The clinical experience with interleukin-2 in cancer therapy

PD-1/PD-L1 Blockade Therapy in Advanced Non-Small-Cell Lung Cancer: Current Status and Future Directions

This article summarizes the latest clinical applications of PD‐1/PD‐L1 blockade therapy in advanced non‐small cell lung cancer (NSCLC) worldwide and in China, reporting the bottlenecks related to the use of this therapy in clinic. An exploration of the underlying mechanism of PD‐1/PD‐L1 blockade therapy and biomarker identification will maximize the application of immune checkpoint inhibitors in advanced NSCLC and facilitate bedside‐to‐bench studies in cancer immunotherapy.

The use of immune checkpoint inhibitors (ICIs) has become one of the most promising approaches in the field of cancer therapy. Unlike the current therapies that target tumor cells, such as chemotherapy, radiotherapy, or targeted therapy, ICIs directly restore the exhausted host antitumor immune responses mediated by the tumors. Among multiple immune modulators identified, the programmed cell death protein 1 (PD‐1)/programmed cell death protein ligand 1 (PD‐L1) axis leading to the exhaustion of T‐cell immunity in chronic infections and tumors has been widely investigated. Therefore, blocking antibodies targeting PD‐1 or PD‐L1 have been developed and approved for the treatment of various advanced cancers, including non‐small‐cell lung cancer (NSCLC), making them the most successful ICIs. Compared with chemotherapy or radiotherapy, PD‐1/PD‐L1 blockade therapy significantly improves the durable response rate and prolongs long‐term survival with limited adverse effects in both monotherapy and combination therapy for advanced NSCLC. However, extensive challenges exist for further clinical applications, such as a small fraction of benefit population, primary and acquired resistance, the lack of predictive and prognostic biomarkers, and treatment‐related adverse effects. In this article, we summarize the latest clinical applications of PD‐1/PD‐L1 blockade therapy in advanced NSCLC worldwide, as well as in China, and discuss the bottlenecks related to the use of this therapy in clinical practice. An exploration of the underlying mechanism of PD‐1/PD‐L1 blockade therapy and biomarker identification will maximize the application of ICIs in advanced NSCLC and facilitate bedside‐to‐bench studies in cancer immunotherapy as well.

Implications for Practice.

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD‐1) and programmed cell death protein ligand 1 (PD‐L1) display apparent benefits for the treatment of advanced non‐small‐cell lung cancer (NSCLC). However, the clinical applications of these therapies are challenged by the limited benefit population with additional high economic burden and adverse events. This review discusses the bottlenecks of ICI therapy in clinical practice and provides appropriate guidance in the development of predictive biomarkers, the establishment of the criteria for combining PD‐1/PD‐L1 blockade therapy with the existing therapies, and the management of adverse events observed both in monotherapy and combination therapy, which will help maximize the applications of ICIs in advanced NSCLC.

Cellular immunotherapy of cancer: an overview and future directions

The clinical success of checkpoint inhibitors has led to a renaissance of interest in cancer immunotherapies. In particular, the possibility of ex vivo expanding autologous lymphocytes that specifically recognize tumor cells has attracted much research and clinical trial interest. In this review, we discuss the historical background of tumor immunotherapy using cell-based approaches, and provide some rationale for overcoming current barriers to success of autologous immunotherapy. An overview of adoptive transfer of lymphocytes, tumor infiltrating lymphocytes and dendritic cell therapies is provided. We conclude with discussing the possibility of gene-manipulating immune cells in order to augment therapeutic activity, including silencing of the immune-suppressive zinc finger orphan nuclear receptor, NR2F6, as an attractive means of overcoming tumor-associated immune suppression.

Genetically modified murine adipose-derived mesenchymal stem cells producing interleukin-2 favor B16F10 melanoma cell proliferation

Adipose-derived mesenchymal stem cells (ADSCs) are attractive tools for cancer gene therapy due to their intrinsic tropism to the tumor environment. Interleukin-2 (IL2) is recognized as a key regulatory molecule, which enhances the activity and growth of the immune effector cell function. High-Dose IL2 Therapy is an option for treatment of malignant melanoma but has frequent, often serious and sometimes life-threatening side effects. Here we investigated the effect of genetically modified ADSCs (GM-ADSCs) expressing IL2 in immunocompetent mouse models of subcutaneous and lung metastatic melanoma. Prior to in vivo studies, we demonstrated that IL2 produced by GM-ADSCs may act as a growth factor for melanoma cells due to the increased viability and reduced apoptosis of melanoma cells after in vitro treatment. Subcutaneous co-injection of IL2-expressing ADSCs with melanoma cells significantly enhanced the melanoma tumor growth. Furthermore, histological analysis of subcutaneous tumors for IL2 and Melan-A (a melanocytic differentiation marker) confirmed that most of cells in melanoma/IL2-ADSC co-injected tumors are melanoma cells, not IL2-ADSCs. In pulmonary metastases model, melanoma cells were injected intravenously and 10 days later mice were treated by systematical injection of GM-ADSCs. Intravenously injected IL2-ADSCs engrafted into melanoma lung tumors but were unable to reduce melanoma lung metastases. Besides, administered IL2-ADSCs significantly reduced systemic CD4+ cells and did not impact the total survival of lung metastases melanoma bearing mice. In conclusion, this study showed that IL2-producing ADSCs can favor B16F10 melanoma cell proliferation. Therefore, therapies utilizing IL2 have to be taken into careful consideration.

Active hexose correlated compound potentiates the antitumor effects of low-dose 5-fluorouracil through modulation of immune function in hepatoma 22 tumor-bearing mice

BACKGROUND/OBJECTIVES

A variety of immunomodulators can improve the efficacy of low-dose chemotherapeutics. Active hexose correlated compound (AHCC), a mushroom mycelia extract, has been shown to be a strong immunomodulator. Whether AHCC could enhance the antitumor effect of low-dose 5-fluorouracil (5-FU) via regulation of host immunity is unknown.

