The oral selective estrogen receptor degrader GDC-0810 (ARN-810) in postmenopausal women with hormone receptor-positive HER2-negative (HR + /HER2 -) advanced/metastatic breast cancer

PURPOSE: GDC-0810 (ARN-810) is a novel, non-steroidal, orally bioavailable, selective estrogen receptor degrader (SERD) that potentially inhibits ligand-dependent and ligand-independent estrogen receptor (ER)-mediated signaling. METHODS: A phase Ia/Ib/IIa dose escalation, combination treatment with palbociclib or a luteinizing hormone-releasing hormone, and expansion study determined the safety, pharmacokinetics, and recommended phase 2 dose (RP2D) of GDC-0810 in postmenopausal women with ER + (HER2 -) locally advanced or metastatic breast cancer (MBC). Baseline plasma ctDNA samples were analyzed to determine the ESR1 mutation status. RESULTS: Patients (N = 152) received GDC-0810 100-800 mg once daily (QD) or 300-400 mg twice daily, in dose escalation, expansion, as single agent or combination treatment. Common adverse events regardless of attribution to study drug were diarrhea, nausea, fatigue, vomiting, and constipation. There was one dose-limiting toxicity during dose escalation. The maximum tolerated dose was not reached. GDC-0810 600 mg QD taken with food was the RP2D. Pharmacokinetics were predictable. FES reduction (\u3e 90%) highlighting pharmacodynamic engagement of ER was observed. Outcomes for the overall population and for patients with tumors harboring ESR1 mutations included partial responses (4% overall; 4% ESR1), stable disease (39% overall; 42% ESR1), non-complete response/non-progressive disease (13% overall; 12% ESR1), progressive disease (40% overall; 38% ESR1), and missing/unevaluable (5% overall; 5% ESR1). Clinical benefit (responses or SD, lasting ≥ 24 weeks) was observed in patients in dose escalation (n = 16, 39%) and expansion (n = 24, 22%). CONCLUSION: GDC-0810 was safe and tolerable with preliminary anti-tumor activity in heavily pretreated patients with ER + advanced/MBC, with/without ESR1 mutations, highlighting the potential for oral SERDs. Clinical Trial and registration date April 4, 2013. NCT01823835

Precision medicine and personalized breast cancer: combination pertuzumab therapy

Trastuzumab (Herceptin), a monoclonal antibody directed against the human epidermal growth-factor receptor 2 (HER2), is the poster child for antibody-based targeted therapy in breast cancer. Pertuzumab, another humanized monoclonal antibody, binds to a different domain of HER2 and prevents the formation of HER2:HER3 dimers, which is the most potent heterodimer in the HER family. The combination of trastuzumab and pertuzumab has synergistic activity, and is associated with improved clinical outcomes. The US Food and Drug Administration (FDA) approved pertuzumab in combination with trastuzumab-based chemotherapy originally as first-line therapy for metastatic HER2-positive breast cancer in 2012, and more recently as neoadjuvant therapy for localized disease in 2013. Pertuzumab is the first neoadjuvant drug to receive accelerated approval by the FDA based on pathological complete response as the primary end point. In this article, we review the mechanism of action, pharmacokinetics, clinical efficacy, safety, and current role of pertuzumab in the management of breast cancer, as well as ongoing clinical trials and future directions regarding the utility of pertuzumab as a personalized therapeutic option for HER2-positive breast cancer. In the coming years, we anticipate increased utilization of neoadjuvant trials for drug development, biomarker discovery, and validation, and envision conduct of personalized breast cancer clinics in which therapies will be routinely selected based on genetic alterations in the tumor. Regardless of the targeted therapy combinations employed based on tumor genomic profile, trastuzumab and pertuzumab will likely continue to form the backbone of the personalized regimen for HER2-positive breast cancer

Phase Ia/b Study of Giredestrant ± Palbociclib and ± Luteinizing Hormone-Releasing Hormone Agonists in Estrogen Receptor–Positive, HER2-Negative, Locally Advanced/Metastatic Breast Cancer

