Palbociclib dose reductions and the effect on clinical outcomes in patients with advanced breast cancer.
Ontology highlight
ABSTRACT: Background
This study aimed to provide insights into the real-world use of palbociclib, dose reductions, and drug effectiveness in (older) patients with advanced breast cancer (BC).Patients and methods
Patients with advanced BC treated with palbociclib from 2017 to 2020 were included. The Kaplan-Meier method was used to calculate time to next treatment (TTNT) and overall survival (OS) for patients with or without dose reductions. These clinical outcomes were also compared in subgroup analyses for older patients (≥70 years) and younger patients (<70 years) and for patients discontinuing palbociclib early (<4 administrations).Results
A total of 598 patients with advanced BC were included, with a median age of 64 years. Palbociclib dose reductions occurred in 33% of all patients. Early discontinuation of palbociclib without dose reductions occurred in 23% of the patients. Patients who required a palbociclib dose reduction were older (median age 67 years vs. 63 years). Patients with dose reductions had a significantly higher TTNT of 16.9 vs. 11.4 months (p < 0.001) and median OS of 29.7 vs. 21.9 months (p = 0.003) compared to patients without dose reductions. The TTNT in older patients was significantly longer (16.9 vs. 11.6 months, p = 0.013) than younger patients, but OS was similar (20.7 vs. 26.7 months, p = 0.051).Conclusion
Palbociclib dose reductions occurred in real-world practice similarly to the PALOMA-3 trial. Patients with dose reductions had no poorer outcomes compared to patients not requiring a dose reduction. Older patients treated with palbociclib had more frequent dose reductions, but this did not appear to affect OS.
SUBMITTER: Ismail RK
PROVIDER: S-EPMC8609048 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The aim of this study was to assess the potential effects of palbociclib in combination with letrozole on QTc. PALOMA-2, a phase 3, randomized, double-blind, placebo-controlled trial, compared palbociclib plus letrozole with placebo plus letrozole in postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. The study included a QTc evaluation substudy carried out as a definitive QT interval prolongation assessment for palbociclib. Time-matched triplicate ECGs were performed at 0, 2, 4, 6, and 8?h at baseline (Day 0) and on Cycle 1 Day 14. Additional ECGs were collected from all patients for safety monitoring. The QT interval was corrected for heart rate using Fridericia's correction (QTcF), Bazett's correction (QTcB), and a study-specific correction factor (QTcS). In total, 666 patients were randomized 2?:?1 to palbociclib plus letrozole or placebo plus letrozole. Of these, 125 patients were enrolled in the QTc evaluation substudy. No patients in the palbociclib plus letrozole arm of the substudy (N=77) had a maximum postbaseline QTcS or QTcF value of ? 480?ms, or a maximum increase from clock time-matched baseline for QTcS or QTcF values of ? 60?ms. The upper bounds of the one-sided 95% confidence interval for the mean change from time-matched baseline for QTcS, QTcF, and QTcB at all time points and at steady-state Cmax following repeated administration of 125?mg palbociclib were less than 10?ms. Palbociclib, when administered with letrozole at the recommended therapeutic dosing regimen, did not prolong the QT interval to a clinically relevant extent.