MATERIALS/METHODS

In the current study Hepatoma 22 (H22) tumor-bearing mice were treated with PBS, 5-FU (10 mg·kg^-1·d^-1, i.p), or AHCC (360 mg·kg^-1·d^-1, i.g) plus 5-FU, respectively, for 5 d. CD3⁺, CD4⁺, CD8⁺, and NK in peripheral blood were detected by flow cytometry. ALT, AST, BUN, and Cr levels were measured by biochemical assay. IL-2 and TNFα in serum were measured using the RIA kit and apoptosis of tumor was detected by TUNEL staining. Bax, Bcl-2, and TS protein levels were measured by immunohistochemical staining and mRNA level was evaluated by RT-PCR.

RESULTS

Diet consumption and body weight showed that AHCC had no apparent toxicity. AHCC could reverse liver injury and myelosuppression induced by 5-FU (P < 0.05). Compared to mice treated with 5-FU, mice treated with AHCC plus 5-FU had higher thymus index, percentages of CD3⁺, CD4⁺, and NK cells (P < 0.01), and ratio of CD4⁺/CD8⁺ (P < 0.01) in peripheral blood. Radioimmunoassay showed that mice treated with AHCC plus 5-FU had the highest serum levels of IL-2 and TNFα compared with the vehicle group and 5-FU group. More importantly, the combination of AHCC and 5-FU produced a more potent antitumor effect (P < 0.05) and caused more severe apoptosis in tumor tissue (P < 0.05) compared with the 5-FU group. In addition, the combination of AHCC and 5-FU further up-regulated the expression of Bcl-2 associated X protein (Bax) (P < 0.01), while it down-regulated the expression of B cell lymphoma 2 (Bcl-2) (P < 0.01).

CONCLUSIONS

These results support the claim that AHCC might be beneficial for cancer patients receiving chemotherapy.

Should high-dose interleukin-2 still be the preferred treatment for patients with metastatic melanoma?

For more than 20 years interleukin-2 (IL2) was the preferred treatment for medically fit metastatic melanoma patients, but recently two new agents, ipilimumab and vemurafenib, were approved for stage IV disease. Single-institution data were used to determine the long-term survival rate for IL2-treated melanoma patients, and whether use of inpatient IL2 had declined recently. Between May 1987 and April 2010, 150 patients were hospitalized for high-dose, intravenous (i.v.) IL2. The average number of IL2 patients increased from 5.4 per year during 1987-1991 to 5.8 during 1992-1997 after regulatory approval of IL2, to 8.3 during 1998-2006 after a marketing indication in metastatic melanoma was granted, but dropped to 3.0 during 2007-2010. At the time of treatment, median age was 52 years; 27% were 60 years of age or older. At the time of analysis 122 patients were deceased. Median survival from the start date of IL2 treatment was 15.6 months, with a 20% 5-year survival. Among patients enrolled in clinical trials, there were as many nonresponders who survived 5 years as responders, which is consistent with a delayed immunotherapy benefit. In the absence of long-term survival data for these newer agents, IL2 probably should still be the preferred initial treatment for most patients with metastatic melanoma who are medically fit.

Intra-lesional interleukin-2 for the treatment of in-transit melanoma

PURPOSE

To investigate the role of intra-lesional interleukin-2 (IL-2) injection for treatment of in-transit melanoma metastases.

METHODS

Consecutive patients with in-transit metastases were treated with intra-lesional IL-2 injections. Two independent observers evaluated response to treatment using the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. A blinded pathologist confirmed clinical response with post-treatment biopsies.

RESULTS

Thirty-nine patients were included. Patients received biweekly IL-2 injections. At each treatment session, a mean of 2.08 ml (5 µ/ml) of IL-2 were distributed amongst a mean of 12 (range 1-57) in-transit lesions. Patients were followed for an average of 30.4 months (range 2.2-66.6 months). The overall patient response rate was 82%. A complete response was obtained in 20 patients (51%), a partial response in 12 (31%), and no response in seven (18%). Of the 629 in-transit metastases, 479 (76%) completely resolved. Complete responders had a significant in transit-free (P = 0.0005) and an overall (P = 0.012) survival advantage compared with partial responders.

CONCLUSIONS

The treatment of in-transit metastatic melanoma with intra-lesional IL-2 resulted in a 76% percent clearance of lesions. Complete response is associated with superior in transit-free and overall survival when compared with partial response.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Enhancement of Th1 type cytokine production and primary T cell activation by PBI-1393

In previous reports, we have shown that PBI-1393 (formerly BCH-1393), N,N-Dimethylaminopurine pentoxycarbonyl D-arginine, stimulates cytotoxic T-lymphocyte (CTL) responses both in vitro and in vivo in normal immune status and immunosuppressed mice. Additionally, PBI-1393 was tested for anticancer activity in syngeneic mouse experimental tumor models and it displayed significant inhibition of tumor outgrowths when given in combination with sub-therapeutic doses of cytotoxic drugs (cyclophosphamide, 5-fluorouracil, doxorubicin and cis-platinum). However, the mechanism of action of PBI-1393 was still unknown. Here, we report that PBI-1393 enhances IL-2 and IFN-gamma production in human activated T cells by 51% and 46% respectively. PBI-1393 increases also IL-2 and IFN-gamma mRNA expression as shown by RT-PCR. The physiological relevance of IL-2 and IFN-gamma gene modulation by PBI-1393 is illustrated by the advantageous increase of T cell proliferation (39+/-0.3% above control) and human CTL response against prostate (PC-3) cancer cells (42+/-0.03%). The enhancement of human T cell proliferation and CTL activation by PBI-1393 demonstrates that this compound potentiates the immune response and in this regard, it could be used as an alternative approach to IL-2 and/or IFN-gamma therapy against cancer.