Breast cancer; Estrogen receptorCáncer de mama; Receptor de estrógenosCàncer de mama; Receptor d'estrògensPurpose: Giredestrant is an investigational next-generation, oral, selective estrogen receptor antagonist and degrader for the treatment of estrogen receptor–positive (ER+) breast cancer. We present the primary analysis results of the phase Ia/b GO39932 study (NCT03332797). Patients and Methods: Patients with ER+, HER2-negative locally advanced/metastatic breast cancer previously treated with endocrine therapy received single-agent giredestrant (10, 30, 90, or 250 mg), or giredestrant (100 mg) ± palbociclib 125 mg ± luteinizing hormone-releasing hormone (LHRH) agonist. Detailed cardiovascular assessment was conducted with giredestrant 100 mg. Endpoints included safety (primary), pharmacokinetics, pharmacodynamics, and efficacy. Results: As of January 28, 2021, with 175 patients enrolled, no dose-limiting toxicity was observed, and the MTD was not reached. Adverse events (AE) related to giredestrant occurred in 64.9% and 59.4% of patients in the single-agent ± LHRH agonist and giredestrant + palbociclib ± LHRH agonist cohorts, respectively (giredestrant-only–related grade 3/4 AEs were reported in 4.5% of patients across the single-agent cohorts and 3.1% of those with giredestrant + palbociclib). Dose-dependent asymptomatic bradycardia was observed, but no clinically significant changes in cardiac-related outcomes: heart rate, blood pressure, or exercise duration. Clinical benefit was observed in all cohorts (48.6% of patients in the single-agent cohort and 81.3% in the giredestrant + palbociclib ± LHRH agonist cohort), with no clear dose relationship, including in patients with ESR1-mutated tumors. Conclusions: Giredestrant was well tolerated and clinically active in patients who progressed on prior endocrine therapy. Results warrant further evaluation of giredestrant in randomized trials in early- and late-stage ER+ breast cancer.This study was funded by Genentech, Inc., South San Francisco, California. K.L. Jhaveri of Memorial Sloan Kettering Cancer Center was also funded by NIH grant P30 CA008748. We thank all the patients who participated in the study, and their families, the investigators, clinicians, and research staff at the 23 centers in five countries. S. Loi is supported by the National Breast Cancer Foundation of Australia Endowed Chair and the Breast Cancer Research Foundation, New York. Support for third-party writing assistance for this article, furnished by Laura Pérez-Pachón, on behalf of Health Interactions in London, UK, was provided by F. Hoffmann-La Roche Ltd. This work was supported by Genentech, Inc., South San Francisco, California (no grant number applicable). The funder was involved in the study design, provision of study drugs, protocol development, regulatory and ethics approvals, safety monitoring, data collection, data analysis, data interpretation, and writing of the report, in collaboration with the study authors. All authors had full access to all study data and had final responsibility for the decision to submit for publication. The publication costs of this article were defrayed in part by the payment of publication fees. Therefore, and solely to indicate this fact, this article is hereby marked “advertisement” in accordance with 18 USC section 1734

Sacituzumab govitecan as second-line treatment for metastatic triple-negative breast cancer—phase 3 ASCENT study subanalysis

Breast cancer; Second-line treatmentCáncer de mama; Tratamiento de segunda líneaCàncer de mama; Tractament de segona líniaPatients with triple-negative breast cancer (TNBC) who relapse early after (neo)adjuvant chemotherapy have more aggressive disease. In the ASCENT trial, sacituzumab govitecan (SG), an antibody-drug conjugate composed of an anti-Trop–2 antibody coupled to SN-38 via a hydrolyzable linker, improved outcomes over single-agent chemotherapy of physician’s choice (TPC) in metastatic TNBC (mTNBC). Of 468 patients without known baseline brain metastases, 33/235 vs 32/233 patients (both 14%) in the SG vs TPC arms, respectively, received one line of therapy in the metastatic setting and experienced disease recurrence ≤12 months after (neo)adjuvant chemotherapy. SG prolonged progression-free survival (median 5.7 vs 1.5 months [HR, 0.41; 95% CI, 0.22–0.76]) and overall survival (median 10.9 vs 4.9 months [HR, 0.51; 95% CI, 0.28–0.91]) vs TPC, with a manageable safety profile in this subgroup consistent with the overall population. In this second-line setting, as with later-line therapy, SG improved survival over conventional chemotherapy for patients with mTNBC.This study was sponsored by Gilead Sciences, Inc

