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Interleukin-1 (IL-1) is a cytokine critical to inflammation, immunological activation, response to infection, and bone marrow hematopoiesis. Cyclophosphamide downmodulates immune suppressor cells and is cytotoxic to a variety of tumors. A phase I trial of IL-1 and cyclophosphamide was conducted by the Eastern Cooperative Oncology Group. This study evaluated 3 dose levels and 3 schedules in patients with solid tumors. The goal was to evaluate the hematopoietic supportive care effect and possible antitumor effect. Toxicity was fever, chills, hypotension, nausea/emesis, hepatic, and neutropenia. Toxicity increased with dose increases of interleukin-1. Treatment at all dose levels resulted in significant increases in total white blood cell (WBC) counts above baseline. Nadir WBC and nadir absolute neutrophil counts were not significantly different by dose level of IL-1 or schedule of IL-1. Toxicity due to IL-1 at higher doses prohibited further evaluation of this agent for hematopoietic support, particularly in view of the activity and tolerability of more lineage-specific hematopoietic cytokines. Therapeutic interventions in the role of IL-1 in inflammatory conditions and cancer may be further informed by our definition of its clinical and biological effects in this evaluation of dose and schedule.

Purpose: Preclinical data suggested that bryostatin-1 (bryo) could potentiate the cytotoxicity of cisplatin when given prior to this drug. We designed a phase I study to achieve tolerable doses and schedules of bryo and cisplatin in combination and in this sequence., Methods: Patients with non-hematologic malignancies received bryo followed by cisplatin in several schedules. Bryo was given as an 1 and a 24 h continuous infusion, while cisplatin was always given over 1 h at 50 and 75 mg/m(2); the combined regimen was repeated on an every 3-week and later on an every 2-week schedule. Bryo doses were escalated until recommended phase II doses were defined for each schedule. Patients were evaluated with computerized tomography every 2 cycles., Results: Fifty-three patients were entered. In an every 2-week schedule, the 1-h infusion of bryo became limited by myalgia that was clearly cumulative. With cisplatin 50 mg/m(2) its recommended phase II dose was 30 microg/m(2). In the 3-week schedule, dose-limiting toxicities were mostly related to cisplatin effects while myalgias were tolerable. Pharmacokinetics unfortunately proved to be unreliable due to bryo's erratic extraction. Consistent inhibition of PKC isoform eta (eta) in peripheral blood mononuclear cells was observed following bryo., Conclusions: Bryo can be safely administered with cisplatin with minimal toxicity; however, only four patients achieved an objective response. Modulation of cisplatin cytotoxicity by bryo awaits further insight into the molecular pathways involved.

Purpose: GEM231 is a second-generation antisense oligonucleotide targeting the mRNA of the R1alpha regulatory subunit of cAMP dependent protein kinase A. Preclinical studies have demonstrated synergistic antitumor activity when GEM231 is combined with docetaxel. This trial assesses the safety of this combination., Experimental Design: Docetaxel was administered once every three weeks (one-cycle) at doses between 50-75 mg/m2. GEM231 was administered twice weekly at 220 mg/m2 for 3 (schedule-A), or 2 (schedule-B) weeks., Results: Twenty patients with chemotherapy-refractory advanced cancer received a total of 39 cycles of therapy. Six patients in schedule-A received docetaxel 50 mg/m2, and 14 patients in schedule-B received docetaxel 50-75 mg/m2. In schedule-A, 2 of 6 patients developed cycle-1 dose limiting toxicity (DLT)-grade-3 fatigue or grade-3 serum transaminase elevation. In schedule-B, 1 of 4 patients developed cycle-1 DLT at the highest dose of docetaxel tested (75 mg/m2)--grade-3 febrile neutropenia. Subsequent dose escalations were not pursued since the overall incidence of grade-3 toxicities (including those that occurred after cycle 1) was 75%, and this dose was close to the single agent MTD of docetaxel. Grade-3 toxicities included fatigue (2 patients), transaminase elevation (4 patients), and altered mentation (1 patient). The mean post-infusion aPTT was significantly higher than the pre-infusion value [14.8 seconds; p<0.001]; however, there were no hemorrhagic episodes., Conclusions: The recommended dose for further development of the combination of docetaxel and GEM231 is 75 mg/m2 and 220 mg/m2, respectively. It is important to administer GEM231 twice weekly for 2 consecutive weeks followed by a one-week break.

