Trans-ungual Delivery of AR-12, a Novel Antifungal Drug.

AR-12 is a novel small molecule with broad spectrum antifungal activity. Recently, AR-12 was found to be highly active against Trichophyton rubrum, one of the predominantly responsible organisms that cause onychomycosis. The primary objective of this project was to investigate the ability of AR-12 to penetrate into and across the human nail plate followed by improving its trans-ungual permeation using different penetration enhancers. TranScreen-N™, a high throughput screening method was utilized to explore the potential nail penetration enhancers to facilitate the drug delivery through the nail. This screen demonstrated that dexpanthenol and PEG 400 were the most efficient enhancers. The in vitro permeation studies were performed across the human cadaver nail plates for 7 days with three AR-12 (5% w/v) formulations containing 10% w/v dexpanthenol (Formulation A), 10% w/v PEG 400 (Formulation B), and a combination of 10% w/v dexpanthenol + 10% w/v PEG 400 (Formulation C). The in vitro studies concluded that dexpanthenol and PEG 400 were able to deliver a significant amount of AR-12 into and across the nail plate that was found to be more than MIC 50 level of the drug.

Escalated MVAC with or without recombinant human granulocyte-macrophage colony-stimulating factor for the initial treatment of advanced malignant urothelial tumors: results of a randomized trial.

PURPOSE: Hematopoietic growth factors have been shown to ameliorate the side effects of chemotherapy. Here we assess the ability of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) to increase the dose-intensity and reduce the side effects of escalated methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) chemotherapy. PATIENTS AND METHODS: A prospective randomized trial to compare escalated MVAC versus escalated MVAC with rhGM-CSF was conducted. All patients were treated at The University of Texas M.D. Anderson Cancer Center (UTMDACC) and had a metastatic or unresectable urothelial tumor. Forty-eight patients were randomized (25 to MVAC with rhGM-CSF and 23 to escalated MVAC alone). The clinical characteristics of the study populations were similar (ie, degree of tumor dissemination and performance status). RESULTS: The dose-intensity in the two arms of the study did not differ significantly. No difference in the frequency of bacteriologically documented infections occurred between the two study arms. CONCLUSION: The use of the hematopoietic growth factor rhGM-CSF did not result in an increased dose-intensity of escalated MVAC. The inability to increase the dose-intensity of MVAC further was a result of nonhematologic side effects of the chemotherapy. Escalation of treatment delivered at its median-tolerated dose is unlikely to result in additional therapeutic benefit for patients with common solid tumors. Future development of therapy may require the development of new agents or concepts, rather than modification of existing therapies.

A phase I study of recombinant human interferon alpha-2b combined with 5-fluorouracil and cisplatin in patients with advanced cancer.

To determine the maximum tolerated dose (MTD) of escalating doses of interferon-alpha-2b (IFN, Intron A) with 5-fluorouracil (5-FU) and cisplatin (DDP) in patients with advanced cancer, 15 patients were accrued between May 1990 and July 1991. Primary sites were unknown (3), colorectal (3), head and neck (2), lung (2), gynecologic (1), gallbladder (1), sarcoma (1), anal canal (1) and pancreas (1). IFN was given s.c. on days 1-5 and then three times weekly with DDP (75 mg/m2, day 1) and 5-FU [750 mg/m2, days 1-5, continuous infusion (CI) on a 28-day cycle. The first two patients treated at level I (3 x 10(6) U/m2 s.c.) experienced possible neurotoxic deaths [massive cerebrovascular accident (CVA) and metabolic encephalopathy], and patient 3 had a grade 4 toxicity of performance status decline. Analysis of these events led us to exclude the enrollment of patients on i.v. morphine and of those with prior exposure to DDP. This resulted in grade 3 toxicity in terms of nausea, vomiting, fatigue and leukopenia but in no further CNS event. All patients were evaluable for toxicity but only ten were evaluable for response. Only two partial responses were seen, one in a patient with an unknown primary tumour and one in a patient with head and neck cancer. The combination of IFN is possible with 5-FU and DDP. The recommended dose of IFN is 2 x 10(6) U/m2 s.c. in patients with no prior exposure to DDP or i.v. morphine, given together with 5-FU (750 mg/m2, days 1-5, CI) and DDP (75 mg/m2, day 1) on a 28-day cycle.