Sacituzumab Govitecan in Hormone Receptor–Positive/Human Epidermal Growth Factor Receptor 2–Negative Metastatic Breast Cancer

Sacituzumab govitecán; Cáncer de mama metastásicoSacituzumab govitecan; Càncer de mama metastàticSacituzumab govitecan; Metastatic breast cancerPURPOSE Hormone receptor–positive (HR+) human epidermal growth factor receptor 2–negative (HER2–) endocrine-resistant metastatic breast cancer is treated with sequential single-agent chemotherapy with poor outcomes. Sacituzumab govitecan (SG) is a first-in-class antibody-drug conjugate with an SN-38 payload targeting trophoblast cell-surface antigen 2, an epithelial antigen expressed in breast cancer. METHODS In this global, randomized, phase III study, SG was compared with physician's choice chemotherapy (eribulin, vinorelbine, capecitabine, or gemcitabine) in endocrine-resistant, chemotherapy-treated HR+/HER2– locally recurrent inoperable or metastatic breast cancer. The primary end point was progression-free survival (PFS) by blinded independent central review. RESULTS Patients were randomly assigned to receive SG (n = 272) or chemotherapy (n = 271). The median age was 56 years, 95% had visceral metastases, and 99% had a prior cyclin-dependent kinase 4/6 inhibitor, with three median lines of chemotherapy for advanced disease. Primary end point was met with a 34% reduction in risk of progression or death (hazard ratio, 0.66 [95% CI, 0.53 to 0.83; P = .0003]). The median PFS was 5.5 months (95% CI, 4.2 to 7.0) with SG and 4.0 months (95% CI, 3.1 to 4.4) with chemotherapy; the PFS at 6 and 12 months was 46% (95% CI, 39 to 53) v 30% (95% CI, 24 to 37) and 21% (95% CI, 15 to 28) v 7% (95% CI, 3 to 14), respectively. Median overall survival (first planned interim analysis) was not yet mature (hazard ratio, 0.84; P = .14). Key grade ≥ 3 treatment-related adverse events (SG v chemotherapy) were neutropenia (51% v 38%) and diarrhea (9% v 1%). CONCLUSION SG demonstrated statistically significant PFS benefit over chemotherapy, with a manageable safety profile in patients with heavily pretreated, endocrine-resistant HR+/HER2– advanced breast cancer and limited treatment options

