A natural cytokine mixture (IRX-2) and interference with immune suppression induce immune mobilization and regression of head and neck cancer

An Update on the Immunotherapy for Oropharyngeal Squamous Cell Carcinoma

Oropharyngeal squamous cell carcinoma (OPSCC) is an uncommon malignancy worldwide. Remarkably, the rising incidence of OPSCC has been observed in many developed countries over the past few decades. On top of tobacco smoking and alcohol consumption, human papillomavirus (HPV) infection has become a major etiologic factor for OPSCC. The radiotherapy-based or surgery-based systemic therapies are recommended equally as first-line treatment, while chemotherapy-based strategy is applied to advanced diseases. Immunotherapy in head and neck squamous cell carcinoma (HNSCC) is currently under the spotlight, especially for patients with advanced diseases. Numerous researches on programmed death-1/programmed death-ligand 1 checkpoint inhibitors have proven beneficial to patients with metastatic HNSCC. In 2016, nivolumab and pembrolizumab were approved as the second-line treatment for advanced metastatic HNSCC by the USA Food and Drug Administration. Soon after, in 2019, the USA Food and Drug Administration approved pembrolizumab as the first-line treatment for patients with unresectable, recurrent, and metastatic HNSCC. It has been reported that HPV-positive HNSCC patients were associated with increased programmed death-ligand 1 expression; however, whether HPV status indicates different treatment outcomes among HNSCC patients treated with immunotherapy has contradicted. Notably, HPV-positive OPSCC exhibits a significantly better clinical response to primary treatment (i.e., radiotherapy, surgery, and chemotherapy) and a more desirable prognosis compared to the HPV-negative OPSCC. This review summarizes the current publications on immunotherapy in HNSCC/OPSCC patients and discusses the impact of HPV infection in immunotherapeutic efficacy, providing an update on the immune landscape and future perspectives in OPSCC.

Telltale tumor infiltrating lymphocytes (TIL) in oral, head & neck cancer

Evidence gleaned from recent studies on the role of tumor-infiltrating lymphocytes (TILs) suggests that cancer is not only a genetic disease but also an immunologic disease. Head and Neck Squamous Cell Carcinoma (HNSCC) has been a significant model to study cancer cell-immune cell interactions. First, immune cell infiltration is an important feature of these tumors. Second, HNSCC frequently develops resistance to immunogenic cytotoxicity, which provides a window to decipher how tumors engage the immune system to establish immune tolerance. Finally, chemoradiation therapy, as a central modality for HNSCC treatment, has been shown to elicit immune activation. The presence of effector immune cells in the tumor microenvironment is often associated with superior clinical response to adjuvant therapy. On the other hand, an activated immune system, in addition to limiting tumor initiation and progression, could also exert selective pressure to promote the growth of less immunogenic tumors, as a pivotal immunoediting process. But it remains unclear how cancer cell signaling regulates tumor immunogenicity and how to mitigate HNSCC-potentiated TIL suppression. In this review, we will revisit the prognostic role of TILs in HNSCC, and collectively discuss how cancer cell machinery impacts upon the plasticity of TILs.

Current adjuvants and new perspectives in vaccine formulation

Given the important role of adjuvants in prophylactic vaccines, identification and development of new adjuvants with enhanced efficacy and safety is necessary. The use of adjuvants with immunopotentiating properties that can direct the immune responses to humoral or cell-mediated immunity and can induce T-cell responses has made it possible to design more protective vaccines. Although current regulations focus on traditional adjuvants, notably aluminum and calcium salts, advances have been made in regulatory considerations. The regulatory agencies for the evaluation of medicinal products are actively drafting guidance on requirements for the evaluation of new adjuvants. This article briefly summarizes the most widely studied adjuvants in vaccination, including those licensed for human vaccines and the regulatory aspects relevant to adjuvant quality at development stages.

Covalent linking of proteins and cytokines to suture: Enhancing the immune response of head and neck cancer patients

BACKGROUND

The immune system of advanced stage head and neck cancer patients is frequently suppressed. Poor immune function has been correlated with poor clinical outcome. Immunotherapeutic strategies have been previously attempted in an effort to enhance immune function and improve survival. Previous studies have shown surgical suture can be transformed into an immune stimulant capable of activating the T lymphocytes of cancer patients. The development of a process for covalently linking proteins and cytokines to suture could have enormous potential for the in vivo manipulation of the immune system.

