analysis of patients with advanced hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer who received a CDKi, in combination with endocrine therapy, at any line of treatment. The primary endpoint was progression-free survival (PFS). Cost analysis was conducted from a public third-payer (National Organization for Healthcare Services Provision (EOPYY)) perspective, assessing only costs related to direct medical care, including drug therapy costs and adverse drug reaction (ADR)-related costs. RESULTS: From July 2015 to October 2019, 365 women received endocrine therapy combined with CDKi; median age was 61 years, postmenopausal 290 (80.6%) patients. CDKi were administered as first-line treatment in 149 (40.9%) patients, second-line treatment in 96 (26.4%) and third-line treatment and beyond in 119 (32.7%) patients. The most common adverse events were neutropenia, anaemia, thrombocytopenia and fatigue. Grade 3-4 adverse events occurred in 86 (23.6%) patients, whereas 8 (2.2%) patients permanently discontinued treatment due to toxicity. The median PFS for patients who received CDKi as first-line, second-line and third-line treatment and beyond was 18.7, 12 and 7.4 months, respectively. The median overall survival since the initiation of CDKi treatment was 29.9 months (95% CI: 23.0-not yet reached (NR)). The mean pharmaceutical therapy cost estimated per cycle was 2 724.12 € for each patient, whereas the main driver of the ADR-related costs was haematological adverse events. CONCLUSIONS: Treatment with CDKi was well tolerated, with a low drug discontinuation rate. Patients who received CDKi as first-line treatment had improved PFS and OS compared with second-line treatment and beyond. The main component of direct medical costs assessed in the cost analysis comprises CDKi pharmaceutical therapy costs. TRIAL REGISTRATION NUMBER: NCT04133207.

An integrated assessment of the ADME properties of the CDK4/6 Inhibitor ribociclib utilizing preclinical in vitro, in vivo, and human ADME data.

Ribociclib (LEE011, Kisqali ®) is a highly selective small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which has been approved for the treatment of advanced or metastatic breast cancer. A human ADME study was conducted in healthy male volunteers following a single oral dose of 600 mg [14 C]-ribociclib. Mass balance, blood and plasma radioactivity, and plasma ribociclib concentrations were measured. Metabolite profiling and identification was conducted in plasma, urine, and feces. An assessment integrating the human ADME results with relevant in vitro and in vivo non-clinical data was conducted to provide an estimate of the relative contributions of various clearance pathways of the compound. Ribociclib is moderately to highly absorbed across species (approx. 59% in human), and is extensively metabolized in vivo, predominantly by oxidative pathways mediated by CYP3A4 (ultimately forming N-demethylated metabolite M4) and, to a lesser extent, by FMO3 (N-hydroxylated metabolite M13). It is extensively distributed in rats, based on QWBA data, and is eliminated rapidly from most tissues with the exception of melanin-containing structures. Ribociclib passed the placental barrier in rats and rabbits and into milk of lactating rats. In human, 69.1% and 22.6% of the radiolabeled dose were excreted in feces and urine, respectively, with 17.3% and 6.75% of the 14 C dose attributable to ribociclib, respectively. The remainder was attributed to numerous metabolites. Taking into account all available data, ribociclib is estimated to be eliminated by hepatic metabolism (approx. 84% of total), renal excretion (7%), intestinal excretion (8%), and biliary elimination (1%).

CDK4/6 inhibition in low burden and extensive metastatic breast cancer: summary of an ESMO Open-Cancer Horizons pro and con discussion.

In December 2017, ESMO Open-Cancer Horizons convened a round-table discussion on the background and latest data regarding cyclin-dependent kinase (CDK)4/6 inhibitors with endocrine therapy (ET) in the treatment of endocrine-sensitive breast cancer (BC). A review on this discussion was published in summer 2018 (https://esmoopen.bmj.com/content/3/5/e000368).Endocrine-sensitive BC with non-visceral disease and limited spread of the metastases.Endocrine-sensitive BC with non-life-threatening visceral involvement. Several open questions were identified, which led to a second ESMO Open discussion on CDK4/6 inhibitors, taking place in December 2018 and covered in this article. The panel discussed two important clinical scenarios and the pro and cons of a treatment approach with CDK4/6 inhibitors for each scenario:Endocrine-sensitive BC with non-visceral disease and limited spread of the metastases.Endocrine-sensitive BC with non-life-threatening visceral involvement. Regarding scenario 1, the panel agreed that CDK4/6 inhibitors should be recommended in first-line therapy for most patients if cost and practicality allow. However, the use of single-agent ET with an aromatase inhibitor in the first-line treatment of these patients is still a possibility for a small group of patients with very limited disease, such as one or two bone lesions or limited lymph node involvement. Regarding scenario 2, chemotherapy is the first approach for patients with endocrine-sensitive metastatic BC with life-threatening visceral involvement because of the need for a faster response. The therapeutic approaches for patients with non-life-threatening visceral involvement are still under debate. Nevertheless, CDK4/6 inhibitors are currently the treatment of choice for most patients with a close follow-up of tumour response. A treatment algorithm has been suggested at the round table.

Reproductive and developmental toxicity assessment of palbociclib, a CDK4/6 inhibitor, in Sprague-Dawley rats and New Zealand White rabbits.

