48 Sacituzumab Govitecan (SG) Efficacy in Hormone Receptor– Positive/Human Epidermal Growth Factor Receptor 2– Negative (HR+/HER2–) Metastatic Breast Cancer (mBC) by HER2 Immunohistochemistry (IHC) Status in the Phase 3 TROPiCS-02 Study

Publication
Article
Miami Breast Cancer Conference® Abstracts Supplement40th Annual Miami Breast Cancer Conference® - Abstracts
Volume 37
Issue suppl 4
Pages: 33-34

TABLE. SG Improved PFS vs TPC in HER2-Low and HER2 IHC0 Groups, Consistent With Outcomes in the ITT Population

TABLE. SG Improved PFS vs TPC in HER2-Low and HER2 IHC0 Groups, Consistent With Outcomes in the ITT Population

Background

Tumors with HER2 IHC1+ or IHC2+ combined with a negative in situ hybridization (ISH) test are described as HER2-low. SG, a novel Trop-2–directed antibody-drug conjugate, is approved for patients (pts) with metastatic triple-negative breast cancer in the second line or greater setting. In the TROPiCS-02 study, SG demonstrated a 34% reduction in risk of progression or death vs treatment of physician’s choice (TPC) in heavily pretreated, endocrine-resistant HR+/HER2– mBC. In this TROPiCS-02 post hoc analysis, we describe SG efficacy in HER2 IHC0 and HER2-low HR+/HER2– mBC.

Methods

Pts with HR+/HER2– unresectable locally advanced or mBC and 2-4 prior chemotherapy regimens for mBC were randomized 1:1 to receive SG (10 mg/kg IV on d1 and d8, every 21d) or TPC (capecitabine, eribulin, vinorelbine, or gemcitabine) until unacceptable toxicity or disease progression. Primary end point was progression-free survival (PFS) per RECIST 1.1 by central review. Pts with known HER2-positive disease were ineligible, with HER2 status (IHC and ISH) assessed locally.

Results

In the intent-to-treat (ITT) population and in each treatment arm, 92% of pts were HER2 IHC0 or HER2-low. Baseline characteristics between HER2 IHC0 and HER2-Low were comparable and similar to that of the ITT population. Median PFS was improved with SG vs TPC in the HER2 IHC0 and HER2-low groups (HR 0.72, P=0.05; and 0.58, P <0.001, respectively; Table). Subgroup safety profiles were consistent with that of the overall safety population.

Conclusions

Clinical benefit with SG vs TPC in HER2 IHC0 and HER2-Low HR+/HER2− mBC was consistent with that of the TROPiCS-02 ITT population. SG should be considered an effective treatment option for pts with HR+/HER2- mBC, regardless of HER2 status.

AFFILIATIONS:

Sara M. Tolaney,1 Peter Schmid,2 Javier Cortes,3 Frederik Marmé,4 Hope S. Rugo,5 Mafalda Oliveira,6 Delphine Loirat,7 Komal Jhaveri,8 Oh Kyu Yoon,9 Monica Motwani,9 Hao Wang,9 Rosemary Delaney,10 Aditya Bardia11

1Dana-Farber Cancer Institute, Boston, MA.

2Barts Cancer Institute, Queen Mary University of London, London, United Kingdom.

3International Breast Cancer Center (IBCC), Quiron Group, Madrid and Barcelona, Spain.

4Heidelberg University, University Hospital Mannheim, Heidelberg, Germany.

5University of California San Francisco, Helen Diller Family Comprehensive Cancer Center, San Francisco, CA.

6Vall d’Hebron University Hospital and Vall d’Hebron Institute of Oncology, Barcelona, Spain.

7Institut Curie, Paris, France.

8Memorial Sloan Kettering Cancer Center, New York, NY.

9Gilead Sciences, Inc, Foster City, CA.

10Gilead Sciences, Inc, Morris Plains, NJ.

11Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA.