Phase I study of tumor necrosis factor plus actinomycin D in patients with androgen-independent prostate cancer.

Based on preclinical studies which reveal enhanced antitumor activity of tumor necrosis factor (TNF) when combined with actinomycin D in human prostate cancer cell lines, we performed a phase I clinical study combining TNF and actinomycin D. All patients had metastatic prostatic carcinoma exhibiting androgen-independent growth. Patients were treated with a combination of a short infusion of actinomycin D followed by a TNF infusion daily for five consecutive days. Soluble TNF receptor p60 was not modulated by treatment but p80 receptor increased significantly following treatment with a combination of TNF and actinomycin D (baseline median 3.4 ng/ml) range 2.5-6.6 ng/ml follow up (9.3 ng/ml) range 6-24 ng/ml. We concluded that the maximum tolerated dose of continuous infusion TNF and short infusion actinomycin D is 400 micrograms/m2 of actinomycin D and 400 micrograms/m2 of TNF. The increased soluble receptor isoform (p80) may account for the lack of clinical activity seen in this trial. Should these results be confirmed, a strategy focused on overcoming the upregulation of the TNF soluble receptor will be required before further study of TNF should be considered.

Phase II trial of low dose gamma-interferon in metastatic renal cell carcinoma.

We conducted a phase II trial to confirm the activity of fixed, low dose gamma-interferon in metastatic renal cell carcinoma. A total of 35 patients with metastatic renal cell carcinoma, who had not received prior immunotherapy and who had a Zubrod performance status of 2 or less, was enrolled in this study. Primary tumors were controlled by nephrectomy or embolization before treatment began. gamma-Interferon was administered weekly as a subcutaneous injection at a fixed dose of 100 micrograms. Toxic effects were limited to low grade fever, chills and myalgias within 24 hours of injection. There were no incidences of grade 3 or 4 toxicity. Responses could be evaluated in 34 patients. There were 1 complete and 4 partial responses, for an objective response rate of 15% (95% confidence interval 5 to 32%). Durations of response to date are 21+, 17+, 13+, 9 and 2 months. We conclude that gamma-interferon is an active agent for metastatic renal cell carcinoma when administered according to this dose and schedule. The response rate compares favorably with those of alpha-interferon and interleukin-2, and toxicity is minimal. gamma-Interferon has excellent potential for use in combination with other biological or chemotherapeutic agents and in the adjuvant setting.

5-Fluorouracil and interferon-alpha in chemotherapy refractory bladder carcinoma: an effective regimen.

Seventy-seven patients with metastatic transitional cell carcinoma of the bladder who were unable to receive primary Cisplatin-based therapy or failed primary chemotherapy received one of three sequential 5-Fluorouracil-based salvage regimens: a) 5-Fluorouracil (1000 mg/m2 B.S.A. x 5 days) and Mitomycin-C (14 mg/m2 B.S.A. 6 week intervals), b) 5-Fluorouracil (750 mg/m2 B.S.A. x 5 days) and a-Interferon (5 miu/m2 B.S.A. daily x 5 then 3 times a week (TIW), c) 5-Fluorouracil (500 mg/m2 B.S.A. x 5 days), a-Interferon (5 miu/m2 B.S.A. x 5 days then TIW) and 13-Cis Retinoic Acid in escalating doses daily. Only 1 (6%) of the patients with regimen A responded, whereas 9 (30%) of the patients with regimen B and 8 (27%) in regimen C responded. Although all responses were partial remissions, responses were seen in patients with advanced and initially refractory transitional cell carcinomas. This data reveals that a-Interferon and 5-Fluorouracil is an effective combination in the treatment of metastatic transitional cell carcinoma and worthy of further study.