Palbociclib is a selective inhibitor of the cyclin-dependent kinase (CDK) 4/6, approved for the treatment of breast cancer. We assessed the potential effects of oral administration of palbociclib on reproduction and development. There were no effects on female or male fertility indices; however, in the male there was seminiferous tubule degeneration in the testes and secondary findings in the epididymides, lower testicular and epididymal weights, sperm density and motility. Palbociclib was not teratogenic in rats or rabbits; however, in the presence of maternal toxicity (lower maternal body weight gain and food consumption), low fetal body weights were observed in rats and small forepaw phalanges were noted in rabbits. There were, however, no adverse effects on the F1 generation in a pre- and post-natal developmental toxicity study in the rat.

Why upfront use of CDK inhibitors for the treatment of advanced breast cancer may be wasteful, and how we can increase their value.

Three Cyclin Dependent Kinase 4/6 (CDK) inhibitors have been approved by the United Stated Food and Drug Administration for front line treatment of advanced hormone receptor positive breast cancer based on improvements in progression free survival against endocrine monotherapy. Two clinical trials have so far reported results on overall survival but both are negative. CDK inhibitors are usually tolerated well but they do add to inconvenience and cost - for example, grade III-IV neutropenia occur at a frequency of over 60% requiring frequent blood work at least during the initial months of treatment. These drugs cost over $ 13,500 for a 4-week cycle in the United States, and are responsible for billions of dollars annually in drug cost alone. Importantly, many women with metastatic breast cancer do well for a long time with endocrine therapy alone and CDK inhibitors do not have a predictive marker. Selective use of these agents in later lines may improve substantially the convenience and cost without compromise in overall outcome. However, with results demonstrating impressive improvements in PFS published in major medical journals coupled with patients' natural desire for "best available" options, the trend among oncologists is to prescribe these drugs as the default front-line treatment. In this commentary I caution readers against over interpretation of results from the CDK inhibitor trials, describe adverse consequences of routine front-line use, and explain why selective use in later line may yield a higher value.

CDK 4/6 inhibitor palbociclib (PD0332991) in Rb+ advanced breast cancer: phase II activity, safety, and predictive biomarker assessment.

PURPOSE: The G1-S checkpoint of the cell cycle is frequently dysregulated in breast cancer. Palbociclib (PD0332991) is an oral inhibitor of CDK4/6. Based upon preclinical/phase I activity, we performed a phase II, single-arm trial of palbociclib in advanced breast cancer. EXPERIMENTAL DESIGN: Eligible patients had histologically confirmed, metastatic breast cancer positive for retinoblastoma (Rb) protein and measureable disease. Palbociclib was given at 125 mg orally on days 1 to 21 of a 28-day cycle. Primary objectives were tumor response and tolerability. Secondary objectives included progression-free survival (PFS) and assessment of Rb expression/localization, KI-67, p16 loss, and CCND1 amplification. RESULTS: Thirty-seven patients were enrolled; 84% hormone-receptor (HR)(+)/Her2(-), 5% HR(+)/Her2(+), and 11% HR(-)/Her2(-), with a median of 2 prior cytotoxic regimens. Two patients had partial response (PR) and 5 had stable disease ≥ 6 months for a clinical benefit rate (CBR = PR + 6moSD) of 19% overall, 21% in HR(+), and 29% in HR(+)/Her2(-) who had progressed through ≥2 prior lines of hormonal therapy. Median PFS overall was 3.7 months [95% confidence interval (CI), 1.9-5.1], but significantly longer for those with HR(+) versus HR(-) disease (P = 0.03) and those who had previously progressed through endocrine therapy for advanced disease (P = 0.02). Grade 3/4 toxicities included neutropenia (51%), anemia (5%), and thrombocytopenia (22%). Twenty-four percent had treatment interruption and 51% had dose reduction, all for cytopenias. No biomarker identified a sensitive tumor population. CONCLUSIONS: Single-agent palbociclib is well tolerated and active in patients with endocrine-resistant, HR(+), Rb-positive breast cancer. Cytopenias were uncomplicated and easily managed with dose reduction.

Recent progress in carcinogenesis, progression and therapy of breast cancer: the 20th Hiroshima Cancer Seminar--the 4th Three Universities' Consortium International Symposium, October 2010: 31 October 2010, International Conference Center Hiroshima.

The 20th Hiroshima Cancer seminar focused upon breast cancer research and treatment particularly on the mechanism of tumorigenesis and drug resistance and development of novel therapeutics. Several molecules such as retinoblastoma and p16 were raised as key factors in tumorigenesis and invasiveness. Estrogen-related pathways seem to be closely involved in the process. For the tumor lacking hormone receptor and human epidermal growth factor 2, some other mechanisms could be responsible. It seems that MicroRNA 22 directing some putative targets such as SIRT1, Sp1 and CDK6 plays a crucial role in breast tumor growth and metastasis. In addition, ribophorin and the associated molecules might be engaged in breast cancer stemness. Obviously, these molecules provide potential for therapeutic targets. It was also discussed about new drug development such as anti-human epidermal growth factor 2 therapy, anti-angiogenesis, pro-tumor aspects of anti-cancer therapy and application of circulating markers for monitoring, imaging and health-care system. Furthermore, we discussed risk factors, prevention and screening to reduce invasive cancers as well. Throughout the conference, panelists and attendee indicated the importance of translational research and biomarker exploration in order to realize efficient and individualized therapy for breast cancer.