Nursing Care of Patients Receiving High-Dose, Continuous-Infusion Interleukin-2 With Pulse Dose and Famotidine

High-dose, continuous-infusion interleukin-2 (IL-2) followed by pulse dose and concurrent administration of famotidine has demonstrated response rates of 64% and 33% in patients with metastatic melanoma and metastatic renal cell carcinoma, respectively. Currently, no information is available concerning the nursing care of patients receiving that IL-2 regimen. Given the high response rates of patients on the treatment, attention by the nursing profession is warranted. Effective nursing care of patients receiving IL-2 is essential to the regimen's success. Recognition and prompt treatment of common side effects lead to better patient outcomes. This article provides nurses with an overview of the treatment regimen, expected side effects, psycho-social considerations, and discharge instructions for patients receiving continuous-infusion plus pulse IL-2 and famotidine.

Continuous Infusion Interleukin-2 and Antihistamines in Metastatic Kidney Cancer

A prior randomized trial suggested a possible survival advantage favoring the combination of histamine and subcutaneous interleukin-2 (IL-2), compared to IL-2 alone in patients with metastatic melanoma. It has been postulated previously that antihistamines may, therefore, actually be antagonistic to IL-2 and thus interfere with its antitumor activity. We have previously shown no such antagonistic effect in patients with melanoma receiving IL-2 and antihistamines when reviewing the known literature. We sought to determine whether there was any negative effect of the combination in patients with metastatic kidney cancer. A PubMed literature search between 1985 and 2005 was done. High-dose continuous (or constant) infusion (CIV) interleukin-2 was used as the reference therapy because of the relatively constant IL-2 levels generated by this approach. Studies in which cimetidine, ranitidine, or famotidine were regularly scheduled and administered concurrently with IL-2 were included. Thirteen studies were identified. A total of 47 patients responded to therapy. Total response rate = 22%; 95%; Confidence Interval: 17%-28%. Eleven complete responses were noted. Complete response rate = 5%; 95% Confidence Interval: 3%-9%. These response rates are consistent with previously noted IL-2 response rates. In this study of CIV IL-2 and antihistamines, this combination appears to be active in metastatic kidney cancer. There appears to be no negative effect of antihistamine on the CIV IL-2 response rate in this disease.

Tumor-infiltrating lymphocytes and interleukin-2: dose and schedules of administration in the treatment of metastatic cancer

PURPOSE

The potential for therapeutic use of tumor-infiltrating lymphocytes (TIL), as adoptive cellular therapy has been touted for many years with some encouraging reports in patients with metastatic melanoma.

MATERIALS AND METHODS

We previously described methodologies for TIL production and phenotypic characterization of TIL generated in our laboratory between 1991 and 1995 in semipermeable bags and between 1996 and 2000 in bioreactors. Patients treated in the earlier era were to have received a hybrid bolus and a 12-hour continuous infusion of interleukin (IL)-2 (total, 48 MIU), while in the latter era 4 days of interferon- alpha preceded the TIL and IL-2; which was given by a hybrid schedule that included bolus and 72- hour continuous IL-2 (total, 96 MIU). There were 55 patients, including 23 patients with melanoma, 9 patients with renal cell carcinoma, and 8 patients with colorectal cancer. There was only 1 objective tumor response, which was noted in a patient with renal cell carcinoma. The 55 patients who received these products were grouped in cohorts by treatment era, quantity of TIL received, amount of IL-2 intended, and different combinations of TIL and IL-2.

RESULTS

There was no difference in survival by production method (treatment era), or amount of IL-2 given with TIL, but 33 patients who received an intermediate or higher dose of TIL (mean = 54.4 x 10(9)) had a median survival of 11.8 months, compared to 6.4 months for 22 patients who received 1 low-dose TIL (mean = 6.48 x 10(9)) (p = 0.059, log rank test). The objective response rate in this heterogeneous group of patients was not encouraging. The data suggest there may be a dose/benefit relationship between the total number of TIL infused and survival.

Continuous Infusion Interleukin-2 and Antihistamines in Melanoma: A Retrospective Review Showing Activity of This Combination

A recent randomized trial suggests that there may be an advantage in terms of survival with the combination of histamine and subcutaneous interleukin-2 (IL-2), compared to IL-2 alone. It has been postulated, then, that antihistamines may actually be antagonistic to IL-2 and, therefore, interfere with its antitumor activity. Because antihistamines such as cimetidine and ranitidine are commonly used as prophylaxis against gastrointestinal toxicity commonly seen with IL-2, and, because antihistamines may increase natural killer cell activity, it is reasonable to examine the response rate for this combination. An OVID Medline literature search between 1985 and 2003 was done. Continuous infusion (CIV) interleukin- 2 was used as the reference therapy because of the relatively constant IL-2 levels generated by this approach. Included studies were those in which either cimetidine, ranitidine, or famotidine were regularly scheduled and administered concurrently with IL-2, typically for gastrointestinal ulcer prophylaxis. Six (6) studies were identified. A total of 21 patients responded to therapy. Total response rate was 11%, with a 95% Confidence Interval: 7-17%. Four (4) complete responses were noted. Complete response rate was 2%, with a 95% Confidence Interval: 1-6%. These response rates are consistent with previously noted IL-2 response rates. In this retrospective review of CIV IL-2 and antihistamines, this combination appears to be active in melanoma. There appears to be no deleterious effect of routine antihistamine on the CIV IL-2 response rate.

Treatment of human solid malignancies with autologous activated lymphocytes and cimetidine: a phase II trial of the cancer biotherapy research group

OBJECTIVE

The Cancer Biotherapy Research Group conducted a clinical trial to verify encouraging reports of antitumor activity of autolymphocyte therapy.

PATIENTS AND METHODS

Patients with a variety of advanced solid malignancies underwent an initial leukapheresis procedure to collect about 5 x 10(9) autologous lymphocytes that were stimulated in vitro for 3 days with anti-CD3 monoclonal antibody in the presence of indomethicin and cis-retinoic acid to obtain media that was frozen in aliquots. This media contained significant amounts of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon-gamma, and IL6, but no IL-2. Subsequently patients underwent up to 6 monthly leukaphereses to collect 2-5 x 10(9) autologous lymphocytes that were incubated in vitro for 6 days in the cryopreserved media containing autologous lymphokines, resulting in a cell population enriched for noncytotoxic T-helper lymphocytes. These were administered intravenously monthly for up to 6 months with daily oral cimetidine at a dose of 600 mg po qid, which was given throughout the treatment period. Tumor response was assessed every 2 months.