| S-EPMC5821476 | biostudies-literature
Project description:BACKGROUND:The cyclin-dependent kinase 4/6 (CDK4/6) inhibitor palbociclib, in combination with endocrine therapy (ET), significantly prolonged progression-free survival in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (HR+/HER2- ABC) in PALOMA-2 and PALOMA-3. Neutropenia and palbociclib dose reductions/interruptions occurred more frequently in the Japanese versus overall populations. We evaluated neutropenia patterns, palbociclib dose management, and clinical responses after dose reduction in Japanese patients in PALOMA-2 and PALOMA-3 and a single-arm Japanese phase 2 study. METHODS:PALOMA-2 and the Japanese phase 2 study enrolled postmenopausal women with estrogen receptor-positive, HER2- ABC who had not received prior systemic therapy for advanced disease; PALOMA-3 enrolled women with HR+/HER2- ABC, regardless of menopausal status, whose disease had progressed after prior ET. Palbociclib (125 mg/day) was administered 3 weeks on/1 week off. Dose reduction/interruption, cycle delay, tumor response, and laboratory-assessed neutropenia were analyzed in Japanese patients who received palbociclib. RESULTS:A total of 101 Japanese patients received palbociclib?+?ET. Among Japanese patients in the 3 studies, the frequency of all-grade/grade 3/grade 4 neutropenia was 94%/53%/34%, 100%/69%/21%, and 100%/67%/26%, respectively. Twenty (63%), 28 (67%), and 15 (56%) patients required palbociclib dose reduction. Dose interruption or reduction did not affect palbociclib treatment duration, and durable tumor response was observed despite dose reduction. CONCLUSION:Neutropenia was manageable with dose modifications, without affecting palbociclib treatment duration or efficacy. TRIAL REGISTRATION:Pfizer (NCT01740427, NCT01684215, NCT01942135).
| S-EPMC6694088 | biostudies-literature
Project description:Neutropenia is the most frequent dose-limiting toxicity reported in patients with metastatic breast cancer receiving palbociclib. The objective of this study was to investigate the pharmacokinetic–pharmacodynamic (PK/PD) relationships for toxicity (i.e., absolute neutrophil count, ANC) and efficacy (i.e., progression-free survival, PFS). A semi-mechanistic PK/PD model was used to predict neutrophils’ time course using a population approach (NONMEM). Influence of demographic and clinical characteristics was evaluated. Cox proportional hazards models were developed to evaluate the influence of palbociclib PK on PFS. A two-compartment model with first-order absorption and a lag time adequately described the 255 palbociclib concentrations provided by 44 patients. The effect of the co-administration of proton-pump inhibitors in fasting conditions increased palbociclib clearance by 56%. None of the tested covariates affected the PD parameters. Model-based simulations confirmed the concentration-dependent and non-cumulative properties of palbociclib-induced neutropenia, reversible after treatment withdrawal. The ANC nadir occurred approximately at day 24 of each cycle. Cox analyses revealed a trend for better PFS with increasing palbociclib exposure in older patients. By characterizing palbociclib-induced neutropenia, this model offers support to clinicians to rationally optimize treatment management through patient-individualized strategies.
| S-EPMC9322950 | biostudies-literature
Project description:Background:The objective of this study was to review the pharmacology, efficacy, and safety of palbociclib, a first-in-class cyclin-dependent kinase 4/6 inhibitor, for the management of advanced breast cancer (ABC). Methods:Pharmacokinetics and drug interactions associated with palbociclib are described. Recent clinical trial data are reviewed, including patient-reported outcomes and subgroup analyses. Results:Palbociclib is indicated in combination with an aromatase inhibitor as initial endocrine therapy (ET) or with fulvestrant for patients with disease progression following ET for hormone receptor positive, human epidermal growth factor receptor 2 negative ABC or metastatic breast cancer. Palbociclib inhibits cyclin-dependent kinases 4/6, resulting in a blockade of phosphorylation of the retinoblastoma protein, which hinders the activation of transcription factors involved in S-phase entry, thereby arresting cell cycle progression at G1 phase. The efficacy and safety of palbociclib in combination with ET was established in three randomized trials (PALOMA-1, -2, and -3); all studies met their primary endpoint of significantly prolonging investigator-assessed progression-free survival versus ET alone. Findings were similar in subgroup analyses of the three PALOMA studies. Palbociclib plus ET also maintained health-related quality of life (QoL) compared with ET alone in PALOMA-2 and -3. A long-term safety profile for palbociclib, up to 3?years, has been established. Neutropenia, the most common any-grade and grade 3 or higher adverse event associated with palbociclib, is consistent with the drug's mechanism of action and can be effectively managed with dose interruption, dose reduction, or delay in starting treatment cycles. Conclusions:Palbociclib in combination with ET improved progression-free survival and QoL in patients with ABC, including in several patient subgroups.
