Gene modulatory effects, pharmacokinetics, and clinical tolerance of interferon-alpha1b: a second member of the interferon-alpha family.

Interferon-alpha1 (IFN-alpha1), which may have a primary role in innate immunity, differs significantly in amino-acid sequence from IFN-alpha2, the only recombinant IFN-alpha with substantial clinical evaluation. Patients with metastatic malignancies received daily subcutaneous doses of 1.5-270 mug/m(2) of recombinant IFN-alpha1b. Gene modulation, pharmacokinetics, tolerability, and disease response were determined. Significant (P<0.01) dose and gene-dependent increases of 2-10 fold occurred in IFN-stimulated genes, including four (tumor necrosis factor-related apoptosis-inducing ligand, cig 5, p56, GEM) never previously identified as increased in patients; significant increases (P<0.01) resulted at the lowest dose (1.5 microg/m(2); 1.5 x 10(4) human antiviral units/m(2)). Increases (P<0.01) were sustainable for >4 weeks. Peak levels of IFN-alpha1b were at 3 h; an increase of approximately eightfold in both C(max) and AUC occurred between 15 microg/m(2) and 270 microg/m(2). Chronic toxicities of anorexia, weight loss, and fatigue were relatively uncommon. Eighteen patients were treated for >8 weeks; none experienced >grade 1 weight loss. Three patients at the highest dose developed grade 3 fatigue after > or =3 months, which required dose reduction or discontinuation. Patient acceptability of fatigue defined a dose for initiation of Phase II trials, 270 microg/m(2). Six patients (five with renal cell carcinoma) had progression-free survival for >1 year, including two who had partial responses. IFN-alpha1b resulted in potent stimulation of IFN-regulated genes and tumor regressions in renal cell carcinoma. Unique gene modulatory effects, when coupled with the moderate severity of side effects and a potentially central role in innate immunity, provide rationale for further clinical evaluation of IFN-alpha1 in virus infections and cancer.

Phase I trial of subcutaneous recombinant human interleukin-12 in patients with advanced renal cell carcinoma.

Patients with advanced renal cell carcinoma were treated in a Phase I trial with escalating doses of recombinant human interleukin-12 (rHuIL-12) given on days 1, 8, and 15 of each 28-day cycle. Treatment in the initial dose scheme consisted of a fixed dose with dose levels of 0.1, 0.5, and 1.0 microg/kg given to cohorts composed of three or six patients. On the basis of the toxicity profile, a second scheme (up-titration) was undertaken wherein rHuIL-12 was escalated for each patient from week 1 to week 2, to a target dose given week 3 and thereafter; cohort target dose levels were 0.5, 0.75, 1.0, 1.25, and 1.5 microg/kg. Fifty-one patients were treated: 32 (63%) had prior cytokine therapy and 19 (37%) had received no prior systemic therapy. The maximum tolerated dose for the fixed dose scheme was 1.0 microg/kg. Dose-limiting toxicities included increase in transaminase concentration, pulmonary toxicity, and leukopenia. The most severe toxicities occurred with the first injection and were milder upon further treatment. With the up-titration dose scheme, the maximum tolerated dose was reached at 1.5 microg/kg, and dose-limiting toxicity consisted of an increase in serum transaminase levels. At the maximum tolerated dose of 1.5 microg/kg, serum IL-12 levels increased to a mean peak level of 706 pg/ml. Serum levels of IFN-gamma increased to a mean peak level of about 200 pg/ml at 24 h after the first maintenance dose of 1.5 microg/kg. The best responses were as follows: one patient had complete response, 34 patients were stable, 14 patients showed progression, and 1 patient was inevaluable. In conclusion, rHuIL-12 was relatively well tolerated when administered by s.c. injection. The recommended dose according to the up-titration schedule of rHuIL-12 (microg/kg) for Phase II trials was as follows: cycle 1, 0.1 (day 1), 0.5 (day 8), 1.25 (day 15); cycle 2 onwards, 1.25. Phase II trials of rHuIL-12 were initiated in previously untreated patients with renal cell carcinoma and in patients with melanoma.

