RESUMEN
As cancer immunotherapies continue to expand across all areas of oncology, it is imperative to establish a standardized approach for defining and capturing clinically important toxicities, such as cytokine release syndrome (CRS). In this paper, we provide considerations for categorizing the variety of adverse events that may accompany CRS and for recognizing that presentations of CRS may differ among various immunotherapies (e.g., monoclonal antibodies, CAR T cell therapies and T cell engagers, which can include bispecific antibodies and other constructs). The goals of this paper are to ensure accurate and consistent identification of CRS in patients receiving immunotherapies in clinical studies to aid in reporting; enable more precise evaluation of the therapeutic risk-benefit profile and cross-study analyses; support evidence-based monitoring and management of important toxicities related to cancer immunotherapies; and improve patient care and outcomes. These efforts will become more important as the number and variety of molecular targets for immunotherapies broaden and as therapies with novel mechanisms continue to be developed.
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Síndrome de Liberación de Citoquinas , Inmunoterapia , Neoplasias , Anticuerpos Biespecíficos , Ensayos Clínicos como Asunto , Síndrome de Liberación de Citoquinas/etiología , Humanos , Inmunoterapia/efectos adversos , Inmunoterapia Adoptiva/efectos adversos , Neoplasias/terapiaRESUMEN
LESSONS LEARNED: The lack of efficacy associated with anti-EGFL7 combined with standard bevacizumab and chemotherapy in this phase II trial in non-small cell lung carcinoma is consistent with the lack of benefit observed in colorectal carcinoma, highlighting the challenge of enhancing the efficacy of VEGF inhibition in unselected populations.Future efforts with agents like anti-EGFL7 should be guided by advances in pharmacodynamic and predictive biomarker development for antiangiogenic agents. BACKGROUND: Epidermal growth factor-like domain 7 (EGFL7) is an extracellular matrix-associated protein that is upregulated during angiogenesis and supports endothelial cell survival. This phase II trial evaluated the efficacy of the anti-EGFL7 antibody, parsatuzumab, in combination with bevacizumab plus platinum-based therapy for advanced or recurrent nonsquamous non-small cell lung cancer (NS-NSCLC). METHODS: Patients (n = 104) were randomized to either placebo or parsatuzumab (600 mg) in combination with bevacizumab (15 mg/kg) and carboplatin/paclitaxel, administered on day 1 of each 21-day cycle. Carboplatin and paclitaxel were administered for up to six cycles. Bevacizumab and parsatuzumab/placebo were administered for a maximum of 24 months. RESULTS: The progression-free survival (PFS) hazard ratio (HR) was 1.7 (95% confidence interval [CI], 1.0-2.8; p = .047). The median PFS was 6.7 months for the parsatuzumab arm versus 8.1 months for the placebo arm. The hazard ratio for overall survival (OS) was 1.1 (95% CI, 0.5-2.2; p = .847). The objective response rate (ORR) was 29% in the parsatuzumab arm and 56% in the placebo arm. Overall safety and tolerability were consistent with the established toxicity profile of bevacizumab. CONCLUSION: There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first-line NS-NSCLC.
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Anticuerpos Monoclonales/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bevacizumab/uso terapéutico , Carboplatino/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Paclitaxel/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados , Bevacizumab/farmacología , Carboplatino/farmacología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Método Doble Ciego , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Paclitaxel/farmacología , Supervivencia sin ProgresiónRESUMEN
LESSONS LEARNED: These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses.Any further clinical development of anti-EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents. BACKGROUND: EGFL7 (epidermal growth factor-like domain 7) is a tumor-enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti-EGFL7 IgG1 monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5-fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC). METHODS: One-hundred twenty-seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles. RESULTS: The progression-free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71-1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46-2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms. CONCLUSIONS: There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first-line mCRC. The Oncologist 2017;22:375-e30.
