Electrochemotherapy as palliative treatment in patients with recurrent and/or metastatic head and neck tumours: features analysis for an early determination of the partial responsive patients

OBJECTIVE

The aim of this study was to identify features mainly involved in determining the partial response (PR) to the Electrochemotherapy (ECT) in patients with recurrent and/or metastatic head and neck (H&N) tumor; the identified features were also used in a decision chart in order to provide the clinician with a support tool in deciding further therapies.

PATIENTS AND METHODS

131 patients (186 treatment sessions) with recurrent and/or metastatic H&N neoplasm were subjected to ECT. Treatment response was evaluated based on Response Evaluation Criteria in Solid Tumors (RECIST) v. 1.1 two months after the ECT. The grade of bleeding and pain before, at the end and one week after ECT treatment were evaluated. Univariate and multivariate analysis were performed to identify features involved in determining the patient PR.

RESULTS

In the context of the univariate analysis, tumor size significantly influenced the response to ECT, with higher PR rate of 58.3%: 28 among 48 patients with lesion size ≤ 3 centimeters (p-value < 0.001 at Chi-square test). Pain and bleeding pre-treatment were positively correlated to PR (p-value < 0.001 at Chi-square test). A difference in the current flowing in the tissue during treatment was also observed in partially responsive patients, where the median current value (6.6 A) was higher than that achieved in patients that did not show PR (3.3 A). In the context of the multivariate analysis, the best performances are achieved with the BART method (accuracy of 84%). The main clinical factors to predict the partial response, among investigated features, that have shown to be considered were the pain value felt before performing the treatment and the median current delivered during the ECT treatment. A decision-making support tool to predict the patient prognosis in terms of response rate could be represented by the decision tree obtained with CART algorithm, where a pain pre-treatment more than 5 and a median delivered current not less than 2.8 A led to the prediction a partial responsive patient with an accuracy of 75%.

CONCLUSIONS

The study confirmed that ECT is an interesting antitumoral therapy in advanced chemo- and radio-refractory H&N neoplasms, able to reduce frequent symptoms and to improve the quality of life. Pain pre-treatment and delivered current are the most important variables when predicting the partial response of patients.

Reduction of muscle contraction and pain in electroporation-based treatments: An overview

BACKGROUND

In the first studies of electrochemotherapy (ECT), small cutaneous metastases were treated and only mild or moderate pain was observed; therefore, pain was not considered a significant issue. As the procedure began to be applied to larger cutaneous metastases, pain was reported more frequently. For that reason, reduction of both muscle contractions and pain have been investigated over the years.

AIM

To present an overview of different protocols described in literature that aim to reduce muscle contractions and pain caused by the electroporation (EP) effect in both ECT and irreversible EP treatments.

METHODS

Thirty-three studies published between January 1999 and November 2020 were included. Different protocol designs and electrode geometries that reduce patient pain and the number of muscle contractions and their intensity were analysed.

RESULTS

The analysis showed that both high frequency and bipolar/biphasic pulses can be used to reduce pain and muscle contractions in patients who undergo EP treatments. Moreover, adequate electrode design can decrease EP-related morbidity. Particularly, needle length, diameter and configuration of the distance between the needles can be optimised so that the muscle volume crossed by the current is reduced as much as possible. Bipolar/biphasic pulses with an inadequate pulse length seem to have a less evident effect on the membrane permeability compared with the standard pulse protocol. For that reason, the number of pulses and the voltage amplitude, as well as the pulse duration and frequency, must be chosen so that the dose of delivered energy guarantees EP efficacy.

CONCLUSION

Pain reduction in EP-based treatments can be achieved by appropriately defining the protocol parameters and electrode design. Most results can be achieved with high frequency and/or bipolar/biphasic pulses. However, the efficacy of these alternative protocols remains a crucial point to be assessed further.

Radionuclide Therapy of Unresectable Tumors with AvidinOX and (90)Y-biotinDOTA: Tongue Cancer Paradigm

Local treatment of unresectable tumors is challenging, particularly with radioactivity. Current practice relies on external beam irradiation or on a variety of medical devices for brachytherapy. Both approaches proved useful in controlling tumor growth, but are characterized by poor compliance of the patient, significant side-effects, high costs, and technological complexity, which hamper widespread use. The authors recently described a novel form of radionuclide therapy based on the oxidized form of avidin that, chemically reacting with tissue proteins, can secure radioactive biotin within the injected tissue, either when precomplexed or when taken from the blood stream after intravenous administration. AvidinOX-pretargeted ¹⁷⁷Lu-biotinDOTA (¹⁷⁷Lu-ST2210) is currently under clinical investigation for the treatment of liver oligometastases from colorectal cancer (clinicaltrials.gov/NCT02053324). In the present work, the authors show that injected AvidinOX can link tissues of various natures such as prostate, kidney, breast, or brain and can react by contact with scraped tissues such as skin or urinary bladder. AvidinOX injected into human OSC19 tongue cancer masses orthotopically transplanted in nude mice takes up intravenously administered ⁹⁰Y-ST2210, which exerts significant antitumor activity, while preserving the integrity and functionality of the tongue. Present data confirm that AvidinOX-based radionuclide therapy is an innovative and promising approach for the local treatment of inoperable tumors.

