Cardiorespiratory effects of immunotherapy with interleukin-2

Induction of lymphokine-activated killing with reduced secretion of interleukin-1 beta, tumor necrosis factor-alpha, and interferon-gamma by interleukin-2 analogs

BACKGROUND

Interleukin-2 (IL-2)-based immunotherapy has been shown to effect clinical responses in 15-35% of patients with metastatic renal cell carcinoma or melanoma. Despite its clinical efficacy, many clinicians refrain from using IL-2 because of the associated toxicity. This toxicity is believed to be mediated by such secondary cytokines as IL-1, tumor necrosis factor (TNF), and interferon (IFN)-gamma, which are produced by the patient's IL-2-stimulated peripheral blood mononuclear cells (PBMCs).

METHODS

Human PBMCs were stimulated with 1 nM wild-type recombinant IL-2 (rIL-2) or IL-2 analogs (R38A or F42K) that preferentially bind to the intermediate affinity IL-2 receptor (IL-2R). PBMCs were activated for lymphokine-activated killer (LAK) activity in 4-h 51Cr-release assays, using Daudi target cells. Cytokine content in the culture supernatants was determined by enzyme-linked immunosorbent assay.

RESULTS

Both R38A and F42K were capable of generating substantial LAK activity. Maximal specific lysis was 54% for PBMCs activated by R38A and 52% for F42K-stimulated cells, in contrast to 64% for rIL-2. In addition, analog-stimulated PBMCs secreted 59% of the IL-1 beta, 25% of the TNF-alpha, and only 8% of the IFN-gamma produced in response to rIL-2 (all p < 0.01 compared with rIL-2-stimulated secretion; one-way ANOVA).

CONCLUSIONS

IL-2 analogs that preferentially bind the intermediate-affinity IL-2R retain the capacity to induce substantial LAK activity despite a greatly reduced secondary cytokine production. Therefore, such IL-2 analogs may provide an effective, yet less toxic means of cancer immunotherapy.

Correlation of serum cytokine and acute phase reactant levels with alterations in weight and serum albumin in patients receiving immunotherapy with recombinant IL-2

Recombinant IL-2 (rIL-2) has been used alone or in combination with other chemotherapeutic agents to enhance host defences against cancer. Prolonged administration of high doses, required for clinical efficacy, may precipitate serious dose-limiting toxicity. rIL-2-induced 'vascular leak syndrome' leads to hypotension, renal insufficiency, respiratory disturbances and other organ dysfunctions. Serial measurements of serum cytokines and the acute phase protein C-reactive protein (CRP) were performed on nine patients who received high-dose i.v. continuous therapy with rIL-2. The influence of these immunological parameters upon alterations in patients' weight and serum albumin, as indicators of toxicity, was assessed. All patients experienced weight increases during the cycle (3-11% of total body weight). The serum levels of tumour necrosis factor (TNF-alpha) and CRP were highly predictive of alterations in patients' weight (both P < 0.001), while no correlation was found with IL-6 and weight change. Serum albumin fell linearly throughout the infusion cycle, but this showed no correlation with variations in serum levels of IL-6, TNF-alpha, or CRP. The complement components C3 and C4 were significantly reduced at the end of the infusion, suggesting a possible role for this cascade system in mediating these clinical changes. The strong association between serum TNF-alpha and weight change, not previously documented, further supports the hypothesis that TNF-alpha is a key mediator in the pathogenesis of the 'vascular leak syndrome'.

The intrapleural administration of recombinant interleukin-2 (rIL-2) to patients with malignant pleural effusion: clinical trials

Recombinant IL-2 (rIL-2) was administered intrapleurally according to an original protocol to 11 patients with malignant pleural effusion, 7 of whom suffered from breast cancer and 4 from esophageal cancer. The pleural effusions either disappeared or decreased roentgenographically, and malignant cells disappeared from all 13 pleural cavities in the 11 patients, confirming the validity of this therapy to be 100%. The mean survival time from the initial administration of rIL-2 was 15.9 months. We ensured that the concentration of IL-2 in the effusion was maintained at a high level for a sufficient period of time, and that the lymphokine-activated killer (LAK) activity of lymphocytes in the effusion was augmented. Fever, eosinophilia, and a transient increase in the pleural effusion were the main side effects, but the symptoms were temporary and not serious. The results of this study therefore suggest the efficacy of intrapleural rIL-2 for patients with malignant pleural effusion.

Immunogenicity of recombinant human interleukin-2: biological features and clinical relevance

The immunogenicity of recombinant interleukin-2 (rIL-2, EuroCetus, Amsterdam, Netherlands) was studied in seventy-six patients receiving different subcutaneous immunotherapy regimens. Patients presented with progressive metastatic renal cell carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, and Hodgkin's disease. An enzyme immunoassay (EIA) was employed to screen patients for development of non-neutralizing antibodies against rIL-2, antibody specificity was confirmed by a standard Western blot. Neutralizing serum activity against rIL-2 was detected using a standard CTLL mouse proliferation assay. Additionally, serum levels of soluble interleukin-2 receptors and lymphocyte subsets expressing the CD56 natural killer (NK) associated antigen were measured. In a proportion of approximately 35% to 90% of the patients treated, non-neutralizing antibodies against rIL-2 could be detected after all treatment courses were evaluated. Antibodies were of the IgG, IgM, IgA and IgD subtypes. None of the 76 patients exhibited serum neutralizing activity after one treatment course. Five patients exhibited neutralizing anti-rIL-2 serum activity after two or more treatment courses of systemic rIL-2. In three of these patients, antibodies neutralized both recombinant and natural IL-2. Patients developing neutralizing anti-rIL-2 antibodies, exhibited significantly lower serum sIL-2 receptor levels upon the emergence of serum neutralizing activity than patients without antibody. Additionally, NK cell associated CD56 positivity was significantly lower in patients who exhibited neutralizing anti-rIL-2 serum activity than in patients who did not. A significant decrease in levels of soluble IL-2 receptors and CD56 NK cell positivity was observed, when comparing values prior to and after onset of serum neutralizing activity against rIL-2. However, while emergence of neutralizing antibodies to rIL-2 diminished rIL-2 induced biological activation, it did not coincide with abrogation of treatment response.

