Inhaled interleukin-2 in combination with low-dose systemic interleukin-2 and interferon alpha in patients with pulmonary metastatic renal-cell carcinoma: effectiveness and toxicity of mainly local treatment

Inhaled gene therapy in lung cancer: proof-of-concept for nano-oncology and nanobiotechnology in the management of lung cancer

Lung cancer still remains one of the leading causes of death among cancer patients. Although novel targeted therapies have been established in everyday treatment practice, and conventional platinum-based doublets have demonstrated effective results regarding overall and progression-free survival, we have still failed to achieve long-term survival. Therefore, several strategies of applying locoregional therapy are under investigation. Aerosol chemotherapy is already under investigation and, taking this a step further, aerosol gene therapies with multiple delivery systems are being developed. Several efforts have demonstrated its efficiency and effectiveness, but there are still multiple factors that have to be considered and combined to achieve an overall more effective multifunctional treatment. In the current review, we present data regarding aerosol delivery systems, transporters, carriers, vectors, genes, toxicity, efficiency, specificity, lung microenvironment and delivery gene therapy systems. Finally, we present current studies and future perspectives.

Phase I/II study of inhaled doxorubicin combined with platinum-based therapy for advanced non-small cell lung cancer

PURPOSE

We have shown the feasibility of administering inhaled doxorubicin to patients with cancer. This study evaluated inhaled doxorubicin combined with cisplatin and docetaxel in patients with non-small cell lung cancer. The principal objective was to determine safety and, secondarily, efficacy.

EXPERIMENTAL DESIGN

Patients who had chemo-naïve advanced non-small cell lung cancer were enrolled in the study. Adequate organ and pulmonary function was required: diffusing capacity for carbon monoxide/forced expiratory volume in 1 second/forced vital capacity > or =50%, resting/exercise O(2) saturation > or =90%/85%. In phase I, doxorubicin was escalated: dose level 1 (6 mg/m(2)) and level 2 (7.5 mg/m(2)). Escalation was permitted if < or =2 of 6 patients experienced pulmonary dose-limiting toxicity (grade 2 Radiation Therapy Oncology Group lung morbidity; resting O(2) saturation of <85%; decrease in diffusing capacity for carbon monoxide, forced vital capacity, or forced expiratory volume in 1 second of > or =20% from baseline or < or =30% of predicted; or grade 3 Common Terminology Criteria for Adverse Events version 3.0 pulmonary toxicity). Doses of cisplatin and docetaxel were 75 mg/m(2). Treatments and pulmonary function tests were repeated every 21 days, with up to eight cycles for responding patients.

RESULTS

Twenty-eight patients were treated at level 1 and eight patients at level 2. Doxorubicin was escalated to 7.5 mg/m(2), however, after two patients developed pulmonary dose-limiting toxicity; the remainder were treated at 6.0 mg/m(2). Twenty-four evaluable patients received at least two courses or had progressive disease following the first course at the phase II dose. Toxicity was associated with i.v. chemotherapy although one patient had delayed pulmonary toxicity responding to corticosteroids and oxygen. Seven (29%) evaluable patients responded (six partial responses and one complete response) and 13 (54%) patients had stable disease for up to eight cycles.

CONCLUSION

Although this combination was safe, the primary objective was not met and will not be pursued further.

Phase I study of inhaled Doxorubicin for patients with metastatic tumors to the lungs

PURPOSE

To evaluate the toxicity profile of inhalational doxorubicin in patients with malignant disease in the lung.

EXPERIMENTAL DESIGN

The OncoMyst Model CDD-2a inhalation device aerosolizes compounds to particles of 2 to 3 mum and prevents exhaled aerosol from escaping into the environment. Deposition efficiency of inhaled Technetium 99m was used to predict deposition of doxorubicin and calculate dose. Treatment was repeated every 3 weeks. No more than moderate pulmonary dysfunction was permitted (forced expiratory volume in 1 s, forced vital capacity, and diffusing capacity for carbon monoxide, all >50% predicted; resting SaO(2) >90%).

