Effects of recombinant human interleukin-6 in cancer patients: a phase I-II study

To define the toxicity profile of recombinant human interleukin-6 (rhIL- 6) and to study its effect on hematopoiesis, biochemical parameters and other cytokines, rhIL-6 was administered in a phase I-II study to 20 patients with breast carcinoma or nonsmall cell lung cancer. RhIL-6 doses were 0.5, 1.0, 2.5, 5.0, 10, and 20 micrograms/kg/d, with at least three patients per dose level. RhIL-6 was administered 24 hours by continuous intravenous infusion followed by subcutaneous (SC) administration for 6 days, partly on an outpatient basis. RhIL-6- related side effects were fever, headache, myalgia, and local erythema. Starting at 2.5 micrograms/kg/d, these side effects were compounded by nausea, reversible increase in liver enzymes, and anemia. Flu-like symptoms were controllable up to and including 10 micrograms rhIL- 6/kg/d with acetaminophen. RhIL-6 increased platelet counts with a decrease in mean platelet volume and increased leukocytes caused by neutrophil, monocyte, and lymphocyte increase, with an increase in T cells and natural killer cells at 1.0 and 2.5 micrograms rhIL-6/kg/d. The reversible anemia was characterized by a decrease in serum iron, and an increase in ferritin and erythropoietin without reticulocytosis. RhIL-6 reduced total cholesterol levels and a dose-related increase of C-reactive protein and serum amyloid A plasma levels was observed. Serum IL-6 levels were increased, especially at 10 and 20 micrograms/kg/d, whereas no change in IL-1 beta and tumor necrosis factor alpha levels was observed. RhIL-6 can be administered with controllable side effects in this setting, up to and including a SC dose of 10 micrograms/kg/d on an outpatient basis, and has a promising stimulating effect on leukopoiesis and thrombopoiesis.     

A phase I/II study of sequential interleukin-3 and granulocyte- macrophage colony-stimulating factor in myelodysplastic syndromes

In this phase I/II study, 9 patients with myelodysplastic syndromes (MDS) were treated with interleukin-3 (IL-3) followed by granulocyte- macrophage colony-stimulating factor (GM-CSF). Each treatment cycle was 28 days long and administered as follows: 1 microgram/kg/d IL-3 on days 1 through 7 and 3 micrograms/kg/d GM-CSF for days 8 through 21, followed by a 7-day rest period. IL-3 dose escalations were planned, but the dose of GM-CSF was fixed. Three patients had refractory anemia, 4 had refractory anemia with ringed sideroblasts, and 2 had refractory anemia with excess blasts. Six patients were dependent on red blood cell transfusions, 1 on platelet transfusions, and 2 on both. The absolute neutrophil count improved in 7 (77%) patients and the platelet count improved in 3 (33%) patients during therapy. Hemoglobin levels were unchanged. A clinically relevant response was seen in only 1 patient with thrombocytopenia, and he received five cycles of therapy. The neutrophil count decreased in 2 patients and the platelet count decreased in 4 patients during treatment. The toxicity of the treatment was significant. In the first cohort of 3 patients, 1 patient developed supraventricular tachycardia and congestive heart failure. In the second group, 1 patient developed progressive granulocytopenia and died of gram-negative septicemia. Because of the disparate toxicity, 3 more patients were treated at the same dose level. One of these experienced a high fever and bone pain requiring hospitalization. Because of these adverse effects, the IL-3 dose was not escalated and all patients received 1 microgram/kg/d for 7 days. We believe that sequential therapy with IL-3 and GM-CSF at these dose levels causes unacceptable toxicity in patients with MDS. The major toxic events occurred during weeks 4 and 5 after starting treatment and may have been primarily caused by GM-CSF therapy. Although neutrophil counts improve in most patients, the effect on red blood cells and platelets is minimal. At present, this form of therapy remains problematic and appears to have a limited potential in the management of MDS.     

