Long-term subcutaneous recombinant interleukin-2 as maintenance therapy: biological effects and clinical implications

Effect of Rutin on Cytarabine-Associated Pulmonary Oedema and Oxidative Stress in Rats

Cytarabine is effectively used in the treatment of adult acute leukemia, but it has a dose-limiting side effect of fatal pulmonary oedema because it increases the vascular permeability of the alveolar capillaries. The aim of the present study was to conduct a radiological, biochemical and histopathological investigation of the effect of rutin on cytarabine-associated pulmonary oedema in rats. Rats were treated with a combination of rutin+cytarabine by administering oral rutin at a dose of 50 mg/kg; other rat groups were orally administered the same volume of physiological saline. One hour after administration of rutin or saline, the rutin+cytarabine and cytarabine groups received an intraperitoneal injection of cytarabine (200 mg/kg). This administration procedure was repeated once a day for 14 days. Radiologically, 50% of the animals given cytarabine alone showed lung oedema, but the rutin+cytarabine group showed no oedema. The inclusion of rutin decreased the amounts of cytarabine-associated malondialdehyde, tumour necrosis factor-α, and nuclear factor-κB in the lung tissue. Rutin also inhibited the reduction of total glutathione by nitric oxide. These findings suggest that rutin may be a beneficial adjunct that can minimise the development of cytarabine-associated pulmonary oedema.

Maintenance biotherapy with interleukin-2 and interferon for metastatic renal cell cancer

The term maintenance immunotherapy comprises at least two different therapeutic approaches: the continuation of immunotherapy beyond disease progression and the use of chronic immunotherapy after the achievement of an initial response (or disease stabilization) with more intensive treatment modalities, such as chemotherapy. The former therapeutic approach was proposed in renal cell carcinoma some years ago relying on several immunological considerations. Some years later, we have learned that it is feasible and endowed with a favorable therapeutic index; furthermore, its immunologic effects are well described and reproducible, and it has antitumor activity. However, due to the lack of adequate randomized Phase III studies, the actual impact of this treatment strategy on patient survival has not yet been proved. The rationale of this treatment, its immunological and clinical results, as well as its pitfalls and perspectives, will be presented and discussed in this review.

Dose finding study for the use of subcutaneous recombinant interleukin-2 to augment natural killer cell numbers in an outpatient setting for stage 4 neuroblastoma after megatherapy and autologous stem-cell reinfusion

PURPOSE

To establish a safe dose of subcutaneous (SC) recombinant interleukin 2 (rIL-2) in an outpatient setting for children with stage 4 neuroblastoma after megatherapy (MGT) and autologous stem-cell reinfusion (ASCR) that is able to sustain an increase of natural-killer cells (NKCs) above the level previously reported for immunomodulatory potency.

PATIENTS AND METHODS

Between August 1997 and November 2000, 33 patients with stage 4 neuroblastoma entered the study from six countries after receiving MGT/ASCR according to national protocols. Dose levels of 3, 6, and 9 × 10(6) U rIL-2/m(2) were given SC in six 5-day cycles every 2 weeks.

RESULTS

Median age at registration was 4.1 years (range, 1.8 to 7.4). Median observation time was 5 years (range, 4 to 9.8). Increase of NKCs was achieved in 89% of courses, with more than 100% increase over baseline and/or more than 1,000 NKCs/μL in 58%. On the basis of outpatient dose-limiting toxicity at dose level 3, dose level 2 was chosen for the confirmation stage. At dose level 2, the median increase in absolute NKCs was 1,180 cells/μL for all 83 cycles, corresponding to a median relative NKC increase over baseline of 711%. Fever was frequent but controllable with adequate supportive care; 6.5% of patients were hospitalized. Localized pain was moderate and acceptable. Event-free and overall survival rates at 5 years were 45% (± 9 standard deviation [SD]) and 48% (± 9 SD), respectively.

CONCLUSION

The low toxicity profile and ability to sustain an increase in NKCs of IL-2 at 6 × 10(6) U/m(2) SC allows its integration in an outpatient setting.