Renal, metabolic, and hemodynamic side-effects of interleukin-2 and/or interferon alpha: evidence of a risk/benefit advantage of subcutaneous therapy

Systemic immunotherapy with recombinant interleukin-2 (rIL-2) via intravenous (i.v.) and subcutaneous (s.c.) administration produces objective responses in a proportion of advanced cancer patients. While most of the previous investigations chose the i.v. route for cytokine application, there is an increasing number of trials employing s.c. rIL-2 therapy. The comparison of reported response rates for i.v. versus s.c. therapy reveals no significant differences between these modalities. In an effort to describe systemic toxicities of s.c. cytokine therapy with regard to renal, metabolic, and hemodynamic abnormalities and to compare these effects to toxicities reported upon i.v. therapy, we retrospectively evaluated 148 treatment cycles of s.c. immunotherapy given to 107 outpatients. Our study cohorts consisted of 15 patients who received s.c. rIL-2 at doses of (4.8-14.4) x 10(6) IU m-2 day-1 5 days/week for a total of 8 weeks, 20 patients who received rIFN alpha 2b at (3.0-6.0) x 10(6) m-2 day-1 thrice weekly for a total of 6 weeks, and 72 patients who were given s.c. rILFN alpha 2b at 6.0 x 10(6) U/m2, three times per week, plus s.c. rIL-2 at (14.4-18.0) x 10(6) IU/m2 on days 1 and 2, followed by 4.8 x 10(6) IU m-2 day-1 5 days/week for 6 consecutive weeks. These treatment regimens were well tolerated in the outpatient setting; no toxic death occurred, and none of the patients developed life-threatening toxicity due to a capillary leak syndrome. Upon s.c. combination therapy, dyspnea at rest occurred in 6% of patients and grade III and IV hypotension occurred in 7% and 4%, respectively; plasma protein was significantly decreased (mean nadir +/- standard deviation, 67 +/- 5 g/l). In addition, s.c. therapy led to a significant increase in serum creatinine (mean peak +/- standard deviation, 115.1 +/- 21.4 mumol/l) and urea nitrogen (mean peak +/- standard deviation, 6.5 +/- 2.5 mmol/l); electrolyte disturbances and direct nephrotoxicity never caused major clinical symptoms. This was in marked contrast to a multitude of dose-limiting and life-threatening adverse reactions reported upon i.v. rIL-2 therapy. We conclude that palliative low to intermediate-dose s.c. rIL-2/rIFN alpha combination therapy, in contrast to i.v. treatment, can be administered in the ambulatory setting with good practicability and excellent safety. This outpatient regimen is as effective against metastatic renal cell cancer as the most aggressive i.v. rIL-2 protocol reported.

Modification of soluble immunological parameters during treatment with interleukin-2

In the present study we tested numerous soluble immunological parameters (soluble Interleukin 2 receptor, Beta 2 microglobulin, Neopterin, soluble CD8 antigen, gamma Interferon and alpha Tumor Necrosis Factor) in sera obtained from 18 advanced cancer patients during subcutaneous treatment with recombinant Interleukin 2. The treatment cycles consisted of a dose of 9 x 10(6) IU/m2 twice daily for 2 days followed by 1.8 x 10(6) IU/m2 twice daily for 5 days/week during 6 weeks. Even before therapy, neoplastic patients had higher levels of soluble Interleukin 2 receptor than a group of healthy subjects. Moreover, basal soluble CD8 antigen levels showed significant differences (p < 0.01) in patients with different clinical responses (responders and non-responders). During treatment we observed a fast increase (in the first or second week) of all parameters considered; soluble Interleukin 2 receptor and soluble CD8 antigen were the markers that were best related to the course of immunotherapy. In conclusion, monitoring recombinant Interleukin 2 immunotherapy with immunological parameters in serum seems to be of interest. However, more data are necessary to confirm the real value of the single markers.

Inpatient continuous-infusion interleukin-2 in 788 patients with cancer. The National Biotherapy Study Group experience

BACKGROUND

Interleukin-2 (IL-2), used alone or in combination with adoptive cellular therapy, is one of the most promising biologic therapeutic agents for cancer treatment.

METHODS

The National Biotherapy Study Group conducted 15 trials of continuous-infusion IL-2 involving 788 patients with cancer, 638 of whom were evaluable for tumor response. The protocols included administration of IL-2 and lymphokine-activated killer (LAK) cells, IL-2 and cyclophosphamide, IL-2 and tumor-infiltrating lymphocytes, IL-2 and alpha-interferon (IFN), IL-2 and tumor necrosis factor, and IL-2 and LAK alternating with combination chemotherapy.

RESULTS

Responses were detected in 33 of 188 patients (18%) with melanomas, 13 of 167 (8%) with renal cell carcinomas, and 1 of 76 (1%) with colorectal cancers. The median survival times in patients with melanoma and renal cell cancer were 9.6 and 9.3 months, respectively. The proportion of patients surviving 1 year were 35% and 43%, respectively. There were responses in 8 of 51 patients (16%) with lung cancer, but many of these patients received IL-2 and LAK alternating with platinum-based chemotherapy. Four of 23 patients (17%) responded who had breast cancer and received IL-2 and IFN. The protocols involving IL-2 plus adoptive cellular therapy produced a higher response rate than those not involving activated cells (48 of 312 [15%] versus 24 of 326 [7%], P = 0.003); however, there was no difference in survival. There was a 1.8% mortality rate attributed to the complications of IL-2 itself.

CONCLUSIONS

IL-2 produces durable tumor responses in some patients, especially in those with melanoma and renal cell carcinoma. Because the drug's toxicity is significant and the overall response rates are low, patient selection may be the most important factor in the clinical use of continuous-infusion IL-2 therapy.

