Position paper on olfactory dysfunction: 2023

BACKGROUND: Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process. CONCLUSIONS: We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

Developing a core outcome set for clinical trials in olfactory disorders: a COMET initiative.

STATEMENT OF PROBLEM: Evaluating the effectiveness of the management of Olfactory Dysfunction (OD) has been limited by a paucity of high-quality randomised and/or controlled trials. A major barrier is heterogeneity of outcomes in such studies. Core outcome sets (COS) - standardized sets of outcomes that should be measured/reported as determined by consensus-would help overcome this problem and facilitate future meta-analyses and/or systematic reviews (SRs). We set out to develop a COS for interventions for patients with OD. METHODS: A long-list of potential outcomes was identified by a steering group utilising a literature review, thematic analysis of a wide range of stakeholders' views and systematic analysis of currently available Patient Reported Outcome Measures (PROMs). A subsequent e-Delphi process allowed patients and healthcare practitioners to individually rate the outcomes in terms of importance on a 9-point Likert scale. RESULTS: After 2 rounds of the iterative eDelphi process, the initial outcomes were distilled down to a final COS including subjective questions (visual analogue scores, quantitative and qualitative), quality of life measures, psychophysical testing of smell, baseline psychophysical testing of taste, and presence of side effects along with the investigational medicine/device and patient's symptom log. CONCLUSIONS: Inclusion of these core outcomes in future trials will increase the value of research on clinical interventions for OD. We include recommendations regarding the outcomes that should be measured, although future work will be required to further develop and revalidate existing outcome measures.

Pembrolizumab in Relapsed and Refractory Mycosis Fungoides and Sézary Syndrome: A Multicenter Phase II Study.

PURPOSE: To assess the efficacy of pembrolizumab in patients with advanced relapsed or refractory mycosis fungoides (MF) or Sézary syndrome (SS). PATIENTS AND METHODS: CITN-10 is a single-arm, multicenter phase II trial of 24 patients with advanced MF or SS. Patients were treated with pembrolizumab 2 mg/kg every 3 weeks for up to 24 months. The primary end point was overall response rate by consensus global response criteria. RESULTS: Patients had advanced-stage disease (23 of 24 with stage IIB to IV MF/SS) and were heavily pretreated with a median of four prior systemic therapies. The overall response rate was 38% with two complete responses and seven partial responses. Of the nine responding patients, six had 90% or more improvement in skin disease by modified Severity Weighted Assessment Tool, and eight had ongoing responses at last follow-up. The median duration of response was not reached, with a median response follow-up time of 58 weeks. Immune-related adverse events led to treatment discontinuation in four patients. A transient worsening of erythroderma and pruritus occurred in 53% of patients with SS. This cutaneous flare reaction did not result in treatment discontinuation for any patient. The flare reaction correlated with high PD-1 expression on Sézary cells but did not associate with subsequent clinical responses or lack of response. Treatment responses did not correlate with expression of PD-L1, total mutation burden, or an interferon-γ gene expression signature. CONCLUSION: Pembrolizumab demonstrated significant antitumor activity with durable responses and a favorable safety profile in patients with advanced MF/SS.

A First-in-Human Phase I Study of Subcutaneous Outpatient Recombinant Human IL15 (rhIL15) in Adults with Advanced Solid Tumors.