| S-EPMC6122240 | biostudies-literature
Project description:Background:This report assesses the efficacy and safety of palbociclib plus endocrine therapy (ET) in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) with or without visceral metastases. Patients and methods:Pre- and postmenopausal women with disease progression following prior ET (PALOMA-3; N?=?521) and postmenopausal women untreated for ABC (PALOMA-2; N?=?666) were randomized 2 : 1 to ET (fulvestrant or letrozole, respectively) plus palbociclib or placebo. Progression-free survival (PFS), safety, and patient-reported quality of life (QoL) were evaluated by prior treatment and visceral involvement. Results:Visceral metastases incidence was higher in patients with prior resistance to ET (58.3%, PALOMA-3) than in patients naive to ET in the ABC setting (48.6%, PALOMA-2). In patients with prior resistance to ET and visceral metastases, median PFS (mPFS) was 9.2?months with palbociclib plus fulvestrant versus 3.4?months with placebo plus fulvestrant [hazard ratio (HR), 0.47; 95% confidence interval (CI), 0.35-0.61], and objective response rate (ORR) was 28.0% versus 6.7%, respectively. In patients with nonvisceral metastases, mPFS was 16.6 versus 7.3?months, HR 0.53; 95% CI 0.36-0.77. In patients with visceral disease and naive to ET in the advanced disease setting, mPFS was 19.3?months with palbociclib plus letrozole versus 12.9?months with placebo plus letrozole (HR 0.63; 95% CI 0.47-0.85); ORR was 55.1% versus 40.0%; in patients with nonvisceral disease, mPFS was not reached with palbociclib plus letrozole versus 16.8?months with placebo plus letrozole (HR 0.50; 95% CI 0.36-0.70). In patients with prior resistance to ET with visceral metastases, palbociclib plus fulvestrant significantly delayed deterioration of QoL versus placebo plus fulvestrant, whereas patient-reported QoL was maintained with palbociclib plus letrozole in patients naive to endocrine-based therapy for ABC. Conclusions:Palbociclib plus ET prolonged mPFS in patients with visceral metastases, increased ORRs, and in patients previously treated for ABC, delayed QoL deterioration, presenting a standard treatment option among patients with visceral metastases amenable to endocrine-based therapy. Clinical trial registration:NCT01942135, NCT01740427.
| S-EPMC5888946 | biostudies-literature
Project description:ObjectiveThe aim of this study was to assess the real-world effectiveness and tolerability of palbociclib combined with endocrine therapy for the treatment of hormone receptor positive (HR-positive), human epidermal growth factor receptor 2 negative (HER2-negative), advanced/metastatic breast cancer that progressed on previous endocrine therapy, and to compare these results with the outcomes of the PALOMA-3 clinical trial.MethodsThis study was a retrospective observational cohort study including all patients who started with palbociclib in the St. Antonius Hospital between September 1, 2016 and April 1, 2018 for the treatment of HR-positive, HER2-negative advanced/metastatic breast cancer that progressed on previous endocrine therapy. Individual patient data were collected from electronic medical records. Primary study outcomes were progression-free survival (PFS) and the number of permanent treatment discontinuations before disease progression due to adverse events (AEs). Secondary outcomes were the frequency of all (serious) AEs and the frequency of and reasons for dose reductions, -interruptions and cycle delays.ResultsA total of 46 patients were studied with a median follow-up of 13.0?months. Overall, the median PFS in real-world clinical practice was 10.0?months (95% confidence interval (CI) 4.9-15.1), compared with 9.5?months in PALOMA-3 (95% CI 9.2-11.0). Two patients discontinued treatment because of AEs. Neutropenia was the most frequent grade 3-4 AE, but with no febrile neutropenia events. Most AEs were managed with palbociclib dose modifications. Regarding these modifications, more cycle delays, less dose reductions, and less dose interruptions occurred in clinical practice compared with PALOMA-3 (59 vs 36%, 22 vs 34%, and 9 vs 54%, respectively). Patients who did not meet the PALOMA-3 study eligibility criteria (n?=?16) showed a lower median PFS of 5.5?months (95% CI 4.7-6.4).ConclusionsThe effectiveness and tolerability of palbociclib in real-world clinical practice corresponded well with the results obtained in the PALOMA-3 clinical trial. Despite the differences in dose modifications, this study suggests that there is no efficacy-effectiveness gap in this patient population.