Purpose: To update and expand on previously published clinical practice guidelines for the treatment of cancer treatment-induced diarrhea., Methods: An expert multidisciplinary panel was convened to review the recent literature and discuss recommendations for updating the practice guidelines previously published by this group in the Journal of Clinical Oncology in 1998. MEDLINE searches were performed and the relevant literature published since 1998 was reviewed by all panel members. The treatment recommendations and algorithm were revised by panel consensus., Results: A recent review of early toxic deaths occurring in two National Cancer Institute-sponsored cooperative group trials of irinotecan plus high-dose fluorouracil and leucovorin for advanced colorectal cancer has led to the recognition of a life-threatening gastrointestinal syndrome and highlighted the need for vigilant monitoring and aggressive therapy for this serious complication. Loperamide remains the standard therapy for uncomplicated cases. However, the revised guidelines reflect the need for recognition of the early warning signs of complicated cases of diarrhea and the need for early and aggressive management, including the addition of antibiotics. Management of radiation-induced diarrhea is similar but may not require hospitalization, and chronic low- to intermediate-grade symptoms can be managed with continued loperamide., Conclusion: With vigilant monitoring and aggressive therapy for cancer treatment-induced diarrhea, particularly in patients with early warning signs of severe complications, morbidity and mortality may be reduced.

Purpose: 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP; Triapine; Vion Pharmaceuticals Inc, New Haven, CT) is a potent inhibitor of ribonucleotide reductase, with activity in preclinical tumor model systems. A phase I trial was initiated to determine the dose-limiting toxicities, maximum-tolerated dose, and pharmacokinetics of a 96-hour intravenous (IV) continuous infusion in patients with advanced cancer., Patients and Methods: Initially, courses were administered every 3 weeks, using an accelerated titration design. Subsequently, courses were administered every 2 weeks, and the dose was escalated in cohorts of three to six patients., Results: Twenty-one patients were enrolled, seven on the every-3-week schedule and 14 on the every-other-week schedule. Three of six patients at 160 mg/m(2)/d developed dose-limiting toxicities including neutropenia, hyperbilirubinemia, and nausea or vomiting. Based on these initial results, the dose for 3-AP was re-escalated beginning at 80 mg/m(2)/d but administered every 2 weeks. At 120 mg/m(2)/d, three of seven patients had dose-limiting but reversible asthenia, hyperbilirubinemia, and azotemia or acidosis; however, in the case of renal and hepatic adverse events, the events were related to pre-existing borderline abnormal organ function. Therefore, the recommended phase II dose for 3-AP administered by 96-hour IV infusion is 120 mg/m(2)/d every 2 weeks. Detailed pharmacokinetic studies demonstrated linear kinetics up to 160 mg/m(2), with substantial inter-patient variability. There was no correlation between dose and clearance (R(2) = 0.0137). There were no objective responses, but there was prolonged stabilization of disease or decreases in serum tumor markers associated with stable disease in four patients., Conclusion: The 96-hour infusion of 3-AP is safe and well tolerated at the recommended phase II doses. Phase II trials of Triapine are ongoing.