HYPOTHESIS

We hypothesize proteins and cytokines can be covalently linked to surgical suture while preserving their functional properties.

STUDY DESIGN

Prospective study testing normal donor and head and neck squamous cell carcinoma (HNSCC) patient lymphocytes.

METHOD

Polyester suture was acid hydrolyzed followed by reacting with 1-ethyl-3(-3-dimethylamino propyl carbodiimide) (EDAC) to create a suture-EDAC intermediate. Next, selected proteins (horseradish peroxidase [HRP] or bovine serum albumin [BSA]) or cytokines (interleukin [IL]-2 or interferon [IFN]-gamma) were reacted with the suture-EDAC intermediate to test the covalent linkage of the selected protein or cytokine to suture. Functional activity of the linked proteins was measured spectrophotometrically. The linking of cytokines to suture was tested by stimulating normal donor peripheral blood lymphocytes (PBL) or HNSCC patients' lymphocytes. The functional activity was confirmed by proliferation, enzyme linked immunoadsorbent assay (ELISA), and phenotype expression of T cells. RESULTS The conditions for optimally linking a protein to polyester suture were defined using HRP as a model protein. HRP retained its enzymatic activity. The optimal conditions for linking IL-2 or IFN-gamma were defined. The covalently linked cytokines retained their immune enhancing properties for stimulating PBL and lymph node lymphocytes (LNL) from HNSCC patients to proliferate, generate a TH1 immunologic profile of cytokines (IL-2, IL-12, IFN-gamma), and stimulate T lymphocytes.

CONCLUSION

This is the first report to demonstrate that cytokines can be covalently linked to surgical sutures and retain their immune-stimulating properties. Proteins linked to suture also retained their enzymatic activity. The clinical implications of functionally active cytokines or proteins linked to surgical suture may be very significant in the future for manipulating the immune system in vivo or enhancing wound healing.

Neoadjuvant Immunotherapy of Oral Squamous Cell Carcinoma Modulates Intratumoral CD4/CD8 Ratio and Tumor Microenvironment: A Multicenter Phase II Clinical Trial

Purpose

To investigate the clinicopathologic effects of local neoadjuvant Leukocyte Interleukin Injection (LI) regimen in oral squamous cell carcinoma (OSCC) patients. Treatment regimen included LI 800 IU/d as interleukin-2 (IL-2), administered half peritumorally and half perilymphatically five times per week for 3 weeks; low-dose cyclophosphamide; indomethacin; zinc; and multivitamins.

Patients and Methods

Thirty-nine patients diagnosed with T2-3N0-2M0 OSCC participated in the pathology portion of this phase II multicenter study (19 LI-treated patients and 20 historical controls). Clinical responses were determined by imaging. Paraffin-embedded tumor samples were obtained at surgery for all patients. Surgery for the LI-treated group was performed between days 14 and 54 after the end of treatment. Histologic evaluation, pathologic staging, necrosis, and American Joint Committee on Cancer grading were performed from hematoxylin and eosin sections. Immunohistochemistry and morphometry determined cellular infiltrate.

Results

Two pathologically complete, two major (> 50%), and four minor responses (> 30% but < 50%) resulted from LI treatment (overall response rate, 42%). Histopathology showed that the intratumoral CD4+:CD8+ ratio was low (< 1) in patients not treated with LI (controls). An increase in tumor-infiltrating CD4+ and a decrease of CD8+ T cells was observed in LI-treated patients, leading to a significantly (P < .05) higher intratumoral CD4+:CD8+ ratio (> 2.5). This was paralleled by dendritic cell transition from tumor surface toward stromal interface (P < .05), with macrophage decrease and neutrophil accumulation, multifocal microscopic necrosis, and significant (P < .05) increase in tumor stroma of LI-treated patients compared with controls.

Conclusion

LI-treated OSCC patients were characterized by a markedly altered composition of tumor-infiltrating mononuclear cells, increased CD4+:CD8+ ratio, and increased tumor stroma to epithelial ratio, all of which were distinct from controls.