| S-EPMC6330732 | biostudies-literature
Project description:Deregulation of the cell cycle is a hallmark of cancer, and research on cell cycle control has allowed identification of potential targets for anticancer treatment. Palbociclib is a selective inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6), which are involved, with their coregulatory partners cyclin D, in the G1-S transition. Inhibition of this step halts cell cycle progression in cells in which the involved pathway, including the retinoblastoma protein (Rb) and the E2F family of transcription factors, is functioning, although having been deregulated. Among breast cancers, those with functioning cyclin D-CDK4/6-Rb-E2F are mainly hormone-receptor (HR) positive, with some HER2-positive and rare triple-negative cases. Deregulation results from genetic or otherwise occurring hyperactivation of molecules subtending cell cycle progression, or inactivation of cell cycle inhibitors. Based on results of randomized clinical trials, palbociclib was granted accelerated approval by the US Food and Drug Administration (FDA) for use in combination with letrozole as initial endocrine-based therapy for metastatic disease in postmenopausal women with HR-positive, HER2-negative breast cancer, and was approved for use in combination with fulvestrant in women with HR-positive, HER2-negative advanced breast cancer with disease progression following endocrine therapy. This review provides an update of the available knowledge on the cell cycle and its regulation, on the alterations in cyclin D-CDK4/6-Rb-E2F axis in breast cancer and their roles in endocrine resistance, on the preclinical activity of CDK4/6 inhibitors in breast cancer, both as monotherapy and as partners of combinatorial synergic treatments, and on the clinical development of palbociclib in breast cancer.
| S-EPMC5298405 | biostudies-literature
Project description:PurposeThe selective cyclin-dependent kinase 4/6 inhibitor palbociclib was approved in Argentina in 2015 for postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) or metastatic breast cancer (MBC) based on phase III study results. The Ibrance Real World Insights (IRIS) study aims to evaluate palbociclib in patients with HR-positive/HER2-negative ABC or MBC in the real-world setting in multiple countries globally. Here we report results from patients enrolled in the IRIS study in Argentina.Patients and methodsThis retrospective medical chart review study included postmenopausal women with confirmed HR-positive/HER2-negative ABC or MBC who were treated with palbociclib plus letrozole as first-line endocrine-based therapy or with palbociclib plus fulvestrant in women with disease progression after endocrine therapy. Participating physicians reviewed medical records of up to six patients each, collecting demographic and clinical data. Outcomes included progression-free and overall survival rates.ResultsRecords were extracted for 162 patients in Argentina (palbociclib plus letrozole, n = 105 [65%]; palbociclib plus fulvestrant, n = 57 [35%]). The 6-month progression-free survival rate was 94% for patients treated with palbociclib plus letrozole and 95% for patients treated with palbociclib plus fulvestrant; 85% and 80% of patients treated with palbociclib plus letrozole were progression free at 12 and 18 months, respectively. Six-month survival rates were 98% for palbociclib plus letrozole and 98% for palbociclib plus fulvestrant; 93% and 89% of patients treated with palbociclib plus letrozole were alive at 12 and 18 months, respectively.ConclusionResults from this first real-world evaluation of clinical outcomes in Argentina suggest that palbociclib plus letrozole or fulvestrant delivers favorable effectiveness, as measured by progression-free and overall survival rates.