Regression of bladder tumors in mice treated with interleukin 2 gene-modified tumor cells

This study explored the use of interleukin 2 (IL-2) and interferon gamma (IFN-gamma) gene-modified tumor cells as cellular vaccines for the treatment of bladder cancer. The mouse MBT-2 tumor used is an excellent model for human bladder cancer. This carcinogen-induced tumor of bladder origin resembles human bladder cancer in its etiology and histology, and responds to treatment in a manner similar to its human counterpart. Using retroviral vectors, the human IL-2 and mouse IFN-gamma genes were introduced and expressed in MBT-2 cells. The tumor-forming capacity of the cytokine gene-modified MBT-2 cells was significantly impaired, since no tumors formed in mice injected intradermally with either IL-2- or IFN-gamma-secreting cells, using cell doses far exceeding the minimal tumorigenic dose of parental MBT-2 cells. Furthermore, mice that rejected the IL-2- or IFN-gamma-secreting tumor cells became highly resistant to a subsequent challenge with parental MBT-2 cells, but not to 38C13 cells, a B cell lymphoma of the same genetic background. To approximate the conditions as closely as possible to the conditions prevailing in the cancer patient, inactivated cytokine-secreting cells were used to treat animals bearing tumors established by orthotopic implantation of MBT-2 cells into the bladder wall of the animal. Treatment of mice carrying a significant tumor burden with IL-2-secreting MBT-2 cells had a significant inhibitory effect on tumor progression with extended survival. Moreover, in 60% of the mice the tumor regressed completely and the animals remained alive and free of detectable tumor for the duration of the observation period. Treatment of tumor-bearing animals with IL-2-secreting MBT-2 cells was superior to the use of cisplatin, a chemotherapeutic agent used in the treatment of bladder cancer. The therapeutic effect of IFN-gamma-secreting cells was minimal and treatment with unmodified MBT-2 cells had no effect on tumor growth or survival, showing that the parental MBT-2 cells were nonimmunogenic in this experimental setting. Most importantly, mice that exhibited complete tumor regression after treatment with IL-2-secreting MBT-2 cells became resistant to a subsequent challenge with a highly tumorigenic dose of parental MBT-2 cells, indicating that long-term immunological memory was established in the "cured" mice.

Cardiotoxicity of human recombinant interleukin-2 in rats. A morphological study

BACKGROUND

One of the side effects of interleukin 2 (IL-2) cancer immunotherapy in humans is the vascular leak syndrome, which is frequently associated with depression of myocardial function, myocarditis, and myocardial necrosis.

METHODS AND RESULTS

To investigate this cardiotoxicity, IL-2 (three doses of 5 x 10(5) Cetus units/day i.p.) was given to rats for 2, 3, or 5 days. Heart, lung, liver, spleen, and kidney tissues were studied by light and electron microscopy and with immunoperoxidase techniques. Cardiac changes consisted of focal lymphocytic and eosinophilic infiltration, myocyte vacuolization, myofibrillar loss, and necrosis. Ultrastructural alterations included swelling of endothelial cells, with dissociation of intercellular junctions, migration of lymphocytes into the interstitium, and interstitial hemorrhage and edema. Close contact between infiltrating lymphocytes, particularly large granular lymphocytes, and cardiac myocytes was often observed in areas of tissue damage. All lesions were more severe on day 5 than on days 2 and 3. Immunoperoxidase stains demonstrated asialo GM1 ganglioside antibody-positive, granular lymphocytes to be much more frequent in myocardium of IL-2-treated rats than in that of control rats.

CONCLUSIONS

Although we cannot exclude the possibility of a direct toxic effect of IL-2 on myocytes, our observations suggest that the myocardial damage produced by this agent is triggered by IL-2-activated lymphocytes that exert cytolytic effects, first on endothelial cells and then on cardiac myocytes, thus producing lesions that involve both the cardiac microcirculation and the muscle cells.

Induction of cytotoxic lymphocyte subsets against leukemia by stimulation with AML blasts

Although the application of interleukin-2 (IL-2) activated lymphocytes in immunotherapy of acute myelogenous leukemia (AML) is of therapeutic interest, the high resistance of AML blasts to lymphocyte lysis may represent an obstacle to this type of therapy. However, our data shows that the leukemia resistance can be conquered by concomitant culture of lymphocytes with IL-2 and AML blasts. This approach induces not only leukemia-directed cytotoxic cells, but also promotes their growth. Additionally, multiple cytotoxic lymphocyte populations with leukemia lytic activity are induced in AML/IL-2 cultures. These include natural killer (NK) cells and subsets of T cells with both the major histocompatibility complex (MHC)-restricted and MHC-nonrestricted cytotoxic function. Thus, this protocol, which is conducive to general stimulation of cellular immune responses against leukemia, may enhance the benefits of lymphocyte therapy.

Intrapleural recombinant IL-2 in passive immunotherapy for malignant pleural effusion

The purpose of this phase 1 study was to determine the toxicity and effectiveness of recombinant interleukin-2 (RU 49637 Roussel Uclaf-France) administered by continuous pleural infusion for 5 days to patients with different histologic subtypes of pleural cancer. Incremental doses of rIL-2 from 3 x 10(6) to 24 x 10(6) were given via a thin catheter inserted into the homolateral pleural cavity. Patients were evaluated before treatment and 36 days after treatment by computed tomography scan and thoracoscopy with biopsy. Twenty-two patients with malignant pleural effusion (15 malignant pleural mesotheliomas, 6 adenocarcinomas, 1 squamous cell carcinoma) were treated. The maximum tolerated dose (MTD) of rIL-2, defined as the dose that produced grade 3 or greater toxic reactions in 50 percent of the patients, was 24 x 10(6) IU/m2/d. Although some side effects were encountered at any dose, tolerance was acceptable. The main side effect was fluid retention (8 of 22) which never exceeded 10 percent of body weight. Responses were achieved in 10 out of 22 patients with 1 complete remission (mesothelioma) and 9 partial remissions (3 adenocarcinomas and 6 malignant pleural mesotheliomas). Based on these results, we recommend that phase 2 studies using rIL-2 at a dose of 21 x 10(6) IU/m2/d via the intrapleural route be undertaken.

Interleukin-2 in combination with interferon-alpha and 5-fluorouracil for metastatic renal cell cancer

Recent clinical trials for the biological therapy of solid tumours have used recombinant human cytokines in combination with conventional chemotherapy. In patients with progressive metastatic renal cell carcinoma, we established a three-drug combination comprising interferon-alpha (IFN-alpha), interleukin-2 (IL-2) and 5-fluorouracil (5-FU), using a regimen which allows outpatient therapy. Treatment consisted of 8 weeks each of IFN-alpha [6-9 MU/m2 once to three times weekly subcutaneously (sc)] combined sequentially with IL-2 (5-20 MU/m2 thrice weekly sc for 4 weeks) and 5-FU [750 mg/m2 intravenously (i.v.) weekly for 4 weeks]. Among the first 35 patients treated, there were 4 complete (11.4%) and 13 partial responders (37.1%), with an overall objective response rate of 48.6% (95% confidence interval 32-66%). Regressions occurred in local relapse, in lung, lymph node, bone, pleural, renal and thyroid metastases. Median response duration was calculated at 7+ months. An additional 13 patients (37.1%) were stable throughout therapy and thereafter (median of 6+ months). Response rate of this three-drug combination regimen compared favourably with single agent IFN-alpha (objective response rate approximately 16%) and against the sc IFN-alpha/IL-2 combination (objective response rate approximately 28%). Systemic toxicity was mild to moderate with no severe 5-FU-related mucositis and no dose-limiting adverse effects of sc IL-2. While the exact mechanisms of the potentially additive or synergistic effects of 5-FU and IFN-alpha/IL-2 remain to be established in more detail, it appears that the sequential use of IFN-alpha/IL-2 and IFN-alpha/5-FU in metastatic renal carcinoma further enhances the therapeutic index of IFN-alpha/IL-2-based biological therapy. Based on the present data, combined biochemotherapy may be a promising new approach to the therapy of advanced renal cancer.