Articles in this issue

1 Elacestrant Versus Fulvestrant or Aromatase Inhibitor in a Phase 3 Trial Evaluating Elacestrant, an Oral Selective Estrogen Receptor Degrader Versus Standard-of- Care Endocrine Monotherapy for ER+/HER2– Advanced/Metastatic Breast Cancer
1 Elacestrant Versus Fulvestrant or Aromatase Inhibitor in a Phase 3 Trial Evaluating Elacestrant, an Oral Selective Estrogen Receptor Degrader Versus Standard-of- Care Endocrine Monotherapy for ER+/HER2– Advanced/Metastatic Breast Cancer
2 Molecular Characterization of HER2-Low Patients Identifies Basal-Enriched Subset With Poor Clinical Outcomes in Real-world Data
2 Molecular Characterization of HER2-Low Patients Identifies Basal-Enriched Subset With Poor Clinical Outcomes in Real-world Data
3 Real-world Outcomes of Sacituzumab Govitecan in Metastatic Breast Cancer Patients: A Single Institution Experience
3 Real-world Outcomes of Sacituzumab Govitecan in Metastatic Breast Cancer Patients: A Single Institution Experience
4 Datopotamab Deruxtecan (Dato-DXd) + Durvalumab (D) as First-Line (1L) Treatment for Unresectable Locally Advanced/ Metastatic Triple-Negative Breast Cancer (a/mTNBC): Updated Results From BEGONIA, a Phase 1b/2 Study
4 Datopotamab Deruxtecan (Dato-DXd) + Durvalumab (D) as First-Line (1L) Treatment for Unresectable Locally Advanced/ Metastatic Triple-Negative Breast Cancer (a/mTNBC): Updated Results From BEGONIA, a Phase 1b/2 Study
5 Treatment Patterns and Clinical Outcomes in Patients Receiving Palbociclib Combinations as First- Line Treatment for Advanced or Metastatic Breast Cancer in Realworld Settings in Argentina and Colombia: Results from the IRIS Study
5 Treatment Patterns and Clinical Outcomes in Patients Receiving Palbociclib Combinations as First- Line Treatment for Advanced or Metastatic Breast Cancer in Realworld Settings in Argentina and Colombia: Results from the IRIS Study
7 EMERALD Phase 3 Trial of Elacestrant Versus Standard-of- Care Endocrine Therapy in Patients With ER+/HER2– Metastatic Breast Cancer: Updated Results by Duration of Prior CDK4/6i in Metastatic Setting
7 EMERALD Phase 3 Trial of Elacestrant Versus Standard-of- Care Endocrine Therapy in Patients With ER+/HER2– Metastatic Breast Cancer: Updated Results by Duration of Prior CDK4/6i in Metastatic Setting
8 Datopotamab Deruxtecan (Dato-DXd) in Advanced Triple- Negative Breast Cancer (TNBC): Updated Results From the Phase 1 TROPION-PanTumor01 Study
8 Datopotamab Deruxtecan (Dato-DXd) in Advanced Triple- Negative Breast Cancer (TNBC): Updated Results From the Phase 1 TROPION-PanTumor01 Study
9 Phase 1 TROPION-PanTumor01 Study Evaluating Datopotamab Deruxtecan (Dato-DXd) in Unresectable or Metastatic Hormone Receptor–Positive/ Human Epidermal Growth Factor Receptor 2–Negative Breast Cancer
9 Phase 1 TROPION-PanTumor01 Study Evaluating Datopotamab Deruxtecan (Dato-DXd) in Unresectable or Metastatic Hormone Receptor–Positive/ Human Epidermal Growth Factor Receptor 2–Negative Breast Cancer
11 Real-world Treatment Patterns and Effectiveness of Palbociclib Plus an Aromatase Inhibitor in Patients With Metastatic Breast Cancer Aged 75 Years or Above
11 Real-world Treatment Patterns and Effectiveness of Palbociclib Plus an Aromatase Inhibitor in Patients With Metastatic Breast Cancer Aged 75 Years or Above
12 TIP HARMONIA SOLTI-2101/ AFT-58: A Head-to-Head Phase III Study Comparing Ribociclib (RIB) and Palbociclib (PAL) in Patients (pts) With Hormone Receptor– Positive/HER2-Negative/HER2- Enriched (HR+/HER2−/HER2-E) Advanced Breast Cancer (ABC)
12 TIP HARMONIA SOLTI-2101/ AFT-58: A Head-to-Head Phase III Study Comparing Ribociclib (RIB) and Palbociclib (PAL) in Patients (pts) With Hormone Receptor– Positive/HER2-Negative/HER2- Enriched (HR+/HER2−/HER2-E) Advanced Breast Cancer (ABC)
13 Improved Sensitivity in Identification of ER- and HER2- Expressing Metastatic Breast Cancers With a Combination of Cell & Cell-Free Liquid Biopsy Analysis
13 Improved Sensitivity in Identification of ER- and HER2- Expressing Metastatic Breast Cancers With a Combination of Cell & Cell-Free Liquid Biopsy Analysis
15 Updated Expert Consensus Recommendations for Managing Hyperglycemia and Rash in Patients With PIK3CA-Mutated, Hormone Receptor–Positive (HR+), Human Epidermal Growth Factor Receptor 2–Negative (HER2–) Advanced Breast Cancer Treated With Alpelisib
15 Updated Expert Consensus Recommendations for Managing Hyperglycemia and Rash in Patients With PIK3CA-Mutated, Hormone Receptor–Positive (HR+), Human Epidermal Growth Factor Receptor 2–Negative (HER2–) Advanced Breast Cancer Treated With Alpelisib
16 Primary Results From the Randomized Phase II RIGHT Choice Trial of Premenopausal Patients With Aggressive HR+/HER2− Advanced Breast Cancer Treated With Ribociclib + Endocrine Therapy vs Physician’s Choice Combination Chemotherapy
16 Primary Results From the Randomized Phase II RIGHT Choice Trial of Premenopausal Patients With Aggressive HR+/HER2− Advanced Breast Cancer Treated With Ribociclib + Endocrine Therapy vs Physician’s Choice Combination Chemotherapy
17 A Clinical Systematic Literature Review of Treatments Among Patients With Advanced/ Metastatic HER2+ Breast Cancer
17 A Clinical Systematic Literature Review of Treatments Among Patients With Advanced/ Metastatic HER2+ Breast Cancer
20 TIP ELONA: An Open-Label, Phase 1b-2 Study of Elacestrant, in Combination With Onapristone in Patients With Estrogen Receptor– Positive, Progesterone Receptor– Positive, HER2-Negative Advanced or Metastatic Breast Cancer
20 TIP ELONA: An Open-Label, Phase 1b-2 Study of Elacestrant, in Combination With Onapristone in Patients With Estrogen Receptor– Positive, Progesterone Receptor– Positive, HER2-Negative Advanced or Metastatic Breast Cancer
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