Targeting the immune system: novel therapeutic approaches in squamous cell carcinoma of the head and neck

Despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for patients with squamous cell carcinoma of the head and neck (SCCHN) have not changed over the last decades. Clearly, novel therapeutic strategies are needed for this cancer, which is highly immunosuppressive. Therefore, biologic therapies able to induce and/or up-regulate antitumor immune responses could represent a complementary approach to conventional treatments. Because patients with SCCHN are frequently immunocompromised due to the elimination or dysfunction of critical effector cells of the immune system, it might be necessary to restore these immune functions to allow for the generation of more effective antitumor host responses. Simultaneously, to prevent tumor escape, it might be necessary to alter attributes of the malignant cells. The present review summarizes recent advances in the field of immunotherapy of SCCHN, including techniques of nonspecific immune stimulation, the use of monoclonal antibodies, advances in adoptive immunotherapy and genetic engineering, as well as anticancer vaccines. These biologic therapies, alone or in combination with conventional treatment, are likely to develop into useful future treatment options for patients with SCCHN.

The effect of leukocyte interleukin injection (Multikine) treatment on the peritumoral and intratumoral subpopulation of mononuclear cells and on tumor epithelia: a possible new approach to augmenting sensitivity to radiation therapy and chemotherapy in oral cancer--a multicenter phase I/II clinical Trial

OBJECTIVES/HYPOTHESIS

The main objective of this study was to investigate the effect of the administration of a novel immunoadjuvant, leukocyte interleukin injection, as part of an immuno-augmenting treatment regimen on the peritumoral and intratumoral subpopulations of the tumor infiltrating mononuclear cells and on the epithelial and stromal components, when administered to patients with advanced primary oral squamous cell carcinoma classified as T2-3N0-2M0, as compared with disease-matched control patients (not treated with leukocyte interleukin injection).

STUDY DESIGN

Multicenter Phase I/II clinical trial. Fifty-four patients from four clinical centers were included in the dose-escalating study (27 in each group [leukocyte interleukin injection-treated and control groups]). Cumulative leukocyte inter-leukin injection doses were 2400, 4800, and 8000 IU (as interleukin-2 equivalent).

METHODS

Paraffin-embedded tumor samples obtained at surgical resection of the residual tumor (between days 21 and 28 after treatment initiation) were used. Histological analysis, necrosis evaluation, and American Joint Committee on Cancer grading were performed from H&E-stained sections. Immunohistochemical analysis was performed on three different tumor regions (surface, zone 1; center, zone 2; and tumor-stroma interface, zone 3). Trichrome staining was used to evaluate connective tissue, and morphometric measurements were made using ImagePro analysis software. Cell cycling was determined by the use of Ki-67 marker.

RESULTS

Leukocyte interleukin injection treatment induced a shift from stromal infiltrating T cells toward intraepithelial T cells and posted a significant (P <.05) increase in intraepithelial CD3-positive T cells independent of the leukocyte interleukin injection dose, whereas the increase in CD25 (interleukin-2 receptor alpha [IL-2Ralpha])-positive lymphoid cells was significant only at the lowest leukocyte interleukin injection dose (P <.05). Furthermore, both low- and medium-dose leukocyte interleukin injection treatment induced a significant (P <.05) increase in the number of cycling tumor cells, as compared with control values.

CONCLUSION

The results could be highly beneficial for patients with oral squamous cell carcinoma. First, leukocyte interleukin injection treatment induces T-cell migration into cancer nests and, second, noncycling cancer cells may enter cell cycling on administration of leukocyte interleukin injection. This latter effect may modulate the susceptibility of cancer cells to radiation therapy and chemotherapy. The findings may indicate a need to re-evaluate the way in which follow-up treatment (with radiation therapy and chemotherapy) of patients with head and neck cancer is currently approached.

Lymph node histology in head and neck cancer: impact of immunotherapy with IRX-2

OBJECTIVE

To determine if lymph nodes (LN) of patients receiving IRX-2 immunotherapy reflect changes in histology.

SETTING

National Cancer Institute, Mexico City, Mexico.

PATIENTS

Thirty patients with advanced squamous cell carcinoma of the head and neck (H and N SCC) and 10 non-cancer controls.