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Anticuerpos Monoclonales/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Bevacizumab/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Factores de Crecimiento Endotelial/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antiidiotipos/administración & dosificación , Anticuerpos Monoclonales Humanizados , Proteínas de Unión al Calcio , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Supervivencia sin Enfermedad , Familia de Proteínas EGF , Factores de Crecimiento Endotelial/genética , Factores de Crecimiento Endotelial/inmunología , Femenino , Fluorouracilo/administración & dosificación , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Leucovorina/administración & dosificación , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Compuestos Organoplatinos/administración & dosificaciónRESUMEN
LESSONS LEARNED: Cobimetinib and duligotuzumab were well tolerated as single agents and in combination with other agents.The cobimetinib and duligotuzumab combination was associated with increased toxicity, most notably gastrointestinal, and limited efficacy in the patient population tested. BACKGROUND: KRAS-mutant tumors possess abnormal mitogen-activated protein kinases (MAPK) pathway signaling, leading to dysregulated cell proliferation. Cobimetinib blocks MAPK signaling. The dual-action antibody duligotuzumab (MEHD7945A) inhibits ligand binding to both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 3 (HER3). Blockade of EGFR/HER3 and inhibition of mitogen-activated protein kinase (MEK) in KRAS-mutant tumors may provide additive benefit. METHODS: Patients with KRAS-mutant solid tumors were eligible for this phase Ib dose-escalation study with a planned expansion phase. Duligotuzumab was given intravenously (IV) at 1,100 mg every 2 weeks (q2w), while cobimetinib was given orally in a standard 3 + 3 design to identify the recommended phase II dose (RP2D). The primary objective was to evaluate the safety and tolerability of this combination. RESULTS: Twenty-three patients were enrolled. Dose-limiting toxicities (DLTs) included grade 4 hypokalemia and grade 3 mucosal inflammation, asthenia, and dermatitis acneiform. Seventy percent of patients experienced grade 3 or worse adverse events (AEs). Five (22%) and 12 (52%) patients missed at least 1 dose of duligotuzumab and cobimetinib, respectively, and 9 (39%) patients required a cobimetinib dose reduction. Three (13%) patients discontinued due to an AE. Best response was limited to 9 patients with stable disease and 13 patients with progressive disease. CONCLUSION: Given the limited tolerability and efficacy of this combination, the study did not proceed to expansion stage and closed for enrollment.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Azetidinas/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Inmunoglobulina G/uso terapéutico , Piperidinas/uso terapéutico , Proteínas Proto-Oncogénicas p21(ras)/genética , Erupciones Acneiformes/epidemiología , Erupciones Acneiformes/etiología , Administración Oral , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Astenia/epidemiología , Astenia/etiología , Azetidinas/farmacología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Relación Dosis-Respuesta a Droga , Erupciones por Medicamentos/epidemiología , Erupciones por Medicamentos/etiología , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Femenino , Humanos , Hipopotasemia/epidemiología , Hipopotasemia/etiología , Inmunoglobulina G/farmacología , MAP Quinasa Quinasa 1/antagonistas & inhibidores , MAP Quinasa Quinasa 1/metabolismo , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Piperidinas/farmacología , Estudios Prospectivos , Receptor ErbB-3/antagonistas & inhibidores , Receptor ErbB-3/metabolismo , Transducción de Señal/efectos de los fármacos , Resultado del TratamientoRESUMEN
