{"id":"palbociclib-plus-letrozole","rwe":[],"tags":[],"phase":"preclinical","safety":{"boxedWarnings":[],"safetySignals":[],"drugInteractions":[],"commonSideEffects":[],"contraindications":[],"specialPopulations":{},"discontinuationRates":[],"seriousAdverseEvents":[]},"status":"active","trials":["NCT03424005","NCT03819010","NCT03628066","NCT02499146","NCT07174336","NCT03820830","NCT03644186","NCT06760637","NCT03709082","NCT04606446","NCT02400567","NCT06607601","NCT04985266","NCT02142868","NCT06525675","NCT00721409","NCT04553133","NCT03921866","NCT02028507","NCT03809988","NCT05505175","NCT01684215","NCT06086340","NCT03870919","NCT02389842"],"aliases":[],"patents":[],"pricing":[],"allNames":"palbociclib plus letrozole","offLabel":[],"timeline":[{"date":"2013","type":"neutral","milestone":"Phase 2 Initiated","description":"Phase 2 trial (Study Of Letrozole With Or Without Palbociclib (PD-0332991) For The First-Line Treatment Of Hormone-) — Breast Cancer"},{"date":"2018","type":"neutral","milestone":"Phase 1 Initiated","description":"Phase 1 trial (Palbociclib Pharmacokinetics Study In Postmenopausal Chinese Women With ER (+), HER2 (-) Advanced Br) — Advanced Breast Cancer"},{"date":"2019","type":"neutral","milestone":"Phase 3 Initiated","description":"Phase 3 trial (Phase III Palbociclib With Endocrine Therapy vs. Capecitabine in HR+/HER2- MBC With Resistance to Ar) — Metastatic Breast Cancer"}],"aiSummary":"Palbociclib is a small molecule inhibitor of the cytochrome P450 19A1 enzyme, which is involved in the production of estrogen. Palbociclib is often used in combination with letrozole, an aromatase inhibitor, to treat hormone receptor-positive breast cancer.","brandName":"palbociclib plus letrozole","companyId":"pfizer","ecosystem":[],"mechanism":{"target":"","novelty":"","modality":"","drugClass":"palbociclib plus letrozole","explanation":"Breast cancer cells that are hormone receptor-positive depend on estrogen to grow and survive. Letrozole works by blocking the enzyme aromatase, which converts other hormones into estrogen in the body. By reducing circulating estrogen levels, letrozole deprives these cancer cells of a critical growth signal, slowing their progression.\n\nPalbociclib takes a complementary approach by targeting the machinery inside cancer cells that controls division. Cancer cells progress through their growth cycle using proteins called CDK4 and CDK6. Palbociclib acts as a brake on these proteins, preventing cells from advancing to the next phase of division. This creates a dual blockade: even if cancer cells aren't completely starved of estrogen, they're locked in a resting state and unable to multiply.\n\nTogether, palbociclib and letrozole work synergistically—one cuts off growth signals from outside the cell while the other prevents the internal machinery from responding. This combination approach has proven more effective than hormone therapy alone, particularly in women whose cancers have progressed despite prior treatments.","oneSentence":"palbociclib plus letrozole","technicalDetail":""},"commercial":null,"references":[],"biosimilars":[],"companyName":"Pfizer Inc.","competitors":[],"genericName":"palbociclib-plus-letrozole","indications":{"approved":[],"offLabel":[],"pipeline":[{"name":"Breast Cancer","phase":"preclinical","trialId":"","patients":null,"diseaseId":"oncology","trialName":"","primaryEndpoint":"","expectedCompletion":""}]},"labelChanges":[],"relatedDrugs":[],"trialDetails":[{"nctId":"NCT03424005","phase":"Phase 1/2","title":"A Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Patients With Metas","status":"Recruiting","sponsor":"Hoffmann-La Roche","isPivotal":false,"enrollment":792,"indication":"Metastatic Breast Cancer","completionDate":"2030-09","primaryEndpoint":"This is an umbrella study evaluating the efficacy and safety of multiple treatment combinations in participants with metastatic or inoperable locally advanced breast cancer."