marked.bio

aromatase inhibitor · small molecule

letrozole

10 active trials across 7 of our biomarkers, targeting aromatase. Not approved for any biomarker on marked.bio yet.

Also known as Femara.

Counts only trials that select patients by one of the biomarkers on marked.bio, not every trial of this drug.

Biomarkers

BiomarkerActive trialsAll trialsFurthest active phase
PIK3CA activating mutation 6 13 Phase 3
BRCA1/2 mutation 1 2 Phase 3
ESR1 mutation 1 2 Phase 3
HER2-low / ultralow (IHC 1+ or 2+/ISH-) 1 3 Phase 2
MSI-H / dMMR 1 1 Phase 2/3
ALK fusion 0 1 –
EGFR exon 19 deletion / L858R 0 1 –

Sponsors

Industry sponsors leading active biomarker-selected trials of letrozole.

  1. Roche 3
  2. Eli Lilly 2
  3. AstraZeneca 2
  4. Pfizer 1

Trials

10 of 22 trials shown

  1. Refining Fertility-sparing Treatment in Endometrial Carcinoma Based on Molecular Classification

    Recruiting Phase 2/3 Fudan University Started 2026Primary completion 2027-12 NCT07319429

    sintilimabMedroxyprogesterone Acetate 500 MGMegestrol Acetate 160 MGletrozole

    2). dMMR (deficient mismatch repair)/MSI-H endometrial cancer: Pathologically and radiologically evaluated as FIGO 2023 Stage I-II e…

    MSI-H / dMMREndometrial Cancer, Fertility

  2. A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA)

    Recruiting Phase 3 Eli Lilly Started 2025Primary completion 2029-05 NCT07174336

    STX-478ribociclibpalbociclib FDA EUabemaciclibanastrozoleletrozoleExemestanefulvestrant FDA EU

    Have evidence of an activating PIK3CA mutation, detected in tumor or blood samples using an appropriate assay.

    PIK3CA activating mutationBreast Neoplasms, Neoplasm Metastasis

  3. A Study Evaluating the Efficacy and Safety of Inavolisib Plus CDK4/6 Inhibitor and Letrozole vs Placebo + CDK4/6i and Letrozole in Participants With Endocrine-Sensitive PIK3CA-Mutated, Hormone Receptor-Positive, HER2-Negative Advanced Breast Cancer

    Recruiting Phase 3 Roche Started 2025Primary completion 2032-01 NCT06790693

    inavolisib FDA EUCDK4/6iletrozole

    …and Letrozole vs Placebo + CDK4/6i and Letrozole in Participants With Endocrine-Sensitive PIK3CA-Mutated, Hormone Receptor-Positive, HER2-Negative Advanced Breast Cancer

    PIK3CA activating mutationBreast Cancer

  4. Saruparib (AZD5305) Plus Camizestrant or Plus Endocrine Therapy, Compared With CDK4/6 Inhibitor Plus Endocrine Therapy or Plus Camizestrant in HR-Positive, HER2-Negative (IHC 0, 1+, 2+/ ISH Non-amplified), BRCA1, BRCA2, or PALB2m Advanced Breast Cancer

    Recruiting Phase 3 AstraZeneca Started 2024Primary completion 2029-12 NCT06380751

    saruparibcamizestrantabemaciclibribociclibpalbociclibfulvestrantletrozoleanastrozoleExemestane

    Documented germline tumour loss of function mutation in BRCA1, BRCA2, or PALB2

    BRCA1/2 mutationAdvanced Breast Cancer

  5. Phase III Study to Assess AZD9833+ CDK4/6 Inhibitor in HR+/HER2-MBC With Detectable ESR1m Before Progression (SERENA-6)

    Active, not recruiting Phase 3 AstraZeneca Started 2021Primary completion 2025-06 NCT04964934

    camizestrant FDAanastrozoleletrozolepalbociclibabemaciclib FDALuteinizing hormone-releasing hormone (LHRH) agonistribociclib

    Have an ESR1 mutation in their cancer;

    ESR1 mutationER-Positive HER2-Negative Breast Cancer

  6. A Study to Test Inavolisib Treatments in Participants With Early-Stage, PIK3CA-Mutated Breast Cancer

    Recruiting Phase 2 Roche Started 2025Primary completion 2027-07 NCT07054190

    inavolisib FDA EUribociclibletrozolegiredestrant

    Confirmed PIK3CA mutation

    PIK3CA activating mutationBreast Cancer

  7. Clinical Study of SHR-A1811 With or Without Letrozole in Neoadjuvant Therapy for Early-Stage HR-Positive, HER2-Low Breast Cancer

    Not yet recruiting Phase 2 First Hospital of China Medical University Started 2025Primary completion 2027-03 NCT07305246

    trastuzumab rezetecanletrozoleTAC/AC-T

    Histopathologically confirmed HR-positive (ER ≥1% and/or PR ≥1%) with HER2-low expression (defined as IHC 1+/2+ and FISH negative);

    HER2-low / ultralow (IHC 1+ or 2+/ISH-)Breast Cancer

  8. A Study to Learn About the Study Medicine Called PF-08165784 in People With PIK3CA-Mutated Advanced or Metastatic Solid Tumors

    Not yet recruiting Phase 1 Pfizer Started 2026Primary completion 2030-03 NCT07897721

    PF-08165784fulvestrant FDA EUAtirmociclibcetuximabletrozole

    Phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) mutation

    PIK3CA activating mutationAdvanced Breast Cancer, Advanced or Metastatic Breast Cancer, Metastatic Breast Cancer (HR+/ HER2-), Metastatic Colorectal Adenocarcinoma

  9. A Study of LOXO-783 in Patients With Breast Cancer/Other Solid Tumors

    Active, not recruiting Phase 1 Eli Lilly Started 2022Primary completion 2025-04 NCT05307705

    LOXO-783fulvestrant FDA EUimlunestrantabemaciclibanastrozoleletrozolepaclitaxel

    … H1047R mutation (or other Sponsor and safety review committee (SRC)-approved, activating PIK3CA mutations other than H1047R mutation)

    PIK3CA activating mutationBreast Cancer

  10. To Evaluate the Safety, Tolerability, and Pharmacokinetics of Inavolisib Single Agent in Participants With Solid Tumors and in Combination With Endocrine and Targeted Therapies in Participants With Breast Cancer

    Active, not recruiting Phase 1 Roche Started 2016Primary completion 2026-12 NCT03006172

    inavolisib FDA EUfulvestrant FDA EUletrozolepalbociclib FDA EUmetformintrastuzumabpertuzumab

    Locally advanced, recurrent, or metastatic, PIK3CA mutant, incurable solid tumor malignancy, including breast cancer

    PIK3CA activating mutationBreast Cancer, Solid Tumor