Thrombopoietic effects and toxicity of interleukin-6 in patients with ovarian cancer before and after chemotherapy: a multicentric placebo- controlled, randomized phase Ib study

Recombinant human interleukin-6 (IL-6) has previously been shown to increase platelet counts in normal and sublethally irradiated mice, dogs, and primates. To assess its tolerance and efficacy in clinical use, we performed a randomized phase Ib study in patients with ovarian carcinoma. IL-6 was administered during an initial 7-day cycle before any chemotherapy. Beginning 7 days later, six cycles of chemotherapy containing carboplatin were administered every 3 weeks. During chemotherapy cycles 2 to 6, IL-6 was administered from day 4 through day 17 at escalating dose levels from 0.5 to 10 micrograms/kg/d. At each level, three patients received IL-6 and one patient received a placebo. During the prechemotherapy cycle of IL-6, a dose-dependent increase in platelet count was observed from day 12 to 15 and was maximal on day 15 (r = .77; P < .01). The median ploidy of bone marrow megakaryocytes shifted from 16 N to 32 N after 7 days of the initial prechemotherapy IL-6 administration. Dose-dependent increases in C- reactive protein (CRP) and fibrinogen levels were observed on day 8 (P < .0001 for both). A significant decrease in hemoglobin level occured rapidly after initiation of IL-6 therapy and was maximal on day 8 (P < .001). When given after chemotherapy, IL-6 accelerated platelet recovery after chemotherapy cycles 2 to 6. Postponements of scheduled chemotherapy due to thrombocytopenia were less frequent in patients treated with IL-6. No difference in either neutrophils or peripheral blood progenitor assays was observed during or after IL-6 treatment. Toxicity of IL-6 appeared mild and was not dose-limiting up to 10 micrograms/kg/d. Systemic symptoms such as fever, headache, and myalgia were the main side effects and were easily relieved by acetaminophen administration. No biologic toxicity was observed. The data indicate that IL-6 is a well-tolerated cytokine and capable of accelerating platelet recovery in patients receiving chemotherapy.     

Corticosteroid modulation of interleukin-1 hematopoietic effects and toxicity in a murine system

Interleukin-1 (IL-1) has been shown to ameliorate the hematopoietic toxicities of antitumor chemotherapeutic agents in both mice and humans. However, IL-1 toxicity in humans is considerable and is similar to the systemic inflammatory toxicities induced by IL-3, IL-6, and other cytokines with pleiotropic biologic activities, eg, fever, nausea, malaise, and hypotension. We hypothesized that corticosteroids may reduce IL-1 toxicity without reducing IL-1 hematopoietic effects in vivo. C3H/HeJ mice (female, 6 weeks) were treated for 7 days subcutaneously with cortisone acetate (CA), (0.1, 0.25, or 0.5 mg/d/mouse), intraperitoneally with IL-1 (1 or 2 micrograms/d/mouse), or both. As expected, IL-1 increased white blood cell counts, splenic granulocyte-macrophage colony-forming units, and spleen cell number, and protected mice from lethal doses of carboplatin (200 mg/kg; Paraplatin, Bristol Laboratories, Evansville, IN) administered the day after completion of the 7 days of IL-1 administration. CA did not significantly block the hematopoietic effects of IL-1 or the ability of IL-1 to protect mice from the hematopoietic toxicity of carboplatin. IL- 1 administered to mice at 8 micrograms/d/mouse for 5 days induced decreased activity, roughening of hair, diarrhea, pancytopenia, multiple metabolic abnormalities, and death in 60% of mice. IL-1 at the therapeutic doses (0.5 to 2 micrograms/d) was not toxic. CA in a dose- dependent manner blocked all of the above mentioned toxicities when administered 24 hours and 30 minutes before each IL-1 injection. CA also decreased IL-1-induced increase in plasma tumor necrosis factor levels at the time point examined.     

