Low-dose cyclophosphamide and low-dose interleukin-2 for malignant melanoma

We have studied the effects of low-dose recombinant interleukin-2 preceded by low-dose cyclophosphamide on malignant melanoma. Thirty eight outpatients aged from 25 to 75 years were treated with interleukin-2, 3.6 million Cetus units/m2 i.v. daily for five days on two successive weeks beginning three days after 350 mg/m2 of intravenous cyclophosphamide. This schedule was repeated at least twice more with a one-week interval between cycles, usually at the same dosage level. Ten of the 38 patients (26.3%) had clinically significant remissions: two complete (5.3%), seven partial (18.4%), and one ongoing, long-term (greater than 18 mo) "minor" response (2.6%). Four others (10.5%) had shorter minor responses and four (10.5%) a mixed response. One patient with disease restricted to the skin had a complete remission, while the other patient with a complete remission had had three lung nodules and an enlarged hilar lymph node. It was gratifying that one of the major sites of disease responding to treatment was the liver. Two complete and two partial remissions (i.e., greater than 50% regressions for greater than four weeks at this site) were obtained in 10 patients with liver involvement. Lung metastases also responded in four of 16 patients (one complete and three partial remissions). Subcutaneous nodules responded in seven of 21 patients (two complete, five partial remissions), while lymph node metastases diminished significantly in four of 14 patients (one complete, three partial remissions). The median duration of response was nine months (range, 1.5-20 months), with four patients treated for more than one year. Toxicity was moderate and controllable, and only two patients required hospitalization, both overnight. Lymphokine activated killer cell activation was induced in 24 of 38 patients, including all nine of the major responders. Conversely, none of 14 patients without lymphokine activated killer cell activation had a significant clinical remission. This regimen appeared to be as effective in melanoma as those involving ex vivo activation of lymphokine activated killer cells, and was more tolerable than therapy with high doses of interleukin-2.

Active specific immunotherapy for melanoma: phase I trial of allogeneic lysates and a novel adjuvant

A Phase I trial of active specific immunotherapy for melanoma was performed to measure the toxicity and immunological effects of the therapy. A mixture of mechanical lysates (homogenates) of two melanoma cell lines was injected together with a novel adjuvant, DETOX, into 22 patients. Several types of cell-mediated and humoral immunity to melanoma-associated antigens were measured serially. In the 17 patients with measurable disease, the sizes of lesions were also noted serially. At least six patients per group were injected s.c. with either 100, 200, or 400 antigenic units (approximately 10, 20, and 40 million tumor cell-equivalents) of the lysates mixed with 0.25 ml of DETOX s.c. on weeks 1, 2, 3, 4, and 6. Three patients at each dose level also received 300 mg/m2 of cyclophosphamide i.v. 4 days before the start of immunization. Evidence for successful immunization was obtained in 13 of the 22 patients. An increase in the frequency of peripheral blood cytolytic lymphocyte precursors reacting against melanoma cells occurred in 12 patients, as measured by a limiting dilution assay involving in vitro re-exposure to irradiated melanoma cells for 9-10 days. Eight of the 12 patients had received cyclophosphamide. By cold-target competition assays, these cytolytic lymphocytes appeared to be atypical T-cells, which recognized melanoma-associated antigens on several allogeneic lines without apparent major histocompatibility complex restriction. An increase in antibody titers against melanoma-associated antigens, measured by enzyme immunoassay, was found in five of 22 patients, and a change in delayed hypersensitivity against the melanoma lysate, in three patients. Responses were found at all three dosage levels of lysate, without an obvious dose optimum. No toxicity except minor local soreness was noted. Therefore, no maximum tolerable dose was defined. Five of 17 patients with measurable lesions had a remission of their melanoma, two complete and three partial, with three additional minor responses. A patient whose complete remission lasted 5.5 months, has no evidence of disease 22+ months after entry onto the study, with the aid of surgical resection of small s.c. recurrences on two separate occasions. Sites of regression included s.c. nodules, lymph nodes, and pulmonary nodules, with no responses in liver, adrenal gland, or bone. The patients who had an increase in cytolytic lymphocyte precursors comprised all eight with a clinical remission (five major, three minor). In contrast, none of the seven patients lacking an increase in cytotoxic lymphocytes had a clinical response.(ABSTRACT TRUNCATED AT 250 WORDS)

Effectiveness and tolerability of low-dose cyclophosphamide and low-dose intravenous interleukin-2 in disseminated melanoma [corrected]

We studied the effects on melanoma of low-dose recombinant interleukin-2 (IL-2) preceded by low-dose cyclophosphamide (CYC). Twenty-seven outpatients, aged 25 to 75 years, were treated with IL-2, 3.6 million U/m2 intravenously (IV), daily for five days on 2 successive weeks beginning three days after 350 mg/m2 of IV CYC. This schedule was repeated at least twice more at 1-week intervals. Six of 24 patients (25%) who received more than one 2-week cycle of treatment had a remission, one complete and five partial, with minor responses in eight others (33.3%). Three patients with rapidly progressive disease, who received only one cycle, were excluded from the analysis of response. The responses comprised remissions of liver metastases in two patients, one of them complete, two complete and two partial regressions of subcutaneous metastases, partial remission of lymph node metastases, and a partial remission of lung nodules. The mean duration of response exceeded 5 months, with two patients treated for greater than 1 year. Toxicity was moderate and controllable and only two patients required hospitalization, both overnight. Lymphokine-activated killer (LAK) cell activation was induced in 17 of the 24 patients, including all six responders, while none of seven patients without LAK activation had a remission. This regimen appeared to be as effective in melanoma as those involving ex vivo activation of LAK cells, and was generally tolerable to patients in all age groups.