Background: The aim of this study was to determine the maximum tolerated dose, recommended phase II dose (RPTD) and toxicities of the FOG regimen (infusional 5-fluorouracil, oxaliplatin, gemcitabine)., Patients and Methods: Patients with advanced solid tumors were treated in an accelerated titration scheme. 5-Fluorouracil was administered intravenously at 200 mg/m(2)/day for 14 days and repeated every 21 days (one cycle). Gemcitabine was administered on days 1 and 8 over 30 min at 450-650 mg/m(2). Oxaliplatin was administered on day 1 over 2 h at 85-130 mg/m(2). For cycles 1, 3 and beyond, gemcitabine followed oxaliplatin; for cycle 2, gemcitabine preceded oxaliplatin., Results: Forty-five and 39 patients were assessable for toxicity and response, respectively. Cycle 1 dose-limiting toxicities (DLT) included neutropenia, thrombocytopenia and diarrhea. No DLT was observed in cycle 1 at the first four dose levels (DL). At DL-5, two of four (50%) patients experienced DLT in cycle 1. Expanding DL-4, nine of 26 (35%) patients experienced DLT in cycle 1. Because recurrent grade 3 toxicities were observed in three of six (50%) patients at DL-3, DL-2 was considered the RPTD. At the RPTD, three patients had a partial response (response rate 23%)., Conclusions: The RPTD for the 5-fluorouracil-oxaliplatin-gemcitabine combination is 200/100/450 mg/m(2). This novel regimen has demonstrated activity in advanced solid tumors and merits further investigation.

We sought to define the tolerance of 9-amino-20(S)-camptothecin (9-AC) when given by the i.p. route to patients with cancer in the peritoneal cavity consisting of nodules that did not exceed 1 cm in maximum diameter. 9-AC was given in six fractions over 12 days, at doses ranging from 1.25 to 13.5 mg/m(2) in cycles repeated every 28 days. Dose escalations after the first two dose levels took place in cohorts of three patients, with expansion of the dose level once a dose-limiting toxicity (DLT) was encountered. All patients had blood and i.p. pharmacokinetic (PK) analysis during cycle 1 of each dose level. Topoisomerase (Topo) I signal was serially measured in peripheral blood mononuclear cells (PBMCs) in blood and cells collected in i.p. cytologic washings. Twelve patients received 31 cycles of 9-AC. Tolerance to repeated i.p. drug administration was generally excellent. The DLT was neutropenia encountered at the highest dose level in two patients, whereas the dose of 9 mg/m(2) was well tolerated. The DLTs were associated with peak plasma levels ranging from 47 to 81 ng/ml and also depletion of Topo I in PBMCs. The i.p.:plasma AUC ratio (+/-SD) was 11.5 (+/-3.8). Two patients had objective evidence of clinical benefit and only one of seven patients deemed evaluable for response had progressive disease. We conclude that i.p. 9-AC demonstrates excellent local tolerance at a dose and schedule associated with evidence of systemic effects. A dose of 9 mg/m(2)/cycle administered in a schedule of six divided fractions is suitable for further evaluation against tumors involving primarily the peritoneal cavity.