RESULTS

There were 47 patients (25 women and 22 men) with a median age of 55 years (range 31-79). One hundred seventy four treatments were delivered and were well tolerated. A mean of 2.05 +/- 1.46 (range 0.82-12.8 x 10(9)) cells were infused. Eighty-five percent received two or more doses; 19% received six doses. Objective tumor responses were observed in 1/15 renal cell, 1/13 colorectal, 0/6 breast, 0/5 lung, 0/2 gastric, 0/2 sarcoma, 0/1 pancreas, 0/1 prostate, 0/1 melanoma, and 0/1 eccrine. Forty-three patients have died. Median survival was 8.8 months, 1-year survival 35%, and 2-year survival 15%.

CONCLUSION

This complex treatment program was feasible. Infusion of these cells was well tolerated. Some antitumor activity was seen in patients with renal cell cancer and colorectal cancer.

Identification of novel expressed sequences, up-regulated in the leucocytes of chronic fatigue syndrome patients

BACKGROUND

Chronic fatigue syndrome (CFS) is an increasing medical phenomenon of unknown aetiology leading to high levels of chronic morbidity. Of the many hypotheses that purport to explain this disease, immune system activation, as a central feature, has remained prominent but unsubstantiated. Supporting this, a number of important cytokines have previously been shown to be over-expressed in disease subjects. The diagnosis of CFS is highly problematic since no biological markers specific to this disease have been identified. The discovery of genes relating to this condition is an important goal in seeking to correctly categorize and understand this complex syndrome.

OBJECTIVE

The aim of this study was to screen for changes in gene expression in the lymphocytes of CFS patients.

METHODS

'Differential Display' is a method for comparing mRNA populations for the induction or suppression of genes. In this technique, mRNA populations from control and test subjects can be 'displayed' by gel electrophoresis and screened for differing banding patterns. These differences are indicative of altered gene expression between samples, and the genes that correspond to these bands can be cloned and identified. Differential display has been used to compare expression levels between four control subjects and seven CFS patients.

RESULTS

Twelve short expressed sequence tags have been identified that were over-expressed in lymphocytes from CFS patients. Two of these correspond to cathepsin C and MAIL1 - genes known to be upregulated in activated lymphocytes. The expression level of seven of the differentially displayed sequences have been verified by quantifying relative level of these transcripts using TAQman quantitative PCR.

CONCLUSION

Taken as a whole, the identification of novel gene tags up-regulated in CFS patients adds weight to the idea that CFS is a disease characterized by subtle changes in the immune system.

Cytokines in parvovirus B19 infection as an aid to understanding chronic fatigue syndrome

Human parvovirus B19 infection has been associated with various clinical manifestations of a rheumatic nature such as arthritis, fatigue, and chronic fatigue syndrome (CFS), which can persist for years after the acute phase. The authors have demonstrated recently that acute B19 infection is accompanied by raised circulating levels of IL-1b, IL-6, TNF-a, and IFN-g and that raised circulating levels of TNF-a and IFN-g persist and are accompanied by MCP-1 in those patients who develop CFS. A resolution of clinical symptoms and cytokine dysregulation after intravenous immunoglobulin (IVIG) therapy, which is the only specific treatment for parvovirus B19 infection, also has been reported. Although CFS may be caused by various microbial and other triggers, that triggered by B19 virus is clinically indistinguishable from idiopathic CFS and exhibits similar cytokine abnormalities and may represent an accessible model for the study of CFS.

Does continuous-infusion interleukin-2 increase survival in metastatic melanoma?

Pharmacy logbooks and clinical trial records were used to identify all 60 patients with metastatic melanoma who were treated as inpatients with intermediate-dose, continuous-infusion interleukin-2 (IL-2) in Hoag Hospital during 1987 to 1998. The hospital tumor registry was used to identify contemporary controls who had not received inpatient IL-2, matched for having distant metastatic melanoma, and by year and stage at original diagnosis, gender, and age. The mean time from original diagnosis to the documentation of distant metastatic disease was similar in both groups, 24 to 26 months. From the date of starting IL-2 therapy, patients had a median survival of 8.8 months, 38% 1-year survival, and 20% 5-year survival, with 8 patients alive beyond 5 years. However, there was no difference in survival from the first date of distant metastatic disease (median 25.8 months for IL-2 versus 31.5 months for controls, with survival rates 5 years after metastatic disease of 26% versus 31%). There was also no difference in overall survival from the date of original diagnosis (60.1 months for the IL-2 group versus 86.3 months for controls, with 5-year survival rates of 51% versus 64%, and 10-year survival rates of 29% versus 33%). This single-institution study failed to establish a survival advantage for patients with metastatic melanoma who received intermediate-dose, continuous-infusion IL-2 administered in the inpatient setting, compared to contemporary, matched-control patients who never received inpatient IL-2 therapy. However, the 5-year survival rates after a diagnosis of distant metastatic disease were a surprisingly high 26% to 31% in both groups. In the absence of a control group, the survival impact of IL-2 has probably been overestimated from single-arm phase II and III trials.

Interleukin-2 production in SC and TK chickens infected with Eimeria tenella

SC and TK inbred chicken strains display differential protective immunity to coccidiosis, SC being more resistant and TK susceptible to disease. In this study, the association between interleukin (IL)-2 and disease phenotype was assessed by cytokine quantification in serum, duodenum, cecum, and spleen cell cultures of SC and TK chickens experimentally infected with Eimeria tenella. In general, after primary infection, SC and TK strains produced equivalent amounts of IL-2 in all sources examined. However, after secondary infection, SC animals displayed significantly greater IL-2 levels in serum and the duodenum compared with strain TK. IL-2 production after reinfection with Eimeria may be an important factor contributing to the genetic differences in coccidiosis between SC and TK chickens and provides a rational foundation for cytokine-based immunotherapeutic approaches to disease control strategies.