Phase II study of ketoconazole combined with weekly doxorubicin in patients with androgen-independent prostate cancer.

PURPOSE: A phase II clinical trial was performed to assess the antitumor activity and toxicity of ketoconazole in combination with doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH) in patients with androgen-independent prostate cancer (AI PCa). PATIENTS AND METHODS: Thirty-nine consecutive patients whose disease progressed following castration were treated with oral ketoconazole (1,200 mg) daily and Adriamycin (20 mg/m2 in a 24-hour infusion) once weekly. Antitumor activity was assessed by the level of prostatic-specific antigen (PSA) decline. RESULTS: PSA levels decreased > or = 50% from baseline in 21 (55%; 95% confidence interval, 38% to 71%) of 38 assessable patients. We observed partial responses (PRs) in seven (58%) of 12 patients with measurable soft tissue disease (in the lung, lymph nodes, and liver). Two patients with history of atherosclerotic heart disease had a sudden cardiac death. Serious toxic reactions included grade III to V stomatitis and grade III to IV acral erythema in 11 patients (29%), and grade III to IV anal and urethral mucositis in five patients (13%). Grade III to IV neutropenia occurred in 11 patients (29%). Seventeen patients (45%) required hospitalization for complications. Fifteen patients (39%) developed hypokalemia, and 24 patients (63%) developed clinical adrenal insufficiency. CONCLUSION: The combination of ketoconazole and Adriamycin has a 55% PSA response rate in patients with AI PCa and is worthy of additional study. This treatment results in frequent adrenal insufficiency. Therefore, future studies should incorporate routine corticosteroid replacement. The cardiac complications caused by this combination should be studied further before it is widely used.

Phase I study of interleukin-2 combined with interferon-alpha and 5-fluorouracil in patients with metastatic renal cell cancer.

Interferon-alpha (IFN-alpha) and interleukin-2 (IL-2) each has produced a 15%-20% response in metastatic renal cell cancer. Combining IFN-alpha with either IL-2 or 5-fluorouracil (5-FU) enhanced IFN-alpha activity. We have therefore conducted a Phase I Study combining IL-2, IFN-alpha, and 5-FU. The patients were continuously infused with IL-2 (1-3 x 10(6) u/m2) and 5-FU (600-750 mg/m2) for a 5-day period every 28 days, and IFN-alpha (4-5 x 10(6) u/m2) was injected subcutaneously daily. Lymphokine-activated killer (LAK) and natural killer (NK) cell activity was measured on days 0 and 8. Twenty-one patients received 76 courses. All primary tumors were controlled by surgery (81%) or angioinfarction. Hematologic toxicity was mild; median nadir of platelets was 117 K/microL and of granulocytes was 1.2 K/microL. Dose-limiting toxicity included mucositis, liver damage, and hypotension. No treatment-related death occurred, and only one patient required intensive-care-unit support. Two patients had an objective response, one of which was a complete response. Increased LAK cell and NK cell activity occurred at all IL-2 dose levels. Simultaneous delivery of IL-2, IFN-alpha, and 5-FU is safe and shows antitumor and biologic activity. 5-FU did not appear to suppress IL-2-induced LAK and NK cell activation. Maximum tolerated dose of the three-drug combination is IL-2, 2 x 10(6) u/m2, 5-FU 600 mg/m2, and IFN-alpha, 4 x 10(6) u/m2.

Phase I trial of murine monoclonal antibody 14G2a administered by prolonged intravenous infusion in patients with neuroectodermal tumors.