A number of distinct surveillance systems are found in mammalian cells that have the capacity to interrupt normal cell-cycle progression. These are referred to as cell cycle check points. Surveillance systems activated by DNA damage act at three stages, one at the G1/S phase boundary, one that monitors progression through S phase and one at the G2/M boundary. The initiation of DNA synthesis and irrevocable progression through G1 phase represents an additional checkpoint when the cell commits to DNA synthesis. Transition through the cell cycle is regulated by a family of protein kinase holoenzymes, the cyclin-dependent kinases (Cdks), and their heterodimeric cyclin partner. Orderly progression through the cell-cycle checkpoints involves coordinated activation of the Cdks that, in the presence of an associated Cdk-activating kinase (CAK), phosphorylate target substrates including members of the "pocket protein" family. One of these, the product of the retinoblastoma susceptibility gene (the pRB protein), is phosphorylated sequentially by both cyclin D/Cdk4 complexes and cyclin E/Cdk2 kinases. Recent studies have identified important cross talk between the cell-cycle regulatory apparatus and proteins regulating histone acetylation. pRB binds both E2F proteins and histone deacetylase (HDAC) complexes. HDAC plays an important role in pRB tumor suppression function and transcriptional repression. Histones are required for accurate assembly of chromatin and the induction of histone gene expression is tightly coordinated. Recent studies have identified an important alternate substrate of cyclin E/Cdk2, NPAT (nuclear protein mapped to the ATM locus) which plays a critical role in promoting cell-cycle progression in the absence of pRB, and contributes to cell-cycle regulated histone gene expression. The acetylation of histones by a number of histone acetyl transferases (HATs) also plays an important role in coordinating gene expression and cell-cycle progression. Components of the cell-cycle regulatory apparatus are both regulated by HATs and bind directly to HATs. Finally transcription factors have been identified as substrate for HATs. Mutations of these transcription factors at their sites of acetylation has been associated with constitutive activity and enhanced cellular proliferation, suggesting an important role for acetylation in transcriptional repression as well as activation. Together these studies provide a working model in which the cell-cycle regulatory kinases phosphorylate and inactivate HDACs, coordinate histone gene expression and bind to histone acetylases themselves. The recent evidence for cross-talk between the cyclin-dependent kinases and histone gene expression on the one hand and cyclin-dependent regulation of histone acetylases on the other, suggests chemotherapeutics targeting histone acetylation may have complex and possibly complementary effects with agents targeting Cdks.

Novel therapeutics in oncology stem from a rational design of drugs targeting selective pathways that stimulate and maintain tumor cell growth. Many of these agents are cytostatic in action and also have a limited toxicity profile. However, some can be cytotoxic if they successfully modulate molecular pathways of apoptosis, such as bcl-2. This article discusses points to consider in the design of one class of cytostatic agents, antisense therapy. Our purpose is to stimulate designs that answer the question specifically with regard to proof-of-concept, and the concepts proposed should be viewed as ideas in development rather than firm recommendations.

Purpose: The hematopoietic growth factor filgrastim has been shown to reduce both chemotherapy-induced myelosuppression and mucosal toxicities. The aim of this study was to conduct four separate pilot trials to determine the maximum-tolerated doses at which interferon alpha (IFN alpha) followed by 5-fluorouracil (5-FU) could be administered in combination with filgrastim support., Patients and Methods: Patients were required to have a histologically documented solid tumor with either measurable or evaluable lesions. All patients were fully ambulatory; had adequate bone marrow, renal, and hepatic function; had recovered from surgery; and gave informed consent. Trials were conducted sequentially. In parts A and B, patients received 5-FU as a continuous intravenous infusion daily for 5 days, followed by weekly bolus therapy at the same dose. In parts C and D, patients received 5-FU as a weekly high-dose, 24-hour infusion. Interferon was administered immediately before the 5-FU three times a week. Filgrastim was administered at 5 micrograms/kg subcutaneously either four (parts A, B) or five (parts C, D) times a week. In part A, the starting doses were as follows: 5-FU, 750 mg/m2, and IFN alpha, 3 MU subcutaneously, and the IFN alpha was escalated between patient cohorts to a maximum of 9 MU. Part B used the dose of IFN alpha established from part A, and the 5-FU was escalated to the maximum-tolerated dose between patient cohorts. In part C, the starting dose of IFN alpha was 3 MU subcutaneously, and that of 5-FU, 2.6 g/m2, and the dose of IFN alpha was escalated to a maximum of 9 MU. In part D, the dose of IFN alpha was determined from part C, and the dose of 5-FU was escalated. The maximum tolerated dose was the highest dose at which three of three or five of six patients were able to tolerate therapy., Results: There were 71 patients entered into the four parts of this trial. In part A (12 patients), the dose of IFN alpha, was escalated to 9 MU subcutaneously three times a week with only one patient experiencing dose-limiting toxicity. In part B (13 patients), the dose of 5-FU could not be escalated beyond 750 mg/m2 because of sepsis (one patient) and gastrointestinal hemorrhage (one patient). The predominant toxicities were diarrhea (46%), vomiting (23%), and mucositis (31%). In part C (24 patients), two patients experienced dose-limiting toxicities (staphylococcal sepsis [one patient] and neuropsychiatric [one patient]). The dose of IFN alpha was escalated to 9 MU. In part D (21 patients), the dose of 5-FU was escalated to 3.4 g/m2 administered weekly. No patients at this dose level experienced serious toxicities. At the next highest dose level, 3.6 g/m2, one patient each experienced gastrointestinal hemorrhage and diarrhea. There were no additive constitutional symptoms resulting from the combination of IFN alpha and filgrastim. In parts C and D, filgrastim could be administered 6 hours after the end of the 5-FU infusion without excessive myelosuppression., Conclusions: The addition of filgrastim allowed escalation of the dose of 5-FU on the weekly, high-dose schedule, but not on the weekly bolus schedule. IFN alpha and filgrastim can be administered without additive toxicities. Filgrastim can be safely administered < 24 hours after completion of the weekly, high dose 5-FU infusion.