BACKGROUND: This open-label, multicenter, phase Ib study assessed the safety and preliminary activity of duligotuzumab, a dual-action antibody that blocks ligand binding to human epidermal growth factor receptor 3 (HER3) and epidermal growth factor receptor, in combination with chemotherapy, in the first-line treatment of patients with recurrent/metastatic squamous cell cancer of the head and neck. METHODS: On day 1, duligotuzumab at a dose of 1650 mg intravenously was combined with cisplatin at a dose of 100 mg/m2 and 5-fluorouracil at a dose of 1000 mg/m2 /day on days 1 to 4 in treatment arm A, or carboplatin (area under the curve, 6 mg/mL/min) and paclitaxel (at a dose of 200 mg/m2 ) in treatment arm B. Up to 6 cycles (21 days/cycle) were followed by duligotuzumab maintenance until disease progression or intolerable toxicity occurred. RESULTS: Nine patients in arm A and 15 patients in arm B received a median of 6 cycles of chemotherapy, and a median of 11 cycles (arm A) and 9 cycles (arm B) of duligotuzumab. Dose-limiting toxicities occurred in 3 patients in arm A and 1 patient in arm B. Grade ≥ 3 treatment-related adverse events (graded according to graded according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]) in ≥ 3 patients were neutropenia (5 patients), hypokalemia (4 patients), dehydration (3 patients), anemia (3 patients), and diarrhea (3 patients) in arm A, and neutropenia (8 patients), anemia (5 patients), febrile neutropenia (4 patients), leukopenia (3 patients), thrombocytopenia (3 patients), and hypomagnesemia (3 patients) in arm B. The chemotherapy dose was reduced in 19 of 24 patients. Sixteen patients (67%) demonstrated objective responses regardless of human papillomavirus status or neuregulin 1 (NRG1) mRNA expression (arm A: 2 confirmed complete responses and 4 confirmed partial responses; arm B: 2 confirmed complete responses and 8 confirmed partial responses). CONCLUSIONS: Duligotuzumab in combination with cisplatin/5-fluorouracil or carboplatin/paclitaxel demonstrated encouraging activity in patients with recurrent/metastatic squamous cell cancer of the head and neck; an association with increased frequency and severity of select adverse events relative to historical data was suggestive of the potentiation of chemotherapy-related adverse events. Cancer 2016;122:3803-3811. © 2016 American Cancer Society.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/efectos adversos , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carboplatino/administración & dosificación , Carboplatino/efectos adversos , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/efectos adversos , Masculino , Persona de Mediana Edad , Paclitaxel/administración & dosificación , Paclitaxel/efectos adversos , Carcinoma de Células Escamosas de Cabeza y CuelloRESUMEN
BACKGROUND: This analysis evaluated the incidence of and risk factors for bevacizumab-related proteinuria and assessed for any associated clinical sequelae, including renal function changes. METHODS: Patient-level adverse event and laboratory data from a pooled safety database were used to characterize alterations in urine protein excretion following interventional therapy ± bevacizumab in 17 randomized trials across multiple tumor types. Severity of renal function change was assessed using changes in serum creatinine concentration from baseline values. Potential predictors of proteinuria and the association between proteinuria and other adverse events were also investigated. RESULTS: Among 14,548 patients, the incidence of any-grade proteinuria was 8.2% (733/8,917) and 4.6% (257/5,631) in the bevacizumab and control groups, respectively; rates of grade ≥3 proteinuria were 1.4 and 0.2%. Post-baseline proteinuria grade and bevacizumab were associated with increased rates of renal dysfunction. Patients developing proteinuria had an increased rate of any-grade infection but not thromboembolic events. History of diabetes was the only examined risk factor that appeared to have a significant association with proteinuria development. CONCLUSIONS: This analysis confirmed a significant increase in the development of proteinuria during bevacizumab treatment. We also observed an increased rate of renal dysfunction associated with bevacizumab treatment and among subjects with proteinuria, although the dysfunction was generally mild. The development of proteinuria was also associated with a modest increase in risk of infection.