Interferon-gamma and CXC chemokine induction by interleukin 12 in renal cell carcinoma.

Interleukin 12 (IL-12) is known to play an important role in the development of an antitumor response. Its activity has been shown to be dependent upon the intermediate production of IFN-gamma and the influx into the tumor of CD8 lymphocytes. In a murine model, tumor regression induced by IL-12 treatment correlated with IFN-gamma, IP-10, and Mig expression in the tumor bed and was abrogated by antibodies to both chemokines. Here we examined the effects of rHuIL-12 on IFN-gamma and CXC chemokine gene expression in patients with renal cell carcinoma (RCC) in an attempt to determine whether a similar series of molecular events leading to IL-12-mediated tumor regression in mice is also detectable in humans. As in the murine RENCA model, cultured RCC cells themselves could be induced by IFN-gamma to synthesize IP-10 and Mig mRNA. Explanted RCC produced IFN-gamma and IP-10 mRNA in response to IL-12 treatment, which was consistent with the finding that biopsied RCC tumors from IL-12-treated patients also variably expressed augmented levels of those molecules after therapy. Although Mig mRNA was present in the majority of biopsied tumors prior to treatment, both the Mig and IP-10 chemokines as well as IFN-gamma were induced in the peripheral blood mononuclear cells of IL-12-treated patients. Skin biopsies of IL-12-treated patients also all synthesized IP-10 mRNA. This study demonstrates that recombinant human IL-12 therapy of patients with RCC has the potential to induce the expression of gene products within the tumor bed that may contribute to the development of a successful antitumor response.

Signal transduction abnormalities in T lymphocytes from patients with advanced renal carcinoma: clinical relevance and effects of cytokine therapy.

Studies have demonstrated abnormalities of the CD3/T-cell antigen receptor (TCR) and pathways of signal transduction in T lymphocytes from animals and patients with advanced malignancy. Diminished expression of TCRzeta and p56(lck) that are associated with the TCR and reduced nuclear localization of RelA containing nuclear factor kappaB (NFkappaB) complexes have been noted. These defects have been described in T cells from patients with malignant melanoma, renal cell carcinoma (RCC), ovarian cancer, and colorectal cancer. Preliminary observations also indicate possible correlation with clinical variables such as stage in selected instances. To further characterize altered expression of TCRzeta, p56(lck), and impaired activation of NFkappaB, T lymphocytes were obtained from 65 patients with RCC, the majority of whom were receiving combination cytokine therapy [interleukin (IL)-2, IFN alpha-containing regimens] and 37 control individuals. In 29 of these patients, levels of TCRzeta and p56(lck) were determined by Western blots of T-cell lysates and semiquantitated using densitometry. Relative levels were then correlated with a series of clinical variables including response to therapy, performance status, survival, disease sites, age, and others. In another group of 28 patients (three individuals from the first group), the frequency of abnormal NFkappaB activation was studied using electrophoretic mobility shift assays after activation of T cells with phorbol myristate acetate/ionomycin or anti-CD3 monoclonal antibody. Changes in these signaling molecules during cytokine treatment were also investigated. TCRzeta and p56(lck) were detected in the peripheral blood T cells in 27 of 29 patients, and overall, reduced levels were noted visually in 12 of 29 (41%) and 13 of 29 (45%) individuals, respectively. When levels were semiquantitated using densitometry, significant decreases of TCRzeta (P = 0.029) and p56(lck) (P = 0.029) but not CD3epsilon (P = 0.131), compared with control levels, were found. In patients treated with IL-2/IFN alpha-based therapy, relative levels of TCRzeta increased significantly (P = 0.002) on day 15 of cycle one compared with the baseline. Correlations of TCRzeta or p56(lck) levels with response or disease variables, except for lower TCRzeta levels (P < 0.001) in the presence of bone metastases, were not found. Abnormal NFkappaB activation after stimulation with phorbol myristate acetate/ionomycin and/or anti-CD3 monoclonal antibody was found in 59% of patients (17 of 28) and was not accounted for by the advanced age of the study cohort. Activation of NFkappaB in peripheral blood T cells was inducible during cytokine therapy in four of six individuals who displayed impaired NFkappaB activity prior to therapy. Moreover, impaired activation of NFkappaB does not appear linked to a reduction of TCRzeta expression, because in five patients, normal TCRzeta levels were present although kappaB binding was not inducible. In the majority of patients with advanced RCC, peripheral blood T cells express TCRzeta and p56(lck), and in a subset, reduced levels of these TCRzeta associated molecules are seen that may increase during cytokine-based therapy. Abnormal activation of NFkappaB is also present in >50% of patients and may also revert to normal during IL-2/IFN alpha-based treatment. This alteration in NFkappaB activation occurred in the presence of normal expression of TCRzeta-associated signaling elements. The clinical significance of these findings remains unclear.

