Randomized comparison of interferon alpha and hydroxyurea with hydroxyurea monotherapy in chronic myeloid leukemia (CML-study II): prolongation of survival by the combination of interferon alpha and hydroxyurea.

The optimum treatment conditions of interferon (IFN) alpha therapy in chronic myeloid leukemia (CML) are still controversial. To evaluate the role of hydroxyurea (HU) for the outcome of IFN therapy, we conducted a randomized trial to compare the combination of IFN and HU vs HU monotherapy (CML-study II). From February 1991 to December 1994, 376 patients with newly diagnosed CML in chronic phase were randomized. In all, 340 patients were Ph/BCR-ABL positive and evaluable. Randomization was unbalanced 1:2 in favor of the combination therapy, since study conditions were identical to the previous CML-study I and it had been planned in advance to add the HU patients of study I (n=194) to the HU control group. Therefore, a total of 534 patients were evaluable (226 patients with IFN/HU and 308 patients with HU). Analyses were according to intention-to-treat. Median observation time of nontransplanted living patients was 7.6 years (7.9 years for IFN/HU and 7.3 years for HU). The risk profile (new CML score) was available for 532 patients: 200 patients (38%) were low, 239 patients (45%) intermediate, and 93 patients (17%) high risk. Complete hematologic response rates were higher in IFN/HU-treated patients (59 vs 32%). Of 169 evaluable IFN/HU-treated patients (75%), 104 patients (62%) achieved a cytogenetic response that was complete in 12% (n=21), major in 14% (n=24), and at least minimal in 35% (n=59). Of the 534 patients, 105 (20%) underwent allogeneic stem cell transplantation in first chronic phase. In the low-risk group, 65 of 200 patients were transplanted (33%), 30 (13%) in the intermediate-risk group, and nine (10%) in the high-risk group. Duration of chronic phase was 55 months for IFN/HU and 41 months for HU (P<0.0001). Median survival was 64 months for IFN/HU and 53 months for HU-treated patients (P=0.0063). We conclude that IFN in combination with HU achieves a significant long-term survival advantage over HU monotherapy. In view of the data of CML-study I, these results suggest that IFN/HU is also superior to IFN alone. HU should be combined with IFN in IFN-based therapies and for comparisons with new therapies.

Phase II evaluation of 5-fluourouracil plus folinic acid and alpha 2b-interferon in metastatic colorectal cancer.

Biochemical modulation of 5-fluorouracil (5-FU) by folinic acid (FA) increases the response rate in patients with metastatic colorectal cancer compared to 5-FU alone. Phase II trials also demonstrated increased efficacy when interferon was added to 5-FU. In two consecutive trials, 76 patients were treated on days 1-5 with FA 200 mg/m2 plus interferon 5 x 10(6) U/m2 and 5-FU 350 mg/m2 as intravenous bolus injection (n = 33, regimen A) or 5-FU 500 mg/m2 as 2-hour infusion (n = 43, regimen B), repeated every 3 weeks with individual 5-FU dose escalation in steps of 50 (regimen A) or 100 mg/m2 (regimen B). In regimen A 5-FU dose reduction to 300 mg/m2 due to toxicity was necessary in 49% of the patients; in regimen B a 5-FU dose of 600 mg/m2 or above was tolerated by 70% of the patients. Dose-limiting toxicity was severe mucositis and/or diarrhea. Objective responses were observed in 5 of 33 patients (15%) in regimen A (3-28%, 95% confidence interval) and 7 of 41 patients (17%) in regimen B (5-29%, 95% confidence interval). Median time to progression was 4.7 and 4.8 months, and median survival 9.9 and 11.4 months for regimens A and B, respectively. Prolonged 5-FU administration over 2 h allows the administration of a higher 5-FU dose compared to bolus injection with no apparent improvement in antineoplastic efficacy. The addition of interferon to the combination of 5-FU plus FA in this dose and schedule does not seem to improve the response rate but appears to increase treatment toxicity.

Failure of orally administered dipyridamole to enhance the antineoplastic activity of fluorouracil in combination with leucovorin in patients with advanced colorectal cancer: a prospective randomized trial.

