Guilherme Rabinowits

Induction chemotherapy followed by concurrent chemoradiotherapy (sequential chemoradiotherapy) versus concurrent chemoradiotherapy alone in locally advanced head and neck cancer (PARADIGM): a randomised phase 3 trial

BACKGROUND The relative efficacy of the addition of induction chemotherapy to chemoradiotherapy compared with chemoradiotherapy alone for patients with head and neck cancer is unclear. The PARADIGM study is a multicentre open-label phase 3 study comparing the use of docetaxel, cisplatin, and fluorouracil (TPF) induction chemotherapy followed by concurrent chemoradiotherapy with cisplatin-based concurrent chemoradiotherapy alone in patients with locally advanced head and neck cancer. METHODS Adult patients with previously untreated, non-metastatic, newly diagnosed head and neck cancer were eligible. Patients were eligible if their tumour was either unresectable or of low surgical curability on the basis of advanced tumour stage (3 or 4) or regional-node stage (2 or 3, except T1N2), or if they were a candidate for organ preservation. Patients were randomly assigned (in a 1:1 ratio) to receive either induction chemotherapy with three cycles of TPF followed by concurrent chemoradiotherapy with either docetaxel or carboplatin or concurrent chemoradiotherapy alone with two cycles of bolus cisplatin. A computer-generated randomisation schedule using minimisation was prepared and the treatment assignment was done centrally at one of the study sites. Patients, study staff, and investigators were not masked to group assignment. Stratification factors were WHO performance status, primary disease site, and stage. The primary endpoint was overall survival. Analysis was by intention to treat. Patient accrual was terminated in December, 2008, because of slow enrolment. The trial is registered with ClinicalTrials.gov, number NCT00095875. FINDINGS Between Aug 24, 2004, and Dec 29, 2008, we enrolled 145 patients across 16 sites. After a median follow-up of 49 months (IQR 39-63), 41 patients had died-20 in the induction chemotherapy followed by chemoradiotherapy group and 21 in the chemoradiotherapy alone group. 3-year overall survival was 73% (95% CI 60-82) in the induction therapy followed by chemoradiotherapy group and 78% (66-86) in the chemoradiotherapy alone group (hazard ratio 1·09, 95% CI 0·59-2·03; p=0·77). More patients had febrile neutropenia in the induction chemotherapy followed by chemoradiotherapy group (16 patients) than in the chemoradiotherapy alone group (one patient). INTERPRETATION Although survival results were good in both groups there was no difference noted between those patients treated with induction chemotherapy followed by chemoradiotherapy and those who received chemoradiotherapy alone. We cannot rule out the possibility of a difference in survival going undetected due to early termination of the trial. Clinicians should still use their best judgment, based on the available data, in the decision of how to best treat patients. The addition of induction chemotherapy remains an appropriate approach for advanced disease with high risk for local or distant failure. FUNDING Sanofi-Aventis.

Overcoming resistance to EGFR inhibitor in head and neck cancer: A review of the literature

Head and neck squamous cell carcinoma (HNSCC) affects over half a million people worldwide. Despite advances in therapy, only half of the patients are alive in 5 years. Epidermal growth factor receptor (EGFR) is overexpressed in approximately 90% of the tumors, and it is correlated with poor response to treatment and worse outcome. Multiple therapies targeting this pathway have been tested. Cetuximab is the only EGFR inhibitor approved in HNSCC, but response rates are low. More recently, significant interest has focus on identifying mechanisms of acquired and de novo EGFR blockage resistance. Here we review some of these mechanisms and describe strategies to overcome that resistance.

Merkel Cell Polyomavirus Exhibits Dominant Control of the Tumor Genome and Transcriptome in Virus-Associated Merkel Cell Carcinoma