Phase I trial of subcutaneous interleukin 3 in patients with refractory malignancy: hematological, immunological, and pharmacodynamic findings.

We conducted a Phase I trial of s.c. recombinant human interleukin 3 (rhIL-3) to evaluate the toxicity, maximal tolerated dose, pharmacokinetics, and in vivo biological effects of this cytokine. Thirty-one patients with refractory cancer were entered into the study between November 1991 and June 1993. Therapy consisted of s.c. rhIL-3 daily for 15 days administered to cohorts of three to nine patients at dose levels of 60-4000 microgram/m2/day. Cycles were repeated at intervals of 28 days. Seventy-five cycles of rhIL-3 were administered (median, two per patient) and the maximal tolerated dose was 2000 microgram/m2/day. Toxicity was moderate, with most patients developing chills, fever, and myalgia. Dose-limiting toxicity consisted of diarrhea (two patients) and headache (one patient). Hematological effects of rhIL-3 included significant dose-related increases of WBC (P < 0.001), neutrophils (P < 0.001), and eosinophils (P < 0.001). Platelet counts and absolute lymphocyte numbers also increased. Various CD3(+) lymphocyte subsets increased; however, lytic activity (natural killer and lymphokine-activated killer) of peripheral blood lymphocytes was not enhanced. Serum levels of the soluble IL-2 receptor increased in a dose-related fashion, and IL-2-induced lymphocyte proliferation also was increased variably. Pharmacokinetic studies were performed in 13 patients, and area under the curve and maximal concentration values increased with increasing rhIL-3 dose levels (P < 0.001) and correlated with maximal changes from baseline in WBC, neutrophils, and eosinophils. rhIL-3 antibodies were detected in 8% of patients by day 29 of cycle 1 but were not neutralizing. rhIL-3 is well tolerated when administered s.c. and has reproducible hematological and immunological effects. The pleiotropic effects of this cytokine on various in vivo biological parameters were demonstrated clearly. Further studies of its immunoregulatory effects are warranted.

Phase I and II trials of subcutaneously administered rIL-2, interferon alfa-2a, and fluorouracil in patients with metastatic renal carcinoma.

PURPOSE: A phase I followed by a phase II trial utilizing rIL-2, IFN alpha, and 5-FU were conducted in patients with unresectable and/or metastatic renal cell carcinoma. METHODS: Treatment consisted of: rIL-2 at 5.0 x 10(6) IU/m2 SQ on days 1-5 for 4 weeks, rHUIFN alpha-2a at 5.0 x 10(6) U/m2 SQ on days 1, 3, and 5 for 4 weeks, and 5-FU by IV bolus on days 1-5 during week 1. In the phase I study, patients were treated at varying doses of 5-FU: I-none, II-250 mg/m2, III-300, and IV 375. A phase II trial was then conducted utilizing the same schedule and maximum tolerated dose (MTD) for 5-FU. RESULTS: Twenty patients were entered into the phase I trial. Dose-limiting toxicity included grade III nausea and vomiting, and one sudden cardiac death. The MTD for 5-FU was determined to be 300 mg/m2. In the phase II trial, a median of two cycles of therapy was administered to 25 evaluable patients. Toxicity was moderate and consisted primarily of fevers, chills, fatigue, nausea/vomiting, and anorexia. Grade IV thrombocytopenia, consistent with ITP, developed in one patient each on the phase I and phase II trial. Seven partial responses were seen among 25 patients treated in the phase II trial for a 28% (CI 12-49%) response rate. CONCLUSIONS: The addition of 5-FU to rIL-2 and rHuIFN alpha-2a appears to increase the toxicity of this therapy. Randomized trials will be required to determine if efficacy is enhanced.