The enzyme/cytokine thymidine phosphorylase/platelet-derived endothelial cell growth factor (TP/PD-ECGF) has diverse functions within cells, including the regulation of steady-state thymidine levels, the conversion of the cancer chemotherapeutic agent 5-fluorouracil (FUra) to an active metabolite, and the mediation of angiogenesis in normal and malignant cells. Although the levels of TP/PD-ECGF vary substantially among different tissues and are generally found to be elevated in tumors, little is known about the control of its expression in vivo in humans. In this study, peripheral blood mononuclear cells were obtained from patients prior to and during treatment with IFN and FUra and analyzed for TP/PD-ECGF expression. Sixteen of 21 patients (76%) exhibited an average 3-4-fold increase of TP/PD-ECGF protein levels after treatment with either IFN-alpha or-beta, with the remaining patients having either a decrease (four patients) or no change (one patient) at the sampling times examined. Expression in vivo increased rapidly within 1-2 h of IFN treatment and remained elevated for up to 48 h after its administration. The increase in TP/PD-ECGF protein was accompanied by a concomitant increase in TP/PD-ECGF mRNA levels. TP/PD-ECGF mRNA expression in cells in vitro was induced by IFN but not by pharmacologically relevant concentrations of FUra, suggesting that the IFN was responsible for the induction seen in the patients. This study demonstrates that IFN induces TP/PD-ECGF expression in vivo by regulation of the level of mRNA expression.

Irinotecan (CPT-11) is a derivative of the chemotherapeutic agent camptothecin. CPT-11 inhibits the nuclear enzyme topoisomerase I. It has demonstrated a broad spectrum of antitumor activity in preclinical tumor model systems. Significant advances have been made toward the understanding of the pharmacokinetics and schedule dependency of this agent. CPT-11 has demonstrated significant clinical activity in the treatment of patients with gastrointestinal, pulmonary, gynecologic, and lymphoid malignancies. Further study of this agent to determine its role in combination chemotherapeutic regimens is currently underway.