Antibody–drug conjugates: smart chemotherapy delivery across tumor histologies

Antibody-drug conjugates; Enfortumab vedotin; Smart chemotherapyConjugats anticossos-medicament; Enfortumab vedotin; Quimioteràpia intel·ligentConjugados anticuerpos-fármaco; Enfortumab vedotin; Quimioterapia inteligenteAs distinct cancer biomarkers have been discovered in recent years, a need to reclassify tumors by more than their histology has been proposed, and therapies are now tailored to treat cancers based on specific molecular aberrations and immunologic markers. In fact, multiple histology-agnostic therapies are currently adopted in clinical practice for treating patients regardless of their tumor site of origin. In parallel with this new model for drug development, in the past few years, several novel antibody–drug conjugates (ADCs) have been approved to treat solid tumors, benefiting from engineering improvements in the conjugation process and the introduction of novel linkers and payloads. With the recognition that numerous surface targets are expressed across various cancer histologies, alongside the remarkable activity of modern ADCs, this drug class has been increasingly evaluated as suitable for a histology-agnostic expansion of indication. For illustration, the anti-HER2 ADC trastuzumab deruxtecan has demonstrated compelling activity in HER2-overexpressing breast, gastric, colorectal, and lung cancer. Examples of additional novel and potentially histology-agnostic ADC targets include trophoblast cell-surface antigen 2 (Trop-2) and nectin-4, among others. In the current review article, the authors summarize the current approvals of ADCs by the US Food and Drug Administration focusing on solid tumors and discuss the challenges and opportunities posed by the multihistological expansion of ADCs.Paulo Tarantino reports personal fees from AstraZeneca outside the submitted work. Roberto Carmagnani Pestana reports consulting fees from Bayer and honoraria from Pfizer, Merck, Bayer, and Servier outside the submitted work. Shanu Modi reports grants and nonfinancial support from Daiichi-Sankyo, Genentech, Novartis, Synta Pharmaceuticals, Seattle Genetics, Macrogenics, Carrick Pharmaceuticals, and Eli Lilly outside the submitted work. Aditya Bardia reports institutional grants from Genentech, Novartis, Pfizer, Merck, Sanofi, Radius Health, Immunomedics Inc, Mersana, Innocrin, and Biotheranostics Inc; consulting fees from Biotheranostics Inc, Pfizer, Novartis, Genentech, Merck, Radius Health, Immunomedics Inc, Spectrum Pharma, Taiho, Sanofi, Daiichi Pharma, AstraZeneca, Puma, Phillips, and Eli Lilly; and meeting support from Biotheranostics Inc, Pfizer, Novartis, Genentech, Merck, Radius Health, Immunomedics Inc, Spectrum Pharma, Taiho, Sanofi, and Phillips outside the submitted work. Sara M. Tolaney reports consulting fees from Novartis, Eli Lilly, Pfizer, Merck, AstraZeneca, Eisai, Puma, Genentech, Immunomedics Inc, Nektar, Tesaro, Daiichi-Sankyo, Athenex, Bristol Myers Squibb, and Nanostring outside the submitted work. Javier Cortes reports grants from Roche, Ariad Pharmaceuticals, AstraZeneca, Baxalta GMBH-Servier Affaires, Bayer Healthcare, Eisai, F Hoffman-LaRoche, Guardant Health, MSD, Pfizer, Piqur Therapeutics, Puma C, and Queen Mary University of London; intellectual property for MedSIR; consulting fees from Roche, Celgene, Cellestia, AstraZeneca, Biothera Pharmaceuticals, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Merck Sharp & Dohme, GlaxoSmithKline, Leuko, Bioasis, and Clovis Oncology; and honoraria from Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, Merck Sharp & Dohme, and Daiichi-Sankyo outside the submitted work. Jean-Charles Soria was formerly employed at AstraZeneca and is now employed by Amgen; owns stock in AstraZeneca, Gritstone Bio, and Relay Therapeutics; and serves on the Board of Directors for Hookipa Pharmaceuticals outside the submitted work. Giuseppe Curigliano reports a grant from Merck; consulting fees from Roche, Pfizer, Novartis, Seattle Genetics, Lilly, Ellipses Pharma, Foundation Medicine, Samsung, Daichii-Sankyo, and Exactsciences; honoraria from Pfizer, Novartis, Seattle Genetics, and Daichii-Sankyo; and meeting support from Foche and Pfizer outside the submitted work. Chiara Corti made no disclosures

The oral selective estrogen receptor degrader GDC-0810 (ARN-810) in postmenopausal women with hormone receptor-positive HER2-negative (HR + /HER2 −) advanced/metastatic breast cancer

