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drugsProductApproved2015🇪🇺🇬🇧🇯🇵🇨🇳🇦🇺

Palbociclib

Palbociclib was the first CDK4/6 inhibitor (2015), and in 2026 became the first approved as maintenance in HER2-positive, hormone-positive breast cancer.

PALOMA-2/3 (PFS benefit, no OS benefit); PALLAS and PENELOPE-B negative in adjuvant setting. PATINA (2024 SABCS; approved Q2 2026): adding palbociclib to anti-HER2 plus endocrine maintenance in HR+/HER2+ metastatic disease extended PFS by ~15 months. Pfizer.

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Palbociclib
PubChem
Mechanism, step by step
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1.Oral drug is absorbed and reaches the tumour

Modality
Small-molecule CDK4/6 inhibitor
Mechanism
Reversible CDK4/6 inhibitor.
Brand / code
Ibrance
Dosing & schedule
Route
Oral
Schedule
125 mg once daily for 21 days, then 7 days off (28-day cycle), with aromatase inhibitor or fulvestrant
Dose modifications
Reduce to 100 then 75 mg for grade 3 neutropenia with fever or grade 4
Monitoring
Complete blood count before each cycle and on day 15 of the first two cycles; ILD symptoms

Source: US prescribing information (DailyMed). Doses are for orientation; the current label governs.

Medicare
Part D (self-administered)

Oral, self-administered, so it is a Part D drug: covered through a stand-alone Part D plan or Medicare Advantage drug benefit, usually on the specialty tier with 25 to 33% coinsurance until the annual cap ($2,000 in 2025, $2,100 in 2026). Ibrance was selected for Medicare price negotiation in January 2025; the negotiated price takes effect 1 January 2027.

Commercial insurance
covered with prior authorisation

Covered for FDA-labelled and NCCN-listed uses, but almost always behind prior authorisation confirming diagnosis, biomarker and line of therapy; dispensed through a specialty pharmacy. Some PBMs designate a preferred CDK4/6 inhibitor and require it first.

Part D out-of-pocket capped at $2,000 (2025) / $2,100 (2026). Medicare patients cannot use manufacturer co-pay cards; charity funds (PAN, HealthWell, CancerCare) and the Extra Help subsidy are the routes.

Sources: Medicare.gov: Drug coverage (Part D) · Medicare.gov: Costs for Medicare drug coverage (annual out-of-pocket cap) · CMS: Medicare Drug Price Negotiation Program. Not medical or financial advice; verify with your plan.

NICE recommendedNICE TA495 · 2017SMC: accepted
Appraised for
With an aromatase inhibitor for untreated HR-positive, HER2-negative advanced breast cancer
Notes
With fulvestrant after endocrine therapy: TA619 (2020, from CDF to routine).
NHS England
Routinely funded for the appraised indication (or via managed access)

Sources: NICE TA495 · SMC advice: palbociclib. Funding decisions are indication-specific and change monthly; verify with NICE and your treating team.

Regulatory

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  1. 3 Feb 2015ApprovalUS

    Accelerated approval with letrozole: first CDK4/6 inhibitor (PALOMA-1) source

  2. 19 Feb 2016ApprovalUS

    With fulvestrant after endocrine therapy (PALOMA-3) source

  3. 31 Mar 2017ApprovalUS

    Full approval (PALOMA-2) source

  4. 4 Apr 2019ApprovalUS

    Men with HR+/HER2- breast cancer source

  5. Q2 2026ApprovalUS

    Maintenance in HR+/HER2+ advanced breast cancer with anti-HER2 and endocrine therapy (PATINA) source

Approvals

RegionYearIndication
US2015HR+/HER2- advanced breast cancer with endocrine therapy
US2026HR+/HER2+ advanced breast cancer maintenance with anti-HER2 and endocrine therapy

Safety

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Toxicity profile
Adverse eventAny gradeGrade 3+
Neutropenia
80%
66%
Infections
60%
7%
Leukopenia
39%
25%
Fatigue
37%
2%
Nausea
35%
1%
Alopecia
33%
Stomatitis
30%
1%
Diarrhoea
26%
1%
Anaemia
24%
6%
Rash
18%
1%

PALOMA-2 with letrozole. Rates read from the US prescribing information. Blank cells mean the figure was not sourced, not that it is zero.

Cost & access

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Cost & access
CountryReimbursement
United StatesMedicare Part D; generic entry expected 2027 in the US
United KingdomNICE: recommended with aromatase inhibitor (TA495) and fulvestrant (TA619)

List prices are manufacturer or Medicare figures where publicly disclosed; net prices after rebates are usually lower. Reimbursement changes; check the payer.

Trials

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ClinicalTrials.gov · phase 2/3
refreshed 2026-09-06
239 studies20 recruiting81 Phase 220 Phase 3
Search “Palbociclib” on ClinicalTrials.gov →
Counts are from a name search and may include unrelated studies; up to 100 studies are summarised.

Recruiting now (live from ClinicalTrials.gov)

Recruiting trials near you · live from ClinicalTrials.gov
Palbociclib
intervention: Palbociclib
Open on ClinicalTrials.gov →

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Latest papers

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Literature trend399 papers in the last 12 months+14% vs prior 12How this is computed
Latest papers · live from Europe PMC
Open in Europe PMC

Query for this drug: (TITLE:"Palbociclib" OR ABSTRACT:"Palbociclib" OR TITLE:"Ibrance" OR ABSTRACT:"Ibrance") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about Palbociclib, not a curated reading list.

Connected

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