INTERVENTION

A 21-day cycle of preoperative immunotherapy, including a single intravenous infusion of low-dose cyclophosphamide (300 mg/M(2)), 10 or 20 daily perilymphatic injections of a natural cytokine mixture (IRX-2) (approximately 200 U interleukin-2 equivalence by enzyme-linked immunosorbent assay), daily oral indomethacin, and daily oral zinc with multivitamins, followed by surgery (20 patients); surgery only (10 patients); LN biopsy controls (10).

OUTCOME MEASURES

Pretreatment biopsies were performed to confirm the diagnosis. Clinical responses were assessed at surgery, and the specimen and a sample of lymph node were analyzed with respect to changes in morphology and lymphoid and inflammatory infiltration (T and B lymphocytes, plasma cells, macrophages, granulocytes, and giant cells). The postsurgical characteristics were ascribed percentages based on a representative section and compared.

RESULTS

All 20 H and N SCC patients treated with IRX-2 showed the changes of immune regression of their tumors, previously characterized [Arch. Pathol. Lab. Med. 122 (1998) 447]. The 10 H and N SCC controls showed no such changes. Lymph node histology of the 10 H and N SCC controls showed, compared to non-cancer controls, reduced size, decreased T cell area and density and increased sinus histiocytosis. The lymph nodes of IRX-2-treated H and N SCC patients showed increased size (over both control groups), increased T cell area and density and decreased follicles and sinus histiocytosis. The T cell and/or B cell areas of LN of IRX-2-treated patients showed a high correlation with T and/or B cell infiltration into these tumors (p<0.001).

CONCLUSION

The lymph nodes of patients with H and N SCC are distinguished by T cell depletion and sinus histiocytosis (SH). Immunotherapy reverses these changes and induces nodal expansion and lymphoid infiltration into the tumor that correlates with LN changes. The correlation of nodal expansion with tumor lymphoid infiltration and regression implies an effective immunization to host tumor antigens occurring at the level of the regional lymph node. The reversal of sinus histiocytosis, by IRX-2 treatment, in association with nodal expansion suggests that tumor antigen processing via dendritic cells is defective in cancer-bearing patients and that it is corrected by the treatment.

Long-term immune dysfunction after radiotherapy to the head and neck area

BACKGROUND

Hematological side effects are not generally expected due to radiotherapy involving limited radiation fields; however, patients with squamous cell carcinoma of the head and neck (SCCH and N) receiving radiation therapy frequently have chronic intraoral infections. Xerostomia has been implicated as a cause of it, but local or systemic immune alterations are not usually considered.

METHODS

With the purpose of evaluating the impact of radiotherapy treatment to different anatomic sites on immune function, 70 patients were evaluated during and after radiotherapy: 50 cases with SCCH and N, 10 with squamous cell carcinoma of the uterine cervix (SCCUC) and 10 patients with central nervous system tumors (CNS). We analyzed lymphocyte counts and T-cell subsets, and over time, their association with the presence of intracellular infections and disease-free survival.

RESULTS

Severe lymphopenia was observed in patients with SCCUC and SCCH and N by the fifth week of treatment. Patients with CNS tumors developed mild lymphopenia. In patients with SCCH and N and UC, lower counts were seen in B cells and total T lymphocyte counts including both CD4(+) and CD8(+) cell subsets. The patients with SCCUC recovered lymphocyte counts by the 24th month but T-cell subsets lagged behind. None of the SCCH and N patients had fully recovered by 60 months of follow-up. Recurrence correlates with low lymphocyte counts.

DISCUSSION

This work highlights the vulnerability of the head and neck area to the impact of radiotherapy as a reservoir of lymphoid cells. The possibility of recovery as a consequence of thymopoiesis and/or peripheral clonal expansion may limit the antigen-specific recognition of relevant tumor or microbial antigens and cause significant and prolonged immune alterations that may impact long-term survival.

T cell targeted immune enhancement yields effective T cell adjuvants

Given the critical role of cell-mediated immunity (CMI) in defense against attack from pathogens that establish chronic infections, it has become abundantly clear that current vaccine methodology will not be sufficient to develop the appropriate immune response for protection and/or clearance of infection. By extension, this logic also applies to cancer vaccines where T cell immune-mediated destruction is a critical mechanism for control of the disease. This review describes our current thoughts on the events associated with immune activation and evaluates the various approaches to achieve successful immune activation with defined or targeted antigens as opposed to using inactivated or attenuated organisms. The advantages and disadvantages of the current adjuvants for antigens that focus on mimicking the infection events via the innate immune system or antigen uptake are described in the context of generation of T cell specific responses. A central theme of the discussions is the importance of cytokines in modulating the immune response towards T cell immunity, either by adjuvant modulation or use of natural cytokine mixtures targeted towards the site of immune activation. Also discussed is the possibility that thymomimetic agents such as thymosin alpha1, levamisole and methyl inosine monophosphate (MIMP) may be useful in enhancing the T cell mediated arm of the immune response.

