Phase II trial of 5-fluorouracil plus eniluracil in patients with advanced pancreatic cancer: a Southwest Oncology Group study.

BACKGROUND: Eniluracil is a potent, irreversible inactivator of dihydropyrimidine dehydrogenase, the major catabolic enzyme for 5-fluorouracil (5-FU). Pretreatment with eniluracil significantly increases plasma half-life, plasma concentration and oral bioavailability of 5-FU. This multicenter phase II trial was designed to estimate the 6-month survival rate in patients with metastatic adenocarcinoma of the pancreas treated with 5-FU and eniluracil. PATIENTS AND METHODS: One hundred and sixteen patients (61 with no prior chemotherapy and 55 with prior chemotherapy) were registered for treatment with eniluracil 50 mg (total dose) p.o. on days 1-7 and 5-FU 20 mg/m(2)/day p.o. on days 2-6 of a 28-day treatment cycle. RESULTS: In 106 patients evaluable for survival, the 6-month survival rate was 34% [95% confidence interval (CI) 22% to 47%, median survival 3.6 months] for patients who had not been treated previously with chemotherapy and 29% (95% CI 16% to 42%, median survival 3.4 months) for those who had received prior chemotherapy. For those patients with measurable disease, the confirmed response rates were 8% and 2%, respectively. The most common grade 3-4 toxicities were neutropenia (29% of patients) and diarrhea (12% of patients). Overall, 69% of patients experienced a grade 3 or worse adverse event during treatment. CONCLUSIONS: These results suggest that the combination of a 7-day course of eniluracil and a 5-day course of oral 5-FU has limited activity in patients with advanced pancreatic cancer, and is associated with a high frequency of clinically significant adverse events.

Phase Ib trial of pentoxifylline and ciprofloxacin in patients treated with interleukin-2 and lymphokine-activated killer cell therapy for metastatic renal cell carcinoma.

The dose of interleukin 2 (IL-2) which can be administered to cancer patients is limited largely by a capillary leak syndrome. Pentoxifylline (PTX) is a methylxanthine which reduces IL-2 toxicity in animals. Ciprofloxacin (Cipro) modifies the metabolism of methylxanthines and, when coadministered with PTX, increases levels of PTX and certain of its metabolites. We conducted a phase Ib trial in patients receiving IL-2 and lymphokine-activated killer cell (LAK) cell therapy for metastatic renal cell carcinoma to identify the maximum tolerated dose of PTX which could be coadministered with Cipro in this setting. Eighteen patients received IL-2 (Roche) by continuous infusion at 6 x 10(6) units/m2/day on days 1-5 and underwent leukapheresis on days 7-9. LAK cells were infused on days 12-14. IL-2 was administered at 2 x 10(6) units/m2/day on days 10-20. Cohorts of patients received PTX at 2.5 (n = 3), 3.1 (n = 6), 3.9 (n = 6), and 4.9 (n = 3) mg/kg by 30 min i.v. infusion every 4 h on days 0-5 and 10-20 and Cipro (500 mg p.o. every 12 h) on days 1-5 and 10-20. Toxicity was compared with that observed in 33 historical control patients who received 37 cycles of an identical regimen of IL-2/LAK without PTX/Cipro. PTX at 2.5-3.9 mg/kg and Cipro were well tolerated. The maximum tolerated dose of PTX was 3.9 mg/kg. Dose-limiting emesis (n = 1) and atrial fibrillation (n = 2) occurred at 4.9 mg/kg and were reversible. Two complete, one partial and one minor, responses were observed. Patients treated with 3.9 mg/kg PTX received 95.0% of the planned dose of IL-2 as compared to 72.8% in the control patients (P < 0.025), primarily due to a lower incidence of azotemia and metabolic acidosis in PTX/Cipro recipients than had been seen in the historical control patients. The results of this study demonstrate that PTX/Cipro can be administered to patients receiving IL-2/LAK without apparent loss of therapeutic efficacy. Moreover, PTX/Cipro recipients exhibited less toxicity than historical controls. Therefore, treatment with PTX/Cipro may allow delivery of higher doses of IL-2, which might induce more responses in IL-2-responsive tumors and regression of tumors unresponsive to conventional doses of IL-2.

Lymphokine-activated killer (LAK) precursor cell activity is present in infused peripheral blood stem cells and in the blood after autologous peripheral blood stem cell transplantation.

Immunotherapy with interleukin-2 (IL-2) early after peripheral blood stem cell transplantation (PBSCT) is being considered as a potential way to eradicate minimal residual disease. The aim of this study was to determine whether lymphocytes which can acquire lymphokine-activated killer (LAK) cell activity are present in PBSC and in the blood of patients after PBSCT. Fresh and cryopreserved G-CSF-mobilized PBSC from eight patients were incubated with IL-2 (1000 U/ml) for 3-6 days and then tested for LAK activity as measured by lysis of the Daudi cell line. LAK activity was present in both fresh and cryopreserved PBSC, with mean lysis of 32% and 36%, respectively, at an effector:target (E:T) ratio of 50:1. To assess the reconstitution of LAK precursor activity after PBSCT, peripheral blood (PB) obtained from eight other patients 15-60 days after PBSCT was similarly tested. LAK activity was detected in PB from every patient (mean lysis of 38% at an E:T ratio of 12.5:1). PB from patients after PBSCT contained a higher percentage of CD8+ cells and CD56+ cells than did PB from 9 normal controls (47.2% vs. 21.4% CD8+ cells, P < 0.005 and 28.6% vs. 8.6% CD56+ cells, P < 0.0005). Moreover, PB from 4 of 5 patients tested after PBSCT exhibited a high percentage of cells expressing p75, the intermediate affinity IL-2R. Thus, precursor cells capable of acquiring IL-2-inducible LAK activity are present in PBSC and are rapidly reconstituted after PBSCT. The findings provide a rationale for testing IL-2 as a way of decreasing relapses after PBSCT.

Disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis (DH) is recognized as an opportunistic infection in patients with the human immunodeficiency virus (HIV), especially in regions where histoplasmosis is endemic. At the Kansas University Medical Center 148 patients were hospitalized with the diagnosis of AIDS from December 1983 to March 1991; 23 of these patients (16%) had disseminated histoplasmosis. The charts of these 23 patients were reviewed. Clinical signs and symptoms included fever (91%), cough (65%), and weight loss (48%). Splenomegaly, hepatomegaly, or lymphadenopathy was present in 52% of all patients. Anemia (39%), leukopenia (65%), and thrombocytopenia (52%) were common, and 22% had pancytopenia. Diagnosis was made by peripheral smear examinations (organisms visualized on 7 of 22 smears [32%]), blood cultures (positive for H capsulatum in 16 of 20 patients, [80%]), bone marrow cultures (positive in 14 of 15 patients, [93%]), and bone marrow aspirate and biopsy examinations (organisms seen on 18 of 21 stains, [86%]). The combination of these four tests revealed the diagnosis of DH in 23 of 23 patients (100%). Induction and maintenance amphotericin B therapy was given to all but 2 patients, and currently 8 of the 23 are alive. DH is a common opportunistic infection in AIDS patients from regions endemic for histoplasmosis. When DH is suspected, a peripheral smear examination, blood cultures, bone marrow cultures and bone marrow aspirate and biopsy should be done to make the diagnosis, since suppression of the disease is possible with appropriate therapy.