AvidinOX&#x2122; for tissue targeted delivery of biotinylated cells

AvidinOX™, a product containing aldehyde groups, generated by ligand-assisted sugar oxidation of avidin by sodium periodate, maintains the capacity to bind biotin with very high affinity and exhibits the property to chemically link cellular and tissue proteins through Schiff's base formation thus residing in tissues for weeks. In recent studies, we have shown that AvidinOX exhibits much higher persistency in the skeletal muscle than native avidin. The aim of the present study is to evaluate whether AvidinOX-biotin interaction might be exploited to target biotinylated cells to an AvidinOX pre-treated muscle. To accomplish this we performed the following experiments: 1) The proliferation and differentiation properties of biotinylated C2C12 myoblasts were tested in vitro upon linkage to AvidinOX; 2) Bone marrow-derived cells (BMDC) were isolated from GFP positive transgenic mice [strain C57 BL/6-tg (UBC-GFP)] and after biotinylation (bBMDC) were intravenously administered to naive and MAVA+ (Mouse anti Avidin Antibody) C57/B6 mice previously injected with AvidinOX in a tibial muscle (TM). Localization efficiency of GFP+ bBMDC was evaluated on serial sections of the AvidinOX- and vehicle-treated (contra lateral limb) TM, 5 days after transplantation. Results show that biotinylated C2C12 cells, once linked to AvidinOX, maintain their proliferation and differentiation capacity, in vitro. Intravenous injection of biotinylated GFP+ bone marrow-derived cells leads to their specific and efficient localization in the AvidinOX-pre-treated, but not contra lateral muscle of both naive and MAVA+ mice. The present data suggest a potential use of AvidinOX to improve tissue targeted delivery of biotinylated cells.

Chemical linkage to injected tissues is a distinctive property of oxidized avidin

We recently reported that the oxidized avidin, named AvidinOX®, resides for weeks within injected tissues as a consequence of the formation of Schiff's bases between its aldehyde groups and tissue protein amino groups. We also showed, in a mouse pre-clinical model, the usefulness of AvidinOX for the delivery of radiolabeled biotin to inoperable tumors. Taking into account that AvidinOX is the first oxidized glycoprotein known to chemically link to injected tissues, we tested in the mouse a panel of additional oxidized glycoproteins, with the aim of investigating the phenomenon. We produced oxidized ovalbumin and mannosylated streptavidin which share with avidin glycosylation pattern and tetrameric structure, respectively and found that neither of them linked significantly to cells in vitro nor to injected tissues in vivo, despite the presence of functional aldehyde groups. The study, extended to additional oxidized glycoproteins, showed that the in vivo chemical conjugation is a distinctive property of the oxidized avidin. Relevance of the high cationic charge of avidin into the stable linkage of AvidinOX to tissues is demonstrated as the oxidized acetylated avidin lost the property. Plasmon resonance on matrix proteins and cellular impedance analyses showed in vitro that avidin exhibits a peculiar interaction with proteins and cells that allows the formation of highly stable Schiff's bases, after oxidation.

Anti-proliferative effect of a triazole derivative (ST1959) on LNCaP human prostate cancer cells through down-regulation of cyclin and androgen receptor expression

BACKGROUND

Previous studies demonstrated that ST1959, a triazole derivative endowed with immunomodulatory activities, also exerts inhibitory effects on proliferation and survival of a panel of tumor cells. In this study, we sought to ascertain the effects of ST1959 on the growth of androgen-dependent and androgen-independent prostate cancer (PCa) cells.

METHODS

The growth of androgen-dependent (LNCaP) and androgen-independent (PC3, DU-145) cells was analyzed in vitro both in the presence and absence of ST1959. Modulation of cyclin and androgen receptor (AR) expression following treatment with ST1959 was analyzed by Western blot and cytofluorimetric analysis.

RESULTS

We observed that ST1959 causes a significant growth inhibition of LNCaP cells without affecting proliferation of androgen-insensitive DU-145 and PC3 cell lines. These effects were associated with G0/G1 cell cycle arrest and down-regulation of cyclin D1, A and B and AR expression.

CONCLUSIONS

Our present findings indicate that the anti-proliferative activity of ST1959 on cell growth of androgen-dependent LNCaP PCa cells may be brought about by decreasing expression of functional AR and selected cyclins, ultimately leading to cell growth inhibition.