RESULTS

Fifty-three patients were enrolled at 13 dose levels ranging from 0.4 to 9.4 mg/m(2). The most common histologic diagnoses were sarcoma (n = 19) and non-small cell lung cancer (n = 16). Dose-limiting toxicity (DLT) was observed at the 9.4 mg/m(2) dose level when two of four patients experienced pulmonary DLT. Of 11 patients treated at the 7.5 mg/m(2) dose level, only one showed DLT consisting of a decline in forced vital capacity of >20% from baseline. No significant systemic drug-related toxicity was observed. Several patients experienced declines in pulmonary function test variables, which were attributed to progressive disease. Observed activity included a partial response in a patient with metastatic soft tissue sarcoma previously treated with i.v. doxorubicin and ifosfamide.

CONCLUSIONS

Inhaled doxorubicin is safe up to a dose of 7.5 mg/m(2) every 3 weeks in patients with cancer who had normal to moderately impaired pulmonary function.

Inhaled cytokines and cytokine antagonists

Cytokine and cytokine antagonist have provided novel and effective therapies for many human diseases. A number of approved cytokines including the interferons (alpha, beta and gamma), interleukin-2 (IL-2), granulocyte macrophage colony stimulating factor (GM-CSF) as well as novel cytokine antagonists have been administered by the pulmonary route for both local lung disease and as a non-invasive method for systemic delivery. We review the published clinical experience of inhaled cytokines and cytokine antagonists. We discuss the limitations of the existing data and the type of clinical data desired to establish the advantages and safety of inhaled cytokines and cytokine antagonists.

Interleukin-2/interferon-alpha2a/13-retinoic acid-based chemoimmunotherapy in advanced renal cell carcinoma: results of a prospectively randomised trial of the German Cooperative Renal Carcinoma Chemoimmunotherapy Group (DGCIN)

We performed a prospectively randomised clinical trial to compare the efficacy of four subcutaneous interleukin-2-(sc-IL-2) and sc interferon-alpha2a (sc-IFN-alpha2a)-based outpatient regimens in 379 patients with progressive metastatic renal cell carcinoma. Patients with lung metastases, an erythrocyte sedimentation rate < or =70 mm h(-1) and neutrophil counts < or =6000 microl(-1) (group I) were randomised to arm A: sc-IL-2, sc-IFN-alpha2a, peroral 13-cis-retinoic acid (po-13cRA) (n=78), or arm B: arm A plus inhaled-IL-2 (n=65). All others (group II) were randomised to arm C: arm A plus intravenous 5-fluorouracil (iv-5-FU) (n=116), or arm D: arm A plus po-Capecitabine (n=120). Median overall survival (OS) was 22 months (arm A; 3-year OS: 29.7%) and 18 months (arm B; 3-year OS: 29.2%) in group I, and 18 months (arm C; 3-year OS: 25.7%) and 16 months (arm D; 3-year OS: 32.6%) in group II. There were no statistically significant differences in OS, progression-free survival, and objective response between arms A and B, and between arms C and D, respectively. Given the known therapeutic efficacy of sc-IL-2/sc-INF-alpha2a/po-13cRA-based outpatient chemoimmunotherapies, our results did not establish survival advantages in favour of po-Capecitabine vs iv-5-FU, and in favour of short-term inhaled-IL-2 in patients with advanced renal cell carcinoma receiving systemic cytokines.

Targeting pulmonary metastases of renal cell carcinoma by inhalation of interleukin-2

INTRODUCTION

Pulmonary metastases of renal cell carcinoma (RCC) are associated with poor prognosis. Inhalation therapy with interleukin-2 (IL-2) is thus an appealing method for palliation. This multicenter study summarizes the national experience of IL-2 inhalation in patients with lung metastases of RCC.

PATIENTS AND METHODS

Forty patients (median, 66.5 years of age) with radiologically documented progressing pulmonary metastases were enrolled. All patients had to be able to comply with inhalation technique, and were not candidates for other treatment options. Twenty-eight patients were systemic treatment-naïve. The protocol included three daily inhalations of IL-2 to a total dose of 18 MU. Treatment had to be continued until one of the following occurred: progression; a complete response; a life threatening toxicity; or patient refusal. Response was assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) system.

RESULTS

The disease-control rate reached 57.5%, with a partial response rate of 2.5% and a disease stabilization rate of 55%. Median time to progression was 8.7 months. The main side-effects were cough and weakness.