A pilot study of perilymphatic leukocyte cytokine mixture (IRX-2) as neoadjuvant treatment for early stage cervical carcinoma

Clinical and experimental data demonstrate that local cytokines are able to induce tumor regression and in some cases antitumor systemic immune response. IRX-2 is a cell-free mixture of cytokines obtained from unrelated donor lymphocytes with demonstrated ability to induce immune mediated regression of squamous cell carcinomas of head and neck. The objective of this study was to evaluate the antitumor activity and toxicity of IRX-2 in untreated early stage cervical cancer patients. Ten consecutive patients clinically staged IB1, IB2 and IIA were treated with a neoadjuvant immunotherapy regimen that consisted in a single IV dose of cyclophosphamide at 300 mg/m2 on day 1, oral indomethacin or ibuprofen and zinc sulfate were administered from days I to 21 and 10 regional perilymphatic injections of IRX-2 on days 3 to 14. All patients were scheduled for radical hysterectomy on day 21. The clinical and pathological responses, toxicity and survival were evaluated. Clinical response was seen in 50% of patients (three partial responses, two minor responses). Seven patients underwent surgery and pathological tumor reduction associated with tumor fragmentation was found in five cases. Histological studies demonstrated a rather heterogeneous cell type infiltrating pattern in the tumor which included lymphocytes, plasma cells, neutrophils, macrophages and eosinophils. Immunohistochemical analysis of the surgical specimens demonstrated an increase of tumor infiltrating CD8+ cells. The treatment was well tolerated except for mild pain and minor bleeding during injections and gastric intolerance to indomethacin. At 31 months of maximum follow-up (median 29), eight patients are disease-free. Our results suggest that the immunotherapy approach used induces tumor responses in cervical cancer patients. Further studies are needed to confirm these results as well as to elucidate the mechanisms underlying these effects.

The immunopharmacology of head and neck cancer: an update

Patients with head and neck squamous cell cancer have cell-mediated immune defects and anergy, which progress with disease. T-lymphocytopenia and dysfunction, monocyte dysfunction, prostaglandins, antigen-antibody complexes, serum and cell suppressive factors, radiation therapy and poor nutrition with zinc deficiency all contribute. Nevertheless, cell-mediated immunoreactivity to tumor is manifest in the majority of the patient's blood and regional nodes, and in the tumor itself by tumor-infiltrating lymphocytes. Lymphocytes from these sources cloned in the presence of interleukin-2 +/- tumor extracts show relatively specific cytotoxicity against squamous cell cancer. Humoral immunity is intact, and increased IgA and IgE levels and antibodies reactive to tumor antigens are common. Tumor-associated antigens detected in serum and tumor include carcinoembryonic antigen, tumor polypeptide antigen, squamous cell cancer antigens, tumor antigen-4 and various mucin antigens. The mucin antigens, in particular, can elicit T-cell responses. Humoral reactivity to such antigens is manifest in circulating immune complexes and immunoglobulin coating of tumor surfaces. Immunotherapeutic efforts in head and neck squamous cell cancer should logically employ T-cell adjuvants, contrasuppression and immunorestoration. Non-specific stimulation with bacille Calmette-Guerin (BCG), levamisole and other agents has not been successful. Encouraging results have been observed in limited trials with indomethacin and plasmapheresis. Early trials with local administration of low dosages of interferon-alpha, natural interleukin-2 and a natural interleukin mixture have produced partial and complete regressions with no toxicity and with intense leukocyte infiltration indicating cellular immunity. Efforts are needed to define the mechanisms and the antigens involved in these reactions. On the contrary, treatments with high dosages of recombinant interferon-alpha and interleukin-2 have yielded few responses and considerable toxicity. Combination strategies are discussed which may improve upon these initial immunotherapeutic effects of these low dose trials.