Accelerated induction therapy and resection for poor prognosis stage III non-small cell lung cancer.

BACKGROUND: Induction therapy and resection may improve the survival of patients with poor prognosis stage III non-small cell lung cancer, at the cost of significant treatment prolongation. The purpose of this study was to assess toxicity, response, and survival of an accelerated induction regimen and resection in poor prognosis stage III non-small cell lung cancer. METHODS: Forty-two surgically staged patients with poor prognosis stage III non-small cell lung cancer received 11 days of induction treatment consisting of 96 hours of continuous chemotherapy infusions of cisplatin (20 mg.m-2.day-2), 5 fluorouracil (1,000 mg.m-2.day-2), and etoposide (75 mg.m-2.day-2) concurrent with accelerated fractionation radiation therapy (1.5 Gy twice a day, to a dose of 27 Gy). Induction was followed in 4 weeks by resection. Postoperatively, a second course of continuous chemotherapy and concurrent accelerated fractionation radiation therapy (postoperative dose 13 to 36 Gy) was given. RESULTS: Despite some degree of induction toxicity in all patients there was only one induction death (2.4%). A clinical partial response was seen in 24 patients (57%). Thirty-six patients (86%) underwent thoracotomy, and resection was possible in 33 (79%). Pathologic downstaging was seen in 17 patients (40%), and 2 patients (5%) had no residual carcinoma at operation. There were 11 postoperative complications (31%) and 4 postoperative deaths (11%). Thirteen patients (31%) are alive and disease-free, 24 (57%) have persistent disease or have recurred (15 distant, 5 locoregional, 4 both), and 9 patients are alive with disease. The median survival is 21 months and the 2-year Kaplan-Meier survival is 43%, with no differences identified between stages IIIA and IIIB patients (p = 0.63). CONCLUSIONS: We conclude that accelerated induction therapy and resection in poor prognosis stage III non-small cell lung cancer (1) is toxic, with a 12% treatment mortality; (2) is effective with a 79% resection rate and 40% pathologic downstaging rate; (3) provides excellent local control; (4) may prolong survival; and (5) is of value in stage IIIB as well as stage IIIA patients.

Should continent diversion be performed in patients with locally advanced bladder cancer?

OBJECTIVES: To assess the effect of local, regional, and distant recurrence on pouch function in patients with locally advanced bladder cancer treated by cystectomy and continent diversion. METHODS: A review of 64 consecutive patients undergoing orthotopic (n = 40) or continent cutaneous (n = 24) urinary diversion was performed; 25 patients (39.1%) had locally advanced cancers as defined by deep muscle invasion, extension into perivesical fat, stromal invasion of the prostate, or node-positive disease. Patients were followed at 6-month intervals with physical examination, assessment of voiding function, and computed tomography (CT) scans. RESULTS: The pelvic recurrence rate was 4.7% in the overall group and 12% in patients with locally advanced disease. In the 39 patients with organ-confined tumors, 34 (87%) are alive without evidence of recurrence and have normal pouch function with a median follow-up of 27 months. Four patients in this group receiving systemic chemotherapy for clinical recurrences have retained normal pouch function until last follow-up or death. In the 25 patients with locally advanced tumors, 15 (60%) are alive without evidence of recurrence and have normal pouch function with a median follow-up of 15 months. Seven patients in this group received a median three cycles of adjuvant chemotherapy, and 4 patients received chemotherapy for clinically evident recurrences. Surgical recovery did not delay the onset of adjuvant therapy in any patient, nor did problems specifically related to the presence of a continent pouch delay any cycle of chemotherapy in those patients treated for recurrent disease in either group. Only 1 patient (1.5%) experienced treatment-related toxicity related to the presence of a continent diversion. CONCLUSIONS: This experience suggests that the use of orthotopic or continent cutaneous diversions after cystectomy in patients with locally advanced bladder cancer is safe, does not interfere with the delivery of subsequent therapy, and allows most patients to anticipate normal pouch function even in the presence of recurrent disease.