CONCLUSIONS

Inhalation of IL-2 for the treatment of pulmonary metastases in RCC is feasible, tolerable and beneficial in controlling progressive disease for considerable periods of time. The definition of response of biological therapy may need to be re-assessed and modified: stable disease should be regarded as a favorable response.

Development of inhalational agents for oncologic use

Because regional chemotherapy has been useful in treatment and palliation of many cancer types, the concept of delivering drugs by inhalation for the treatment of cancers in the lung is attractive. Much higher local drug exposure can be achieved with total doses considerably lower than those required for systemic administration, resulting in lower exposure of nonrespiratory tract tissues to potentially toxic drugs. Regional delivery of chemotherapy to the respiratory tract has been shown to have activity in preclinical and clinical studies. Technical improvements in delivery methods have now made it possible to conduct trials of inhalational agents, both to treat cancers affecting the respiratory tract and to deliver other drugs used in cancer patients. This review discusses the rationale of drug delivery by the inhalational route, its technical challenges, preclinical and clinical experiences, limitations, and promise.

Locoregional immunotherapy in cancer patients: review of clinical studies

Many patients with invasive cancer have a compromised immune system. This immune dysfunction does appear to start at the site of the tumor. Locoregional immunotherapy is given to stimulate the immune system in order to kill tumor cells either indirectly via a specific or a non-specific way or directly via cell transfer therapy. Advantages to give this immunotherapy locoregionally in stead of systemically are a higher concentration of the immunomodulator at the site of the tumor, to attract or activate effector cells, and diminished toxicity. In this review we have summarised the clinical studies using loco-regional immunotherapy in patients with cancer. Only phase I and II studies were performed. Clinical responses were seen. No single locoregional treatment has become a standard therapy. Relatively few investigations were performed to estimate the influence on the locally effector mechanisms or immune dysfunction. In future clinical trials it is essential to get a better insight in these mechanisms.

Pharmacological elements in clinical application of synthetic peptides

The research carried out on the biological properties of synthetic peptides and the possibility of obtaining them in adequate amounts through the recombinant DNA technology allows their use as therapeutical agents. Procedures following the synthesis of peptides must be performed in order to verify their structure, conformation, immunogenicity and biological activity and to make them suitable for clinical applications. The size of synthetic peptides together with some modifications such as amidation, acetylation and sulfatation must be taken into consideration as they may have a significant impact on half-life, stability and biological activity. Endothelial, epithelial and enzymatic interference which may hinder the absorption of drugs must be evaluated in order to choose the most appropriate route of administration. The considerable bioavailability related to the intravenous route, the effectiveness of the circulation of the intramuscular route and the possibility of reaching specific targets by the intra-arterial route must also be taken into consideration. There is the possibility of applying transdermal therapeutic systems and transdermal iontophoresis only for peptides of low molecular weight. Among synthetic peptides provided with antianaemic activity, erythropoietin, growth factors and interleukin 3 must be mentioned because of their effectiveness both in optimal stimulation of melopoiesis after chemotherapy or bone-marrow transplantation and in the treatment of anaemia occurring during chronic renal failure. Furthermore, interferon alpha was shown to be one of the most used synthetic peptides provided with antiviral and antineoplastic activity. Remarkable results have been obtained in the treatment of chronic hepatitis C, haematological malignancies and some solid tumours. More recently, interleukin 2 has been tested in the treatment of melanoma and renal cancer, inducing a reasonable proportion of overall response rate. Finally, the antagonist of gonadotropin-releasing-hormone may be regarded as effective agent both in the treatment of prostate cancer and in the inhibition of luteinizing-hormone surges during controlled ovarian stimulation. Toxic side effects can be related to the administered dose as well as to metabolites derived from bacteria in which peptides have been synthesized.