PURPOSE: The purpose of this phase I trial was to determine the toxicity and maximum-tolerated dose (MTD) of murine monoclonal antibody (Mab) 14G2a (anti-GD2) in cancer patients. PATIENTS AND METHODS: Following tracer doses of iodine-131-labeled 14G2a to determine tumor uptake, 18 patients with refractory melanoma, neuroblastoma, or osteosarcoma received unlabeled 14G2a at total concentrations of 50, 100, and 200 mg/m2 administered as daily 24-hour infusions for 5 days. RESULTS: The overall sensitivity of external immunoscintigraphy was 64 of 74 known metastases (86%). Toxicity from prolonged infusion of 14G2a consisted of severe generalized pain, hyponatremia, fever, rash, paresthesias, weakness, and chronic refractory postural hypotension (two patients). Toxicity was less severe in pediatric patients. The MTD of Mab was 100 mg/m2. Sixteen of 18 patients developed human antimouse antibodies (HAMA) to 14G2a. Terminal-phase half-life (T1/2) of unlabeled Mab was 6.6 +/- 1.8 hours for patients receiving 50 mg/m2 and 39.5 +/- 13.3 hours at the 100-mg/m2 level. Tumor biopsies from six melanoma patients were positive for GD2 antigen, but only two of six had trace amounts of 14G2a present. Three mixed responses (two melanoma, one osteosarcoma) and two partial responses (PRs; neuroblastoma) were observed. CONCLUSION: Mab 14G2a has modest antitumor activity at the expense of significant toxicity. Dose-limiting neurologic sequelae may significantly limit phase II studies other than in pediatric patients with neuroblastoma.

A phase I study of escalating interferon alpha-2a combined with 5-fluorouracil and leucovorin in patients with gastrointestinal malignancies.

On the basis of preclinical data showing synergy between 5-fluorouracil (5-FU), leucovorin (LV) and IFN-alpha-2a, a phase I study was carried out to determine the maximum tolerable dose (MTD) of IFN-alpha-2a with this combination in patients with gastrointestinal malignancies. The treatment consisted of 370 mg/m2 5-FU and 200 mg/m2, LV on days 1 to 5, and IFN-alpha-2a on days 1 to 5 of the first week of chemotherapy and on days 1, 3, 5 of each subsequent week, on a 28-day cycle. Six patients with colorectal, 3 with pancreas, 2 with oesophagus, 2 with hepatocellular and one with gastric cancer were treated. At level III (5 x 10(6) U/m2) all patients experienced grade 3 or 4 toxicity during the first 56 days of treatment and the MTD was declared level II. Grade 3 toxicity comprised of anorexia, mucositis, diarrhoea, and fatigue; in one instance, grade 4 neutropenia occurred. Ten patients were evaluable for response, one patient with an oesophageal cancer had a minor response and one patient with rectal cancer and liver metastases had a radiological complete response lasting 3 months. The recommended dose for this schedule in phase II studies is 5-FU 370 mg/m2, LV 200 mg/m2, and IFN-alpha-2a 4 x 10(6) U/m2.

Regional biologic therapy. Hepatic arterial infusion of recombinant human tumor necrosis factor in patients with liver metastases.

Twenty-two chemotherapy-resistant patients with liver metastases received 46 courses of recombinant human tumor necrosis factor (rhTNF) administered by 5-day continuous infusion through percutaneously inserted hepatic arterial catheters. The maximum tolerated daily dose of rhTNF was 150 micrograms/m2. This is six times the maximum tolerated daily dose of rhTNF that could be given systemically (intravenous) on the same schedule. The dose-limiting toxicity resulted in severe, although transient, hypophosphatemia (less than 1.0 mg/dl) associated with myocardial dysfunction. Objective tumor response (partial tumor response or greater) was observed in 2 of 14 patients (14%) with colorectal cancer and lasted as long as 3 months. Three additional minor responses occurred among these patients with colorectal cancer. Plasma carcinoembryonic antigen levels also decreased significantly (greater than 25%) in 7 of the 14 (50%) patients with colorectal cancer. Regional biologic therapy with rhTNF as a sole modality has definite antitumor activity in colorectal cancer metastatic to the liver and warrants additional study in previously untreated patients.