Pulmonary vascular obstruction in severe ARDS: angiographic alterations after i.v. fibrinolytic therapy

IV streptokinase was infused to test the potential reversibility of adult respiratory distress syndrome (ARDS) associated pulmonary vascular thrombosis in five patients suffering from severe ARDS with elevated mean pulmonary artery pressure, increased pulmonary vascular resistance, and angiographically documented pulmonary vascular thrombosis. At 48 hr there was clearance of obstructions in arteries larger than 1 mm in diameter in all patients, increased filling of the microvasculature and small arteries less than 1 mm in diameter in four patients, a fall in pulmonary vascular resistance in all patients, a rise in cardiac output in four patients, improved oxygenation (PAO2/FlO2) in three patients, and variable changes in shunt fraction and ventilator pressures. Expressed as a mean fraction of the preinfusion controls, the postinfusion physiologic values were pulmonary artery pressure = 0.89 mm Hg, pulmonary vascular resistance = 0.68 mm Hg X min/L, cardiac output = 1.36 L/min, central venous pressure = 0.77 cm H2O, pulmonary capillary wedge pressure = 0.92 mm Hg, PAO2/FlO2 = 1.08, and shunt fraction = 0.95. Follow-up angiography showed no evidence of reocclusion. Postmortem studies of the three nonsurvivors confirmed recanalization of thrombosed pulmonary arteries. One documented bleeding episode occurred. We conclude that fibrinolytic infusion can lyse thrombi and possibly improve hemodynamics and oxygenation in ARDS-associated pulmonary vascular thrombosis.

Influence of local anesthetics upon human polymorphonuclear leukocyte function in vitro. Reduction of lysosomal enzyme release and superoxide anion production

Cationic local anesthetics have been reported to influence cellular responses to surface stimuli by interfering with the function of microtubules and microfilaments. Since unimpaired microtubule and microfilament functions are required by human polymorphonuclear leukocytes in order to respond normally to surface stimulation, we have studied effects of the local anesthetic, tetracaine on the function and morphology of these cells in vitro. Tetracaine (0.25--1.0 mM) significantly reduced extracellular release of the lysosomal enzymes, beta-glucuronidase and lysozyme from polymorphonuclear leukocytes exposed to serum-treated zymosan (a particulate stimulus), zymosan-treated serum (a soluble stimulus), and to the surface-active lectin, concanavalin A. Tetracaine also significantly reduced superoixde anion production (superoxide dismutase-inhibitable cytochrome c reduction) by these cells. Tetrancaine was not cytotoxic and its effects could be reversed completely by washing cells once with buffer. Electron microscope examination of tetracaine-treated cells revealed marked alterations of surface membranes. Microtubules and microfilaments appeared normal in "resting" polymorphonuclear leukocytes, but the increase in microtubules normally observed in stimulated cells was not seen after tetracaine treatment. These results suggest that tetracaine interferes with those interactions between immune reactants and the polymorphonuclear leukocyte cell surface which provoke exocytosis and increased oxidative metabolism.

Evidence that the superoxide-generating system of human leukocytes is associated with the cell surface

Superoxide anion (O-2-) generation by human peripheral blood polymorphonuclear leukocytes is enhanced when these cells encounter appropriate soluble or particulate stimuli. O-2- generation requires intact, viable cells and proceeds independently of phagocytosis. To investigate the possibility that the O-2--generating system is associated with the outer surface of the polymorphonuclear leukocyte plasma membrane, we have examined the effects upon O-2- production of p-diazobenzenesulfonic acid, a reagent which can react predominantly with proteins of the external cell membrane. When normal human polymorphonuclear leukocytes were preincubated with cytochalasin B (to minimize endocytosis) and then exposed to the surface-active lectin, concanavalin A, the cells were stimulated to generate O-2- in a concentration- and time-dependent fashion and selectively to discharge the granule-associated enzyme, lysozyme, into the surrounding medium. These responses, as well as cellular binding of [H] concanavalin A, could be blocked by alpha-methyl-D-mannoside. Brief treatment (less than 5 min at 4 degrees C) of the cells with p-diazobenzenesulfonic acid (1.0-5.0 mM) significantly interfered with concanavalin A-mediated O-2- generation but had no influence upon lysozyme release or upon binding of [3H] concanavalin A. The diazonium salt did not alter cell viability or the specific activity of the cytoplasmic enzyme, lactate dehydrogenase (inhibitable under conditions which allowed entry of this reagent into the cytosol). p-Diazobenzenesulfonic acid, therefore, very likely exerted its effects at the cell surface of the intact polymorphonuclear leukocyte, selectively inhibiting O-2- production (either directly or indirectly) without influencing another response to lectin-cell contact: release of lysozyme. These results support the possibility that a polymorphonuclear leukocyte ectoenzyme is responsible for O-2- production.