Tumor-infiltrating B lymphocytes as an efficient source of highly specific immunoglobulins recognizing tumor cells

BACKGROUND

There is much evidence that tumor cells elicit a humoral immune response in patients. In most cases, the presence of antibodies in peripheral blood is detected only in small proportion of patients with tumors overexpressing the corresponding antigen. In the present study, we analyzed the significance of local humoral response provided by tumor-infiltrating lymphocytes in breast cancer patients.

METHODS

The ability of a patient's immune system to produce specific antibodies inside tumor tissue, capable of recognizing tumor cells, was explored through analysis of the oligoclonality of antibodies derived from tumor-infiltrating lymphocytes and construction of a series of recombinant antibody libraries in scFv format, derived from breast tumor-infiltrating B lymphocytes. These libraries and one from peripheral blood lymphocytes of a single breast cancer patient were panned against three purified surface tumor antigens, such as CEA, MUC1 and ED-B domain, and against intact MCF7 breast carcinoma cells.

RESULTS

Application of novel display vector, pKM19, allowed isolation of a large panel of breast cancer-specific antibodies against known tumor antigens, as well as against breast carcinoma cells. Reactivity of novel scFvs was confirmed by ELISA, immunohistochemistry, fluorescence staining and flow cytometry. We demonstrated that seven of ten primary breast tumor specimens, obtained using discarded surgical material, could be exploited as an appropriate source for generation of phage display libraries, giving highly specific antitumor antibodies which recognize heterologous tumor cells.

CONCLUSION

Local humoral immune response within tumor tissue in breast cancer patients frequently has an oligoclonal character. Efficient selection of specific antitumor antibodies from recombinant antibody libraries, derived from such oligoclonal tumor-infiltrated B lymphocytes, indicates the presence of natural immune response against tumor antigens in these patients. The described method is very promising for development of antitumor antibodies, potentially useful for diagnostic and therapeutic approaches.

Low and High Tenascin-Expressing Tumors Are Efficiently Targeted by ST2146 Monoclonal Antibody

ST2146biot is a biotinylated anti-tenascin monoclonal antibody (mAb) to be used for Pretargeted Antibody Guided Radioimmunotherapy (PAGRIT) of solid tumors. In vivo biodistribution studies of (125)I-labeled ST2146biot were done in nude mice transplanted with human HT-29 colon carcinoma and/or human U-118MG glioblastoma cells characterized for low and high tenascin expression, respectively. In vitro results show that ST2146 retains immunoreactivity upon biotinylation, in contrast to other anti-tenascin mAbs. In vivo biodistribution of ST2146 shows specific tumor accumulation up to 10 days after the i.v. injection, with no relevant differences between biotinylated and nonbiotinylated ST2146. A dose of 4 microg/mouse saturates the low tenascin-expressing human colon carcinoma HT-29, whereas the high tenascin-expressing human glioblastoma U-118MG seems to be saturated at a ST2146biot dose between 320 and 640 microg/mouse. The percentage of injected dose per gram of tumor ranges from 10% to 30%, corresponding to an amount of ST2146biot/g of tumor of approximately 400 ng/g and >200 microg/g for HT-29 and U-118MG, respectively. Tumor to normal organs uptake ratios are between 15 and 60, confirming high tumor selectivity of ST2146biot despite its cross-reactivity with the tenascin expressed at low level in the normal mouse organs. The ST2146biot localization data are substantially confirmed even when both low and high tenascin-expressing tumors are implanted in the same animal. To our knowledge, the absolute amount of ST2146biot, specifically localized in xenotransplanted human tumors, is the highest thus far described and supports the clinical use of this mAb in PAGRIT(R).

Selection, affinity maturation, and characterization of a human scFv antibody against CEA protein

BACKGROUND

CEA is a tumor-associated antigen abundantly expressed on several cancer types, including those naturally refractory to chemotherapy. The selection and characterization of human anti-CEA single-chain antibody fragments (scFv) is a first step toward the construction of new anticancer monoclonal antibodies designed for optimal blood clearance and tumor penetration.

METHODS

The human MA39 scFv, selected for its ability to recognize a CEA epitope expressed on human colon carcinomas, was first isolated from a large semi-synthetic ETH-2 antibody phage library, panned on human purified CEA protein. Subsequently, by in vitro mutagenesis of a gene encoding for the scFv MA39, a new library was established, and new scFv antibodies with improved affinity towards the CEA cognate epitope were selected and characterized.

RESULTS

The scFv MA39 antibody was affinity-maturated by in vitro mutagenesis and the new scFv clone, E8, was isolated, typed for CEA family member recognition and its CEACAM1, 3 and 5 shared epitope characterized for expression in a large panel of human normal and tumor tissues and cells.