ABSTRACT Merkel cell polyomavirus is the primary etiological agent of the aggressive skin cancer Merkel cell carcinoma (MCC). Recent studies have revealed that UV radiation is the primary mechanism for somatic mutagenesis in nonviral forms of MCC. Here, we analyze the whole transcriptomes and genomes of primary MCC tumors. Our study reveals that virus-associated tumors have minimally altered genomes compared to non-virus-associated tumors, which are dominated by UV-mediated mutations. Although virus-associated tumors contain relatively small mutation burdens, they exhibit a distinct mutation signature with observable transcriptionally biased kataegic events. In addition, viral integration sites overlap focal genome amplifications in virus-associated tumors, suggesting a potential mechanism for these events. Collectively, our studies indicate that Merkel cell polyomavirus is capable of hijacking cellular processes and driving tumorigenesis to the same severity as tens of thousands of somatic genome alterations. IMPORTANCE A variety of mutagenic processes that shape the evolution of tumors are critical determinants of disease outcome. Here, we sequenced the entire genome of virus-positive and virus-negative primary Merkel cell carcinomas (MCCs), revealing distinct mutation spectra and corresponding expression profiles. Our studies highlight the strong effect that Merkel cell polyomavirus has on the divergent development of viral MCC compared to the somatic alterations that typically drive nonviral tumorigenesis. A more comprehensive understanding of the distinct mutagenic processes operative in viral and nonviral MCCs has implications for the effective treatment of these tumors. A variety of mutagenic processes that shape the evolution of tumors are critical determinants of disease outcome. Here, we sequenced the entire genome of virus-positive and virus-negative primary Merkel cell carcinomas (MCCs), revealing distinct mutation spectra and corresponding expression profiles. Our studies highlight the strong effect that Merkel cell polyomavirus has on the divergent development of viral MCC compared to the somatic alterations that typically drive nonviral tumorigenesis. A more comprehensive understanding of the distinct mutagenic processes operative in viral and nonviral MCCs has implications for the effective treatment of these tumors.

Ex Vivo Profiling of PD-1 Blockade Using Organotypic Tumor Spheroids

Ex vivo systems that incorporate features of the tumor microenvironment and model the dynamic response to immune checkpoint blockade (ICB) may facilitate efforts in precision immuno-oncology and the development of effective combination therapies. Here, we demonstrate the ability to interrogate ex vivo response to ICB using murine- and patient-derived organotypic tumor spheroids (MDOTS/PDOTS). MDOTS/PDOTS isolated from mouse and human tumors retain autologous lymphoid and myeloid cell populations and respond to ICB in short-term three-dimensional microfluidic culture. Response and resistance to ICB was recapitulated using MDOTS derived from established immunocompetent mouse tumor models. MDOTS profiling demonstrated that TBK1/IKKε inhibition enhanced response to PD-1 blockade, which effectively predicted tumor response in vivo Systematic profiling of secreted cytokines in PDOTS captured key features associated with response and resistance to PD-1 blockade. Thus, MDOTS/PDOTS profiling represents a novel platform to evaluate ICB using established murine models as well as clinically relevant patient specimens.Significance: Resistance to PD-1 blockade remains a challenge for many patients, and biomarkers to guide treatment are lacking. Here, we demonstrate feasibility of ex vivo profiling of PD-1 blockade to interrogate the tumor immune microenvironment, develop therapeutic combinations, and facilitate precision immuno-oncology efforts. Cancer Discov; 8(2); 196-215. ©2017 AACR.See related commentary by Balko and Sosman, p. 143See related article by Deng et al., p. 216This article is highlighted in the In This Issue feature, p. 127.

Definitive chemoradiation alters the immunologic landscape and immune checkpoints in head and neck cancer

Background:Preclinical and clinical studies suggest potential synergy between high dose per fraction focal radiation and immunotherapy. However, conventionally fractionated radiation regimens in combination with concurrent chemotherapy are more commonly administered to patients as definitive treatment and may have both immune-stimulating and -suppressive effects.Methods:We prospectively collected longitudinal samples from head and neck squamous cell carcinoma patients receiving definitive radiation therapy. We quantified changes in populations of circulating immune cells and chemokines CXCL9, 10, and 16. Analyses of humoral and cellular immune responses were conducted in select patients via proteomic analysis and T-cell receptor sequencing.Results:Treatment not only increased circulating CD-8+ T-effector cells, but also myeloid-derived suppressor cells, regulatory T cells, and checkpoint receptor-expressing T cells, particularly PD-1+ T cells. Significant decreases in CXCL10 and increases in CXLC16 were noted. Treatment also increased the percentage of unique and dominant TCR clones, and increased humoral responses as measured by proteomic array.Conclusions:Our results suggest that fractionated chemoradiation leads to quantifiable effects in circulating immune mediators, including a balance of stimulatory and suppressive mechanisms. These results suggest future combinations with immune checkpoint blockade.