Purpose: Preclinical data established IL15 as a homeostatic factor and powerful stimulator of NK and CD8+ T-cell function, the basis for clinical testing.Experimental Design: A first-in-human outpatient phase I dose escalation trial of subcutaneous (SC) rhIL15 was conducted in refractory solid tumor cancer patients. Therapy consisted of daily (Monday-Friday) subcutaneous injections of rhIL15 for two consecutive weeks (10 total doses/cycle). Clinical response was assessed by RECIST. Pharmacokinetics of rhIL15 and immune biomarkers were evaluated.Results: Nineteen patients were treated with rhIL15 at dose levels of 0.25, 0.5, 1, 2, and 3 mcg/kg/day. Fourteen patients completed ≥ 2 cycles of therapy that was well tolerated. One serious adverse event (SAE), grade 2 pancreatitis, required overnight hospitalization. Enrollment was halted after a patient receiving 3 mcg/kg/day developed a dose-limiting SAE of grade 3 cardiac chest pain associated with hypotension and increased troponin. No objective responses were observed; however, several patients had disease stabilization including a renal cell carcinoma patient who continued protocol treatment for 2 years. The treatment induced profound expansion of circulating NK cells, especially among the CD56bright subset. A proportional but less dramatic increase was found among circulating CD8+ T cells with maximal 3-fold expansion for the 2 and 3 mcg/kg patients.Conclusions: SC rhIL15 treatment was well tolerated, producing substantial increases in circulating NK and CD8+ T cells. This protocol establishes a safe outpatient SC rhIL15 regimen of 2 mcg/kg/day dosing amenable to self-injection and with potential as a combination immunotherapeutic agent. Clin Cancer Res; 24(7); 1525-35. ©2017 AACR.

Antigen presentation profiling reveals recognition of lymphoma immunoglobulin neoantigens.

Cancer somatic mutations can generate neoantigens that distinguish malignant from normal cells. However, the personalized identification and validation of neoantigens remains a major challenge. Here we discover neoantigens in human mantle-cell lymphomas by using an integrated genomic and proteomic strategy that interrogates tumour antigen peptides presented by major histocompatibility complex (MHC) class I and class II molecules. We applied this approach to systematically characterize MHC ligands from 17 patients. Remarkably, all discovered neoantigenic peptides were exclusively derived from the lymphoma immunoglobulin heavy- or light-chain variable regions. Although we identified MHC presentation of private polymorphic germline alleles, no mutated peptides were recovered from non-immunoglobulin somatically mutated genes. Somatic mutations within the immunoglobulin variable region were almost exclusively presented by MHC class II. We isolated circulating CD4+ T cells specific for immunoglobulin-derived neoantigens and found these cells could mediate killing of autologous lymphoma cells. These results demonstrate that an integrative approach combining MHC isolation, peptide identification, and exome sequencing is an effective platform to uncover tumour neoantigens. Application of this strategy to human lymphoma implicates immunoglobulin neoantigens as targets for lymphoma immunotherapy.

Position paper on olfactory dysfunction.

Background: Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: • Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. • Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. • Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. • Comprehensive chemosensory assessment should include gustatory screening. • Smell training can be helpful in patients with olfactory loss of several aetiologies. Conclusions: We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.

Distinct patterns of B-cell receptor signaling in non-Hodgkin lymphomas identified by single-cell profiling.

Kinases downstream of B-cell antigen receptor (BCR) represent attractive targets for therapy in non-Hodgkin lymphoma (NHL). As clinical responses vary, improved knowledge regarding activation and regulation of BCR signaling in individual patients is needed. Here, using phosphospecific flow cytometry to obtain malignant B-cell signaling profiles from 95 patients representing 4 types of NHL revealed a striking contrast between chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) tumors. Lymphoma cells from diffuse large B-cell lymphoma patients had high basal phosphorylation levels of most measured signaling nodes, whereas follicular lymphoma cells represented the opposite pattern with no or very low basal levels. MCL showed large interpatient variability in basal levels, and elevated levels for the phosphorylated forms of AKT, extracellular signal-regulated kinase, p38, STAT1, and STAT5 were associated with poor outcome. CLL tumors had elevated basal levels for the phosphorylated forms of BCR-signaling nodes (Src family tyrosine kinase, spleen tyrosine kinase [SYK], phospholipase Cγ), but had low α-BCR-induced signaling. This contrasted MCL tumors, where α-BCR-induced signaling was variable, but significantly potentiated as compared with the other types. Overexpression of CD79B, combined with a gating strategy whereby signaling output was directly quantified per cell as a function of CD79B levels, confirmed a direct relationship between surface CD79B, immunoglobulin M (IgM), and IgM-induced signaling levels. Furthermore, α-BCR-induced signaling strength was variable across patient samples and correlated with BCR subunit CD79B expression, but was inversely correlated with susceptibility to Bruton tyrosine kinase (BTK) and SYK inhibitors in MCL. These individual differences in BCR levels and signaling might relate to differences in therapy responses to BCR-pathway inhibitors.