Subcutaneous recombinant interleukin-2 and alpha-interferon in patients with advanced renal cell carcinoma: results of a multicenter Phase II Study

A phase II multiinstitutional clinical trial was conducted to evaluate the safety and efficacy of the subcutaneous outpatient administration of recombinant human interleukin-2 and alpha-interferon in patients with progressive metastatic renal cell carcinoma. One hundred and forty-five patients were entered on this study between October 1989 and May 1991. Among 134 patients evaluable for treatment response, there were six complete (4.5%) and twenty partial (14.9%) responders, with an overall response rate of 19.4% (95% confidence interval, 13-26%). The median duration of complete remissions was 228 (range 51(+)-520+) days; the median duration of partial tumor regressions was calculated at 226 (range 112-473+) days. The overall median survival from start of therapy was 14.2 (range 1-23+) months. Fever, chills and general fatigue occurred in the majority of patients treated and were measured at grade II, III and IV in up to 55%, 24% and 3% of all evaluable patients, respectively. Three patients each developed grade III hypotension, dyspnea and diarrhea; two patients each had grade III and grade IV elevations of alkaline phosphatase; two and one patients respectively, exhibited grade III anemia and grade IV thrombocytopenia; two patients experienced severe cutaneous toxicity. The majority of patients received treatment in the outpatient setting. In summary, the outpatient use of subcutaneous interleukin-2 and alpha-interferon was effective in patients with advanced metastatic renal cell carcinoma; it was associated with less toxicity and thus, could improve the therapeutic index of interleukin-2 based biologic therapy when compared against high dose intravenous therapy.

Interleukin-2 in cancer treatment: disappointing or (still) promising? A review

The central question to discuss in this review is whether the results of interleukin-2 (IL-2) treatment are still disappointing or again promising. Although in the (recent) past application of high doses of systemically applied rIL-2 has led to some success, the overall results are not as one had hoped. Considering these poor results it seems clear that the application of high systemic doses rIL-2 was not a good choice. IL-2 has been used more or less as a chemotherapeutic compound in the highest tolerable dose. This has led to a great number of unwanted toxic side-effects. In addition, these doses mainly stimulated nonspecific lymphokine-activated killer activity through low-affinity IL-2 receptors, which does not lead to systemic immunity. On the other hand, several groups have shown that application of intratumoral low doses of IL-2 can be highly effective against cancer and without toxic side-effects. Significant tumor loads constituting up to 6% of the total body weight of a mouse were eradicated after treatment with low-dose rIL-2 given locally. Furthermore local treatment can lead to eradication of a tumor at a distant site. This type of therapy is effective in many systems namely against different tumor types in mice, hepatocellular carcinoma in guinea-pigs and vulval papilloma and carcinoma and ocular carcinoma in cattle. Low-dose IL-2 is very effective in experimental animals if it is given relatively late after inoculation of the tumor cells. In other words, it seems necessary that some sort of immune reaction has started or is developing before low doses of rIL-2 effectively stimulate it. In fact there is strong evidence that T lymphocytes, both CD4+ and CD8+ cells, are directly involved in the process leading to induction of specific immunity. In our opinion rIL-2 therapy should therefore aim at the stimulation of such (originally weak) specific immune reaction. Under these conditions also systemic immunity can be induced. In conclusion, application of rIL-2 as a modality for cancer treatment is still promising. High priority should be given to a further delineation of the mechanisms involved after local application. The method of giving IL-2 systemically in the highest tolerable dose should be abandoned. Specific stimulation of the immune system by low-dose rIL-2 is a much more promising option.

Symptom assessment and management of outpatients receiving biotherapy: the application of a symptom report form

Patients treated with high doses of biologic response modifiers (BRMs) often require hospitalization for monitoring and management of toxicities. However, with careful symptom assessment and management, patients can be treated safely with low-dose, long-term BRM regimens in an outpatient setting. Quantifiable, consistent, and accurate symptom assessment sets the groundwork for regular, effective symptom management. A symptom report form or nursing care flow sheet is a helpful daily assessment tool for recording and quantifying the most common side effects experienced by patients receiving BRMs. Parameters can be established and converted to a numerical code to provide a consistent guide for evaluating a patient's toxicities during treatment. Additional space on the report form allows for narrative comments about symptoms or concerns not addressed elsewhere. To be safe and effective, outpatient therapy of this kind requires excellent patient education and compliance, with easy access to a health care professional when necessary.