Inhalational interleukin-2 liposomes for pulmonary metastases: a phase I clinical trial

The lung is a common site of both metastases and primary neoplasia. This phase I study was designed to test the feasibility and toxicity of administering interleukin (IL)-2 liposomes by aerosol to patients with pulmonary metastases. The goal was to test whether IL-2 liposomes could be given by aerosol using biologically effective but non-toxic doses in an outpatient setting. Liposomes containing IL-2 or placebo (buffer) were synthesized and mixed to provide a constant lipid dose, and were nebulized using a Puritan twin jet nebulizer and a standard compressor. The liposome-containing mist was inhaled for about 20 min 3 times a day in order to selectively stimulate immune function within the lung and to avoid systemic toxicity. The dose chosen was based on canine efficacy and toxicity studies that used bronchoalveolar lavage to demonstrate increased cell numbers and activation of mononuclear cells after inhalation of nebulized IL-2 liposomes. Nine patients were treated in three cohorts of three patients at 1.5, 3.0 and 6.0 x 10(6) IU of IL-2 3 times a day. No significant toxicity was observed. We conclude that the delivery of IL-2 liposomes by inhalation is well tolerated. Further studies of inhalational IL-2 liposomes to determine efficacy as an anti-cancer therapy are warranted.

High dose inhalation interleukin-2 therapy for lung metastases in patients with malignant melanoma

BACKGROUND

The lungs are a frequent site of metastasis in patients with melanoma, and this may cause respiratory problems in the terminal phase of the illness. Inhalation interleukin (IL)-2 therapy to the lung has been piloted and appears to be well tolerated.

METHODS

Twenty-seven patients were treated with single agent dacarbazine and concurrent high dose inhalation IL-2 36 million IU per day). The patients previously had progressed on chemotherapy, predominately dacarbazine-based regimens. Patients included those with American Joint Committee on Cancer Stage IV melanoma, predominately those with lung metastases, but patients with extrapulmonary metastases also were allowed on the study.

RESULTS

Five of the 27 patients experienced a complete pulmonary remission. Eight patients achieved a partial pulmonary remission, and 5 patients experienced stabilization of their disease. Eight patients developed pulmonary metastases. One patient was not evaluable. Four of the five patients who achieved a complete response and seven of the eight patients who achieved a partial response previously were treated with dacarbazine and progressed. There were no responses in extrapulmonary metastases. Side effects of treatment were minimal. The complete responses all were durable with a follow-up of 12 months, whereas patients with partial responses and stable disease progressed when IL-2 was discontinued.

CONCLUSIONS

Inhalation therapy with IL-2 for pulmonary metastases from melanoma appears to be safe. The current preliminary study suggests efficacy although concurrent chemotherapy was given, thus confounding results to some extent. Therefore, these results need to be reproduced without concomitant chemotherapy. In addition, a strategy comprised of therapy with IL-2 inhalation until disease progression may prolong responses.

Subjective and objective prospective, long-term analysis of quality of life during inhaled interleukin-2 immunotherapy

PURPOSE

We conducted both a subjective and objective, prospective quality-of-life analysis during high-dose (36 x 10(6) immunizing units/d) inhalational interleukin (IL)-2 treatment (mean treatment time, 13.4 months) of 15 patients with metastatic renal cell carcinoma (mRCC). Additionally, quality of life for 10 patients with mRCC receiving low-dose (9 x 10(6) IU/m(2)/d for 5 days) intravenous IL-2 treatment also was evaluated.

PATIENTS AND METHODS

Patients responded to the European Organization for Research and Treatment of Cancer quality-of-life questionnaire QLQ-C30 before and during inhalational IL-2 treatment at 1, 3, 6, 9, and 12 months and before and once during intravenous IL-2 treatment. A clinician assessed patient well-being using the Quality of Well-Being scale to calculate once weekly quality-adjusted life-years (QALYs) during inhalational IL-2 treatment.

RESULTS

Patients completed 103 questionnaires and clinicians performed 892 QALY calculations. For patients treated with inhalational IL-2, the mean quality-of-life score deteriorated modestly but significantly 1 month after treatment initiation (15.1%, P =.01) but did not differ significantly from pretreatment scores after 3, 6, 9, and 12 months of treatment. Inhalational IL-2 therapy stabilized patient quality of life for a mean of 13.4 months. The resulting QALY calculation for patients on inhalation IL-2 was 70.1% of 13.4 months, representing 9.4 months of QALY. In comparison, patients who received intravenous IL-2 showed a more marked, statistically significant deterioration in mean quality-of-life score during treatment (27%, P =.006); moreover, three of these 10 patients experienced treatment-related toxicity that prevented questionnaire completion.