Characterization of human tumor-infiltrating lymphocytes expanded in hollow-fiber bioreactors for immunotherapy of cancer

We attempted to grow tumor-infiltrating lymphocytes (TIL) from 34 fresh tumors of eight different histologies using flasks for the initiation phase and hollow fiber bioreactors to expand TIL to therapeutic numbers. Overall success rate was 76% (26/34) including melanoma (9/14, 64%) and renal cell carcinoma (11/11, 100%). The mean number of days required to reach successful initiation (1 x 10(9) TIL) for all tumor types was 29 +/- 16 days (mean +/- S.D.). Therapeutic doses of TIL required an average of 88 +/- 23 days (initiation plus expansion) with an average TIL number of 3.2 x 10(10) +/- 2.8 x 10(10). TIL phenotype was predominantly CD4+ in 53% (16/30) and CD8+ in 47% (14/30), renal cell carcinoma samples accounted for 12/14 of the predominantly CD8+ TIL. Cells bearing the natural killer (NK) phenotype represented only 0-7% of TIL while LAK phenotype represented 0-68% (mean 11 +/- 15%); LAK was the predominant phenotype in one patient with kidney cancer. Cytotoxicity tests showed consistent NK and LAK activity in addition to cytolysis of autologous tumor. Autologous tumor cell restricted cytolysis was noted for three TIL cultures. The overall success rate and characteristics of TIL were similar to our results with TIL expanded in semi-permeable plastic bags. This work confirms that hollow-fiber bioreactors are a suitable alternative to semi-permeable bags and roller bottle systems for the expansion of human TIL for therapeutic use in cancer patients.

Biologic response modifiers in pediatric cancer

Biologic response modifiers are becoming an important addition to surgery, chemotherapy, and radiotherapy in the management of cancer. As this field of research grows and expands, more biologic response modifiers will be incorporated into therapeutic regimens. By stimulating the immune system to eradicate minimal residual disease, these agents may improve the disease-free and long-term survival rates of patients with a variety of malignancies. The challenge is to incorporate biologic response modifiers into the treatment armamentarium in ways that will maximize their tumorigenicity.

Phase II trial of subcutaneous interleukin-2, subcutaneous interferon-alpha, intravenous combination chemotherapy, and oral tamoxifen in the treatment of metastatic melanoma: final results of cancer biotherapy research group 94-11

BACKGROUND

The treatment of metastatic melanoma remains unsatisfactory despite encouraging results with biotherapy and combination chemotherapy. Combining these two modalities may improve outcomes for such patients.

METHODS

Eligible patients had metastatic melanoma, were in good medical condition, and had not been treated previously for metastatic disease. A 42-day treatment cycle consisted of: tamoxifen 10 mg p.o. b.i.d. days 1-42, carmustine 150 mg/m2 i.v. on day three, dacarbazine 220 mg/m2 and cisplatin 25 mg/m2 i.v. q.d. days 3-5, and 24-26, interferon-alpha 2b 6.0 MU/m2 s.c. days 8-12 and 29-33, and interleukin-2 11 MU/m2 s.c. days 8, 10, 12 and 29, 31, 33. In the absence of tumor progression, patients could receive up to six cycles of alternating treatment. Toxicity and tumor response was assessed following each treatment cycle; survival was determined from the first date of treatment.

RESULTS

The 28 melanoma patients included 21 men and 7 women, with a median age of 55 years with a range of 26-77. Fifty-four percent were asymptomatic when treatment was initiated. Eighty percent had soft tissue metastases, 32% lung, 28% liver, and 8% bone. There were nine patients with significant tumor responses (three complete, six partial) for a response rate of 32% (18-57% 95% CI) based on intent-to-treat analysis, and 38% (18-57%, 95% CI) for the 24 patients who were evaluable for response. The months of duration of survival for responders were 38.9+, 27.2+, 22.8+, 16.3, 13.2, 9.4, 7.5, 6.5+, and 5.8. At a median follow-up of 31 months, the median duration of event-free survival was 4.6 months; median survival was 9.4 months. The survival rate one year from initiating treatment was 42%; 2-year survival was 14%. The most frequent toxicities were 96% nausea/vomiting, 80% fatigue, 73% thrombocytopenia, 60% neutropenia, and 44% fever. Two patients experienced early death that may have been treatment related; one died of cardiovascular complications and the other of a central nervous system event.

CONCLUSION

This outpatient regimen was associated with significant toxicity including a 7% rate of possible treatment-related death. Tumor regression rates and survival were similar to results reported for chemotherapy alone, or inpatient IL-2-based therapy, but did not suggest an improvement in outcome.

What to do with IL-2?

It has been 15 years since the first positive clinical reports of Interleukin-2 (IL-2) appeared in the medical literature, ten years since moderate dose continuous infusion IL-2 was approved in Europe, and five years since high-dose bolus IL-2 was approved for general use in the United States. IL-2 is accepted as a standard treatment used alone, or in combination with chemotherapy or biotherapy in the management of metastatic melanoma and metastatic renal cell carcinoma. Various physicians utilize high-dose bolus IL-2, moderate-dose continuous infusion IL-2, and low-dose outpatient intravenous or subcutaneous IL-2. There is still no consensus regarding the best way to deliver IL-2 alone in terms of dose and schedule of administration from a risk-to-benefit standpoint. Despite yielding higher tumor response rates, regimens that combine IL-2 with chemotherapy and/or interferon have not produced better long-term survival.