PURPOSE: A randomized trial was performed to investigate the ability of the nucleoside transport inhibitor dipyridamole (DP) to enhance the antitumor activity of fluorouracil (5-FU)/leucovorin (folinic acid [FA]). PATIENTS AND METHODS: One hundred eighty-one untreated patients with advanced colorectal cancer were randomized to receive 5-FU 600 mg/m2 plus FA 300 mg/m2 on days 2 to 4 with or without DP 75 mg orally three times daily on days 1 to 5. Cycles were repeated every 3 weeks. Only patients with documented tumor progression before therapy were eligible. 5-FU pharmacokinetics using high-performance liquid chromatography (HPLC) were assessed in 11 nonrandomized patients receiving paired cycles with or without DP. RESULTS: One hundred seventy-four patients were assessable for toxicity and response. There was no significant difference in toxicity, except DP-related headache in 24% of patients. An objective response rate of 15% (one complete response [CR] and 13 partial responses [PRs]) for 5-FU/FA and 13% (two CRs and nine PRs) for 5-FU/FA/DP was observed. The dose-intensity of 5-FU delivered was significantly higher (1.09- to 1.16-fold) for the DP-containing arm. Pharmacokinetic parameters of 5-FU did not differ significantly, except for a prolonged half-life (t1/2) induced by DP. The median time to progression (P = .8) and the median survival time (11.6 months for 5-FU/FA v 9.3 months for 5-FU/FA/DP; P = .14, log-rank test) were not different between treatment arms. CONCLUSION: Orally administered DP did not improve the antineoplastic activity of 5-FU/FA in patients with advanced colorectal cancer when used at this dose and schedule. The observed increase in 5-FU dose-intensity for FU/FA/DP was not clinically relevant.

Interferon alpha-2b, 5-fluorouracil, and folinic acid combination therapy in advanced colorectal cancer: preliminary results of a phase I/II trial.

We conducted a phase I/II trial of 5-fluorouracil (5-FU)/folinic acid (FA) and alpha-2b interferon (IFN) in 43 previously untreated patients with measurable metastatic colorectal cancer. Patients had disease progression prior to therapy consistent of 5-FU 500 mg/m2 (level A) or 600 mg/m2 (level B) as starting dose administered as a 2-hour infusion, FA 200 mg/m2, and alpha-2b IFN 5MU/m2 subcutaneously. All drugs were given on days 1 to 5 and cycles were repeated after 3 to 4 weeks. The aim of the study was to define the maximal tolerable dose (MTD) of 5-FU for this schedule. In the absence of toxicity above MTD, defined as diarrhea and mucositis of World Health Organization grade 2 and leukopenia of World Health Organization, grade 3 5-FU was increased in increments of 100 mg/m2 for further cycles. Twenty-four patients were started on level A; 18 were started on level B. Forty-two patients were evaluable for toxicity, 32 for response. Three of 32 patients achieved a partial response; in 22 of 32 patients, tumor stabilization occurred. Forty percent of patients started on level A developed grade 2 diarrhea; 28% of patients developed grade 2 or 3 mucositis. Of 18 patients on level B, two patients experienced grade 4 mucositis (11%) and grade 3 or 4 diarrhea (11%). One drug-related death in the presence of sepsis occurred. Due to 11% of patients with grade 4 toxicity when started on 600 mg/m2 5-FU and 40% of patients with grade 2 diarrhea when started on level A, MTD as starting dose for 5-FU is 500 mg/m2 as a 2-hour infusion when used in combination with FA and IFN on a day 1 to 5 active schedule. We observed a wide range of 5-FU dose tolerated by individual patients. While some patients experienced severe, mainly gastrointestinal, toxicity on lower levels of 5-FU, others tolerated much higher 5-FU doses (11 patients, 700 mg/m2; 5 patients, 800 mg/m2; and one patient, 900 mg/m2). Our data suggest that double modulation of 5-FU by FA and IFN may not be superior to modulation of 5-FU with either drug alone.

Stem cell defects after cytoreductive therapy in man.

The study of stem cell defects in man after cytoreductive therapy appears to be of particular importance since hematotoxicity represents the major limiting side effect in many instances. On the other hand, such studies are met by difficult methodological problems. In particular, bone marrow sampling in man cannot be done on a quantitative basis. Furthermore, ethical considerations restrict the sampling of serial bone marrow specimens. We have studied the reaction of hematopoiesis including stem cells in man with the available methods, in particular CFU-GM (CFU-C), CFU-E, and BFU-E in bone marrow (BM) and peripheral blood (PB) during the course of various cytostatic regimens given for adjuvant and palliative chemotherapy of human cancer. Major findings of these studies were The acute reaction of BM stem cells and differentiated BM precursor pools corresponds to the mechanisms known to be effective in animal experiments. The PB CFU-GM may be of particular importance in man in demonstrating long-term derangements. In an attempt at quantification of human BM data, an index was developed from BM spicule morphometry and from standardized BM aspirate cellularity. Stem cell defects in BM and PB were observed that did not show up in the PB counts, in particular after nitrosoureas. Indication of prolonged derangements in stem cells up to five years after chemotherapy were observed after adjuvant therapy for breast cancer. From these data, it appears advisable to study stem cell data in man for newly developed chemotherapeutic regimens in order to minimize early and late side effects on hematopoiesis.