Interleukin-2 for the treatment of solid tumors other than melanoma and renal cell carcinoma

Interleukin-2 (IL-2) is a lymphokine produced by T cells whose main function is to stimulate the growth and cytotoxic response of activated T lymphocytes. It has been used to stimulate the immune system for the treatment of multiples tumors. This article is intended to review the reports published from 1990 to 2004 on the IL-2 treatment of tumors other than melanoma and renal carcinoma. A literature search was made in various databases (MEDLINE, EMBASE and BioAssay), focused on IL-2 clinical efficacy in such tumors. A selection was made over 150 publications reporting on administration of IL-2 in multiple tumors: lung carcinoma (small cell and non-small cell), colorectal, gastric, pancreatic, ovarian and breast cancer, sarcomas, hepatocarcinoma, mesothelioma, and brain, urological, and head and neck tumors. IL-2 was mainly used in metastatic disease, associated with other immunotherapy or chemotherapy schedules. We conclude that adjuvant IL-2 may be of value in early stages combined with standard treatment for colon and pancreas cancers. In other neoplasms, the indication for adjuvant IL-2 has been sporadic and does not allow conclusions to be drawn. Assessment of the efficacy of IL-2 combined with chemotherapy as treatment for advanced stages is complex, due to the lack of a control, and the variety of dosages and schemes. The activity of IL-2 in monotherapy or in association with immunotherapy is clinically relevant in hepatocarcinoma, mesothelioma and in malignant overflows as palliative treatment. Randomized trials would be required in order to be able to draw conclusions about its indication in other tumors.

Cytokines in breast cancer

In recent decades many advances have occurred in the understanding of the role of cytokines in breast cancer. New signalling pathways of interleukin (IL)-1 family, IL-6, IL-11, IL-18, interferons (IFNs) and interferon regulatory factors 1 (IRF-1) and 2 (IRF-2) have been found within tumour microenvironments and in metastatic sites. Some cytokines (IL-1, IL-6, IL-11, TGFbeta) stimulate while others (IL-12, IL-18, IFNs) inhibit breast cancer proliferation and/or invasion. Similarly, high circulating levels of some cytokines seem to be favourable (soluble IL-2R) while others are unfavourable (IL-1beta, IL-6, IL-8, IL-10, IL-18, gp130) prognostic indicators. So far IL-2, IFNalpha, IFNbeta and occasionally IFNgamma, IL-6, IL-12 have been the cytokines used for anti tumour treatment of advanced breast cancer either to induce or increase hormone sensitivity and/or to stimulate cellular immunity. Disappointing results occurred in most trials; however, two long-term pilot studies suggest that IL-2 and IFNbeta, when used appropriately can have a positive effect on clinical benefit and overall survival of patients with minimal residual disease after chemotherapy or with disseminated disease controlled by conventional endocrine therapy.

Basal level and behaviour of cytokines in a randomized outpatient trial comparing chemotherapy and biochemotherapy in metastatic melanoma

Cytokines play a crucial role in the host's immune response. In melanoma patients, cytokine profiles seems to be related to the clinical course and their imbalance could be associated to tumour progression. Thus, we studied a panel of baseline cytokines and their behaviour during treatment in order to verify their correlation with clinical outcomes. Interleukin-6, interleukin-8, interleukin-10, interleukin-12 and soluble receptor of interleukin-2 were evaluated in 90 out of 176 metastatic melanoma patients enrolled in a phase III study comparing chemotherapy and biochemotherapy. We divided patients into three different groups according to their own cytokine levels (low, intermediate and high) and then we correlated these groups with some clinical features. We also monitored the cytokines during the treatment in a subgroup of 37 patients. In univariate analysis, higher values of interleukin-6 (P = 0.005), soluble receptor of interleukin-2 (P = 0.001) and interleukin-12 (P = 0.010) were correlated with a worse survival. Conversely, interleukin-8 was unable to discriminate patients with different prognoses, and interleukin-10 was undetectable in the majority of patients. In multivariate analysis, only soluble receptor of interleukin-2 maintained its independent role in survival. The impact of baseline cytokines on response was insignificant. Regarding the behaviours of cytokines during treatment, the most remarkable aspect was a progressive increase of interleukin-12 and soluble receptor of interleukin-2 in patients with a better survival. In our metastatic melanoma patients, higher basal levels of interleukin-6, interleukin-12 and soluble receptor of interleukin-2 were associated with a worse survival. In contrast, a progressive increase of interleukin-12 and soluble receptor of interleukin-2 was observed during treatment in patients with a better survival.