The ribonucleotide reductase inhibitor, hydroxyurea (HU), augments the cytotoxic effects of 5-fluorouracil (5FU) in vitro; both drugs are synergistic with interferon-alpha (IFN) in vitro. The aim of this phase I study was to determine the maximal duration of HU, 4.3 g/m2, administered as a parenteral infusion in combination with 5FU, 2.6 g/m2 administered over 24 hrs each week, + IFN, 9 MU, subcutaneously three times per week. There were 26 patients enrolled and evaluable. This included 14 patients with colorectal cancer of whom 13 had been previously treated, and 12 patients with other refractory malignancies (pancreas, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, and others), of whom 10 were previously untreated. The dose-limiting toxicity of this regimen was myelosuppression. This prohibited dose escalation of HU above the starting dose (24 hrs) on a 6-weeks-on, 2-weeks-off therapy schedule. When filgrastim, 480 microg, was administered subcutaneously on days 3-6, the duration of HU could be extended to 48 hrs on a 2-weeks-on, 1-week-off therapy schedule. There were two instances of fatal infection, one in a patient with a rectovaginal fistula with neutropenic sepsis and the second in a patient with non-neutropenic Clostridium septicum sepsis. All therapy was administered in the ambulatory setting. There were three responders, all among previously untreated patients. High-dose parenteral hydroxyurea, 4.3 g/m2 administered over 24 hrs, can be safely combined with high-dose weekly 5FU, 2.6 g/m2 over 24 hrs + IFN, 9 MU subcutaneously three times per week, without filgrastim in the ambulatory setting. Parenteral hydroxyurea, 4.3 g/m2 over 24 hrs daily x 2 can also be combined with high-dose 5FU + IFN, but requires the addition of filgrastim to avoid severe myelosuppression.

The combination of cytokines and cytotoxic drugs offers a new approach to increase the therapeutic index in the treatment of neoplastic diseases. There is no consensus on optimal strategies for combining these agents so far. The molecular mechanisms underlying the interaction, however, should be defined in order to design clinical trials based on preclinical rationales. The broad spectrum of cytotoxic drugs whose activity can be enhanced by cytokines argues for multiple levels of drug interaction in vitro: alteration in the cellular drug uptake, modulation of drug target enzymes, and changes in metabolism or disposition of a drug. In vivo interaction between cytokines and cytotoxic agents involves an additional layer of complexity because of the effects of cytokines on the host immune system and on drug-metabolizing enzymes. A major mechanism involved in the synergistic interaction of interferon (IFN) and 5-fluorouracil (5-FU) seems to be the increase of active 5-FU metabolites by IFN. Moreover, IFN can reverse resistance against 5-FU by inhibiting the overexpression of thymidylate synthase. The absence of cytokinetic effects of IFN and FU argues against the recruitment of Gs cells into the cell cycle. Topoisomerase has emerged as a critical intracellular target of cytotoxic drugs. There is convincing evidence that the synergy between tumor necrosis factor (TNF) and topoisomerase-targeted intercalative (Adriamycin, doxorubicin hydrochloride; m-AMSA, amsacrine; mitoxantrone) and nonintercalative (VM-16, etoposide; VM-26, teniposide) drugs is related to a rapid increase in specific activity of topoisomerase I and II, resulting in enhanced DNA strand breaks and cleavage complex. Furthermore, sensitivity to topoisomerase II targeted drugs can be enhanced by granulocyte colony-stimulating factor (G-CSF) through elevated enzyme activity in tumor cell response to G-CSF. The synergistic interaction between cytokines and cytotoxic agents seems to be sequence dependent. It has recently been demonstrated that newly synthesized metal compounds and IFN are synergistic only after preincubation with cytokines. Cytokines can modulate expression of adhesion receptors on tumor cell lines, thereby influencing their metastatic potential. A considerable number of phase II trials with combination of cytokines and cytotoxic drugs based on these mechanisms have demonstrated promising response rates and tolerable toxicity. Phase III trials are currently in progress to identify enhanced activity combining cytokines and cytotoxic drugs in the treatment of malignancies.