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Inhibidores de la Angiogénesis/efectos adversos , Anticuerpos Monoclonales Humanizados/efectos adversos , Neoplasias/tratamiento farmacológico , Proteinuria/inducido químicamente , Insuficiencia Renal/inducido químicamente , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Bevacizumab , Comorbilidad , Diabetes Mellitus/epidemiología , Femenino , Tasa de Filtración Glomerular , Humanos , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Ensayos Clínicos Controlados Aleatorios como Asunto , Insuficiencia Renal/epidemiología , Insuficiencia Renal/metabolismo , Factores de Riesgo , Factores Sexuales , Adulto JovenRESUMEN
PURPOSE: MINT1526A is a monoclonal antibody that blocks the interaction of integrin alpha 5 beta 1 (α5ß1) with its extracellular matrix ligands. This phase I study evaluated the safety and pharmacokinetics of MINT1526A with or without bevacizumab in patients with advanced solid tumors. METHODS: MINT1526A was administered every 3 weeks (Q3W) as monotherapy (arm 1) or in combination with bevacizumab 15 mg/kg, Q3W (arm 2). Each arm included a 3 + 3 dose-escalation stage and a dose-expansion stage. RESULTS: Twenty-four patients were enrolled in arm 1 (dose range 2-30 mg/kg) and 30 patients were enrolled in arm 2 (dose range 3-15 mg/kg). Monocyte α5ß1 receptor occupancy was saturated at a dose of 15 mg/kg. No dose-limiting toxicities were observed, and the maximum tolerated dose was not reached in either arm. The most common adverse events, regardless of causality, included abdominal pain (25%), diarrhea (25%), nausea (21%), vomiting (21%), and fatigue (21%) in arm 1 and nausea (40%), fatigue (33%), vomiting (30%), dehydration (30%), headache (30%), and hypertension (30%) in arm 2. No grade ≥ 3 bleeding events were observed in either arm. No confirmed partial responses (PR) were observed in arm 1. In arm 2, one patient with thymic carcinoma experienced a confirmed PR and two patients with hepatocellular carcinoma (HCC) experienced durable minor radiographic responses. CONCLUSIONS: MINT1526A, with or without bevacizumab, was well-tolerated. Preliminary evidence of combination efficacy, including in patients with HCC, was observed, but cannot be distinguished from bevacizumab monotherapy in this phase I study.
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Antineoplásicos Inmunológicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos Inmunológicos/inmunología , Protocolos de Quimioterapia Combinada Antineoplásica/inmunología , Bevacizumab/administración & dosificación , Bevacizumab/inmunología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Integrina alfa5beta1/antagonistas & inhibidores , Integrina alfa5beta1/inmunología , Masculino , Persona de Mediana Edad , Neoplasias/inmunologíaRESUMEN
BACKGROUND: Indoleamine-2,3-dioxygenase 1 (IDO1) catalyzes the oxidation of tryptophan into kynurenine and is partially responsible for acquired immune tolerance associated with cancer. The IDO1 small molecule inhibitor navoximod (GDC-0919, NLG-919) is active as a combination therapy in multiple tumor models. METHODS: This open-label Phase Ia study assessed safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary anti-tumor activity of navoximod in patients with recurrent/advanced solid tumors, administered as 50-800 mg BID on a 21/28 day and at 600 mg on a 28/28 day schedule. Plasma kynurenine and tryptophan were longitudinally evaluated and tumor assessments were performed. RESULTS: Patients (n = 22) received a median of 3 cycles of navoximod. No maximum tolerated dose was reached. One dose-limiting toxicity of Grade 4 lower gastrointestinal hemorrhage was reported. Adverse events (AEs) regardless of causality in ≥20% of patients included fatigue (59%), cough, decreased appetite, and pruritus (41% each), nausea (36%), and vomiting (27%). Grade ≥ 3 AEs occurred in 14/22 patients (64%), and were related to navoximod in two patients (9%). Navoximod was rapidly absorbed (Tmax ~ 1 h) and exhibited dose-proportional increases in exposure, with a half-life (t1/2 ~ 11 h) supportive of BID dosing. Navoximod transiently decreased plasma kynurenine from baseline levels with kinetics consistent with its half-life. Of efficacy-evaluable patients, 8 (36%) had stable disease and 10 (46%) had progressive disease. CONCLUSIONS: Navoximod was well-tolerated at doses up to 800 mg BID decreasing plasma kynurenine levels consistent with its half-life. Stable disease responses were observed. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02048709 .