Blood Stem Cell Activity Is Arrested by Th1-Mediated Injury Preventing Engraftment following Nonmyeloablative Conditioning.

T cells are widely used to promote engraftment of hematopoietic stem cells (HSCs) during an allogeneic hematopoietic cell transplantation. Their role in overcoming barriers to HSC engraftment is thought to be particularly critical when patients receive reduced doses of preparative chemotherapy and/or radiation compared with standard transplantations. In this study, we sought to delineate the effects CD4+ cells on engraftment and blood formation in a model that simulates clinical hematopoietic cell transplantation by transplanting MHC-matched, minor histocompatibility-mismatched grafts composed of purified HSCs, HSCs plus bulk T cells, or HSCs plus T cell subsets into mice conditioned with low-dose irradiation. Grafts containing conventional CD4+ T cells caused marrow inflammation and inhibited HSC engraftment and blood formation. Posttransplantation, the marrows of HSCs plus CD4+ cell recipients contained IL-12-secreting CD11c+ cells and IFN-γ-expressing donor Th1 cells. In this setting, host HSCs arrested at the short-term stem cell stage and remained in the marrow in a quiescent cell cycling state (G0). As a consequence, donor HSCs failed to engraft and hematopoiesis was suppressed. Our data show that Th1 cells included in a hematopoietic allograft can negatively impact HSC activity, blood reconstitution, and engraftment of donor HSCs. This potential negative effect of donor T cells is not considered in clinical transplantation in which bulk T cells are transplanted. Our findings shed new light on the effects of CD4+ T cells on HSC biology and are applicable to other pathogenic states in which immune activation in the bone marrow occurs such as aplastic anemia and certain infectious conditions.

Anti-CD137 enhances anti-CD20 therapy of systemic B-cell lymphoma with altered immune homeostasis but negligible toxicity.

Studies of sequential anti-CD137/anti-CD20 therapy have previously shown that the efficacy of anti-CD20 was heavily reliant upon anti-CD137; however, the exact mechanism of the anti-B-cell lymphoma efficacy, and whether this correlates with enhanced adverse effects or toxicity, had not been elucidated. Here, we observed that sequential anti-CD137 administration with anti-CD20 resulted in a synergistic therapy, largely dependent upon Fc receptors (FcR), to prolong survival in an experimental B-cell lymphoma therapy model. Tumor suppression was accompanied by B cell depletion, which was not dependent on one activating FcR. Surprisingly, the B-cell activating factor (BAFF) was elevated in the plasma of mice receiving anti-CD137 alone or in combination with anti-CD20, while a selective increase in some plasma cytokines was also noted and triggered by anti-CD137. These effects were independent of activating FcR. Sustained treatment of advanced lymphoma revealed increased lymphocyte infiltrates into the liver and a significant decrease in the metabolic capability of the liver in mice receiving anti-CD137. Importantly, these effects were not exacerbated in mice receiving the anti-CD20/CD137 combination, and elevations in classical liver damage markers such as alanine aminotransferase (ALT) were less than that caused by the lymphoma itself. Thus, combined anti-CD20/anti-CD137 treatment increases the therapeutic index of anti-CD20 or anti-CD137 alone. These mouse data were corroborated by ongoing clinical development studies to assess safety, tolerability and pharmacodynamic activity of human patients treated by this approach. Together, these data support the use of this sequential antibody therapeutic strategy to improve the efficacy of rituximab in B-cell lymphoma patients.

Assessing Immune-Related Adverse Events of Efficacious Combination Immunotherapies in Preclinical Models of Cancer.