Phase I trial of capecitabine in combination with interferon alpha in patients with metastatic renal cancer: toxicity and pharmacokinetics.

PURPOSE: The present study was designed to determine the toxicity and maximum tolerated doses of oral intermittent oral capecitabine and subcutaneous (s.c.) rHuIFNalpha2a in patients with metastatic renal cell carcinoma (RCC). The pharmacokinetics of capecitabine and its metabolites were also investigated. METHODS: A total of 27 patients were treated at four dose levels of capecitabine (825 or 1000 mg/m2 twice daily orally, days 1-14, 22-36) and rHuIFNalpha2a (1.5 or 3.0 MU/m2 s.c. three times weekly). Unchanged capecitabine and its metabolites were analyzed in plasma using liquid chroatography/mass spectrometry in ten patients. RESULTS: The toxicity of combined capecitabine and rHuIFNalpha2a was moderate. Patients experienced mild nausea/vomiting (70%) and diarrhea (63%). The hand-foot syndrome was seen in 67% of patients and was generally mild, as was hematologic toxicity. Dose-limiting toxicity included diarrhea, mucositis, neutropenia and the hand-foot syndrome. The dose level recommended for further trials included capecitabine 1000 mg/m2 twice daily and rHuIFNalpha2a 3.0 MU/m2 three times weekly. One patient had a partial response of a liver lesion (duration > 200 days). Pharmacokinetic parameters of capecitabine and its metabolites (5'-deoxy-5-fluorouridine, 5-fluorouracil and alpha-fluoro-beta-alanine) were similar to those reported by other authors. There was rapid conversion to 5'-deoxyuridine. The peak plasma concentrations of capecitabine occurred between 0.5 and 3.0 h. CONCLUSIONS: The combination of capecitabine and rHuIFNalpha2a was well tolerated. The recommended dose levels for phase II trials are: rHuIFNalpha2a 3.0 MU/m2 s.c. three times weekly and oral capecitabine 1000 mg/m2 twice daily for 2 weeks. No evidence of an effect of rHuIFNalpha2a on the pharmacokinetics of capecitabine or its metabolites was apparent. A phase II trial in untreated patients with metastatic RCC is planned.

A phase II pharmacodynamic study of pyrazoloacridine in patients with metastatic colorectal cancer.

PURPOSE: To perform a phase II trial of pyrazoloacridine (PZA), a novel DNA intercalator, in patients with metastatic colorectal carcinoma and no previous therapy. METHODS: PZA was administered at a dose of 750 mg/m2 intravenously over 3 h every 21 days. Pharmacokinetic studies to determine PZA plasma concentrations were performed. RESULTS: No responses were seen in 14 response-evaluable patients. Patients received a median of two cycles of PZA (range 1-6). Toxicity included neutropenia and neurologic side-effects, which were > or = grade III in 73% and 14%, respectively. High plasma concentrations of PZA (Cmax) correlated with low neutrophil counts (P = 0.04). CONCLUSIONS: PZA is inactive at this dose and schedule in colorectal cancer, and produces moderately severe toxicity.

Mature results from a phase II trial of accelerated induction chemoradiotherapy and surgery for poor prognosis stage III non-small-cell lung cancer.