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Inhibidores Enzimáticos/uso terapéutico , Indolamina-Pirrol 2,3,-Dioxigenasa/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Inhibidores Enzimáticos/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Neoplasias/enzimología , Recurrencia , Resultado del TratamientoRESUMEN
Purpose: Duligotuzumab is a dual-action antibody directed against EGFR and HER3.Experimental Design: Metastatic colorectal cancer (mCRC) patients with KRAS ex2 wild-type received duligotuzumab or cetuximab and FOLFIRI until progression or intolerable toxicity. Mandatory tumor samples underwent mutation and biomarker analysis. Efficacy analysis was conducted in patients with RAS exon 2/3 wild-type tumors.Results: Of 134 randomly assigned patients, 98 had RAS ex2/3 wild-type. Duligotuzumab provided no progression-free survival (PFS) or overall survival (OS) benefit compared with cetuximab, although there was a trend for a lower objective response rate (ORR) in the duligotuzumab arm. No relationship was seen between PFS or ORR and ERBB3, NRG1, or AREG expression. There were fewer skin rash events for duligotuzumab but more diarrhea. Although the incidence of grade ≥3 AEs was similar, the frequency of serious AEs was higher for duligotuzumab.Conclusions: Duligotuzumab plus FOLFIRI did not appear to improve the outcomes in patients with RAS exon 2/3 wild-type mCRC compared with cetuximab + FOLFIRI. Clin Cancer Res; 24(10); 2276-84. ©2018 AACR.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Camptotecina/análogos & derivados , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Biomarcadores de Tumor , Camptotecina/efectos adversos , Camptotecina/uso terapéutico , Cetuximab/administración & dosificación , Cetuximab/farmacocinética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Femenino , Fluorouracilo/efectos adversos , Fluorouracilo/uso terapéutico , Genes ras , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/farmacología , Leucovorina/efectos adversos , Leucovorina/uso terapéutico , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Mutación , Metástasis de la Neoplasia , Estadificación de Neoplasias , Supervivencia sin Progresión , Retratamiento , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Duligotuzumab, a novel dual-action humanized IgG1 antibody that blocks ligand binding to epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 3 (HER3), inhibits signaling from all ligand-dependent HER dimers, and can elicit antibody-dependent cell-mediated cytotoxicity. High tumor-expression of neuregulin 1 (NRG1), a ligand to HER3, may enhance sensitivity to duligotuzumab. METHODS: This multicenter, open-label, randomized phase II study (MEHGAN) evaluated drug efficacy in patients with recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN) progressive on/after chemotherapy and among patients with NRG1-high tumors. Patients received duligotuzumab (1100 mg IV, q2w) or cetuximab (400 mg/m2 load, 250 mg/m2 IV, q1w) until progression or intolerable toxicity. Tumor samples were assayed for biomarkers [NRG1, ERBB3, and human papillomavirus (HPV) status]. RESULTS: Patients (N = 121) were randomized (duligotuzumab:cetuximab; 59:62), median age 62 years; ECOG 0-2. Both arms (duligotuzumab vs. cetuximab, respectively) showed comparable progression-free survival [4.2 vs. 4.0 months; HR: 1.23 (90% confidence interval (CI): 0.89-1.70)], overall survival [7.2 vs. 8.7 months; HR 1.15 (90% CI: 0.81-1.63)], and objective response rate (12 vs. 14.5%), with no difference between patients with NRG1-high tumors or ERBB3-low tumors. Responses in both arms were confined to HPV-negative patients. Grade ≥3 adverse events (AEs) (duligotuzumab vs. cetuximab, respectively) included infections (22 vs. 11.5%) and GI disorders (17 vs. 7%), contributing to higher rates of serious AEs (41 vs. 29.5%). Metabolic disorders were less frequent with duligotuzumab (10 vs. 16%); any grade rash-related events were less with duligotuzumab (49 vs. 67%). CONCLUSION: While several lines of preclinical evidence had supported the premise that the blockade of HER3 in addition to that of EGFR may improve outcomes for patients with R/M SCCHN overall or specifically in those patients whose tumors express high levels of NRG1, this study provided definitive clinical evidence refuting this hypothesis. Duligotuzumab did not improve patient outcomes in comparison to cetuximab despite frequent expression of NRG1. These data indicate that inhibition of EGFR alone is sufficient to block EGFR-HER3 signaling, suggesting that HER2 plays a minimal role in this disease. Extensive biomarker analyses further show that HPV-negative SCCHN but not HPV-positive SCCHN are most likely to respond to EGFR blockage by cetuximab or duligotuzumab.