Incorporation of next-generation sequencing into routine clinical care to direct treatment of head and neck squamous cell carcinoma

Purpose: The clinical impact of next-generation sequencing (NGS) in patients with head and neck squamous cell carcinoma (HNSCC) has not been described. We aimed to evaluate the clinical impact of NGS in the routine care of patients with HNSCC and to correlate genomic alterations with clinical outcomes. Experimental Design: Single-center study examining targeted NGS platform used to sequence tumor DNA obtained from 213 HNSCC patients evaluated in outpatient head and neck oncology clinic between August 2011 and December 2014. We correlated tumor genomic profiling results with clinical outcomes. Results: PI3K/RTK pathway activation occurred frequently [activating PIK3CA mutation or amplification (13%), PTEN inactivation (3%), RAS activation (6%), EGFR or ERBB2 activation (9%)]. Alterations in pathways affecting cell-cycle regulation [CCND1 amplification (9%), CDKN2A inactivation (17%), BRCA2 inactivation (2%)] and squamous differentiation [NOTCH1 inactivation (8%) andEP300 inactivation (6%)] were identified. PIK3CA amplification (n = 43), not PIK3CA mutation, was associated with significantly poorer progression-free survival (P = 0.0006). Oncogenic RAS mutations (n = 13) were associated with significantly poorer progression-free survival (P = 0.0001) and lower overall survival (P = 0.003). Eight patients with advanced, treatment-refractory HNSCC enrolled on clinical trials matched to tumor profiling results, and 50% achieved a partial response. Conclusions: Incorporation of NGS clinical assays into the routine care of patients with HNSCC is feasible and may readily facilitate enrollment into clinical trials of targeted therapy with a higher likelihood of success. Data can be utilized for discovery of genomic biomarkers of outcome. PIK3CA amplification and RAS mutations were frequently identified and associated with poorer prognosis in this cohort. Clin Cancer Res; 22(12); 2939–49. ©2016 AACR.

Human Papillomavirus-Associated Oropharynx Cancer (HPV-OPC): Treatment Options

Opinion statementHuman papillomavirus-associated oropharynx cancer (HPV-OPC) is growing in incidence and has distinct clinical, pathologic, molecular, and epidemiologic features. However, the management of HPV-OPC does not presently differ from HPV-negative OPC based on the current evidence and requires complex multidisciplinary approaches. The superior prognosis of HPV-OPC and the toxicities of current multimodality treatment in a young population serve as the impetus to evaluate de-intensification treatment regimens aimed at reducing toxicity while maintaining therapeutic efficacy. Clinical trials are underway to evaluate reduced doses of radiation or less toxic systemic therapy regimens in HPV-OPC. Minimally invasive surgical approaches in the HPV-OPC population with early tumor stage also are being investigated. De-intensification strategies should only be employed in the context of clinical trials, and HPV-OPC patients should be offered clinical trials’ participation. Appropriate patient selection is critical to the development of de-intensification regimens, and this requires greater understanding of risk factors within the HPV-OPC population, HPV-OPC biology, and how HPV modulates response to specific therapies. Smoking history and bulky nodal disease have been shown to impact negatively the favorable prognosis of HPV association. Validated biomarkers within the HPV-OPC population are lacking, although alterations in the PI3K pathway and markers of immune response may emerge as important considerations in the future. Novel therapeutic strategies are desperately needed particularly for HPV-OPC patients who fail definitive therapy, and select patients with recurrent or metastatic disease may benefit from aggressive approaches.

Systemic Therapy for Merkel Cell Carcinoma: What's on the Horizon?

Merkel cell carcinoma is an aggressive neuroendocrine skin cancer that usually affects elderly patients. Despite being uncommon, incidence has been steadily increasing over the last two decades, likely due to increased awareness, better diagnostic methods and aging of the population. It is currently one of the most lethal cutaneous malignancies, with a five-year overall survival of approximately 50%. With the better understanding of the molecular pathways that lead to the development of Merkel cell carcinoma, there has been an increasing excitement and optimism surrounding novel targeted therapies, in particular to immunotherapy. Some of the concepts surrounding the novel targeted therapies and currently ongoing clinical trials are reviewed here.