Single-dose murine monoclonal antibody ricin A chain immunotoxin in the treatment of metastatic melanoma: a phase I trial.

To determine the maximally tolerated dose of a ricin A chain-conjugated antimelanoma antibody (XomaZyme-Mel), 20 patients with metastatic melanoma were treated with escalating doses of the murine immunotoxin given as single intravenous infusion over 30 minutes. The starting dose was 0.6 mg/kg and was escalated in five groups to a maximum of 1.6 mg/kg. The maximally tolerated dose was 1.25 mg/kg as three of six patients treated at 1.6 mg/kg developed unacceptable toxicity. The dose-limiting toxicity consisted of profound fatigue, myalgias, and arthralgias. These occurred within 4 days and resolved in 7 to 10 days. Other non-dose-limiting toxicities encountered consisted of hypoalbuminemia, weight gain, peripheral edema, mild hypotension, and flu-like syndrome; the severity of these was also dose related. In addition, two allergic reactions occurred, one severe. There was one durable complete response of 12+ months' duration and one brief mixed response lasting 3 months. We conclude that the maximum tolerated single dose of XomaZyme-Mel is 1.25 mg/kg. Phase I studies evaluating 1.25 mg/kg given in multiple doses at 2- to 4-week intervals and phase II studies to determine the response rate of a single 1.25 mg/kg dose are warranted.

Immunological properties of melanoma tumor-infiltrating lymphocytes before and after IL-2-based biotherapies.

Immunological properties of melanoma TILs before and/or after IL-2-based biotherapies were investigated. TILs harvested before therapies, including those for adoptive transfer, proliferated well in culture with IL-2 and displayed cytotoxicity relatively restricted to autologous tumor cells. In contrast, TILs during or at the end of IL-2 based therapies did not proliferate in culture with IL-2. TILs from tumors even harvested 45 days after the end of IL-2 therapy modestly proliferated in culture with IL-2 and showed MHC-nonrestricted cytotoxicity. The number of live tumor cells that were yielded from melanomas during or at the end of IL-2-based therapies significantly decreased in all nine patients with metastatic melanomas, regardless of their clinical responses (2 PR, 2 MR, 2 SD, and 3 PD). Collectively, these results suggest that current IL-2-based therapies resulted in both transient nonresponsiveness of TILs to IL-2 and transient decrease in the number of live tumour cells in most melanoma patients.

Regression of hepatic metastases from gastrointestinal leiomyosarcoma after hepatic arterial chemoembolization.

Two patients with gastrointestinal leiomyosarcoma metastatic to the liver were treated by hepatic chemoembolization with cisplatin and polyvinyl sponge followed by hepatic arterial infusion of vinblastine. Effective palliation in terms of durable tumor regression was achieved in both patients after two chemoembolization-infusion procedures. These results suggest that regional therapy may offer new hope for the subset of sarcoma patients who have liver metastases resistant to combination systemic chemotherapy.

Indium-111-labeled B72.3 monoclonal antibody in the detection and staging of breast cancer: a phase I study.

Sixteen patients with primary breast cancer were studied with a pancarcinoma monoclonal antibody B72.3, an IgG1 molecule directed against tumor-associated glycoprotein (TAG-72) present in several tumors. Five millicuries of 111In was used to label 0.2 mg (six patients), or 2 mg (six patients), or 20 mg using the site-directed bifunctional DTPA method (at carbohydrate moiety). Digital, planar, and SPECT images were obtained at 2, 48, 72 and 96 hr when possible. HAMA levels were obtained before the Mab infusion and at 1, 3, and 6 wk postinfusion. Fourteen of 14 known primary breast lesions were detected by imaging (100% sensitivity). Two fibrocystic lesions were negative. Seven of 14 patients had lymph node metastases by histologic methods, but all were missed by radioimmunoscintigraphy. Tumor uptake of Mab ranged 0.00054%-0.0038% of the ID/g. The tumor-to-normal breast tissue ratio was 4.3 +/- 0.91 (mean +/- s.e.m.). Lymph nodes localization of 111In-B72.3 by tissue analysis was similar for tumor-bearing and normal nodes (0.0039 +/- 0.0023 versus 0.0025 +/- 0.0019). Pharmacokinetics revealed mean plasma half-life of 33.3-41.2 hr for the different doses. There was no statistical difference between any of the pharmacokinetic parameters of different doses. HAMA was positive only in 17% of the patients. The study suggests that this antibody has 100% sensitivity for primary breast cancers, but very poor detection rate of metastatic lesions in axillary lymph nodes; thus making it of questionable value in the initial staging process of this disease.