Mature results are reported from a phase II trial of accelerated induction chemoradiotherapy and surgical resection for stage III non-small-cell lung cancer whose prognosis is poor. Surgically staged patients with poor prognosis stage III non-small-cell lung cancer were eligible for this study. Four-day continuous intravenous infusions of cisplatin 20 mg/m2/day, 5-fluorouracil 1,000 mg/m2/day, and etoposide 75 mg/m2/day were given concurrently with accelerated fractionation radiation therapy, 1.5 Gy twice a day, to a total dose of 27 Gy. Surgical resection followed in 4 weeks. Identical postoperative chemotherapy and concurrent radiation to a total dose of 40 to 63 Gy was subsequently given. Between February 1991 and June 1994, 42 eligible and evaluable patients, 23 with stage IIIA disease and 19 with stage IIIB disease, were entered in this trial. Treatment was well tolerated. The pathologic response rate was 40%. This response was complete in 5%. With a median follow-up of 54 months, the Kaplan-Meier 4-year survival estimate is 19%: 26% for stage IIIA and 11% for stage IIIB patients. Patients with a pathologic response, resectable disease, or pathologic downstaging to stage 0, I, or II had a better survival. The 4-year estimates of locoregional and distant disease control are 70% and 19%, respectively. It is concluded that although the ultimate role of concurrent chemoradiotherapy and surgery in stage III non-small-cell lung cancer must await the results of phase III clinical trials, survival and locoregional control in this study appear improved in comparison with historical experience. There is a subset of patients, able to undergo resection with pathologic downstaging, who have a projected survival equivalent to that of patients with more limited disease. Clinical or pathologic tools to identify these patients before treatment would be highly useful.

Phase I trial of weekly docetaxel and daily temozolomide in patients with metastatic disease.

UNLABELLED: Docetaxel is second generation taxoid that has shown activity against a variety of cancers and has been approved for use in cancers of the breast, lung, head and neck, ovaries and prostate. Temozolomide is an alkylating agent which crosses the blood brain barrier and has demonstrated antitumor activity against a broad range of tumor types, including malignant glioma, melanoma, non small cell lung cancer and carcinoma of the ovary and colon. A Phase I trial was conducted to determine the toxicity of this combination in refractory solid tumor patients. METHODS: Twenty five patients with metastatic cancers were enrolled in a Phase I dose escalation trial. Docetaxel was administered weekly in 5 escalating doses of 25 to 35 mg/ m(2) as a one-hour bolus intravenous infusion for 3 consecutive weeks. Temozolamide was administered orally daily for 3 weeks (escalating doses of 75 to 100 mg/m(2)). Cycles were repeated at 4 week intervals. RESULTS: The maximum tolerated dose (MTD) was not determined in this study. The most commonly reported adverse events were mild to moderate nausea, vomiting and fatigue. Thrombocytopenia was the most commonly observed grade 3 and 4 hematological toxicity. Eight patients had dose interruptions for adverse events and only one patient had a dose reduction while receiving 30 mg/ m(2) of docetaxel and 90 mg/ m(2) of temozolomide due to grade 3 thrombocytopenia. Two patients achieved partial responses and 88% of the patients are deceased. The median survival is 8.4 months. CONCLUSIONS: The combination of docetaxel and temozolomide was well tolerated and these agents can be safely combined. For phase II trials, docetaxel 35 mg/ m(2) IV day 1, 8 and 15, and daily temozolomide at 100 mg/ m(2) day 1-21 are recommended.

Interleukin-3 (IL-3) stimulates the clonal growth of pulmonary alveolar macrophage of the mouse: role of IL-3 in the regulation of macrophage production outside the bone marrow.