CONCLUSION

The binding affinity of the scFv E8 is in a range for efficient, in vivo, antigen capture in tumor cells expressing a shared epitope of the CEACAM1, 3 and 5 proteins. This new immunoreagent meets all criteria for a potential anticancer compound: it is human, hence poorly or not at all immunogenic, and it binds selectively and with good affinity to the CEA epitope expressed by metastatic melanoma and colon and lung carcinomas. Furthermore, its small molecular size should provide for efficient tissue penetration, yet give rapid plasma clearance.

Improved Tumor Targeting by Combined Use of Two Antitenascin Antibodies

PURPOSE

In the pretargeted antibody-guided radioimmunotherapy (PAGRIT) system, the combined use of two different antibodies directed against the same tumor antigen could represent a valid approach for improving tumor targeting and therapeutic efficacy. We developed a novel monoclonal antitenascin antibody, ST2485, and studied its biochemical and functional properties by in vitro and in vivo assays. We then investigated the first of the three-step therapy combining ST2485 with another antitenascin antibody, ST2146, previously described, to increase accumulation of biotinylated antibodies at the tumor site.

EXPERIMENTAL DESIGN

Studies of immunoreactivity, affinity, immunohistochemistry, and biodistribution in xenograft model were carried out on ST2485. Analysis of the ST2485 and ST2146 combination was preliminary carried out by ELISA and BiaCore tests and then by in vivo distribution studies after administration of the radiolabeled biotinylated antibodies, followed by a chase with avidin as clearing agent.

RESULTS

ST2485 was found to be a suitable antibody for therapeutic applications. Indeed, for its behavior in all tests, it was comparable with ST2146 and better than BC2, an antibody already used for clinical trials. The additivity of ST2146 and ST2485 in tenascin C binding, shown by in vitro tests, was confirmed by biodistribution studies in a xenograft model where tumor localization of the antibodies was near the sum of each antibody alone, with a tumor-to-blood ratio higher than 24.

CONCLUSION

The results reported in this study suggest that a monoclonal antitenascin antibody mixture can improve tumor targeting. This strategy could represent progress for therapeutic approaches such as PAGRIT.

Novel antitenascin antibody with increased tumour localisation for Pretargeted Antibody-Guided RadioImmunoTherapy (PAGRIT)

The Pretargeted Antibody-Guided RadioImmunoTherapy (PAGRIT) method is based on intravenous, sequential administration of a biotinylated antibody, avidin/streptavidin and (90)Y-labelled biotin. The hybridoma clone producing the monoclonal antitenascin antibody BC4, previously used for clinical applications, was found not suitable for further development because of the production of an additional, nonfunctional light chain. In order to solve this problem, the new cST2146 hybridoma clone was generated. The monoclonal antibody ST2146, produced by this hybridoma, having the same specificity as BC4 but lacking the nonfunctional light chain, was characterised. ST2146 was found able to bind human tenascin at an epitope strictly related, if not identical, to the antigenic epitope of BC4. It showed, compared to BC4, higher affinity and immunoreactivity and similar selectivity by immunohistochemistry. Biodistribution studies of biotinylated ST2146 and three other monoclonal antitenascin antibodies showed for ST2146 the highest and more specific tumour localisation in HT29-grafted nude mice. On the overall, ST2146 appears to be a good alternative to BC4 for further clinical development of PAGRIT.

[Active specific immunotherapy of cancer using anti-idiotypic monoclonal antibodies]

Innovative approaches to cancer treatment have been made possible today by genetic engineering and hybridoma technologies. In this paper, attention is focused on the use of anti-idiotypic monoclonal antibodies such as internal tumor-associated antigens. These MoAbs may be able to overcome the immunosuppression in cancer patients by stimulating "silent" clones, or by allowing T cell help to become active, thus enhancing the overall immune response which the nominal antigen is unable to do. Preliminary experiences of active specific immunotherapy with monoclonal antiidiotypic antibodies in cancer patients are reported.

Urinary neopterin and immunological features in patients with Kaposi's sarcoma

We studied neopterin excretion levels and immunological features of 20 patients affected by Kaposi's sarcoma (KS), compared to 30 normal controls. Eighteen patients had the classic form of Kaposi's sarcoma (CKS), while two patients were anti-human immunodeficiency virus (HIV) seropositive and affected by the epidemic form associated with the acquired immunodeficiency syndrome (AIDS). In CKS patients, a trend of an increase of neopterin levels with more advanced stages appeared from our data whereas a significant reduction in CD3+ and CD4+ lymphocytes subsets was observed already at early stages (P less than 0.01). CD8+ cells did not show significant variations. A significant increase in serum IgA immunoglobulins (P less than 0.05) was also observed. Comparative analysis of the two patients affected by AIDS/KS showed the profound deficit in T-cell immunity but also the prognostic value of neopterin monitoring. Furthermore these findings seem to confirm Kaposi's sarcoma as an 'opportunistic neoplasia' and indicate neopterin as a useful prognostic marker.