Treatment of stage III-IV nasopharyngeal carcinomas by external beam irradiation and local low doses of IL-2

Immunotherapy as sensitizer for local radiotherapy

The purpose of this report was to systematically review the radiation enhancement factor (REF) effects of immunotherapy on radiotherapy (RT) to the local tumor in comparison with other traditional radiation sensitizers such as cisplatin. PubMed and Medline databases were searched until February 2019. Reports with abscopal effect in the results were excluded. Graphs of the selected papers were digitized using Plot Digitizer (Sourceforge.net) in order to calculate the tumor growth delay (TGD) caused by immunotherapy. To enable comparison between different studies,the TGD were used to define the REF between RT versus the RT/immunotherapy combination. Thirty-two preclinical papers, and nine clinical series were selected. Different mouse models were exposed to RT doses ranging from 1 to 10 fractions of 1.8 to 20 Gray (Gy) per fraction. Endpoints were heterogeneous, ranging from regression to complete local response. No randomized clinical studies were identified. The median preclinical REF effect of different immunotherapy was varying from 1.7 to 9.1. There was no relationship observed either with subclasses of immunotherapy orRT doses. In the clinical studies, RT doses ranged from 1 to 37 fractions of 1.8 to 24 Gy per fraction. Most clinical trials used ipilimumab and interleukin-2. Local control rate in the clinical series ranged from 66% to 100%. A strong REF of immunotherapy (1.7 to 9.1) was observed, this being higher than traditionally sensitizers such as cisplatin (1.1). This result implies that for the same RT dose, a higher local control was achieved with a combination of immunotherapy and RT in preclinical settings. This study therefore supports the use of combined RT and immunotherapy to improve local tumor control in clinical settings without exacerbation of toxicities.

Poly(lactic acid) for delivery of bioactive macromolecules

Therapeutic biomolecules often require frequent administration and supramolecular dosing to achieve therapeutic efficiencies and direct infusion into treatment or defect sites results in inadequate physiological response and at times severe side effects or mis-targeting. Delivery systems serve several purposes such as increased circulatory time, increased biomolecule half-life, and incorporation of new innovations can enable highly specific cell targeting and improved cell and nucleus permeability. Poly(lactic acid) (PLA) has become a "material of choice" due to wide availability, reproducible synthetic route, customization, versatility, biodegradability and biocompatibility. Furthermore, PLA is amenable to a variety of fabrication methodologies and chemistries allowing an expansive library correlating physio-chemical properties, characteristics, and applications. This article discusses challenges to biomolecule delivery, and classical approaches of PLA based biomolecule delivery and targeting strategies under development and in trials.

Prognostic role of serum cytokines in patients with nasopharyngeal carcinoma

BACKGROUND

Th1/Th2 cytokine network imbalance plays a major role in cancer development and progression. In this study, we aim to evaluate the relationship between those cytokines and clinical outcome in patients with nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

The concentrations of Th1 cytokines (IL-2, TNF-α, IFN-γ) and Th2 cytokines (IL-4, IL-5, IL-10) in the serum were examined by Cytometric Bead Array in a total of 80 nasopharyngeal carcinoma patients pre and post treatment. Associations of those cytokines with clinical pathological factors, treatment response, and overall survival were analyzed.

RESULTS

Pretreatment serum levels of IL-2 and TNF-α were closely associated with overall survival. Compared to patients with low IL-2 expression, those with high expression had less risk of death (hazard ratio (HR) = 0.31, 95% confidence interval (CI) 0.13-0.75, p = 0.009). In contrast, TNF-α showed opposite effects on overall survival in patients with NPC. Patients with high TNF-α expression had a more than 2-fold increase in risk of death than those with low TNF-α (HR = 2.66, 95% CI 1.04-6.78, p = 0.041). All HRs were adjusted for age, sex, stage, histology, and treatment. Kaplan-Meier survival analysis showed similar survival differences between the 2 groups.

CONCLUSION

Lower serum IL-2 or elevated serum TNF-α concentrations predict an unfavorable prognosis for patients with NPC.

Direct and indirect antitumor effects by human peripheral blood lymphocytes expressing both chimeric immune receptor and interleukin-2 in ovarian cancer xenograft model

Human peripheral blood lymphocytes (PBLs) electroporated with RNA encoding anti-Her-2/neu-specific chimeric immune receptor (CIR) have been reported to elicit potent immune responses against SKOV3 tumors in a nude mouse model. However, CIR-electroporated PBL (CIR-PBL) did not proliferate, and the cell number rapidly decreased in the absence of exogenous interleukin-2 (IL-2). In this study, PBLs electroporated with both CIR and IL-2 RNA (CIR/IL-2-PBL) were studied to determine whether antitumor effects could be improved by adoptive immunotherapy. CIR and IL-2 were expressed in CIR/IL-2-PBL at levels similar to PBLs electroporated, with IL-2 RNA (IL-2-PBL) or CIR-PBL. Transfer of IL-2 RNA induced proliferation and prolonged survival of PBLs in vitro. In a xenograft model, both IL-2-PBL and CIR/IL-2-PBL showed significantly higher antitumor effects than CIR-PBL. The number of tumor-infiltrating natural killer (NK) cells was significantly increased in IL-2-PBL and CIR/IL-2-PBL. After NK cell depletion, IL-2-PBL showed significantly lower antitumor effects than CIR/IL-2-PBL. These results suggest that transfer of IL-2 RNA to CIR-PBL can promote NK cell infiltration of tumors and prolong survival of infused PBLs in vivo. RNA electroporated PBLs may represent efficient tools for delivery of functional molecules to tumors by multiple gene transfer.