Interleukin-3 (IL-3) is one of the hematopoietic growth factors that regulates the growth and differentiation of pluripotent stem cells, thereby leading to the production of all the major blood cell types. The role of IL-3 in the regulation of pulmonary alveolar macrophage (PAM) production was investigated. IL-3 stimulated the proliferation and clonal growth of murine PAM with a dose-response curve similar to that of bone marrow granulocyte-macrophage colony-forming cells. The IL-3-induced colony formation by cells outside the bone marrow appeared to be unique to PAM; IL-3 failed to cause colony formation by both peritoneal exudate macrophages (PEM) and blood monocytes. Unlike bone marrow stem cells, PAM are unipotential and in vitro gave rise to only mononuclear phagocytes under the influence of IL-3. Nevertheless, cells derived from PAM cultures in media containing IL-3 displayed a high degree of heterogeneity in terms of their Fc receptor-mediated phagocytic activity. At low concentrations, IL-3 induced a synergistic response with colony-stimulating factor 1 (CSF-1), which resulted in an enhanced proliferative capacity of PAM. A synergistic effect was also observed by short-term exposure of PAM to IL-3 followed by incubating with CSF-1 alone. This study shows that IL-3 exhibited a macrophage growth factor activity unique to PAM.

Linitis plastica of the esophagus.

A 62-yr-old woman was evaluated for a 2-wk history of regurgitation and weight loss. Radiologic studies demonstrated a stenotic region in the distal third of the esophagus. Multiple endoscopic biopsies were nondiagnostic. Esophagectomy and esophagogastrostomy revealed a diffusely infiltrating adenocarcinoma ("linitis plastica") of the distal esophagus, sparing the gastroesophageal junction and stomach. Despite the absence of metastatic disease at laparotomy, the patient developed metastases unresponsive to chemotherapy. The pathologic, radiographic, and endoscopic findings are consistent with primary linitis plastica of the esophagus.

Interleukin-2: use in solid tumors.

Recombinant interleukin-2 (rIL-2) is a cytokine that has a central immunoregulatory role in controlling T cell function and growth. Clinical trials of rIL-2 regimens in various solid tumors have been initiated, and 337 patients at the Cleveland Clinic Foundation have been treated in a sequence of trials. The studies have involved rIL-2 or polyethylene-glycol conjugated rIL-2 (PEG-IL-2) as single agents, combinations of rIL-2 with recombinant interferon alpha, IL-4, or doxorubicin, and trials of rIL-2 with tumor infiltrating lymphocytes (TILs). These studies are summarized and involve Phase I or Phase II investigations in patients with renal cell carcinoma (191 patients), malignant melanoma (49 patients) or miscellaneous solid tumors (97 patients). Response rates in each category, respectively, were 12%, 20% and 2%. Toxicity varied depending on the regimen and generally reflected the dose and schedule of rIL-2 being employed. This series of clinical studies demonstrates the role of rIL-2 in various malignancies and documents the activity in patients with malignant melanoma and renal cell carcinoma. Additional studies to investigate potential mechanisms of antitumor activity and response determinants are underway.

Pleiotropic effects of cytokines: clinical and preclinical studies.

Cytokines have diverse and pleiotropic effects including immunologic, hematopoietic and pro-inflammatory activities. A total of 135 patients have been treated in a series of phase I clinical trials utilizing five different recombinant cytokines: granulocyte-macrophage colony-stimulating factor (rhuGM-CSF), interleukin 3 (rhIL-3) interleukin 4 (rhuIL-4), and interleukin 6 (rhIL-6). The toxicity, maximum tolerated dose and biologic activities were determined. Hematopoietic, immunologic and pro-inflammatory effects were noted during therapy with these agents. Prominent effects on lymphocyte and monocyte functional activities were demonstrated. The diversity of biologic effects in vivo demonstrates the pleiotropic nature of the cytokines investigated and the difficulties encountered in their in vivo evaluation.

Selective cytokine gene expression in renal cell carcinoma tumor cells and tumor-infiltrating lymphocytes.