Clinical toxicity of interleukin-2

Interleukin-2 (IL-2) is increasingly used to treat patients with cancers refractory to conventional treatment. Flu-like syndromes are extremely frequent but usually mild. A variety of skin complications (mostly erythema and mucositis) have been reported. Life-threatening skin reactions have also been described. Acute reactivation of psoriasis can also occur. Immediate hypersensitivity reactions have so far not been described, but IL-2 treatment has been shown to predispose to acute hypersensitivity reactions to iodine-containing contrast media. Hypothyroidism is the major endocrine complication and antithyroid antibodies have been detected in approximately 50% of patients. Neurological and psychiatric disturbances with moderate or severe mental status changes are common and sometimes treatment-limiting. The occurrence of peritumoural oedema in patients with brain metastases can also be a major practical problem. Musculoskeletal disorders are transient and resolve spontaneously. The vascular leak syndrome is the most frequent and severe complication of IL-2 of which weight gain, generalised oedema, hypotension and impaired renal function are the main features. Even though a damaging effect on vascular endothelium cells by various cytokines released by activated lymphoid cells or mediated by non-lymphocyte-dependent factors has been proposed to be involved, the mechanism remains unclear. Other cardiovascular injuries, possibly life-threatening, including myocarditis, angina pectoris and myocardial infarction, can occur during the first days of treatment. Supraventricular arrhythmias are the most common rhythmic disorder. Decreases in myocardial contractility and haemodynamic pattern similar to those of septic shock have been encountered in most cases. Acute renal dysfunction is common but resolves with symptomatic management. Intrahepatic cholestasis with hyperbilirubinaemia is observed in most patients but permanent liver damage has not been described. Several cases of pancreatitis have been reported. Anaemia, thrombocytopenia, lymphocytopenia and eosinophilia are frequent and occur in most if not all patients. Some data suggest a high incidence of infectious complications, particularly in patients with surgically tunnelled catheters, but marked flu-like syndromes may be confounding. Finally, death directly related to IL-2 treatment has been noted in less than 1% of all patients. Investigations are under way to minimise IL-2 toxicity with varying dose regimens and combined treatments.

Oral changes in interleukin-2 treated patients: a preliminary report

Immunotherapy with high doses of interleukin-2 (IL-2) in patients with metastatic cancer is accompanied by multiorgan side effects. To determine the effect of this treatment on oral tissues, 5 cancer patients receiving a course of recombinant IL-2 (rIL-2) were followed. Oral pathology and subjective oral complaints were noted. Whole saliva parameters and routine blood and urine values were recorded daily before, during and after treatment. Mucositis and diminution of salivary flow occurred in all patients. Concomitantly, salivary sodium and protein were elevated.

Chest roentgenographic abnormalities in IL-2 recipients. Incidence and correlation with clinical parameters

The chest roentgenograms of 54 patients receiving high dose interleukin-2 with or without lymphokine-activated killer cell therapy for advanced cancer were retrospectively reviewed. Thirty-nine patients (72 percent) developed chest roentgenographic abnormalities consisting of pleural effusions, 28 (52 percent); diffuse infiltrates (pulmonary edema), 22 (41 percent); and focal infiltrates, 12 (22 percent). These abnormalities resolved in 30 of 39 (77 percent) patients by four weeks after therapy. Simple pleural effusions were the only residual roentgenographic abnormalities seen and were present primarily in patients receiving IL-2 by bolus intravenous injection (8 of 28) (29 percent) as compared to continuous intravenous infusion (1 of 24) (4 percent) (p = 0.03). Only roentgenographic evidence of pulmonary edema appeared to correlate with the degree of clinical pulmonary toxicity (p = 0.001). The development of chest roentgenographic abnormalities correlated with the administration of IL-2 solely by bolus intravenous injection (p = 0.04), a pretreatment FEV1 of less than 3 L (p = 0.04), and treatment associated bacteremia (p = 0.09), but not with prior therapy, the presence of pulmonary metastases or the degree of systemic capillary leak as measured by percentage of weight gain during therapy. Although the roentgenographic abnormalities did not relate to the number of LAK cells received, two patients developed sudden onset of dyspnea and chest roentgenographic evidence of pulmonary edema shortly after the first LAK cell administration, implying that a direct cause-and-effect relationship exists in some patients. Possible mechanisms for these IL-2 related chest roentgenographic abnormalities and pulmonary toxicity in general are discussed.

Tumour necrosis factor mediates the survival benefit of interleukin 2 in a murine pulmonary metastases model

Antibody to tumour necrosis factor (TNF Ab) markedly decreases the toxicity of systemic interleukin-2 (IL-2) in mice but does not completely abrogate the anti-tumour response in terms of number of pulmonary metastases. Experiments were performed with a murine model of pulmonary metastases treated with high-dose IL-2 and concomitant TNF Ab or control antibody (CON Ab) to determine the effects of TNF Ab on survival. Mice were given either equal doses of IL-2 and TNF Ab or CON Ab or equitoxic doses of IL-2. In four consecutive experiments mice given TNF Ab tolerated 5 to 6 additional IL-2 doses (a 40-60% increase in total doses) in the equitoxic IL-2 dose group compared to the maximally tolerated dose with CON Ab. In all four experiments TNF Ab-treated mice had decreased survival compared to the CON Ab group given equal doses of IL-2 and in two of four experiments this difference was statistically significant (P2 < 0.01). Mice given 40-60% additional doses of IL-2 with TNF Ab had no improvement in survival compared with equitoxic doses of IL-2 with CON Ab in three of four experiments (P2 = 0.32, P2 = 0.67, P2 = 0.69). The TNF Ab preparation had no direct inhibition of IL-2 activity in an in vitro IL-2 proliferation bioassay. TNF Ab consistently blocks IL-2 toxicity and it also abrogates IL-2 therapeutic efficacy such that survival parallels treatment toxicity in this experimental model.

Cytokines induce stress protein formation in cultured cardiac myocytes

Diseases accompanied by severe cardiac impairment like sepsis and chronic uremia are frequently linked to an increase in cytokine release. In order to investigate possible toxic effects of the immune mediators on myocardial cells, we studied the contractility of cardiac myocytes and the de novo formation of stress proteins in cultured heart cells under cytokine exposition. All cytokines investigated induce, concentration-dependently, arrhythmias and cessation of spontaneous contractions. Interleukin(IL)-2, IL-3, IL-6, and tumor necrosis factor (TNF) stimulate the synthesis of a 30 kD stress protein in heart cells, whereas IL-1 additionally evokes two proteins of the 70 kD family. These findings confirm a direct interference of the interleukins and TNF with myocytes and, especially, myocardial protein formation. As the induction of stress proteins makes cells more resistant towards a subsequent challenge, the cytokines are possibly involved in the activation of cell protecting mechanisms in cardiac myocytes.

Recombinant interleukin-2 in metastatic renal cell carcinoma--a European multicentre phase II study

This multinational, multicentre study represents the introduction of recombinant interleukin-2 (rIL-2) in Europe. From December 1987 to June 1989, 57 eligible patients with metastatic renal cell cancer were treated with rIL-2 administered as continuous intravenous infusion. 8 out of 51 evaluable patients responded (16%), 2 complete remission (CR) and 6 partial remission (PR). 10 patients had no change (20%). The response duration for CR was 209 and 394+ days. The median response duration for PR was 371 (range 140-506+) days. Dose-limiting grade 3-4 toxicities were hypotension in 52% of the patients, arrhythmia (4%), dyspnoea (8%), creatinine rise (4%), peripheral neurotoxicity (10%) and central neurotoxicity (10%). Toxicities most often recovered solely on interrupted therapy. 2 patients died due to catheter-related septicaemia and one patient died of rIL-2 induced renal failure. The study confirmed the antitumour efficacy of rIL-2 in renal cell cancer. Toxicities were numerous, but manageable by close observation in a normal oncology ward without routine use of an intensive care unit.