Differential dose-related haematological effects of GM-CSF in pancytopenia: evidence supporting the advantage of low- over high-dose administration in selected patients

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a multifunctional haematopoietin which can promote production of several blood cell lineages, though the predominant target cells are neutrophils, monocytes, and their precursors. Occasional undesirable clinical effects include eosinophilia, an increase in blasts, or thrombocytopenia. Here, we describe four patients who were treated with GM-CSF, at subcutaneous doses significantly lower than are conventional, and experienced an unusual response pattern. Three patients had severe pancytopenia associated with chronic lymphocytic leukaemia (CLL) or myelodysplastic syndrome (MDS) and exhibited an unexpected switch in the responsive lineage on high- versus very low-dose therapy. The two CLL patients developed marked eosinophilia (up to 10.0 x 10(9) cells/l) without an increase in neutrophils on 125-300 micrograms/m2/d of GM-CSF. In contrast, when the dose was lowered to 10 micrograms/m2/d, the neutrophils rose to physiological levels, without significant eosinophilia. The MDS patient showed a rapid rise in peripheral blasts (baseline level = 0; post-therapy level = 5.0 x 10(9)/l), without a change in other cell types, when receiving 60 micrograms/m2/d of GM-CSF. After GM-CSF was held, blasts returned to baseline levels; reinstituting therapy at the very low dose of 6 micrograms/m2/d was followed by an increase in platelet counts from 50 to 185 x 10(9)/l with only a minor increase in blasts. The fourth patient, who suffered from severe aplastic anaemia complicated by recurrent gastrointestinal haemorrhage, was only treated with the low-dose regimen. He showed a predominant platelet effect with counts rising from 9 to 169 x 10(9)/l. Very low-dose GM-CSF therapy was devoid of constitutional side effects. The biological implications of these GM-CSF responses are discussed. Our results indicate that, in some patients, GM-CSF may stimulate different target cells depending on the dose. Therefore, in contrast to the results of administration of many classical drugs, there may not always be a direct relationship between the amount of GM-CSF given and the optimal effect.     

A phase II trial of recombinant human granulocyte colony-stimulating factor in the myelodysplastic syndromes

We conducted a phase II study of the intravenous administration of a glycosylated recombinant human granulocyte colony-stimulating factor (rhG-CSF) for 7-14 d in 41 patients with the myelodysplastic syndromes (MDS). Administration of rhG-CSF elicited striking rises in both leucocyte and neutrophil counts in the majority of the patients irrespective of the FAB subtypes of MDS. The rises in neutrophil counts were dose dependent and 5 micrograms/kg/d of rhG-CSF yielded approximately an 8-fold increase in neutrophil counts. Leucocytes and neutrophil counts started to increase shortly after the first injection of 5 micrograms/kg, was maintained at significantly elevated levels during 14 d of treatment, and returned to the pretreatment levels within several days following discontinuation of rhG-CSF. The action of rhG-CSF was specific for neutrophils since leucocytosis was due exclusively to neutrophilic increase associated with an increased marrow myeloid maturation. There were no consistent changes in the monocyte, eosinophil, lymphocyte, platelet or reticulocyte counts. After treatment, the percentage of marrow blast cells was reduced in eight of 13 evaluable patients with refractory anaemia with an excess of blasts (RAEB) or RAEB in transformation (RAEB-t). No patients developed acute leukaemia during the treatment or in the immediate follow-up period. The treatment was well tolerated with only minimal toxicity. The results suggest that rhG-CSF is a safe and effective way to promptly improve neutropenia in MDS patients.     

A phase I study of sequential versus concurrent interleukin-3 and granulocyte-macrophage colony-stimulating factor in advanced breast cancer patients treated with FLAC (5-fluorouracil, leucovorin, doxorubicin, cyclophosphamide) chemotherapy