| S-EPMC6550052 | biostudies-literature
Project description:PurposeUse of cyclin-dependent kinase 4/6 inhibitors improved survival outcome of hormone receptor (HR) positive metastatic breast cancer (MBC) patients, including Asian population. However, Asian real-world data of palbociclib is limited. We analyzed the real-world clinical practice patterns and outcome in HR-positive, MBC Asian patients treated with palbociclib.Materials and methodsBetween April 2017 to November 2019, 169 HR-positive, human epidermal growth factor-2-negative MBC patients treated with letrozole or fulvestrant plus palbocilib were enrolled from eight institutions. Survival outcome (progression-free survival [PFS]), treatment response and toxicity profiles were analyzed.ResultsMedian age of letrozole plus palbociclib (145 patients, 85.8%) and fulvestrant plus palbociclib (24 patients, 14.2%) was 58 and 53.5 years, with median follow-up duration of 14.63 months (range 0.2 to 33.9 months). Median PFS (mPFS) of letrozole plus palbociclib and fulvestrant plus palbociclib was 25.6 (95% confidence interval [CI], 19.1 to not reached) and 6.37 months (95% CI, 5.33 to not reached), comparable to previous phase 3 trials. In letrozole plus palbociclib arm, luminal A (hazard ratio, 2.86; 95% CI, 1.20 to 6.80; p=0.017) and patients with good performance (Eastern Cooperative Oncology Group 0-1 [hazard ratio, 3.68; 95% CI, 1.70 to 7.96]) showed better mPFS. In fulvestrant plus palbociclib group, chemotherapy naïve patients showed better mPFS (hazard ratio, 12.51, 95% CI, 1.59 to 99.17; p=0.017). The most common grade 3 or 4 adverse event was neutropenia (letrozole 86.3%, fulvestrant 88.3%).ConclusionTo our knowledge, this is the first real-world data of palbociclib reported in Asia. Palbociclib showed comparable benefit to previous phase 3 trials in Asian patients during daily clinical practice.
| S-EPMC8053880 | biostudies-literature
Project description:OBJECTIVE:To review palbociclib, a novel small-molecule inhibitor of cyclin-dependent kinases 4 and 6, and its current place in therapy for the treatment of hormone receptor (HMR)-positive, human epidermal growth factor receptor 2 (Her2)-negative advanced breast cancer. STUDY SELECTION AND DATA ABSTRACTION:Four phase I trials, 2 phase II trials, and 1 phase III trial were identified from May 2004 to May 2015 using PubMed, American Society of Clinical Oncology (ASCO) abstracts, and European Society of Medical Oncology (ESMO) abstracts. DATA SYNTHESIS:In the first-line setting, the phase II PALbociclib: Ongoing trials in the Management of breast cAncer (PALOMA)-1 trial randomized patients to receive letrozole alone or letrozole plus palbociclib 125 mg daily for 3 weeks, followed by 1 week off, as initial therapy for advanced breast cancer. The investigator-assessed median progression-free survival (PFS) was 20. 2 months for the combination versus 10.2 months for letrozole alone (hazard ratio [HR] = 0.488; 95% CI = 0.319-0.748; 1-sided P = 0.0004). The ensuing Food and Drug Administration approval of palbociclib was given a "breakthrough therapy" designation, where preliminary evidence suggests substantial improvement over existing therapies for a serious or life-threatening disease. A confirmatory phase III trial, PALOMA-2, is under way. In patients who were previously treated with endocrine therapy for advanced breast cancer, the phase III PALOMA-3 trial randomized patients to fulvestrant plus palbociclib versus fulvestrant plus placebo. The investigator-assessed median PFS at the time of a preplanned analysis was 9.2 months with palbociclib-fulvestrant compared with 3.8 months with placebo-fulvestrant (HR = 0.42; 95% CI = 0.32-0.56; P < 0.001). CONCLUSIONS:Palbociclib, the first-in-class CDK4/6 inhibitor, significantly extended PFS in combination with endocrine therapy in the first and subsequent lines of treatment for HMR-positive, Her2-negative advanced breast cancer.
| S-EPMC7331461 | biostudies-literature