Background: Originally described as antiviral agents, interferons (IFN) were investigated as potential anticancer agents because of their antiproliferative and cytotoxic effects, their ability to activate specific components of the immune system, and their relatively modest toxicities. Interest intensified when durable complete remissions were observed in patients with hairy cell leukemia after IFN treatment; modest, but reproducible activity also was found against tumors such as melanoma and renal cell carcinoma which are unresponsive to conventional chemotherapy. Observations of synergy between IFN and cytotoxic drugs in vitro and in vivo suggested that IFN may have additional utility as modulating agents., Methods: Reports of major clinical trials using IFN either alone or in combination with other agents were reviewed. Activity was identified by disease site. Correlations were made with important preclinical studies., Results: IFN has reproducible, but modest, single-agent activity against melanoma, renal cell carcinoma, and acquired immune deficiency syndrome-related Kaposi sarcoma. IFN may be useful in the treatment of a number of benign, in situ, or low-grade tumors. IFN in combinations with cytotoxic agents have demonstrated activity in solid tumors. Clinical trials using combinations of IFN and 5-fluorouracil or dacarbazine suggested a potential benefit for the combination compared with single-agent chemotherapy. These are preliminary findings that require confirmation, but they suggest that combination therapy should be investigated further. In early preclinical and clinical studies, combinations of IFN and other biologic agents, hormonal agents, and radiation therapy appear to be interesting., Conclusions: The role of IFN in the treatment of solid tumors may be evolving from that of single-agent therapy to combination therapy with other active agents. Additional studies are required to determine the optimal doses, schedules, and sequencing of these combination therapies.

The combination of interferon (IFN) and conventional chemotherapeutic agents offers a promising therapeutic approach for the treatment of cancer. However, there is as yet no consensus on optimal strategies for combining this family of compounds with other cancer therapies. While in vitro studies have demonstrated both direct cytotoxic and cytokinetic effects for IFN, a more interesting role derives from its ability to synergistically potentiate the activity of a wide variety of cytotoxic agents against multiple human and rodent tumors, both in vitro and in animal models. The interaction between IFN and cytotoxic agents in vitro is complex and depends not only on the choice of cytotoxic agent but also on the concentrations, ratios, duration, and sequence of exposure to the two drugs. Preliminary data suggest that some combinations are not merely additive but rather that IFN may biochemically modulate the cellular uptake or metabolism of the cytotoxic agent resulting in synergistic antineoplastic activity. In vivo interactions between IFN and cytotoxic agents involve an additional layer of complexity because of the potential effects of the biological agent on the host immune system and drug-metabolizing enzymes. Furthermore, IFN may have a protective effect on normal host tissues which theoretically could allow for the delivery of higher doses of cytotoxic agents. The results of early clinical trials using combinations of IFN with chemotherapeutic agents have generally been disappointing. This may be due to the inability of preclinical models to accurately predict the clinical situation or alternatively from a failure to incorporate information on dose, scheduling, and sequence of drug administration into clinical trials. Preliminary clinical studies with IFN-alpha and the fluorinated pyrimidine, 5-fluorouracil, in patients with advanced colorectal carcinoma suggest that IFN may enhance the effects of the antimetabolite. Confirmatory trials are in progress. Further trials designed to exploit the preclinical experience with combinations of IFN and cytotoxic agents are warranted.

Cisplatin is a chemotherapeutic coordination complex that has been evaluated extensively. It is particularly active against testicular cancer, but carcinomas of the ovary, bladder, cervix, and head and neck are also responsive. To increase efficacy and decrease toxicity, a number of platinum analogues have been developed and tested. One of these, carboplatin, is of particular interest. In clinical trials, it has demonstrated antitumor activity comparable to that of cisplatin, without evidence of significant renal toxicity or neurotoxicity. A second interesting platinum analogue is iproplatin. Preliminary phase I studies suggest reduced adverse renal and neurologic effects similar to those seen with carboplatin, with efficacy comparable to cisplatin. Attempts to overcome the dose-limiting toxicity of cisplatin by administering high-dose cisplatin (40 mg/m2/d for five days) in hypertonic saline or with thiosulfate protection are also reviewed. These techniques have eliminated nephrotoxicity as the dose-limiting toxicity of cisplatin. However, nonrenal toxicity, especially neurotoxicity, remains substantial. The extent to which high-dose cisplatin-based chemotherapy should be used in routine clinical practice has not been determined.