New combination immunotherapies are displaying both efficacy and immune-related adverse events (irAE) in humans. However, grade 3/4 irAEs occur in a high proportion, which can lead to discontinuation of treatment and can result in fatalities if not promptly treated. Prolonged T regulatory cell (Treg) depletion in tumor-bearing Foxp3-DTR mice using diphtheria toxin (DT) mirrored the spectrum of antitumor responses and severity of irAEs that can occur in ipilimumab/nivolumab-treated patients. In contrast, transient Treg depletion or anti-CTLA-4/PD-1 therapy had equivalent effects in mice, lowering the immune tolerance threshold and allowing irAEs to be more easily induced following treatment with additional immunomodulatory antibodies. Transient Treg depletion of DT in combination with anti-PD-1 or anti-TIM-3 monoclonal antibodies had a high therapeutic window compared with DT plus anti-CD137. In contrast, DT plus anti-CD137-treated mice developed severe irAEs similar to grade 3/4 clinical symptoms. These irAEs appeared because of an infiltration of activated proliferating effector T cells in the tissues producing IFNγ and TNF; however, TNF blockade decreased irAEs severity without impacting on tumor growth. Cancer Res; 76(18); 5288-301. ©2016 AACR.

Strategic Combinations: The Future of Oncolytic Virotherapy with Reovirus.

The dominant cancer treatment modalities such as chemotherapy, radiotherapy, and even targeted kinase inhibitors and mAbs are limited by low efficacy, toxicity, and treatment-resistant tumor subclones. Oncolytic viral therapy offers a novel therapeutic strategy that has the potential to dramatically improve clinical outcomes. Reovirus, a double-stranded benign human RNA virus, is a leading candidate for therapeutic development and currently in phase III trials. Reovirus selectively targets transformed cells with activated Ras signaling pathways; Ras genes are some of the most frequently mutated oncogenes in human cancer and it is estimated that at least 30% of all human tumors exhibit aberrant Ras signaling. By targeting Ras-activated cells, reovirus can directly lyse cancer cells, disrupt tumor immunosuppressive mechanisms, reestablish multicellular immune surveillance, and generate robust antitumor responses. Reovirus therapy is currently being tested in combination with radiotherapy, chemotherapy, immunotherapy, and surgery. In this review, we discuss the current successes of these combinatorial therapeutic strategies and emphasize the importance of prioritizing combination oncolytic viral therapy as reovirus-based treatments progress in clinical development. Mol Cancer Ther; 15(5); 767-73. ©2016 AACR.

PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma.

BACKGROUND: Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1. METHODS: In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti-PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing. RESULTS: A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients. CONCLUSIONS: In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors and those with virus-negative tumors. (Funded by the National Cancer Institute and Merck; ClinicalTrials.gov number, NCT02267603.).

4-1BB agonism: adding the accelerator to cancer immunotherapy.

The success of checkpoint inhibitors has validated immunomodulatory agents as a valuable class of anticancer therapeutics. A promising co-stimulatory immunologic target is 4-1BB, or CD137, a member of the tumor necrosis factor receptor superfamily. Ligation of 4-1BB induces an activating signal in CD8(+) T cells and natural killer cells, resulting in increased pro-inflammatory cytokine secretion, cytolytic function, and antibody-dependent cell-mediated cytotoxicity. Targeting 4-1BB with agonistic monoclonal antibody (mAb) therapy demonstrated potent antitumor effects in murine tumor models. While anti-4-1BB mAbs have entered clinical trials, optimal efficacy of 4-1BB-targeted agents will inevitably come from combination therapeutic strategies. Checkpoint blockade is a compelling combination partner for 4-1BB agonism. This novel immunotherapeutic approach has the potential to active antitumor immune effectors by a complementary mechanism: simultaneously "removing the brakes" via blocking inhibitory signaling and "stepping on the accelerator" via co-stimulation. While important considerations should be given to 4-1BB-mediated toxicities, the current understanding of 4-1BB biology suggests it may play a key role in advancing the capabilities of cancer combination therapy.