Metastatic breast cancer; PostmenopausalCàncer de mama metastàtic; PostmenopausaCáncer de mama metastásico; PostmenopausiaPurpose GDC-0810 (ARN-810) is a novel, non-steroidal, orally bioavailable, selective estrogen receptor degrader (SERD) that potentially inhibits ligand-dependent and ligand-independent estrogen receptor (ER)-mediated signaling. Methods A phase Ia/Ib/IIa dose escalation, combination treatment with palbociclib or a luteinizing hormone-releasing hormone, and expansion study determined the safety, pharmacokinetics, and recommended phase 2 dose (RP2D) of GDC-0810 in postmenopausal women with ER + (HER2 −) locally advanced or metastatic breast cancer (MBC). Baseline plasma ctDNA samples were analyzed to determine the ESR1 mutation status. Results Patients (N = 152) received GDC-0810 100–800 mg once daily (QD) or 300–400 mg twice daily, in dose escalation, expansion, as single agent or combination treatment. Common adverse events regardless of attribution to study drug were diarrhea, nausea, fatigue, vomiting, and constipation. There was one dose-limiting toxicity during dose escalation. The maximum tolerated dose was not reached. GDC-0810 600 mg QD taken with food was the RP2D. Pharmacokinetics were predictable. FES reduction (> 90%) highlighting pharmacodynamic engagement of ER was observed. Outcomes for the overall population and for patients with tumors harboring ESR1 mutations included partial responses (4% overall; 4% ESR1), stable disease (39% overall; 42% ESR1), non-complete response/non-progressive disease (13% overall; 12% ESR1), progressive disease (40% overall; 38% ESR1), and missing/unevaluable (5% overall; 5% ESR1). Clinical benefit (responses or SD, lasting ≥ 24 weeks) was observed in patients in dose escalation (n = 16, 39%) and expansion (n = 24, 22%). Conclusion GDC-0810 was safe and tolerable with preliminary anti-tumor activity in heavily pretreated patients with ER + advanced/MBC, with/without ESR1 mutations, highlighting the potential for oral SERDs.This work was supported by Genentech, Inc., South San Francisco, CA. and K.J. would like to acknowledge a Memorial Sloan Kettering Cancer Center Support Grant (P30 CA008748)

Safety analyses from the phase 3 ASCENT trial of sacituzumab govitecan in metastatic triple-negative breast cancer

Breast cancer; Drug safetyCàncer de mama; Seguretat dels medicamentsCáncer de mama; Seguridad de los medicamentosSacituzumab govitecan (SG) is an anti-Trop-2 antibody-drug conjugate with an SN-38 payload. In the ASCENT study, patients with metastatic triple-negative breast cancer (mTNBC) relapsed/refractory to ≥2 prior chemotherapy regimens (≥1 in the metastatic setting), received SG or single-agent treatment of physician’s choice (eribulin, vinorelbine, capecitabine, or gemcitabine). This ASCENT safety analysis includes the impact of age and UGT1A1 polymorphisms, which hinder SN-38 detoxification. SG demonstrated a manageable safety profile in patients with mTNBC, including those ≥65 years; neutropenia/diarrhea are key adverse events (AE). Patients with UGT1A1 *28/*28 genotype versus those with 1/*28 and *1/*1 genotypes had higher rates of grade ≥3 SG-related neutropenia (59% vs 47% and 53%), febrile neutropenia (18% vs 5% and 3%), anemia (15% vs 6% and 4%), and diarrhea (15% vs 9% and 10%), respectively. Individuals with UGT1A1 *28/*28 genotype should be monitored closely; active monitoring and routine AE management allow optimal therapeutic exposure of SG.This study was sponsored by Immunomedics, Inc., a subsidiary of Gilead Sciences, Inc. We thank the ASCENT patients, their caregivers, study investigators, and team members. We thank William A. Wegener, MD, PhD, Robert M. Sharkey, PhD, and Pius Maliakal, PhD, former employees of Immunomedics, for their contributions to the development of the ASCENT protocol and the clinical development of sacituzumab govitecan. Medical writing and editorial assistance were provided by Robert Rydzewski, MS, CMPP, and Shala Thomas, PhD, CMPP, of Team 9 Science, and funded by Immunomedics, Inc., a subsidiary of Gilead Sciences, Inc

Biomarker analyses in the phase III ASCENT study of sacituzumab govitecan versus chemotherapy in patients with metastatic triple-negative breast cancer