Severe, symptomatic, dose-limiting hypophosphatemia induced by hepatic arterial infusion of recombinant tumor necrosis factor in patients with liver metastases.

Twenty-two patients with liver metastases received 45 courses of recombinant tumor necrosis factor (rTNF) by hepatic arterial infusion in doses ranging from 12.5 to 175 micrograms/m2/d for 5 days by continuous infusion. The induction of statistically significant, dose-related, severe, albeit transient, hypophosphatemia (less than 1.0 mg/dl) associated with clinically significant, right-sided myocardial dysfunction and severe lassitude was observed. These side effects were promptly reversed after rTNF was stopped and intravenous phosphate supplementation was started. As no significant or consistent increase in urinary phosphate excretion was detected, the rTNF-induced hypophosphatemia probably resulted from an intracellular shift of phosphate. Since tumor regression was clearly associated with the lowest levels of serum phosphate, hypophosphatemia may be important in the antitumor effects of rTNF.

Alteration in interactions between tumor-infiltrating lymphocytes and tumor cells in human melanomas after chemotherapy or immunotherapy.

Alteration in interactions between tumor-infiltrating lymphocytes (TILs) and tumor cells after chemotherapy or immunotherapy was studied in metastatic melanoma patients. Tumors were harvested from surgical specimens 17 days after the end of chemotherapy with cisplatin, vinblastine, and dacarbazine (CVD). Tumors of nonlymph-node metastases from two responders yielded neither TILs nor tumor cells, whereas those from all four nonresponders had both TILs [(1.1-13.8) x 10(6) cells/g tumor] and tumor cells [(2.8-30.8) x 10(6) cells/g tumor). Tumors of lymph node metastases from nine patients yielded substantial numbers both of TILs and tumor cells, regardless of different clinical responses, except with one complete responder, whose tumor did not contain tumor cells. The mean increase of TILs from these tumors (n = 14) 3-4 weeks after incubation with 200 U/ml recombinant interleukin-2 (rIL-2) was 2.5-fold, whereas there was a 56-fold increase in TILs from untreated tumors (n = 3). CD3+ T cells predominated in TILs before and after expansion with IL-2. IL-2-activated TILs from five of six tumors tested displayed higher cytotoxicity against autologous tumor cells than against cells from any of three allogeneic tumors. Mean tumor cell numbers (10(6) cells/trial) obtained by serial needle biopsies for the same tumor in five patients decreased from 1.2 before therapy to 0.25 at day 4 of therapy (interferon alpha alone), and to 0.02 at day 8 (interferon alpha and IL-2). This decrease did not correlate with clinical responses. Yields (x 10(6) cells/g tumor) of TILs and tumor cells in subcutaneous melanomas obtained by excisional biopsies in one nonresponder under IL-2 therapy were respectively 0.2 and 1.1 before therapy (day 0), 0.1 and less than 0.01 during (day 7), 0.2 and less than 0.01 at the end of therapy (day 21), and 0.5 and 0.5 at the time of tumor progression (day 66). Yields of TILs and tumor cells in the other nonresponder were respectively 3 and 26 before (day 0), 16 and 3 during (day 7), and 0.4 and less than 0.01 at the end of IL-2 therapy (day 17), and 2.5 and 6 at the time of progression (day 62). TILs in these two patients before therapy proliferated well in culture with IL-2 (570- and 720-fold, respectively), and showed higher cytotoxicity against autologous tumor cells, whereas none of those from the five tumors biopsied during or at the end of IL-2 therapy proliferated. TILs at the time of progression showed modest proliferation (54- and 76-fold, respectively) and showed major-histocompatibility-complex-nonrestricted cytotoxicity. In summary, a decrease in the number of live tumor cells did not always correlate with clinical response in either therapy. CVD chemotherapy may simply impair IL-2-induced proliferation of TILs. IL-2 therapy may induce transient unresponsiveness of TILs to IL-2.