},{"nctId":"NCT03819010","phase":"Phase 2","title":"Neoadjuvant Letrozole and Palbociclib in Patients With Stage II-IIIB Breast Cancer, HR+, HER2 -","status":"Completed","sponsor":"MedSIR","isPivotal":false,"enrollment":66,"indication":"Breast Cancer","completionDate":"2019-07","primaryEndpoint":"This is an international, multicenter, open-label, non-comparative, Simon´s two-stage design, phase II clinical trial."},{"nctId":"NCT03628066","phase":"Phase 2","title":"Biological and Clinical Effects of Palbociclib With Ovarian Suppression and Letrozole in the Neoadju","status":"Completed","sponsor":"NSABP Foundation Inc","isPivotal":false,"enrollment":24,"indication":"Breast Cancer","completionDate":"2020-11","primaryEndpoint":"This study will look at the safety and effectiveness of the combination of palbociclib and letrozole and ovarian suppression for premenopausal patients who have ER-positive/HER2-negative breast cancer"},{"nctId":"NCT02499146","phase":"Phase 1","title":"Palbociclib Pharmacokinetics Study In Postmenopausal Chinese Women With ER (+), HER2 (-) Advanced Br","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":26,"indication":"Advanced Breast Cancer","completionDate":"2018-07","primaryEndpoint":"As part of the global clinical development program for Palbociclib, studies are planned in cancer patients in China."},{"nctId":"NCT07174336","phase":"Phase 3","title":"A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Adv","status":"Recruiting","sponsor":"Eli Lilly and Company","isPivotal":false,"enrollment":920,"indication":"Breast Neoplasms","completionDate":"2029-05","primaryEndpoint":"The purpose of the study is to assess the efficacy and safety of the addition of Tersolisib (LY4064809/STX-478) to other anti-cancer drugs as first treatment for advanced hormone receptor-positive (HR"},{"nctId":"NCT03820830","phase":"Phase 3","title":"Palbociclib for HR Positive / HER2-negative Isolated Locoregional Recurrence of Breast Cancer","status":"Active Not Recruiting","sponsor":"ETOP IBCSG Partners Foundation","isPivotal":false,"enrollment":405,"indication":"Breast Cancer Recurrent","completionDate":"2026-01","primaryEndpoint":"POLAR is a phase III clinical trial, which will test the safety and efficacy of an investigational combination of drugs to learn whether the combination of drugs works for a specific cancer."},{"nctId":"NCT03644186","phase":"Phase 2","title":"To Reduce the Use of Chemotherapy in Postmenopausal Patients With ER-positive and HER2-positive Brea","status":"Completed","sponsor":"ETOP IBCSG Partners Foundation","isPivotal":false,"enrollment":147,"indication":"Breast Cancer","completionDate":"2023-01","primaryEndpoint":"This is a phase II open-label, multicentre, randomized trial."},{"nctId":"NCT06760637","phase":"Phase 3","title":"Study of PF-07220060 With Letrozole in Adults With HR-positive HER2-negative Breast Cancer Who Have ","status":"Recruiting","sponsor":"Pfizer","isPivotal":false,"enrollment":1020,"indication":"Breast Cancer","completionDate":"2029-01","primaryEndpoint":"The purpose of this study is to determine the safety and efficacy of PF-07220060 with letrozole compared to approved treatments (ie, palbociclib, ribociclib or abemaciclib with letrozole) in people wi"},{"nctId":"NCT03709082","phase":"Phase 1/2","title":"Palbociclib in Estrogen Receptor Positive (ER+) Human Epidermal Growth Factor Receptor 2 Positive (H","status":"Terminated","sponsor":"University of Kansas Medical Center","isPivotal":false,"enrollment":3,"indication":"HER2-positive Breast Cancer","completionDate":"2020-03","primaryEndpoint":"This study will determine the recommend dose of palbociclib in combination with letrozole and another medication, Ado-trastuzumab emtansine (T-DM1)."