BRCA; Cáncer de mama triple negativo: Antígeno 2 de la superficie celular del trofoblastoBRCA; Càncer de mama triple negatiu; Antigen 2 de la superfície cel·lular del trofoblastBRCA; Triple-negative breast cancer; Trophoblast cell-surface antigen 2Background The pivotal phase III ASCENT trial demonstrated improved survival outcomes associated with sacituzumab govitecan (SG), an anti-trophoblast cell-surface antigen 2 (anti-Trop-2) antibody-drug conjugate linked with the topoisomerase-inhibitor SN-38, over single-agent chemotherapy treatment of physician’s choice (TPC) in previously treated metastatic triple-negative breast cancer (mTNBC). This prespecified, exploratory biomarker analysis from the ASCENT trial evaluates the association between tumor Trop-2 expression and germline BRCA1/2 mutation status with clinical outcomes. Patients and methods Patients with mTNBC refractory to or progressing after two or more prior chemotherapies, with one or more in the metastatic setting, were randomized to receive SG (10 mg/kg intravenously days 1 and 8, every 21 days) or TPC (capecitabine, eribulin, vinorelbine, or gemcitabine) until disease progression/unacceptable toxicity. Biopsy or surgical specimens were collected at study entry to determine Trop-2 expression level using a validated immunohistochemistry assay and histochemical scoring. Germline BRCA1/2 mutation status was collected at baseline. Results Of 468 assessable patients, 290 had Trop-2 expression data [64% (n = 151 SG) versus 60% (n = 139 TPC)] and 292 had known BRCA1/2 mutation status [63% (n = 149 SG) versus 61% (n = 143 TPC)]. Median progression-free survival in SG- versus TPC-treated patients was 6.9, 5.6, and 2.7 months versus 2.5, 2.2, and 1.6 months for high, medium, and low Trop-2 expression, respectively. Median overall survival (14.2, 14.9, and 9.3 months versus 6.9, 6.9, and 7.6 months) and objective response rates (44%, 38%, and 22% versus 1%, 11%, and 6%) were numerically higher with SG versus TPC in patients with high, medium, and low Trop-2 expression, respectively. Efficacy outcomes were numerically higher with SG versus TPC in patients with and without germline BRCA1/2 mutations. Conclusions SG benefits patients with previously treated mTNBC expressing high/medium Trop-2 compared with standard-of-care chemotherapy and regardless of germline BRCA1/2 mutation status. The small number of patients with low Trop-2 expression precludes definitive conclusions on the benefit of SG in this subgroup.This work was supported by Immunomedics, Inc., a subsidiary of Gilead Sciences, Inc. (no grant number)

AKT1[low] quiescent cancer cells persist after neoadjuvant chemotherapy in triple negative breast cancer

Background: Absence of pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) correlates with poor long-term survival in patients with triple negative breast cancer (TNBC). These incomplete treatment responses are likely determined by mechanisms that enable cancer cells to resist being killed. However, the detailed characterization of a drug-resistant cancer cell state in residual TNBC tissue after NACT has remained elusive. AKT1(low) quiescent cancer cells (QCCs) are a quiescent, epigenetically plastic, and chemotherapy-resistant subpopulation initially identified in experimental cancer models. Here, we asked whether QCCs exist in primary tumors from patients with TNBC and persist after treatment with NACT. Methods: We obtained pre-treatment biopsy, post-treatment mastectomy, and metastatic specimens from a retrospective cohort of TNBC patients treated with NACT at Massachusetts General Hospital (n = 25). Using quantitative automated immunofluorescence microscopy, QCCs were identified as AKT(low)/H3K9me2(low)/HES1(high) cancer cells using prespecified immunofluorescence intensity thresholds. QCCs were represented in 2D and 3D digital tumor maps and QCC percentage (QCC-P) and QCC cluster index (QCC-CI) were determined for each sample. Results: We showed that QCCs exist as non-random and heterogeneously distributed clusters within primary breast tumors. In addition, these QCC clusters persist after treatment with multi-agent, multi-cycle, neoadjuvant chemotherapy in both residual primary tumors and nodal and distant metastases in patients with triple negative breast cancer. Conclusions: These first-in-human data potentially qualify AKT1(low) quiescent cancer cells as a non-genetic cell state that persists after neoadjuvant chemotherapy in triple negative breast cancer patients and warrants further study