Immunodynamics: a cancer immunotherapy trials network review of immune monitoring in immuno-oncology clinical trials.

The efficacy of PD-1/PD-L1 targeted therapies in addition to anti-CTLA-4 solidifies immunotherapy as a modality to add to the anticancer arsenal. Despite raising the bar of clinical efficacy, immunologically targeted agents raise new challenges to conventional drug development paradigms by highlighting the limited relevance of assessing standard pharmacokinetics (PK) and pharmacodynamics (PD). Specifically, systemic and intratumoral immune effects have not consistently correlated with standard relationships between systemic dose, toxicity, and efficacy for cytotoxic therapies. Hence, PK and PD paradigms remain inadequate to guide the selection of doses and schedules, both starting and recommended Phase 2 for immunotherapies. The promise of harnessing the immune response against cancer must also be considered in light of unique and potentially serious toxicities. Refining immune endpoints to better inform clinical trial design represents a high priority challenge. The Cancer Immunotherapy Trials Network investigators review the immunodynamic effects of specific classes of immunotherapeutic agents to focus immune assessment modalities and sites, both systemic and importantly intratumoral, which are critical to the success of the rapidly growing field of immuno-oncology.

In situ vaccination for the treatment of cancer.

Vaccination has had a tremendous impact on human health by harnessing the immune system to prevent and eradicate infectious diseases and this same approach might be used in cancer therapy. Cancer vaccine development has been slowed hindered by the paucity of universal tumor-associated antigens and the difficulty in isolating and preparing individualized vaccines ex vivo. Another approach has been to initiate or stimulate an immune response in situ (at the tumor site) and thus exploit the potentially numerous tumor-associated antigens there. Here, we review the many approaches that have attempted to accomplish effective in situ vaccination, using intratumoral administration of immunomodulators to increase the numbers or activation state of either antigen present cells or T cells within the tumor.

CD44+ Cells in Head and Neck Squamous Cell Carcinoma Suppress T-Cell-Mediated Immunity by Selective Constitutive and Inducible Expression of PD-L1.

PURPOSE: Human tumors consist of heterogeneous populations of cells with distinct marker expression and functional properties. In squamous cell carcinoma of the head and neck (SCCHN), CD44 is a well-characterized marker of a resilient subpopulation of cells associated with increased tumorigenesis, radioresistance, and chemoresistance. Evidence indicates that these cells have an immunosuppressive phenotype; however, mechanisms have been elusive. EXPERIMENTAL DESIGN: Using primary human SCCHN tumor samples and patient-derived xenografts, we examined the phenotypes of subsets of tumor cells and investigated mechanisms regulating their immunogenicity. RESULTS: CD44(+) cells in primary human SCCHN were found to have an epithelial-to-mesenchymal (EMT) phenotype and were less immunogenic than CD44(-) cells when cultured with autologous CD8(+) tumor-infiltrating T cells. Selective expression of the programmed death-ligand 1 (PD-L1) was observed on CD44(+) cells compared with CD44(-) cells and was associated with constitutive phosphorylation of STAT3 on CD44(+) cells. Importantly, inhibition of STAT3 decreased expression of PD-L1 on CD44(+) cells. IFNγ treatment preferentially induced even further PD-L1 expression on CD44(+) cells and was associated with enhanced IFNγ receptor expression and phosphorylation of STAT1. Finally, the decreased immunogenicity of CD44(+) cells was partially reversed by antibody blockade of the programmed death 1 (PD-1) receptor, indicating that the differences in PD-L1 expression between CD44(+) and CD44(-) cells are biologically and clinically relevant. CONCLUSIONS: Our findings provide a mechanism by which long-lived CD44(+) tumor-initiating cells can selectively evade host immune responses and provide rationale for targeting the PD-1 pathway in the adjuvant therapy setting of SCCHN. Clin Cancer Res; 22(14); 3571-81. ©2016 AACR.