Noncardiogenic pulmonary edema: an unusual and serious complication of anticancer therapy

Noncardiogenic pulmonary edema (NCPE) is a rare and less well-recognizable pulmonotoxic syndrome of anticancer therapy than pneumonitis/fibrosis. NCPE is a clinical syndrome characterized by simultaneous presence of severe hypoxemia, bilateral alveolar infiltrates on chest radiograph, and no evidence of left atrial hypertension/congestive heart failure. The diagnosis of drug-related NCPE relies upon documented exclusion of any infectious, metabolic, or cancer-related causes. The time proximity to therapy with drugs that are known to precipitate NCPE, any preceding episodes of flu-like symptoms during previous chemotherapy courses and possible response to corticosteroids may further support such a diagnosis. Cancer therapeutic agents clearly associated with NCPE are cytarabine, gemcitabine, and interleukin-2, as well as all-trans retinoic acid in acute promyelocytic leukemia patients, while a few other compounds have rarely or occasionally been implicated. The pathophysiology of lung injury in drug-induced NCPE remains unclear. There are indications suggesting that both a direct cytotoxic insult to the lung epithelial cells and induction of a cytokine-triggered inflammatory response may be involved in its pathogenesis. By distinction to drug-induced pulmonary pneumonitis that may lead to permanent pulmonary fibrosis, NCPE if not fatal, can be reversed upon prompt recognition, following immediate discontinuation of the offensive drug and start of intensive supportive treatment and intravenous corticosteroids.

Low-dose subcutaneous interleukin-2 in patients with minimal residual lymphoid neoplasm disease

Interleukin-2 (IL-2) is a cytokine that became available for clinical use with the development of recombinant DNA technology. Patients with resistant or relapsed lymphoid neoplasm have been treated with high-dose IL-2 with some responses. The aim of the present study is to determine whether there may be a biological justification for the use of low dose subcutaneous (s.c.) IL-2 as maintenance therapy in patients with lymphoid neoplasm in complete remission with high risk of relapse. We treated 15 patients with sc IL-2, 4.5 Million International Units (MIU) daily, 5 days per week for 12 consecutive weeks, in the outpatient clinic. This therapy was well tolerated and could be administered in an outpatient regimen. It increased the eosinophil count (p = 0.009), but the number of granulocytes, monocytes, T-lymphocytes and B-lymphocytes did not change. The number of natural killer (NK) cells increased from 11% to 35% of all lymphocytes during IL-2 therapy (p = 0.0006). Effector lymphokine-activated killer activity (eLAK) also increased from 6x10(-3) Lytic Units (LU)/ml to 80x10(-3) LU/ml (p = 0.02). All these changes reached a "plateau" after the 4th week of therapy. The increase in the number of NK cells correlated strongly with the increase in eLAK activity (r = 0.96, p<0.0001). Disease-free survival was determined in 14 patients who completed the treatment and compared with historical controls. Patients treated with IL-2 had the same relapse risk (median time to relapse 11.1 months, 95% confidence interval 5.5-16.6) as did controls (median time to relapse 9.7 months, 95% confidence interval 1-27.7) (p = 0.9). Low dose s.c. IL-2 stimulated NK proliferation, which generated cytotoxic activity in vivo in patients with lymphoid neoplasms. However, these patients did not have a lower risk of disease relapse compared to historical controls.

[Managing cutaneous melanoma]

Cutaneous melanoma represents the main cause of death among skin cancers. Early diagnosis gives, for the time being, the only possibility for high rate of curative treatment. Diagnosis is based on pathological findings, and at primary tumor stage. Breslow thickness of the lesion is the best prognostic index. At local stage of the disease, treatment is precisely codified by international recommendations and consensus conferences. Follow-up after surgical treatment is also well codified. Treatment of lymph node invasion or metastatic disease is, on the other hand, less codified. Despite recent advances, especially in immunotherapy, treatment of advanced stages of melanoma remains difficult.