Recombinant alpha-interferon enhances tumor targeting of an antimelanoma monoclonal antibody in vivo.

To determine whether recombinant human alpha-interferon (rIFN alpha A) could enhance tumor uptake of an antimelanoma monoclonal antibody (Mab) 96.5 in vivo, groups of nude mice bearing P97 antigen-positive human melanoma subcutaneous xenografts were given i.m. injections of normal saline or rIFN alpha A daily for 10 days. On day 7, mice received either 5 micrograms of 111In-labeled Mab 96.5 or irrelevant 111In-labeled subclass-matched or non-subclass-matched control Mabs. Animals were killed 72 h later and the percent injected dose per gram (%ID/g) in tumor and normal organs was determined. There was a significant (p less than 0.001) increase in 96.5 in tumors of IFN-treated mice compared to saline-treated mice and mice receiving irrelevant Mabs. There was also a significantly increased uptake of 96.5 in blood, heart, lung, kidney, and muscle of IFN-treated vs. control mice (p less than 0.05). This finding was most likely due to increased antigen shedding since significant differences in %ID/g were not observed between IFN-treated and control mice bearing antigen-negative tumors. Furthermore, P97 content in tumor and tissues of IFN-treated mice bearing melanoma xenografts was significantly higher than in mice without tumors. In summary, IFN enhanced targeting of 96.5 via an antigen-specific mechanism. These data confirm and extend previous studies in other tumor systems, and suggest that clinical trials of Mabs plus IFN might be useful in overcoming poor Mab localization that occurs as a result of antigenic heterogeneity in humans.

Increased incidence of hypersensitivity to iodine-containing radiographic contrast media after interleukin-2 administration.

Eight of 28 (28%) cancer patients with liver metastases treated by either splenic (four) or hepatic (four) arterial infusion of recombinant interleukin-2 (rIL-2) developed hypersensitivity reactions to iodine-containing radiographic contrast media. These reactions consisted of fever, chills, malaise, nausea and vomiting, skin rash, diarrhea, and occasionally, hypotension. Reactions usually occurred 1 month after the initial arteriographic procedure and rIL-2 infusion, with 1-hour to 4-hour intervals between procedure and reexposure of the patient to the iodine-containing contrast medium (used in conjunction with computerized tomography or repeated arteriography for subsequent courses of rIL-2 infusions) and the onset of symptoms. Prompt administration of corticosteroids during the reaction and premedication of patients who were known to have had a reaction in the past were very effective in stopping reactions or preventing them from reoccurring. The high incidence (28%) of hypersensitivity reactions, the temporal relationship (4 hours) between the arteriographic procedure (utilizing iodine-containing contrast medium) and the initial infusion of rIL-2 (while some of the contrast medium was still present), and the absence of such hypersensitivity reactions among patients receiving systemic (intravenous) rIL-2 (not requiring the use of concomitant iodine-containing contrast medium) provide additional evidence that in the presence of a potentially immunogenic moiety, rIL-2, a potent stimulant of the human immune system, can produce an initial sensitization followed by subsequent anamnestic reaction upon reexposure of the patient to the immunogen (even without the additional rIL-2).