Efficacy and Safety of First-line Avelumab Treatment in Patients With Stage IV Metastatic Merkel Cell Carcinoma: A Preplanned Interim Analysis of a Clinical Trial

Importance Merkel cell carcinoma (MCC) is an aggressive skin cancer that is associated with poor survival outcomes in patients with distant metastatic disease. Results of part A of the JAVELIN Merkel 200 trial (avelumab in patients with Merkel cell carcinoma) showed that avelumab, an anti–programmed cell death ligand 1 (PD-L1) antibody, demonstrated efficacy in second-line or later treatment of patients with metastatic MCC (mMCC). Objective To evaluate the efficacy and safety of avelumab as first-line treatment for patients with distant mMCC. Design, Setting, and Participants JAVELIN Merkel 200 part B is an international, multicenter, single-arm, open-label clinical trial of first-line avelumab monotherapy. Eligible patients were adults with mMCC who had not received prior systemic treatment for metastatic disease. Patients were not selected for PD-L1 expression or Merkel cell polyomavirus status. Data were collected from April 15, 2016, to March 24, 2017, and enrollment is ongoing. Interventions Patients received avelumab, 10 mg/kg, by 1-hour intravenous infusion every 2 weeks until confirmed disease progression, unacceptable toxic effects, or withdrawal occurred. Main Outcomes and Measures Tumor status was assessed every 6 weeks and evaluated by independent review committee per Response Evaluation Criteria in Solid Tumors version 1.1. The primary end point was durable response, defined as an objective response with a duration of at least 6 months. Secondary end points include best overall response, duration of response, progression-free survival, safety, and tolerability. Results As of March 24, 2017, 39 patients were enrolled (30 men and 9 women; median age, 75 years [range, 47-88 years]), with a median follow-up of 5.1 months (range, 0.3-11.3 months). In a preplanned analysis, efficacy was assessed in 29 patients with at least 3 months of follow-up; the confirmed objective response rate was 62.1% (95% CI, 42.3%-79.3%), with 14 of 18 responses (77.8%) ongoing at the time of analysis. In responding patients, the estimated proportion with duration of response of at least 3 months was 93% (95% CI, 61%-99%); duration of response of at least 6 months, 83% (95% CI, 46%-96%). First-line avelumab treatment was generally well tolerated, and no treatment-related deaths or grade 4 adverse events occurred. Conclusions and Relevance High rates of response to first-line avelumab therapy in patients with distant mMCC build on previously reported antitumor activity after second-line or later treatment, and maturing progression-free survival data suggest that responses are durable. These data further support avelumab’s approval in the United States and European Union and use as a standard-of-care treatment for mMCC. Trial Registration clinicaltrials.gov Identifier: NCT02155647

Salivary and serum HPV antibody levels before and after definitive treatment in patients with oropharyngeal squamous cell carcinoma

BACKGROUND HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) is increasing in incidence. Laboratory assays that identify virally-mediated disease and predict HPV clearance in OPSCC may have important prognostic implications. OBJECTIVE Here we investigated serum, salivary HPV16 early (E) antibodies before and after definitive chemoradiotherapy (CRT) in patients with locoregionally advanced OPSCC. METHODS We prospectively measured salivary, serum samples at the beginning of and 6-7 weeks following the completion of CRT in 44 patients. IgG antibodies targeting N- and C-terminal fragments of E2 (NE2, CE2), E6 and E7 were measured by programmable enzyme-linked immunosorbent assay. RESULTS We observed serum antibodies directed against HPV-associated E proteins in patients with HPV-associated OPSCC. E7 directed antibodies were detected in saliva in the majority of patients, and were associated with HPV status (p= 0.03). When analyzed longitudinally, median salivary E7 antibody levels decreased significantly post-treatment (p= 0.007). CONCLUSIONS Our results demonstrate the feasibility of measuring HPV16 E antibodies in saliva and serum. E7 antibodies, in particular, are more detectable in saliva as compared with other E protein antibodies. Measuring E7 salivary antibody levels at various time points may have utility in understanding HPV clearance and should be explored for their ability to predict the risk of recurrence.