Local therapy of cancer with free IL-2

This is a position paper about the therapeutic effects of locally applied free IL-2 in the treatment of cancer. Local therapy: IL-2 therapy of cancer was originally introduced as a systemic therapy. This therapy led to about 20% objective responses. Systemic therapy however was very toxic due to the vascular leakage syndrome. Nevertheless, this treatment was a break-through in cancer immunotherapy and stimulated some interesting questions: Supposing that the mechanism of IL-2 treatment is both proliferation and tumoricidal activity of the tumor infiltrating cells, then locally applied IL-2 should result in a much higher local IL-2 concentration than systemic IL-2 application. Consequently a greater beneficial effect could be expected after local IL-2 application (peritumoral = juxtatumoral, intratumoral, intra-arterial, intracavitary, or intratracheal = inhalation). Free IL-2: Many groups have tried to prepare a more effective IL-2 formulation than free IL-2. Examples are slow release systems, insertion of the IL-2 gene into a tumor cell causing prolonged IL-2 release. However, logistically free IL-2 is much easier to apply; hence we concentrated in this review and in most of our experiments on the use of free IL-2. Local therapy with free IL-2 may be effective against transplanted tumors in experimental animals, and against various spontaneous carcinomas, sarcomas, and melanoma in veterinary and human cancer patients. It may induce rejection of very large, metastasized tumor loads, for instance advanced clinical tumors. The effects of even a single IL-2 application may be impressive. Not each tumor or tumor type is sensitive to local IL-2 application. For instance transplanted EL4 lymphoma or TLX9 lymphoma were not sensitive in our hands. Also the extent of sensitivity differs: In Bovine Ocular Squamous Cell Carcinoma (BOSCC) often a complete regression is obtained, whereas with the Bovine Vulval Papilloma and Carcinoma Complex (BVPCC) mainly stable disease is attained. Analysis of the results of local IL-2 therapy in 288 cases of cancer in human patients shows that there were 27% Complete Regressions (CR), 23% Partial Regressions (PR), 18% Stable Disease (SD), and 32% Progressive Disease (PD). In all tumors analyzed, local IL-2 therapy was more effective than systemic IL-2 treatment. Intratumoral IL-2 applications are more effective than peritumoral application or application at a distant site. Tumor regression induced by intratumoral IL-2 application may be a fast process (requiring about a week) in the case of a highly vascular tumor since IL-2 induces vascular leakage/edema and consequently massive tumor necrosis. The latter then stimulates an immune response. In less vascular tumors or less vascular tumor sites, regression may require 9-20 months; this regression is mainly caused by a cytotoxic leukocyte reaction. Hence the disadvantageous vascular leakage syndrome complicating systemic treatment is however advantageous in local treatment, since local edema may initiate tumor necrosis. Thus the therapeutic effect of local IL-2 treatment is not primarily based on tumor immunity, but tumor immunity seems to be useful as a secondary component of the IL-2 induced local processes. If local IL-2 is combined with surgery, radiotherapy or local chemotherapy the therapeutic effect is usually greater than with either therapy alone. Hence local free IL-2 application can be recommended as an addition to standard treatment protocols. Local treatment with free IL-2 is straightforward and can readily be applied even during surgical interventions. Local IL-2 treatment is usually without serious side effects and besides minor complaints it is generally well supported. Only small quantities of IL-2 are required. Hence the therapy is relatively cheap. A single IL-2 application of 4.5 million U IL-2 costs about 70 Euros. Thus combined local treatment may offer an alternative in those circumstances when more expensive forms of treatment are not available, for instance in resource poor countries.

In vitro and in vivo protein delivery from in situ forming poly(ethylene glycol)–poly(lactide) hydrogels