Haemodynamic effects of recombinant interleukin-2 administered by constant infusion

Adoptive immunotherapy with recombinant interleukin-2 (rhIL-2) has been reported to induce tumour regression in some patients with refractory cancer. However, the cardiovascular toxicity of bolus therapy requires invasive monitoring of patients in the intensive care unit (ICU). In an effort to examine the haemodynamic alterations caused by a constant infusion of IL-2, as opposed to bolus therapy, we studied the haemodynamic variables of 10 patients, with no evidence of heart disease, receiving 3 x 10(6) IU/m2 per day of rhIL-2 as a continuous infusion for 5 days. Measured and derived haemodynamic variables were obtained immediately prior to, at 2, 24, and 48 h during, and upon termination of the infusion. There was no evidence of clinical haemodynamic instability in these patients. Except for development of fever and tachycardia, there were no clinically significant differences in any measured or derived haemodynamic parameter. Moreover, continuous electrocadiographic monitoring of these patients during the infusion did not reveal any abnormalities. Invasive haemodynamic monitoring in an ICU is not necessary in carefully selected patients receiving constant infusion rhIL-2, at the described dose and schedule.

The out-patient use of recombinant human interleukin-2 and interferon alfa-2b in advanced malignancies

We studied the safety, tolerance, and clinical effects of the combined administration of subcutaneous recombinant human interleukin-2 and interferon alfa-2b in 54 patients with advanced cancer, for whom no effective standard therapy was available. Treatment courses consisted of a 2-day interleukin-2 pulse (14.4-18 million units (MU) m2/day), followed by 3.6 up to 4.8 MU/m2/day, 5 days per week, over 6 consecutive weeks and interferon alfa-2b at 3 up to 6 MU/m2, administered two-three times weekly for 6 weeks. Overall, patients received more than 90% of the projected dose of interleukin-2 and interferon alfa-2b, respectively. Of 54 evaluable patients (32 renal cell cancer, 12 melanoma, eight colorectal cancer, one B-cell lymphoma, one Hodgkin's disease), four complete responses occurred in patients with renal cell carcinoma, and a greater than 50% reduction in tumour size (partial response) in six renal cell carcinoma patients and one melanoma patient. Moreover, 21 patients (13 renal carcinoma) had stable disease. The median duration of response was 19 months (range 16-22 months) in complete responders. Clinical responses were associated with a mean peripheral blood eosinophil count of more than 1,000/microL (P less than 0.05 versus non-responders). Systemic toxicities included fever, chills, nausea, anorexia, and hypotension limited to WHO grades I and II in more than 80% of patients treated. No treatment-related deaths occurred. This combination of subcutaneously administered recombinant interleukin-2 and interferon alfa-2b has significantly diminished the side effects normally observed with high-dose intravenous recombinant interleukin-2, which requires admission to hospital. It has been shown to induce objective tumour regression in out-patients with progressive metastatic renal cell carcinoma and malignant melanoma.

Pulmonary capillary leak syndrome complicating generalized pustular psoriasis: possible role of cytokines

Two cases are reported of generalized pustular psoriasis complicated by profound alterations in pulmonary capillary permeability. Several features suggest the involvement of cytokines in the pathogenesis of this condition.

Acute renal failure with preserved renal plasma flow induced by cancer immunotherapy

Adoptive immunotherapy in patients with advanced cancer produces significant regression of metastatic disease in selected patients, but it is complicated by severe side effects. Prevention of these complications is still limited because their precise mechanisms remain unknown. For this reason we have investigated renal function and hemodynamic parameters in 16 patients with renal cell carcinoma before and during treatment with a combination of high doses of both recombinant interleukin-2 (rIL2) and recombinant alpha-interferon. After patients had received three injections of combined immunotherapy, there was a decrease in mean blood pressure (-20%), glomerular filtration rate (-25%), urine output (-50%), and fractional sodium excretion (-0.8%). This was associated with an increase in heart rate (+30%), plasma creatinine level (+30%), fractional potassium excretion (+14%) and microalbuminuria (+130%). However, renal plasma flow remained constant. The increment in microalbuminuria may reflect an alteration of glomerular capillary permeability. The reduction in GFR may be accounted either for a decrease in efferent to afferent arteriolar resistance ratio, leading to a decrease in glomerular capillary pressure, or for a decrease in ultrafiltration coefficient, or both. Nonsteroidal antiinflammatory drugs, such as ketoprofen, used to minimize side effects, could considerably worsen renal function and should be avoided in patients treated by rIL2. Our results bring new insights into the pathogenesis of functional acute renal failure and provide a rational basis for the use of vasopressors in the treatment of cytokine-induced acute renal failure.

Clinical use of biologic response modifiers in cancer treatment: an overview. Part II. Colony-stimulating factors and interleukin-2

Colony-stimulating factors (CSFs) are hematopoietic growth hormones that stimulate the production, maturation, and function of white blood cells. The best studied are granulocyte-macrophage CSF (GM-CSF) and granulocyte CSF (G-CSF), both of which can be produced by recombinant DNA technology. Clinical indications for these agents include bone marrow failure secondary to administration of chemotherapeutic drugs or radiation, bone marrow transplantation, and a variety of congenital or iatrogenic neutropenias. Toxicity in usual clinical doses is mild, and consists mainly of bone pain and constitutional symptoms such as fever, headache, and myalgias. Interleukin-2 (IL-2) is a lymphokine that stimulates that multiplication of several types of killer cells. These cells can recognize and destroy foreign substances, such as tumors, without destroying normal cells. Major applications of IL-2 include treatment of patients with renal cell carcinoma, in whom the overall objective response rate is 15-30 percent, and malignant melanoma with response rates of about 18 percent. Combination therapy with other biologics and conventional cytotoxic drugs may increase IL-2's efficacy against these tumors. Toxicity is generally severe, but reversible. Hemodynamic toxicity, consisting of hypotension, edema, weight gain, and decreased renal function, is most characteristic. Suggestions are given for pharmacologic management of these and other IL-2 toxicities.