},{"nctId":"NCT04606446","phase":"Phase 1","title":"Study of PF-07248144 in Advanced or Metastatic Solid Tumors","status":"Recruiting","sponsor":"Pfizer","isPivotal":false,"enrollment":320,"indication":"Locally Advanced or Metastatic ER+ HER2- Breast Cancer","completionDate":"2028-02","primaryEndpoint":"This is an open-label, multi center study to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-07248144 and early signs of clinical efficacy of PF-07248144 as a sin"},{"nctId":"NCT02400567","phase":"Phase 2","title":"Efficacy of Letrozole + Palbociclib Combination as Neoadjuvant Treatment of Stage II-IIIA PAM 50 ROR","status":"Completed","sponsor":"UNICANCER","isPivotal":false,"enrollment":125,"indication":"Neoadjuvant Operable Breast Cancer","completionDate":"2018-01","primaryEndpoint":"The investigators propose in the present study an innovative approach, combining the most recent therapeutic opportunities in high risk ER+ breast cancer with the most recent and innovative diagnostic"},{"nctId":"NCT06607601","phase":"N/A","title":"CARE Initiative: Real-world Emulation of the PALOMA-2 Trial","status":"Completed","sponsor":"Aetion, Inc.","isPivotal":false,"enrollment":724,"indication":"Metastatic Breast Cancer","completionDate":"2023-07","primaryEndpoint":"The goal of this non-interventional study is to emulate the PALOMA-2 randomized controlled trial of palbociclib as first-line therapy in patients with estrogen receptor-positive (ER+)/human epidermal "},{"nctId":"NCT04985266","phase":"Phase 2","title":"A Trial of Early Detection of Molecular Relapse With Circulating Tumour DNA Tracking and Treatment W","status":"Recruiting","sponsor":"Royal Marsden NHS Foundation Trust","isPivotal":false,"enrollment":1100,"indication":"ER+ Breast Cancer","completionDate":"2027-09","primaryEndpoint":"Detection of molecular relapse with circulating tumour DNA analysis can identify which patients with ER positive breast cancer are relapsing on adjuvant endocrine therapy."},{"nctId":"NCT02142868","phase":"N/A","title":"Expanded Access Study Of Palbociclib (PD-0332991) In Combination With Letrozole As Treatment Of Post","status":"No Longer Available","sponsor":"Pfizer","isPivotal":false,"enrollment":null,"indication":"Advanced Breast Cancer (Female)","completionDate":"","primaryEndpoint":"To provide access to palbociclib to post-menopausal women with HR-positive, HER2-negative advanced breast cancer who are deemed appropriate for letrozole therapy (Canada: first-line patients only)."},{"nctId":"NCT06525675","phase":"N/A","title":"Study to Evaluate the Extended Overall Survival (OS) Data From PARSIFAL Study (The PARSIFAL-LONG Stu","status":"Completed","sponsor":"MedSIR","isPivotal":false,"enrollment":419,"indication":"Metastatic Breast Cancer","completionDate":"2024-05","primaryEndpoint":"The goal of this study is to evaluate the extended Overall Survival (OS) from PARSIFAL trial - NCT02491983 focused on the efficacy and safety of palbociclib in combination with fulvestrant or letrozol"},{"nctId":"NCT00721409","phase":"Phase 2","title":"Study Of Letrozole With Or Without Palbociclib (PD-0332991) For The First-Line Treatment Of Hormone-","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":177,"indication":"Breast Cancer","completionDate":"2013-11","primaryEndpoint":"The study is aimed to confirm that letrozole + PD 0332991 is safe and tolerable and to assess the effect of the combination on advanced breast cancer"},{"nctId":"NCT04553133","phase":"Phase 2","title":"PF-07104091 as a Single Agent and in Combination Therapy","status":"Active Not Recruiting","sponsor":"Pfizer","isPivotal":false,"enrollment":154,"indication":"Small Cell Lung Cancer","completionDate":"2026-03","primaryEndpoint":"To assess the safety and tolerability of increasing doses of PF-07104091 and to estimate the Maximum Tolerated Dose (MTD) and/or select the Recommended Phase 2 dose (RP2D) for PF-07104091 as a single "},{"nctId":"NCT03921866","phase":"N/A","title":"UK Ibrance Patient Program (IPP) Study","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":191,"indication":"HR+/HER2- Locally Advanced, Metastatic Breast Cancer","completionDate":"2021-03","primaryEndpoint":"What