Cumulative thrombocytopenia is a dose-limiting toxicity of dose- intensive chemotherapy for advanced breast cancer. In this phase I study, we have studied the hematologic toxicity associated with sequential interleukin-3 (IL-3) and granulocyte-macrophage colony- stimulating factor (GM-CSF; molgramostim) administration after multiple cycles of FLAC (5-fluorouracil, leucovorin, doxorubicin, cyclophosphamide) chemotherapy compared with that after concurrent cytokine administration or to each cytokine administered alone. Ninety- three patients with advanced breast cancer were treated with five cycles of FLAC chemotherapy and either IL-3 alone, GM-CSF alone, sequential IL-3 and GM-CSF administered by schedule A (5 days of IL-3 followed by 10 days of GM-CSF) or schedule B (9 days of IL-3 followed by 6 days of GM-CSF), or concurrent administration of IL-3 and GM-CSF for 15 days. Cohorts of patients were treated with one of four dose levels of IL-3 (1,2.5, 5, and 10 micrograms/kg) administered subcutaneously for each schedule of cytokine administration. The GM-CSF dose in all schedules was 5 micrograms/kg/day. Sequential IL-3 and GM- CSF (schedule B) was associated with higher platelet nadirs, shorter durations of platelet counts less than 50,000/microL, and the need for fewer platelet transfusions over five cycles of FLAC chemotherapy compared with concurrent cytokines, sequential IL-3 and GM-CSF schedule A, and GM-CSF alone. Concurrent IL-3 and GM-CSF was associated with unexpected platelet toxicity. The duration of granulocytopenia after FLAC chemotherapy was significantly worse with IL-3 alone compared with each of the GM-CSF-containing cytokine regimens. Although no cycle 1 maximum tolerated dose for IL-3 was defined in this study, 5 micrograms/kg was well tolerated over multiple cycles of therapy and is recommended for future studies. The data from this phase I study suggest that sequential IL-3 and GM-CSF with IL-3 administered for 9 days before beginning GM-CSF may be superior to shorter durations of IL- 3 administered sequentially with GM-CSF, to concurrent IL-3 and GM-CSF, and to either colony-stimulating factor alone in ameliorating the cumulative hematologic toxicity associated with multiple cycles of FLAC chemotherapy. Additional studies of sequential IL-3 and GM-CSF are warranted.     

Interleukin 4 therapy for patients with chronic lymphocytic leukaemia: a phase I/II study

Interleukin 4 (IL-4) is a pleiotropic type II cytokine which has been shown to have a direct killing effect on lymphoma and B-cell chronic lymphocytic leukaemia (B-CLL) cells in vitro. The clinical effects and toxicity of IL-4 treatment in patients with B-CLL were evaluated. Fourteen patients with B-CLL who were in partial remission after chemotherapy received one, two or three 8-week cycles of escalating doses (2, 4 or 6 microg/kg/d s.c.) of IL-4 for 3 d/week. Clinical response was analysed after each treatment cycle and toxicity was monitored continuously. Ten patients (71%) had progressive disease (PD) during IL-4 treatment. This was mainly attributable to an increase (two- to fourfold) of the blood lymphocyte count during IL-4 therapy. After cessation of IL-4 treatment, the lymphocytosis decreased spontaneously in 8 out of 12 evaluable patients. Splenomegaly remained unchanged in 7/7 patients, whereas enlarged lymph nodes were reduced by > 50% in 1/13 patients and by 25-50% in 4/13 patients. None of the patients achieved an objective tumour regression (complete or partial remission). A temporary increase (16-60%) of the platelet count was observed during IL-4 treatment. The platelet count decreased in 8/11 patients after the end of IL-4 therapy. World Health Organization (WHO) grade I/II fever, arthralgia and fatigue was observed in one-third of the patients and was more commonly seen with the highest dose (6 microg/kg/d). One patient developed pulmonary oedema and WHO grade III neutropenia was recorded in three patients. IL-4 was well tolerated by most patients in an outpatient setting. The anti-tumour activity observed in previous in vitro studies was not verified by the present in vivo trial which showed that IL-4 may instead increase the number of CLL cells in blood, indicating that IL-4 may have induced a stimulatory or antiapoptotic effect on the CLL cells in blood. These results may have important implications for the development of immunotherapy of CLL. In addition, the potential platelet-stimulatory effect of IL-4 warrants further studies.     