Use of an antibody against the soluble interleukin 2 receptor alpha subunit can modulate the stability and biodistribution of interleukin-2

The authors have previously reported that the soluble serum form of the alpha subunit of the IL-2 receptor (sIL-2Ralpha), whose natural half-life is approximately 40 min, survived much longer in the circulation when bound by a specific antibody. In the present study, the authors evaluated the extent to which sIL-2Ralpha protected IL-2 in freshly collected serum using biochemical analyses, and a functional CTLL-2 assay. In particular, sIL-2Ralpha protected IL-2 from forming complexes with alpha(2)-macroglobulin and from inactivation in vitro. In addition, the authors demonstrated that the anti-IL-2Ralpha monoclonal antibody 7G7/B6, which does not inhibit the binding of IL-2 to its binding site on sIL-2Ralpha, protected IL-2 from degradation and inactivation in vivo in the presence of sIL-2Ralpha. Both(125)I-labelled and unlabelled IL-2 were injected into mice preinjected with humanized anti-Tac (hTac) or 7G7/B6 and sIL-2Ralpha, or sIL-2Ralpha alone. Using size-exclusion HPLC, ELISA, and CTLL-2 cell proliferation assays, we observed that the presence of 7G7/B6 led to formation of complexes with sIL-2Ralpha and increased the serum levels of IL-2 more than 3- to 40-fold those of groups receiving IL-2 alone, sIL-2Ralpha, or hTac. Taken as a whole, these results suggest that the complex of 7G7/B6 and sIL-2Ralpha not only prolongs the survival of IL-2 in vivo, but also maintains the bioactivity of IL-2. The use of antibodies against endogenous soluble receptors could increase the in vivo survival of cytokines, protect their bioactivity and thereby facilitate their clinical use in the treatment of various malignancies and AIDS.

Redirecting Effector T Cells Through Their IL-2 Receptors

Fusion proteins constructed of a tumor-specific Ab joined to IL-2 (Ab-IL-2) have been used in the past to deliver cytokine directly to the site of tumor cells in vivo. These molecules mimic the activity of IL-2 and assist in activating and expanding antitumor effector cells. To enhance the cytolytic activity of CTL specific for peptide epitopes of the Her-2/neu tumor Ag presented by HLA-A*0201 molecules, a fusion protein was constructed consisting of a single chain Ab specific for Her-2/neu, linked to IL-2 (neu-Ab-IL-2). When added to a mixture of tumor cells and Her-2/neu-specific CTL, the protein was found to augment lysis of tumor cells. In addition, the hybrid molecule also promoted lysis of Her-2/neu expressing tumors by non-tumor-specific cloned T cell lines, including Th1 CD4 cells. Analysis of the mechanism of cytotoxicity revealed that the fusion protein mediates the formation of stable conjugates between T cells expressing IL-2R and tumor cells expressing Her-2/neu, resulting in lysis through the Fas-Fas ligand pathway. Lysis induction was independent of specific engagement by the TCR. When tested for its ability to enhance tumor cell eradication by Her-2/neu-specific CD8+ T cells in an adoptive transfer model in SCID mice, neu-Ab-IL-2 facilitated the elimination of tumor cells in vivo. Surprisingly, the combination of non-tumor-specific CD8+ T cells and fusion protein also induced a significant delay of tumor growth. This represents a novel approach for redirecting non-tumor-specific T cells to eliminate tumors.

Common cancers--immunotherapy and multidisciplinary therapy: Parts III and IV

The refractoriness of many solid tumors to cytotoxic chemotherapy has led to the exploration of new therapeutic modalities, including immunotherapy. Immunotherapy does not have a direct cytotoxic effect on the cancer cell but is an attempt to promote rejection of the tumor by the host, chiefly through the cellular arm of the immune system. The clinical success with immunotherapy (primarily adoptive immunotherapy) among patients with unresectable malignant melanoma and cancer of the kidney has not been marked by the large numbers of patients responding but by occasional dramatic effectiveness of therapy for these cancers, which usually are refractory to chemotherapy. Long-lasting responses and even complete disappearance of all known metastases are possible for a small percentage of patients with melanoma or renal cell carcinoma who undergo immunotherapy. A reasonable approach for patients with good performance status (no symptoms or ambulatory with symptoms but not bedridden) is entrance to clinical trials, especially trials examining adoptive or active immunotherapy for melanoma or adoptive immunotherapy for renal cancer. The overall treatment of patients with cancer has changed. Primary-care physicians detect almost all cancers. The days when "taking it out" is the best we could offer a patient are over. As we learn more about the use of adjuvant or neoadjuvant chemotherapy and radiation therapy, it is likely one or both of these modalities will be incorporated into the treatment of additional solid tumors previously managed solely with surgical resection. Increasingly, additional therapy is being given for earlier-stage disease as we define how to maximize the potential for cure with minimal toxicity. Many new therapies are on the horizon, including the use of noncytotoxic treatments as an adjunct to a surgical procedure. Such therapies include the use of angiogenesis inhibitors, tumor vaccines, and immunotherapy. Now and in the future, patients will be best served when treated in an environment that can integrate medical, surgical, and radiation oncology actively.

Hybrid high-dose bolus/continuous infusion interleukin-2 in patients with metastatic melanoma: a phase II trial of the Cancer Biotherapy Research Group (formerly the National Biotherapy Study Group)

PURPOSE

Interleukin-2 (IL-2) is an active agent for the treatment of melanoma. In animal studies, polyethylene glycol conjugated (PEG) IL-2 was found to be effective in certain IL-2-resistant models. Bolus/infusional IL-2 administered to approximate the pharmacokinetics of PEG-IL-2 also overcame resistance in these models. Based on these observations, the Cancer Biotherapy Research Group (CBRG) [formerly the National Biotherapy Study Group (NBSG)] previously had conducted a pilot study and then a phase I trial of bolus IL-2 followed by continuous IL-2 (NBSG 90-01).

METHODS

In the current study, NBSG 92-09, a phase II trial was conducted using IL-2 at a dose of 36 MIU/m2 followed by a 72-hour continuous infusion of IL-2 at 18 MIU/m2/day, so that over 3 days a total of 90 MIU/m2 of IL-2 were delivered; the same amount as previously given during 5 days of continuous i.v. IL-2 at 18 MIU/m2/day. This schedule was repeated every 2 weeks for 2 months, and then monthly for up to 6 months.

RESULTS

Twenty-two patients with metastatic melanoma were enrolled in this trial. Toxicities were qualitatively similar to those seen with other IL-2 regimens, but grade 3 and 4 toxicities were observed only in patients who received at least four cycles of treatment; only one patient went off study because of toxicity. For 18 patients with measurable disease, there were two complete and two partial responses in patients ages 32, 66, 72 and 83 years, for a response rate of 22% (6% to 48%; 95% confidence interval [Ci]). The median survival for all 21 evaluable patients enrolled in the trial was 8.5 months.