The immunotherapy of human cancer with interleukin 2: present status and future directions

Interleukin-2 (IL-2) is the principal soluble factor responsible for the proliferation of activated T cells. In animal models and humans, administration of IL-2 can induce regressions of established cancers. These antitumor effects may be partially mediated by cytotoxic effector cells activated by IL-2, including lymphokine-activated killer (LAK) cells and cytotoxic T lymphocytes. IL-2 has additional effects on other components of the cellular immune system, including B cells and macrophages, and induces secretion of other soluble mediators, including tumor necrosis factors (TNF) alpha and beta, and interferon-gamma. These effects may contribute to the antitumor activity of IL-2 as well as its dose-related toxicity. Multiple Phase I and II trials have been completed or are ongoing evaluating the clinical and biological effects of IL-2 given by diverse routes and schedules, both alone and in combination with infusions of ex vivo IL-2-activated autologous LAK cells. Other studies have begun to explore the potential for antitumor synergy when IL-2 is combined with the different interferons, TNF, monoclonal antibodies, and cytotoxic drugs. The biology, toxicity, and clinical activity documented in IL-2 clinical trials to date are reviewed, and prospects for future directions outlined.

New therapeutic modalities for cancer

A review is given on new biological approaches to cancer therapy based on knowledge concerning interferons, interleukins. LAK-cells, tumour-infiltrating lymphocytes, tumour necrosis factor, colony-stimulating factors, monoclonal antibodies and oncogenes. There are many potential permutations for the application of biological therapy for cancer. One of the most important developments has been the increased understanding of the molecular mechanisms of malignancy through which biological manipulation can be tailored to an individual tumour. Although current clinical studies are not demonstrating high response rates they may well be analogous to the advances seen with chemotherapy in its early days. As yet only relatively small numbers of patients have had access to, or been suitable for, treatment. With further refinements in production, administration, and an increase in the specificity of treatment, the possibility of curing metastatic solid tumours may become a reality.

Interleukin-2 enhances the release of endothelin-1 from the rat mesenteric artery

We measured the ET-1 concentration in plasma and in the perfusate of the mesenteric arteries of rats treated with a therapeutic dose of IL-2 for 7 days (100000 U/Kg, iv.). The plasma ET-1 concentration in rats given IL-2 was 14.2 +/- 3.2 pg/ml which was significantly greater than that in the controls (2.5 +/- 0.4 pg/ml, P less than 0.05). The mesenteric arteries also released a significantly greater amount of ET-1 (29.5 +/- 1.6 pg/h) than that in controls (16.8 +/- 2.3 pg/h, P less than 0.01). The arterial blood pressure was significantly lower after IL-2 treatment than the pre-dosing level (P less than 0.05). It is concluded that IL-2 induces ET-1 release from the vascular wall, possibly as a result of reversible endothelial dysfunction caused by IL-2.

Rationale for immunotherapy of renal cell carcinoma

Metastasis to distant organs is the principal cause of death from renal cell carcinoma (RCC). No commonly accepted therapy is available for disseminated RCC at present. Immunotherapy is a mode of therapy that either interferes with the immune system or makes use of drugs that have been derived from soluble mediators of the immune system. Several lines of evidence suggest that combinations of genetically engineered cytokines (e.g. interleukin-2 and interferon alpha) may be particularly active in the treatment of advanced RCC. There are two major rationales for considering immunotherapy for RCC: (1) there is currently no other therapy available, and (2) there is hardly any innovative approach besides immunotherapy. Still, immunotherapy is far from being a standard therapy for disseminated RCC.

Myocarditis or acute myocardial infarction associated with interleukin-2 therapy for cancer

The hearts of eight patients aged 22 to 67 years (mean, 41 years) who died during or within 4 days of interleukin-2 (IL-2) based immunotherapy for treatment of renal cell carcinoma or melanoma were studied at necropsy. Death resulted from combined cardiorespiratory failure in two patients, sepsis in four patients, acute myocardial infarction in one patient, and myocarditis in one patient. Transmural left ventricular necrosis was present in one of the two patients with significant atherosclerotic coronary artery narrowing. Noninfectious myocarditis was present in five patients: the inflammatory infiltrate was lymphocytic in four and composed of a mixture of eosinophils and lymphocytes in one. Although treatment-related deaths associated with high-dose IL-2 therapy are uncommon (1.5% in 652 consecutive patients), the potential for significant myocardial ischemia or myocarditis exists, and careful monitoring for arrhythmias or myocardial failure is warranted.

Biologic response modifiers: the future of cancer therapy?

The major shift today has been away from nonspecific compounds acting on immune mechanisms to using biologics which have specific, defined roles in acting on the immune response. The field of biologic response modification is progressing very rapidly. New peptides are being identified, as are receptors for these peptides, autocrines, lymphokines, cytokines, growth factors, differentiation factors, hormones, and so on-all of which will control body function, cell populations, and cell to cell interactions. This rapidly advancing area of research in cancer biology and cancer therapy may hold the key to the future of successful therapy.

Mechanisms of immunologic antitumor therapy: lessons from the laboratory and clinical applications

The use of interleukin 2-based immunotherapies for cancer has been associated with significant responses in tumor models in both mouse and humans. Further definition of the elements responsible for response is now possible. It appears that the response is associated with T-cell infiltration of the tumor, and transfer of tumor-infiltrating lymphocytes expanded in tissue culture with interleukin 2 is associated with significant antitumor effects. Further expansion of cultured human melanoma tumor-infiltrating lymphocytes with suppression of lymphokine-activated killer activity as well as the modulation of monocyte activity by interleukin 4 suggests that this cytokine may be clinically useful alone or in combination with interleukin 2. Other means of enhancing the activity of interleukin 2-based immunotherapy are suggested by the finding that tumor cell susceptibility to lysis by natural killer cells is depressed following treatment with interferon gamma and tumor necrosis factor, but susceptibility to lysis by tumor-infiltrating lymphocytes is markedly enhanced. Further development of these therapies will require innovative interpretation and application of findings related to the processing and presentation of human tumor antigens and the nature of tumor antigens and careful analysis of the T-cell receptor in antitumor effectors.