Previous studies have shown that stereocomplexed hydrogels are rapidly formed in situ by mixing aqueous solutions of eight-arm poly(ethylene glycol)-poly(L-lactide) and poly(ethylene glycol)-poly(D-lactide) star block copolymers (denoted as PEG-(PLLA)(8) and PEG-(PDLA)(8), respectively). In this study, in vitro and in vivo protein release from stereocomplexed hydrogels was investigated. These hydrogels were fully degradable under physiological conditions. Proteins could be easily loaded into the stereocomplexed hydrogels by mixing protein containing aqueous solutions of PEG-(PLLA)(8) and PEG-(PDLA)(8) copolymers. The release of the relatively small protein lysozyme (d(h)=4.1 nm) followed first order kinetics and approximately 90% was released in 10 days. Bacteria lysis experiments showed that the released lysozyme had retained its activity. The relatively large protein IgG (d(h)=10.7 nm) could be released from stereocomplexed hydrogels with nearly zero order kinetics, wherein up to 50% was released in 16 days. The in vitro release of the therapeutic protein rhIL-2 from stereocomplexed hydrogels also showed nearly zero order kinetics, wherein up to 45% was released in 7 days. The therapeutic efficacy of stereocomplexed hydrogels loaded with 1x10(6) IU of rhIL-2 was studied using SL2-lymphoma bearing DBA/2 mice. The PEG-(PLLA)(8)/PEG-(PDLA)(8)/rhIL-2 mixture could be easily injected intratumorally. The released rhIL-2 was therapeutically effective as the tumor size was reduced and the cure rate was 30%, whereas no therapeutic effect was achieved when no rhIL-2 was given. However, the cure rate of rhIL-2 loaded stereocomplexed hydrogels was lower, though not statistically significant, compared to that of a single injection with 1x10(6) IU of free rhIL-2 at the start of the therapy (cure rate=70%). The therapeutic effect of rhIL-2 loaded stereocomplexed hydrogels was retarded for approximately 1-2 weeks compared to free rhIL-2, most likely due to a slow, constant release of rhIL-2 from the hydrogels.

Locoregional IL-2 low dose applications for gastrointestinal tumors

AIM: To explore the feasibility of local interleukin 2 (IL-2) in patients with different forms of abdominal cancer. This required experimentation with the time interval between IL-2 applications and the methods of application.

METHODS: Sixteen patients with stages III and IV of gastrointestinal malignancies (primary or metastatic) who were admitted to our Department of Gastroenterology were treated with locoregionally applied IL-2 in low doses.

RESULTS: No major problems applying locoregional IL-2 were encountered. In 6 out of 16 patients, a modest but clinically worthwhile improvement was obtained. Adverse effects were minimal. The therapeutic scheme was well tolerated, even in patients in a poor condition.

CONCLUSION: This study demonstrates the feasibility of low dose locoregional IL-2 application in advanced abdominal cancer. Local IL-2 therapy gives only negligible adverse effects. The results suggest that it is important to apply intratumorally. Local IL-2 may be given adjunct to standard therapeutic regimes and does not imply complex surgical interventions. These initial results are encouraging.

Local interleukin-2 and interleukin-12 therapy of bovine ocular squamous cell carcinomas

Interleukin-2 and interleukin-12 have been used independently to successfully treat the induced and the spontaneous tumours in animals. This trial was done to determine if a combination of IL-2 and IL-12 in the treatment of spontaneous bovine ocular squamous cell carcinomas (BOSCC) would be more successful than IL-2 or IL-12 therapy by themselves. For this trial, we selected 25 BOSCC tumours seen on Holstein Fresian cows in Beatrice, Zimbabwe. The cows were randomly assigned to a treatment group of 5 days of IL-2 (200,000 U/day), 5 days of IL-12 (0.5 microg/day) or 5 days of IL-2 (200,000 U/day) and IL-12 (0.5 microg/day). At 20 months after treatment, the IL-2 therapy group had 63% complete regressions; the combination group had 38% complete regressions, which were significantly higher than the IL-12 group, which had 0% complete regressions at 20 months, despite having 29% complete regressions at 6 months. These results show that IL-2 therapy by itself and in combination with IL-12 is more successful than IL-12 by itself. However, combination therapy does not improve the outcome in comparison to IL-2 as a single therapy. It also proves that IL-2 is consistently successful in the therapy of BOSCC with over 60% complete regression, which corresponds to a number of other studies we have done on IL-2 therapy of BOSCC [Rutten, V.P.M.G., Klein, W.R., De Jong, W.A., Misdorp, W., Den Otter, W., Steerenberg, P.A., De Jong, W.H., Ruitenberg, E.J., 1989. Local interleukin-2 therapy in bovine ocular squamous cell carcinoma. A pilot study. Cancer Immunol. Immunother. 30, 165--169; Stewart, R.J.E., Hill, F.W.G., Masztalerz, A., Jacobs, J.J.L., Koten, J.W., Den Otter, W., 2003. Local low dose interleukin-2 therapy of bovine ocular squamous cell carcinomas in cattle in Zimbabwe, submitted for publication; Den Otter, W., Hill, F.W.G., Klein, W.R., Koten, J.W., Steerenberg, P.A., De Mulder, P.H.M., Rutten, V.P.M.G., Ruitenberg, E.J., 1993. Low doses of interleukin-2 can cure large bovine ocular squamous cell carcinoma. Anticancer Res. 13, 2453-2455; Den Otter, W., Hill, F.W.G., Klein, W.R., Koten, J.W., Steerenberg, P.A., De Mulder, P.H., Rhode, C., Stewart, R., Faber, J.A., Ruitenberg, E.J., 1995. Therapy of bovine ocular squamous cell carcinoma with local doses of interleukin-2: 67% complete regressions after 20 months of follow-up. Cancer Immunol. Immunother. 41, 10-14].