CONCLUSION

The hybrid schedule of drug delivery in NBSG 92-09 allowed the same dose and intensity of IL-2 to be delivered over 3 days instead of 5 days, which resulted in fewer days of hospitalization and therefore decreased cost; but with no increase in toxicity and no decrease in efficacy in patients with metastatic melanoma.

Long-term survival after continuous infusion interleukin-2

PURPOSE

Between 1987-1990, 612 patients received high-dose continuous intravenous interleukin-2 (IL-2) in phase II clinical trials of the National Biotherapy Study Group (NBSG). The purpose of this analysis was to determine the long-term survival rates associated with such therapy and the correlation, if any, between objective tumor response, and survival.

METHODS

Patients who are known to have survived at least 3 years or more were identified. Actual and actuarial survival rates were determined for various malignancies and by tumor response.

RESULTS

At least 37 (6.0%) survived > or = 3 years from the initiation of IL-2 therapy, and it is possible the 3-year survival rate is as high as 20%. This included 14/168 (8%) of patients with renal cell carcinoma, 10/175 (6%) melanoma, 2/51 (4%) lung cancer, 0/61 colorectal, 0/36 breast, 1/17 sarcoma, 1/14 pancreas, 1/19 ovary, 3/11 lymphoma, 2 adenocystic carcinomas, 2 carcinoid, and one Hodgkin's disease. Four hundred ninety-one of 612 (80%) are known to have died, 121 were still alive at the time of the last follow-up. Median survival was 7.9 months. Among 547 evaluable patients, there were eight complete responses (CR) and 42 partial responses (PR), for an objective response rate of 9%. An additional 32 patients had mixed or minimal responses (MR) for a total response rate of 15%. The 3-year survival rates were 25% for PR, 17% for PR, 16% for MR, 8% for stable disease (SD), and 2% for patients with progressive disease (PD). Responders made up a higher proportion of patients who survived > or = 3 years than of patients who survived < or = 3 years (14/37 = 38% vs 68/500 = 14%; p < .0001, X2). A higher proportion of responders survived > or = 3 years than non-responders (14/82 = 17% vs 23/230 = 4%, p < .0001, X2). Patients with CR, PR, or MR had a > or = 3-year survival rate (14/82 = 17%) than patients who had SD (20/249 = 8%; p = .02, x2, who in turn had a > or = 3-year survival rate that was greater than patients who had PD (3/206 = 2%; p = .001, X2). For individual trials in which 10 or more patients were enrolled, the percentage of patients surviving > or = 3 years ranged between 4% and 8%.

CONCLUSION

We conclude that in the setting of IL-2 therapy for metastatic cancer, the probability of surviving > or = 3 years was approximately 12 times greater for responders, and five times greater for patients with SD; as compared to patients who had PD. Furthermore, despite diagnoses of metastatic cancer, often in settings in which disease had been refractory to standard therapy there was an actual 3-year survival rate of at least 6% to 8% for patients with metastatic melanoma and renal cell carcinoma.

Hybrid high-dose bolus/continuous infusion interleukin-2 in patients with metastatic renal cell carcinoma: a phase II trial of the National Biotherapy Study Group

BACKGROUND

Interleukin-2 (IL-2) is an active agent for the treatment of renal cell carcinoma. In animal studies, polyethylene glycol conjugated (PEG) IL-2 was found to be effective in certain IL-2-resistant models. When bolus/infusion IL-2 was administered to approximate the pharmacokinetics of PEG-IL-2, resistance was also overcome in these models. Based on these observations, the National Bio-therapy Study Group (NBSG) previously had conducted a pilot study (NBSG 90-01) and then a phase I trial of a hybrid regimen of bolus IL-2 followed by continuous IL-2 (NBSG 91-04).

METHODS

In the current study, NBSG 92-09, a phase II trial was conducted in patients with metastatic renal cell carcinoma using IL-2 at a dose of 36 MIU/m2 followed by a 72-hour continuous infusion of IL-2 at 18 MIU/m2 per day, so that over 3 days a total of 90 MIU/m2 of IL-2 were delivered; the same amount as previously given during 5 days of continuous intravenous (i.v.) IL-2 at 18 MIU/m2 per day. This was repeated every 2 weeks for 2 months, and then monthly for up to 4 months.

RESULTS

Thirty-one patients with a median age of 62 years were enrolled in this trial. During the first 4 biweekly treatments, the percentages of planned IL-2 administered were 98% for 31 patients, 99% for 27, 98% for 23, and 99% for 20 patients. Toxicities were qualitatively the same as those seen with other IL-2 regimens. During the first 2 months, 4 patients ceased treatment because of rapidly progressive disease while 7 patients stopped because of toxicity; 5 of the 7 were > 65 years of age. At the time of formal reassessment after 2 months of treatment, 7 additional patients had progressive disease for a treatment failure rate of 55% prior to monthly maintenance therapy. There were two partial responses among 22 patients who had measurable disease for a response rate of 9% (1 to 29%, 95% CI). Median survival was 10.2 months and failure-free survival (FFS) 3.4 months for the entire group.

CONCLUSION

The response rate seen with this regimen is similar to those of other schedules of IL-2 requiring more prolonged hospitalization. This hybrid bolus/continuous infusion IL-2 schedule appears to be an equally effective and less expensive schedule of IL-2 administration than previously reported inpatient regimens. However, it is not likely that this regimen is superior to outpatient combination biotherapy regimens which are currently under investigation.

Antibody immunoglobulin G (IgG) against human prostatic specific antigen (PSA) as a carrier protein for chemotherapeutic drugs to human prostate tumors: Part 1. A double immunofluorescence analysis

BACKGROUND

Adenocarcinoma of the prostate (CaP) is the the second highest cause of cancer deaths in U.S. males. Current chemotherapeutic and/or endocrine treatments do not specifically and selectively target tumor cells of prostate cancer and benign prostatic hyperplasia (BPH). We hypothesized that because of the specific binding characteristics of antibody immunoglobulin G (IgG) to human prostatic-specific antigen (PSA), PSA-IgG could function as a carrier protein for conjugated chemotherapeutic drugs and that the immunoconjugate would selectively bind to prostatic epithelial cells and their tumors, but not to epithelial cells of unrelated organs. Our objective was to test the hypothesis using human prostatectomy specimens.