The problem of permanent bone marrow damage after cytotoxic drug treatment.

The majority of cytotoxic drugs exert a dose-dependent injury to the hemopoietic bone marrow. In experimental systems, two different types of damage to the hemopoietic stem cell compartments have been demonstrated to occur following cytotoxic drug exposure. First, a reversible reduction of the size of these stem cell compartments; recovery of compartment size results from a transiently increased proliferative activity of those stem cells surviving the cytotoxic drug exposure. Second, irreversibly decreased proliferative potential of pluripotent stem cells has been observed after some cytotoxic agents. Experimental evidence indicates that such permanent stem cell damage may lead to the failure of the hemopoietic bone marrow to produce sufficient numbers of blood cells. There are indications that a similar permanent damage to the hemopoietic system may occur in man following repeated exposure to at least some cytotoxic agents.

Adjuvant chemo(immuno-)-therapy of primary breast cancer with adriamycin-cyclophosphamide (and levamisole)--six-year evaluation.

In a phase II-type study 52 patients with no signs of metastases but with a high risk of recurrence were treated with 6 courses of adriamycin-cyclophosphamide as adjuvant systemic therapy following modified radical mastectomy of primary breast cancer. Half of the patients were randomized to receive additional immunotherapy with levamisole for 2 yr. The scheduled dose and time regimen could be achieved in over 90% of patients. A comparison of the actuarial disease-free and overall survival with data reported in the literature indicates a similar positive effect of adjuvant systemic therapy as described in adjuvant studies using polychemotherapy regimens. Immunotherapy with levamisole has no effect on disease-free and overall survival but added to general toxicity. Particular attention was paid to psychological consequences of adjuvant systemic therapy; consistent attention by one specifically trained physician during the whole therapy and follow-up period was effective in coping with the emotional problems. The difficulties in treating recurrences after adjuvant therapy became apparent. A high rate of loco-regional recurrences and of cerebral metastases was noted.

5-Fluorouracil, 1,3-bis(2-chloroethyl)-1-nitrosourea, and 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea: effect on the human granulopoietic system.

The reaction pattern of the normal (nonleukemic) human granulopoietic system to single-agent treatment with 5-fluorouracil (FUra) and to a combination of FUra with two nitrosoureas, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU), was studied serially by morphologic and in vitro culture methods. The granulopoietic toxicity of FUra was acute and rapidly (by day 21) reversible. In contrast, the toxicity of the combination regimens was long lasting. Evidence exists that an early toxicity (that of FUra) and a delayed toxicity (that of the nitrosourea) were overlapping. Toxicity of BCNU and MeCCNU was most pronounced at the level of in vitro colony-forming units of the granulopoietic system (G-CFUc). G-CFUc compartments of bone marrow and peripheral blood continued to be reduced in size at the time of recovery of the peripheral blood granulocyte count from nitrosourea-induced toxicity. This finding may be responsible for the cumulative toxicity to the human hematopoietic system that frequently has been observed after repeated administration of nitrosourea compounds.

Attempt at quantification of the cytotoxic drug-induced changes of the human bone marrow compartments.

In order to describe the changes of the human bone marrow compartments after repeated courses of adriamycin/cyclophosphamide in quantitative terms, 2 methods have been studied for their usefulness as indices of bone marrow cellularity: cell counts per ml of bone marrow aspirates obtained under standardized conditions, and cell counts per microliter of bone marrow spicules evaluated by morphometric techniques. Applied to a sufficiently large group of patients, both methods were useful to describe the cytotoxic drug-induced changes of the bone marrow compartments in accordance with the following indirect criteria: (a) the results in man are quite compatible with the changes of haematopoiesis described in animal experiments after cytotoxic drugs; (b) the changes of the peripheral blood cell pools - PMN and reticulocytes -, which can be assessed quantitatively, correspond to the changes of the respective bone marrow pools as determined by the described indices of cellularity; (c) this quantitative description of drug-induced changes in the human bone marrow compartments yields 'reasonable' results on the basis of both the mechanism of action of the cytotoxic drugs employed and the kinetics of the haematopoietic system studied.