The progression of tumors such as renal cell carcinoma (RCC), despite the presence of substantial lymphocytic infiltrates (TIL), suggests that the ability of the local immune response to control tumor growth is impaired. Cytokine gene expression was examined to further investigate the nature of this response. Initial studies were performed with frozen tumors using PCR-assisted mRNA amplification with cytokine-specific primers for interleukin 10 (IL-10), interleukin 2 (IL-2) and interferon-gamma (IFN-gamma). IL-2 mRNA was not detected, despite the presence of T cells as defined by the expression of CD3 gamma mRNA. In contrast, mRNA for IFN-gamma was expressed in 4/9 and for IL-10 in 5/9 tumors. To confirm this, 5 fresh tumor specimens were examined, and PCR demonstrated that IL-10 mRNA was detectable in 4/5 tumors from which RNA was isolated at the time of nephrectomy. In these experiments multiple cycles and dilutions were employed to semi-quantitate the expression of IL-10. To identify potential sources of this cytokine in the tumor bed, IL-10 mRNA expression in freshly isolated lymphocytes and tumor cells, TIL lines, cultured RCC and established RCC lines was examined. Our studies demonstrate that within the tumor TIL may be one source of IL-10. Lymphocyte-enriched populations from 4/5 tumors expressed IL-10 mRNA as did 4/6 freshly isolated tumor cell preparations. IL-10 gene expression was not detected, however, in tumor cells after one passage in vitro in short-term cultured RCC tumor cells (passages 2-5) or in established RCC tumor cell lines. Finally, 4/9 CD4+ and 2/5 CD8+ TIL lines expressed IL-10 mRNA either constitutively or after stimulation with anti-CD3 antibody. This finding was associated with IL-10 production in vitro. Our studies demonstrate that IL-10 mRNA is frequently present in RCC tumors and may originate from the tumor-infiltrating mononuclear cell population.

Amifostine: potential for clinically useful cytoprotection.

The ability to target malignant cells for cytotoxicity while sparing normal host tissues has proven to be limited. These limitations have resulted in unacceptable toxicity or insufficiently effective therapy. Continuing investigation of new, potentially useful cytotoxic agents must continue. An alternative approach, also worthy of study, is the selective protection of normal tissues. This approach, used in conjunction with available therapeutic agents, may open the therapeutic window and incrementally enhance the effectiveness of cytotoxic therapy. A variety of methods have been used to protect normal tissues selectively. Regional protection can be used for certain organ systems, such as the oral mucosa. Selective protection on a systemic level is more difficult but agents that seem to protect normal but not malignant tissues selectively are being developed. Among these is amifostine, which was originally selected by the U.S. defense department for study as a radioprotectant. Pre-clinical studies have suggested that amifostine is differentially concentrated in normal tissues but not in malignant tissues. Tissue-specific differences in the activity of alkaline phosphatase, which dephosphorylates amifostine to its active metabolite WR-1065, and in pH are thought to be involved in this relative specificity. Clinical studies indicate that amifostine can reduce the myelosuppression produced by cyclosphosphamide, the combination of cyclophosphamide and cisplatin, and, perhaps, carboplatin. The protective effects of amifostine on nonhematopoietic toxicities are being investigated. Future trials will investigate the integration of amifostine with cytokine-based supportive care in order to define the role of this potentially clinically useful cytoprotectant agent.

Phase II trial of circadian infusion floxuridine (FUDR) in hormone refractory metastatic prostate cancer.

Circadian administration of chemotherapy has been reported to decrease toxicity and possibly enhance efficacy. Between March 1991 and December 1993, 18 evaluable patients with progressive, hormone-refractory metastatic prostate cancer were treated in this phase II trial of circadian infusion floxuridine (FUDR). The drug was delivered through a central venous catheter using a CADD-Plus computerized pump such that approximately 70% of the drug was administered between 3 and 9 p.m. and the rest (30%) was administered between 9 p.m. and 3 p.m. The dose of FUDR was 0.15 mg/kg/day x 14 days every 4 weeks. A total of 79 complete cycles was administered. Two of 18 evaluable patients (11.1%) had decreases in PSA lasting five and eight months. No objective responses or improvement in bone scans was noted. The major toxicity observed was diarrhea. Although circadian infusion FUDR is feasible and tolerable, it has limited activity in hormone refractory prostate cancer.