CONCLUSION

Quality-of-life analysis during immunotherapy provides valuable information regarding cancer treatment outcomes.

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.

Treatment-induced antibodies to interleukin-2

Interleukin-2 (IL-2) is a 15 kDa glycoprotein with proven activity as an immune stimulant in the treatment of malignant disorders, congenital and acquired immune deficiencies, infectious disorders, and as an adjuvant to vaccines. Both natural and recombinant type IL-2 preparations have been applied in clinical treatment trials and have turned out to be immunogenic, although to a varying extent. Enzyme immunoassays and western blotting are standard procedures for the detection of IL-2-binding antibodies, whereas the neutralizing capacity of these antibodies is frequently demonstrated by inhibition of IL-2-dependent cell growth in vitro. The rate of treatment-induced IL-2 antibodies has varied from 0% to 100% in reported trials and frequently exceeded 50% in patients exposed to recombinant IL-2, whereas natural type IL-2 appeared to be little immunogenic. Duration of treatment, cumulative IL-2 dose, and route of IL-2 administration are likely to determine both the rate of seroconversion as well as composition and properties of the anti-IL-2 antibodies. Interleukin-2 antibodies are polyclonal in nature and predominantly composed of IgM and IgG types. Frequently they react with both recombinant and natural IL-2 types. As a rule, neutralizing IL-2 antibodies are detected in serum samples with high IL-2-binding titers and are recognized later than their non-neutralizing predecessors. Neutralization in vitro, however, does not predict neutralization in vivo, and there are very rare patients with documented, antibody-mediated loss of response to IL-2 treatment. More frequently, IL-2 antibodies will limit the expression of IL-2-dependent proteins in vivo, but the opposite has also been observed. Although the precise mechanism of antibody induction by IL-2 is unknown, immunogenicity of some drug formulations rather than polyclonal B-cell activation appears to play a critical role. Approaches aiming at limiting the immunogenicity of IL-2 preparations are discussed, and strategies how to recognize and circumvent antibody-mediated IL-2 resistance are presented.

Treatment of advanced renal cell carcinoma with a combination of human lymphoblastoid interferon-alpha and cimetidine

Human lymphoblastoid interferon (IFN)-alpha was administered intramuscularly at doses of 5 megaunits/day 5 to 7 days a week to 32 advanced renal cell carcinoma patients. To augment the antitumor effect of IFN, cimetidine was also administered orally in doses oi 800 mg/day. This combination therapy resulted in a complete response (CR) in 6 patients (19%), a partial response (PR) in 7 (22%), a stable disease (SD) in 11 (34%), and a progressive disease (PD) in 8 (25%). The response rate (CR+PR) was 41%. The pulmonary metastases were more receptive to IFN therapy than those at other sites. The median times to response were 2 months for PR, and 4.5 months for CR. The survival of the responder patients was significantly longer than the nonresponder patients. These results suggest that IFN-alpha and cimetidine combination therapy may be of use in the management of advanced renal cell carcinoma.

Interferon-gamma and interleukin-2 suppress the experimental metastasis of mouse renal adenocarcinoma

While cytokines such as interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) are partially effective in the treatment of metastatic renal cell carcinoma, these cytokines have not been investigated for their ability to suppress the development of metastasis. We investigated whether they suppressed experimental pulmonary metastasis by subline-2 of streptozotocin-induced mouse renal adenocarcinoma (MRAC-PM2). IFN-gamma (1 x 10(4) and 1 x 10(5) U/mouse) and IL-2 (1 x 10(4) and 1 x 10(5) U/mouse) suppressed the experimental pulmonary metastasis of MRAC-PM2 in a dose-dependent manner, but 1 x 10(5) IU/mouse of IFN-alpha did not. The combination of 1 x 10(5) U IFN-gamma with 1 x 10(5) U IL-2 had the most powerful inhibitory effect on pulmonary metastasis without any side-effects. In addition, the combination of 1 x 10(5) U IFN-gamma with 1 x 10(5) U IL-2 had a synergistic inhibitory effect on the growth of subcutaneous tumors. These results indicate that either IFN-gamma or IL-2, or their combination, produce a more favorable effect than IFN-alpha on the metastatic development of renal adenocarcinoma.