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PF-08165784

Phase 1

Advanced Breast Cancer | Small molecule | Oncology |Pfizer, Inc.|Trials Updated: Oct 28, 2026

PF-08165784 development status

Highest phase Phase 1
Registered trials 1 across 1 sponsor since Oct 2026

Success Probability

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Market & Valuation

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Trial Design

CONTROLLEDBiomarker
Total Trials1
Total Enrollment268

FDA Designations

No designations recorded

PF-08165784 clinical trials

PF-08165784 · 1 trial · 4 indications

Phase 1 1
NCT07897721A Study to Learn About the Study Medicine Called PF-08165784 in People With PIK3CA-Mutated Advanced or Metastatic Solid TumorsAdvanced Breast Cancer
NOT YET_RECRUITING268 Analytics
PHASE1NOT YET_RECRUITING
A Study to Learn About the Study Medicine Called PF-08165784 in People With PIK3CA-Mutated Advanced or Metastatic Solid Tumors
Advanced Breast Cancer
NCT07897721268
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Study Endpoints

Primary Endpoints

Part 1 (Dose Escalation): Number of participants with Dose-Limiting Toxicities (DLT)
Baseline up to 28 days

Any adverse events that are attributable to one, the other, or both study treatments, occurring in the DLT observation period are considered DLTs, excluding toxicities clearly due to underlying disease or extraneous causes.

Part 1 (Dose Escalation): Incidence of Adverse Events (AEs)
From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

An adverse event (AE) was any untoward medical occurrence in a participant who received study medication without regard to possibility of causal relationship to it.

Part 1 (Dose Escalation): Number of participants with laboratory abnormalities
From start of treatment up to 30 days after last dose or start of new anticancer therapy, whichever occurred first

Number of participants with laboratory test abnormalities.

Part 2 (Dose Expansion): Objective Response Rate (ORR)
Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)

ORR defined as per Response Evaluation Criteria in Solid Tumors (RECIST v1.1).

Secondary Endpoints

Part 1: Objective Response Rate (ORR) as per Response Evaluation Criteria in Solid Tumors (RECIST v1.1)
Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)
Part 1 & Part 2: Disease Control Rate (DCR) as per RECIST v1.1
Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)
Part 1 & Part 2: Clinical Benefit Rate (CBR) as per RECIST v1.1
Baseline and every 8 to 12 weeks through time of confirmed disease progression, death, unacceptable toxicity, or through study completion (approximately 2 years)
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Study Design & Arms

AllocationNON_RANDOMIZED
MaskingNONE
ModelSEQUENTIAL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Part 1 Dose Escalation Cohort 1AEXPERIMENTALPF-08165784 monotherapy dose escalation for participants with advanced or metastatic BC at different doses of the study drug
Part 1 Dose Escalation Cohort 1BEXPERIMENTALCombination (PF-08165784 + fulvestrant) dose escalation for participants with advanced or metastatic BC, at different doses of the study drug
Part 1 Dose Escalation Cohort 1CEXPERIMENTALCombination (PF-08165784 + fulvestrant + atirmociclib) dose escalation for participants with advanced or metastatic BC, at different doses of the study drug
Part 1 Dose Escalation Cohort 1DEXPERIMENTALCombination (PF-08165784 + cetuximab) dose escalation for participants with advanced or metastatic CRC at different doses of the study drug
Part 2 Dose Optimization/Expansion Cohort 2AEXPERIMENTALCombination (PF-08165784 + letrozole + atirmociclib) dose optimization/expansion for participants with advanced or metastatic BC, at different doses of the study drug

Interventions

NameTypeDescription
PF-08165784DRUGTaken by mouth (PO)
FulvestrantDRUGSelective Estrogen Receptor Degrader (SERD)
AtirmociclibDRUGSelective cyclin-dependent kinase 4 (CDK4) inhibitor
CetuximabDRUGMonoclonal antibody (EGFR inhibitor)
LetrozoleDRUGNonsteroidal aromatase inhibitor
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo

Inclusion Criteria: * 18 years of age or older * Advanced or metastatic cancer of the breast or colon Part 1A, 1B, and 1C: HR+/HER2- advanced or metastatic breast cancer with disease progression after at least 1 line of treatment with an endocrine therapy and cyclin-dependent kinase (CDK)4/6 inhibi...

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Competitive Landscape -Breast Cancer 611 trials (matched to "Advanced Breast Cancer")

Top 20 of 87 competitors

CompanyTickerTrialsLead PhaseDrugs
AstraZeneca PLCAZN54PHASE3Fulvestrant, Capivasertib, Trastuzumab deruxtecan, Dato-DXd, Durvalumab
Merck & Co., Inc.MRK21PHASE3Pembrolizumab, Sacituzumab tirumotecan, Patritumab Deruxtecan, Olaparib, Belzutifan
Eli Lilly and CompanyLLY27PHASE3Abemaciclib, Imlunestrant, LY4064809, LOXO-783, LY4101174
BioNTech SE Sponsored ADRBNTX7PHASE3BNT323, Pumitamig, BNT326
Gilead Sciences, Inc.GILD18PHASE3Sacituzumab govitecan, TUB-030
Novartis AG Sponsored ADRNVS44PHASE3Ribociclib, Letrozole, Alpelisib, Capecitabine, Spartalizumab
Pfizer Inc.PFE36PHASE3Vepdegestrant, PF-07220060, Palbociclib, Tucatinib, Trastuzumab
BeOne Medicines Ltd. Sponsored ADRONC6PHASE3BGB-43395, BG-75202, BGB-21447, BG-68501
Olema Pharmaceuticals, Inc.OLMA5PHASE3Palazestrant, OP-3136
Jazz Pharmaceuticals Public Limited CompanyJAZZ3PHASE3Zanidatamab
Celcuity Inc.CELC3PHASE3Gedatolisib
Relay Therapeutics, Inc.RLAY2PHASE3Zovegalisib
GSK plc Sponsored ADRGSK2PHASE3Niraparib
Greenwich LifeSciences, Inc.GLSI1PHASE3GLSI-100
Bristol-Myers Squibb CompanyBMY7PHASE2Nivolumab, Ipilimumab, Iza-bren, Nab-paclitaxel, RYZ101
BriaCell Therapeutics CorpBCTX1PHASE3SV-BR-1-GM
Hoffmann-La RocheRHHBY30PHASE3Phesgo, Giredestrant, Atezolizumab, Trastuzumab Emtansine, Trastuzumab
Incyte CorporationINCY4PHASE2Ruxolitinib, Axatilimab
Puma Biotechnology, Inc.PBYI3PHASE2Neratinib, Alisertib
AbbVie, Inc.ABBV4PHASE1ABBV-927, ABBV-368, ABBV-181, Ibrutinib, ABBV-400
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Recent Changes (Last 90 Days)

LOWOct 28, 2026NCT07897721lastUpdatePostDate: changed
LOWOct 28, 2026NCT07897721lastUpdatePostDate: changed
LOWOct 27, 2026NCT07897721NEW_TRIAL: changed
LOWOct 27, 2026NCT07897721NEW_TRIAL: changed

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