METHODS

WE used several derivatives of 5'-fluorouracil, namely, 5'-fluoro- 2'-deoxyuridine (5'-Fu-2'-d), 5'-fluoro-2'-deoxyuridine-5' monophosphate (5'-Fu-2'-d-5'-mp), 5'-fluoro-2'-deoxyuridine-5'-(p-aminophenyl) monophosphate (5'-Fu-2'-d'-5'-amp), to conjugate with rabbit anti-PSA-IgG together with fluorescent markers (such as rhodamine and fluorescein or fluorescein isothiocyanate: FITC). Prostate specimens were obtained from prostatectomy patients who had not been treated with cytotoxic drugs before surgery. We evaluated formalin-fixed and paraffin-embedded sections as well as cryostat sections of frozen specimens for localization of PSA-IgG alone and PSA-IgG-drug immunoconjugate using immunoperoxidase (IP) and single and/or double immunofluorescence (IF) localization techniques.

RESULTS

Our study showed that the immunoconjugate (PSA-IgG-5'-Fu-2'-d) bound to PSA (molecular size of approximately 34 KDa) on nitrocellulose sheets in Western immunoblots of extracts of BPH and CaP tissues. This binding of immunoconjugate to PSA on immunoblots was similar to that of the unconjugated PSA-IgG. Immunostaining patterns for rabbit anti-PSA-IgG and PSA-IgG-5'-Fu-2'-d immunoconjugate were similar and specific for prostate epithelial cells and their tumors, as revealed by IP techniques. To demonstrate that both the antibody and drug localized in the same group of prostatic epithelial cells, we used an immunoconjugate in which the PSA-IgG was labeled with rhodamine and 5'-Fu-2'-d-5'-amp with FITC. Our study showed that fluorescence for rhodamine and FITC was present in the same group of prostatic epithelial cells. Phase contrast microscopy demonstrated details of prostatic glandular epithelium and connective tissues. Our study showed that fluorescence for rhodamine and FITC and immunostaining by IP techniques were not observed in prostate sections incubated with normal rabbit serum.

CONCLUSIONS

We have shown that conjugation of 5'-Fu derivatives to PSA-IgG did not affect either the selectivity or specificity of the antibody for prostatic epithelial cells. Differential immunofluorescence study has shown that PSA-IgG may function as a carrier protein for chemotherapeutic drugs to prostate epithelial cells and their tumors. Furthermore, FITC-labeled 5'-Fu-2'-d did not specifically localize in prostatic glands, kidney, lungs, bladder, or colon. Because of the specificity and selectivity of the immunoconjugate for prostatic epithelial cells and their tumors, the immunoconjugate could be used in small dosages to treat prostatic tumors and such treatment would greatly reduce many unpleasant side effects in patients. This is the first report to show that PSA-IgG can function as an organ specific carrier protein for chemotherapeutic drugs to human prostate epithelium and its tumors.

Coexistence of renal cell carcinoma and malignant lymphoma. A causal relationship or coincidental occurrence?

BACKGROUND

Secondary malignant neoplasms are increasingly being observed in cancer populations and a considerable amount of data have accumulated in the literature. Among the secondary malignant neoplasms that occur with a higher incidence in cancer patients are lymphomas and renal cell carcinoma (RCC), as well as melanoma, lung/bronchus carcinoma.

METHODS

The authors analyzed the patient population at the Memorial Sloan-Kettering Cancer Center in New York City between 1985 and 1995 for coexisting carcinomas, and identified 15 patients who had both RCC and malignant lymphoma among a total of 1262 patients with RCC and 1660 patients with malignant lymphoma. The occurrence and time of diagnosis of both malignant neoplasms and their clinical features, types, and stages, as well as short term follow-up, results, are presented.

RESULTS

The data show a greater than coincidental coexistence of RCC and malignant lymphoma (P < 0.01). In addition, there was a significant increase in the number of patients with both melanoma and RCC (P < 0.01), as well as melanoma and malignant lymphoma (P < 0.01). No significant increase was found in cases of coexisting RCC or malignant lymphoma with either lung/bronchus carcinoma or colorectal carcinoma (P > 0.05).

CONCLUSIONS

Causes of this increased coexistence may include a genetic predisposition to cancer, similar immune mechanisms associated with these neoplasms, closer scrutiny of this group of patients, or a combination of these factors. Studies are underway to elucidate a common genetic component in these patients.

Natural killer cells and cancer

BACKGROUND

Natural cytotoxicity, mediated by natural killer (NK) cells and cell with lymphokine-activated killer (LAK) activity, is believed to play an important role in host anti-cancer mechanisms.

METHODS

The authors critically review recent publications on the role of natural cytotoxicity in patients with cancer.

RESULTS

In patients with cancer, several studies have noted variations in the numbers and activity of NK and cells with LAK activity in different body compartments. NK cell activity in the peripheral blood lymphocytes (PBLs) is higher than that found in lymph nodes and within tumors, and this appears to be due to the presence of suppressor factors. The natural cytotoxicity of PBLs in patients with different types of cancers varies. However, there appears to be a trend for natural cytotoxicity to be reduced in certain cancer patients, possibly related to tumor volume or dissemination. Anti-cancer treatments (e.g., surgery, hormonal modulation, radiotherapy and chemotherapy) can also result in suppression of natural cytotoxicity, although the long-term effect on response to treatment and development of metastases is at present unknown.

CONCLUSIONS

NK and LAK cells, through the use of immune biologic modifiers, have been demonstrated to have a therapeutic role in the treatment of human cancers. Further studies are required to determine the optimal dosages and combinations of chemotherapeutic agents, the timing of surgery, and the adjuvant use of immune biologic response modifiers. An increasing awareness and understanding of this field, may allow for the future development of anti-cancer therapies.