are the real-world treatment patterns, patients' characteristics, clinical outcomes and healthcare resource utilisation associated with palbociclib treatment in the 3 years following initiation i"},{"nctId":"NCT02028507","phase":"Phase 3","title":"Phase III Palbociclib With Endocrine Therapy vs. Capecitabine in HR+/HER2- MBC With Resistance to Ar","status":"Completed","sponsor":"Spanish Breast Cancer Research Group","isPivotal":false,"enrollment":693,"indication":"Metastatic Breast Cancer","completionDate":"2019-01","primaryEndpoint":"This is an international (4 countries) randomized phase III study with 2 cohorts, patients will be randomized 1:1 to endocrine therapy (cohort 1: exemestane 25 mg daily, cohort 2: fulvestrant 500mg da"},{"nctId":"NCT03809988","phase":"Phase 2","title":"PALbociclib Rechallenge in horMone Receptor-posItive/HER2- Negative Advanced Breast Cancer (PALMIRA)","status":"Completed","sponsor":"MedSIR","isPivotal":false,"enrollment":198,"indication":"Breast Cancer","completionDate":"2022-11","primaryEndpoint":"Hormone Receptor (HR)-positive/Human Epidermal Growth Factor Receptor 2 (HER2)-negative advanced breast cancer (ABC)"},{"nctId":"NCT05505175","phase":"N/A","title":"Outcomes Among Patients in Brazil Receiving Palbociclib Combinations for HR+/HER2- MBC","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":120,"indication":"Breast Cancer","completionDate":"2023-05","primaryEndpoint":"The objective of this study is to describe patient demographics, clinical characteristics, treatment patterns and clinical outcomes of adult female patients who have received palbociclib combination t"},{"nctId":"NCT01684215","phase":"Phase 2","title":"A Study Of Oral Palbociclib (PD-0332991), A CDK4/6 Inhibitor, As Single Agent In Japanese Patients W","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":61,"indication":"Neoplasms","completionDate":"2016-03","primaryEndpoint":"This study is comprised of two portions: a Phase 1 portion and a Phase 2 portion."},{"nctId":"NCT06086340","phase":"N/A","title":"Study to Compare Overall Survival in Medicare Patients With Metastatic Breast Cancer Treated With a ","status":"Completed","sponsor":"Pfizer","isPivotal":false,"enrollment":779,"indication":"Breast Cancer","completionDate":"2024-01","primaryEndpoint":"A retrospective study of de-identified (to preserve patient privacy) patient information from the SEER-Medicare Database to compare overall survival of first line palbociclib + aromatase inhibitor (AI"},{"nctId":"NCT03870919","phase":"N/A","title":"Locoregional Treatment and Palbociclib in de Novo, Treatment Naive, Stage IV ER+, HER2- Breast Cance","status":"Active Not Recruiting","sponsor":"UNICANCER","isPivotal":false,"enrollment":200,"indication":"Breast Cancer Stage IV","completionDate":"2024-08","primaryEndpoint":"Approximately 3.5% to 6% of newly diagnosed breast cancer patients are stage IV metastatic."},{"nctId":"NCT02389842","phase":"Phase 1","title":"PIPA: Combination of PI3 Kinase Inhibitors and PAlbociclib","status":"Completed","sponsor":"Royal Marsden NHS Foundation Trust","isPivotal":false,"enrollment":79,"indication":"Advanced Solid Tumours","completionDate":"2018-10","primaryEndpoint":"Part A: This is a phase Ib trial combining the CDK4/6 inhibitor palbociclib with the PI3K inhibitors taselisib, or pictilisib."}],"genericFilers":[],"latestUpdates":[],"manufacturing":[],"administration":{"icon":"","route":"","frequency":"","formulation":""},"crossReferences":{"chemblId":"CHEMBL1444"},"formularyStatus":[],"developmentCodes":[],"ownershipHistory":[],"therapeuticAreas":["Oncology"],"biosimilarFilings":[],"firstApprovalDate":"","companionDiagnostics":[],"firstApprovalCountry":null,"genericManufacturerList":[],"modality":"","enrichmentLevel":3,"visitCount":3,"trialStats":{"total":1,"withResults":1},"verificationStatus":"partial","dataCompleteness":{"mechanism":true,"indications":false,"safety":false,"trials":true,"score":2}}