Nebulized interleukin 2 liposomes: aerosol characteristics and biodistribution

Although interleukin 2 (IL-2) has been associated with modest anti-tumour responses in man, treatment-related toxicity has limited its widespread use. The local delivery of liposomal formulations of interleukin 2 to the lung as aerosols has been demonstrated to be non-toxic, biologically active, and associated with regression of spontaneous pulmonary metastases in dogs. This study was undertaken to evaluate the physical and biological characteristics of nebulized interleukin 2 liposomes. The aerosol droplet size distribution and the physical stability of interleukin 2 liposomes were examined in-vitro using an Andersen cascade impactor and studies of liposome entrapment of interleukin 2 before and after nebulization. The biological stability of interleukin 2 liposomes after nebulization was demonstrated using the CTLL-2 bioassay for interleukin 2. In-vivo studies of pulmonary biodistribution and clearance of inhaled technetium (99mTc)-labelled interleukin 2 liposomes were undertaken in a normal dog. Aerosols of free interleukin 2 and of interleukin 2 liposomes were compared in both in-vitro and in-vivo experiments. The mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of interleukin 2 liposomes were 1.98 microns and 2.02, respectively. Independent analysis of aerosol particle-size distribution using the constitutive components of the interleukin 2 liposomes (interleukin 2: lipid:HSA) demonstrated a close correlation of size distributions (r = 0.9445; P < 0.001). The entrapment of interleukin 2 in liposomes was 93 +/- 4.3% before nebulization and 90 +/- 8.9% after. After delivery to an anaesthetized dog, interleukin 2 liposome aerosols were deposited evenly throughout the lung (mean +/- s.d. central lung-to-peripheral lung deposition was 1.12 +/- 0.03). After approximately 24 h inhalation, interleukin 2 liposomes were retained within the lung and were taken up in part by the spleen. The results of this study are indicative of the stability of this interleukin 2 liposome formulation to nebulization. Such nebulization might be an attractive immunotherapeutic strategy for treatment of pulmonary metastases and primary lung cancers.

Interleukin-2 liposome inhalation therapy is safe and effective for dogs with spontaneous pulmonary metastases

BACKGROUND

Systemic in vivo toxicity of interleukin-2 (IL-2) has been problematic. Antineoplastic activity of IL-2 has been modest. The authors have previously demonstrated the biologic activity and safety of aerosols of IL-2 liposomes in normal dogs. They now report objective regression of naturally occurring pulmonary metastases in dogs after 1 month of nebulized IL-2 liposome therapy.

METHODS

Dogs with pulmonary metastases (n = 7) and primary lung carcinoma (n = 2) were treated with aerosols of IL-2 liposomes. Response to therapy was monitored with serial chest radiographs. Effector populations, collected by bronchoalveolar lavage (BAL) and from heparinized whole blood, were assessed for cell type, immunophenotype, and tumor cytolytic activity. Immunogenicity of human IL-2 and human serum albumin (HSA) in dogs was assessed by immunofluorescence assay.

RESULTS

Two of four dogs with metastatic pulmonary osteosarcoma had complete regression of metastases; the regression remained stable for more than 12 and more than 20 months, respectively. One of two dogs with lung carcinoma had stabilization of disease for more than 8 months; the other had disease progression. Toxicity was minimal. BAL cell numbers increased more than fourfold (P = 0.01) and included significantly greater proportions and total numbers of eosinophils (P = 0.006) and lymphocytes (P = 0.008). Mean BAL effector lytic activity was significantly greater after 15 days of IL-2 liposome inhalation compared with pretreatment activity (P = 0.01); however, mean BAL lytic activity decreased after 30 days and was no longer significantly greater than pretreatment BAL lytic activity. No allergic reactions were associated with inhaled IL-2 liposome therapy. Canine antibodies against human IL-2 and HSA were detected in all dogs.

CONCLUSIONS

Pet dogs with naturally occurring pulmonary metastases and primary lung carcinomas accepted inhalation treatments easily. Nontoxic and effective treatment of pulmonary metastases of osteosarcoma is possible with nebulized IL-2 liposomes.