Short-term and long-term effects of chemoimmunotherapy on granulopoiesis: adjuvant therapy of breast cancer.

The effect of adjuvant chemoimmunotherapy on normal human granulopoiesis has been studied. The short-term pattern of hemopoietic depletion and regeneration confirms that human bone marrow shows reaction to cytotoxic agents similarly to that observed in animal experiments. A regenerative response to the drug-induced depletion of the committed stem cell compartment occurs very early, thus suggesting local CFUC population size control of negative feedback from the early granulocytic compartments. Levamisole in that particular regimen did not influence the reaction pattern of granulopoiesis following cytotoxic drug exposure. A model of quantitative evaluation leads to a description of compartment changes which is compatible with the concepts of hemopoietic reaction to cytotoxic drugs. Of particular importance to the planning of adjuvant therapy is the observation of a long-term defect of granulopoiesis after discontinuation of chemotherapy. Studies like those presented here should be performed on any regimen of adjuvant therapy to select the least toxic regimen when several cytotoxic combinations with similar activities are available.

Adjuvant intermittent chemoimmunotherapy for primary breast cancer: a prospective study with immunologic follow-up.

In an interdisciplinary prospective study 50 patients surgically treated for breast cancer were treated with six monthly courses of aggressive adjuvant chemotherapy (adriamycin and cyclophosphamide) and were randomized to receive either immunotherapy with levamisole or no additional therapy. Probability of disease-free survival for the whole group is 54.9% at 42 months. There was no noticeable difference in disease-free survival for either pre- and postmenopausal women or for patients treated with or without levamisole. The addition of levamisole had no effect on the depression of in vitro immunologic functions during chemotherapy.

Effect of high-dose methotrexate with citrovorum factor on human granulopoiesis.

The present studies were performed to delineate the effect of high-dose methotrexate with citrovorum factor rescue on the measurable compartments of human granulopoiesis, including peripheral blood cells and bone marrow stem cells committed to granulopoiesis-monocytopoiesis. Parameters of granulopoiesis were determined during the first course of high-dose methotrexate with citrovorum factor rescue in five patients, and during four consecutive courses in one patient. The remarkably mild toxicity of high-dose methotrexate with citrovorum factor rescue reported in clinical studies was substantiated on the level of the committed stem cell compartment. The data suggest a higher sensitivity of in vitro colony-forming units in agar culture as compared to the more mature granulopoietic cells and document the exquisite sensitivity and regenerating capacity of erythroid precursors after this type of chemotherapy.

No effects of levamisole on cytotoxic drug-induced changes of human granulopoiesis.

The effect of Levamisole on the human granulopoiesis was studied in patients randomized to receive, in addition to adjuvant chemotherapy for primary breast cancer, either no other treatment or additional unspecific immune therapy with Levamisole. The reaction of granulopoiesis to the cytostatic drugs, as characterized by changes of peripheral blood polymorphonuclear neutrophils (PMN), functional bone marrow granulocyte reserve, serial bone marrow cytology, and granulopoietic stem cells (CFU-C) in marrow and blood, was not affected by administration of Levamisole. The data support the concept that Levamisole has no direct effect on human bone marrow granulopoiesis, but that an allergic mechanism is involved in the pathogenesis of Levamisole-induced agranulocytosis. The expectation that Levamisole exerts a beneficial effect by stimulation of the granulopoiesis, as previously suggested for BCG and Corynebacterium parvum, could not be substantiated in our studies.

Sensitivity of human granulopoiesis in vitro to adriamycin before and after exposure in vivo.

The present studies were performed to determine whether the sensitivity of a normal human granulopoiesis to Adriamycin changes after repeated exposure to the drug in vivo. A single-layer agar culture for the in vitro growth of granulocytic colonies from committed stem cells was used as the assay system. The in vitro sensitivity of the human granulopoiesis to different doses of Adriamycin was determined from the reduction in colony incidence (a) following exposure of marrow cells to Adriamycin for 30 min before initiation of cultures and (b) in the presence of Adriamycin during the total culture period. Using both test systems, the sensitivity of granulopoiesis in vitro remained unchanged after patients had received six courses of chemotherapy incorporating Adriamycin. Sensitivity to Adriamycin appeared to increase by Day 4 after chemotherapy, probably as a result of the increased proliferative activity of granulopoietic precursor cells at this time. The data thus fail to provide evidence that a granulopoietic subpopulation with increased resistance to the cytotoxic effects of Adriamycin emerges after repeated in vivo exposure to the drug.