Pathologic findings associated with interleukin-2-based immunotherapy for cancer: a postmortem study of 19 patients

The use of interleukin-2 (IL-2), either alone or in combination with lymphokine-activated killer cells, tumor infiltrating lymphocytes, or other immunotherapeutic agents has added a new list of alternatives to conventional antineoplastic regimens. Little information is available about the pathologic changes occurring in patients treated with these agents. In this study, we reviewed the necropsy materials from 19 patients, 12 men and 7 women, with a variety of malignancies including melanoma, renal cell carcinoma, gastrointestinal and pulmonary adenocarcinoma, and metastatic gastrinoma, who died after receiving IL-2-based immunotherapy. Death occurred at intervals ranging from less than 1 hour to 143 days following the last dose of therapy. All patients dying at or less than 43 days following cessation of therapy had lymphoid infiltrates of varying intensity in residual tumor. At necropsy, the major cause of death unrelated to the presence of metastatic tumor was bacterial sepsis. In addition, we found evidence of significant cardiac and pulmonary toxicity: two patients with acute myocardial infarction, one with and one without significant coronary artery disease, two cases of unexplained lymphocytic myocarditis, and one case of fatal pulmonary capillary plugging following an infusion of lymphokine-activated killer cells. Thus, not unlike other forms of therapy for cancer, IL-2-based immunotherapy does not appear to be without significant toxicity.

Haemodynamic effects induced by intravenous administration of high doses of r-Met Hu IL-2 [ala-125] in patients with advanced cancer

We analyzed the haemodynamic effects of high doses of r-Met Hu IL-2 [ala-125] in four patients with advanced cancer. Haemodynamic parameters were measured daily from days 1 to 6 of treatment. Mean arterial pressure decreased significantly (98 +/- 11 mmHg on day 1 versus 84 +/- 7 mmHg on day 5; p = 0.0435) as did systemic vascular resistance (2042 +/- 296 dynes s cm-5 m-2 on day 1 versus 1166 +/- 87 dynes s cm-5 m-2 on day 5; p = 0.003). There was a significant increase in mean pulmonary artery pressure (13.25 +/- 3.30 mmHg on day 1 versus 20.75 +/- 7.41 mmHg on day 5; p = 0.03), systemic oxygen consumption (173.5 +/- 37.8 ml min-1 m-2 on day 1 versus 257.8 +/- 20.5 ml min-1 m-2 on day 5; p = 0.02) and cardiac index (3.86 +/- 0.58 l min-1 m-2 on day 1 versus 5.77 +/- 0.21 l min-1 m-2 on day 5; p = 0.008). There was no significant decrease in the arteriovenous oxygen content difference (4.5 +/- 0.8 ml dl-1 on day 1 versus 4.46 +/- 0.22 ml dl-1 on day 5). Increases in oxygen delivery (570 +/- 163 ml min-1 m-2 on day 1 versus 750 +/- 109 ml min-1 m-2 on day 5 and oxygen extraction ratio (29.95% +/- 6.37% on day 1 versus 34.60% +/- 4.35% on day 5) were not statistically significant. We concluded that the haemodynamic effect induced by high doses of r Hu-IL-2 is similar to that seen in septic shock.

Cancer, cytokines, and cytotoxic cells: interleukin-2 in the immunotherapy of human neoplasms

Modern immunotherapy of human cancer has evolved as a rapidly expanding field of clinical and experimental research. Employing the systemic application of recombinant interleukin-2 (IL-2) in humans, Rosenberg and colleagues from the National Cancer Institute reported the regression of advanced metastatic tumors in approximately 10%-30% of patients treated. The additional adoptive transfer of autologous patient-derived activated lymphocytes was performed to enhance therapeutic efficacy. While the exact mechanisms of IL-2 based immunotherapy in cancer remain unclear, it has been hypothesized that both the IL-2 activated lymphocyte and its secretory products such as interferon-gamma or tumor-necrosis factor beta may contribute to the lysis of tumor cells in vivo. Accordingly, research has been directed toward enhancing both the activation state and the specificity of IL-2 induced killer cells in humans. Based on in vitro and animal data, the retransfusion of tumor-infiltrating lymphocytes has been shown to mediate the regression of metastatic neoplasms in up to 50% of patients receiving systemic IL-2. Considerable toxicity from the use of high-dose IL-2 has prompted attempts to develop low-dose regimens which allow for the outpatient treatment of patients presenting poor prognosis. While in most clinical trials involving IL-2, patient follow-up has been short, and no or only limited data have become available from controlled prospective and randomized clinical studies, IL-2 has shown some promise in patients with metastatic renal cell cancer or malignant melanoma. Novel approaches toward the improvement of clinical efficacy of IL-2 include local (e.g., intracavitary) application or combinations with other cytokines such as interferon-alpha or cytostatic drugs.

Passive immunization against tumor necrosis factor partially abrogates interleukin 2 toxicity

Passive immunization against TNF allowed non-tumor-bearing C3H/HEN mice and tumor-bearing C57BL/6 mice to tolerate significantly more doses of IL-2 before death (p less than 0.005 and p less than 0.001, respectively). The antitumor effect of IL-2 against both 3-d and 10-d pulmonary metastases was maintained in mice treated concurrently with neutralizing antibodies to TNF. In one experiment with 10-d pulmonary metastases, increased administration of IL-2 made possible by passive immunization against TNF significantly improved the antitumor response compared to equitoxic doses of IL-2 and control antibody. The results indicate that TNF is a mediator of IL-2 toxicity but contributes minimally to the antitumor effects of IL-2. Strategies to inhibit TNF may improve the therapeutic index of IL-2 as a neoplastic agent.

Biological approaches to cancer therapy

Advances in the biological approach to cancer therapy are reviewed. The mechanisms of actions, clinical effects and uses of interferons, the first biological modifiers to be used, are reviewed first. The interleukins and monoclonal antibodies are also mentioned in detail. This review also covers the clinical use and production of lymphokine activated killer cells, which are used in conjunction with interleukin-2. A brief review of tumour infiltrating lymphocytes, which comprise a subset of lymphocytes found within solid tumours is given. In mice, tumour infiltrating lymphocytes have been shown to be more therapeutic than lymphokine activated killer cells. Tumour necrosis factor, a protein released by activated macrophages in response to stimulation by endotoxin, is also briefly mentioned although clinical data are disappointing. Finally, the role which oncogenes may play in cancer therapy and understanding is discussed.