A phase I/II trial of recombinant granulocyte-macrophage colony-stimulating factor for children with aplastic anemia

Nine pediatric patients (median age, 8 years; range, 0.7 to 19 years), eight with refractory aplastic anemia and one with newly diagnosed aplasia, were enrolled in a phase I/II trial of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) administered via continuous intravenous infusion. Doses ranged from 8 to 32 micrograms/kg/d. Six of eight evaluable patients responded with a significant rise in neutrophil count (median fourfold increase; range, 2.5- to 31-fold) during the 28-day induction period. Five patients completed 2 further months of therapy (maintenance) with persistent or improved neutrophil responses. Three patients had bone marrow aspirates suggestive of increased erythropoiesis, although only one patient had improvement in peripheral hematocrit and platelet count. In the five patients completing maintenance, three experienced a rapid return to baseline counts after rhGM-CSF was discontinued, one maintained a neutrophil response for 2 months after drug discontinuation, and one has maintained a trilineage response for greater than 1 year off study. Drug therapy was well tolerated. Toxicity was minimal at doses from 8 to 16 micrograms/kg/d. Fever and rash were more commonly seen at 32 micrograms/kg/d. No patient developed an infection during the course of rhGM-CSF administration. These results demonstrate that rhGM-CSF increases peripheral neutrophil counts in children with refractory and newly diagnosed aplastic anemia and may be able to stimulate a multilineage response in a more limited number. Randomized, prospective trials are necessary to determine if rhGM-CSF administration will impact favorably on the morbidity and mortality of severe aplastic anemia.     

A phase I/II trial of recombinant human interleukin-6 in patients with aplastic anaemia

Summary. In a phase I/II study, 11 patients with marrow failure (10 with acquired aplastic anaemia and one with pancytopenic Fanconi anaemia) were treated with recombinant human interleukin-6 (rhIL-6) to assess the safety and tolerability of rhIL-6 and its effects on peripheral blood counts, bleeding complications and transfusion requirements. All patients with acquired aplastic anaemia were refractory to immunosuppressive treatment or had relapsed after immunosuppressive therapy and were not bone marrow transplantation candidates. Recombinant hIL-6 was to be given as a once-daily subcutaneous injection for 28 d at doses ranging from 0-5 to 5-0βg/kg. After an observation period of 2 weeks, five patients received a second treatment course of 28 d.
Only one patient had a sustained increase in platelet count from 18 000 to 72 000/ fA. Bleeding occurred in four patients and caused premature discontinuation of rhIL-6 therapy in three patients. A deterioration of pre-existing anaemia was observed in nine patients. No significant changes of leucocyte counts were observed during the first cycle. During the second cycle the peripheral blood monocyte counts decreased significantly. No significant changes in bone marrow cellularity were observed. Recombinant hIL-6 induced a dose-dependent increase in acute-phase reactants in all patients. Other adverse events included fever, headache, arthralgia, tachycardia and hypertension. In conclusion, rhIL-6 given alone at low doses does not increase platelet counts in the majority of patients with aplastic anaemia and can precipitate a sudden worsening of pre-existing anaemia and thrombocytopenia. This study was discontinued prematurely on account of the toxicity of rhIL-6 seen in patients with aplastic anaemia.     

In vivo effects of interleukin-6 on thrombopoiesis in healthy and irradiated primates.

We have studied the in vivo effects of recombinant human interleukin-6 (rhIL-6) on hematopoiesis in eight healthy and nine irradiated cynomolgus monkeys. Of the healthy animals, three received rhIL-6 alone (10 micrograms/kg/d, subcutaneously [SC]), one received rhIL-6 in combination with rhIL-3 (10 micrograms/kg/d, SC), one received rhIL-6 in combination with recombinant cynomolgus granulocyte-macrophage colony-stimulating factor (rcGM-CSF; 10 micrograms/kg/d, SC), two received rhIL-6 in combination with recombinant human granulocyte-CSF (rhG-CSF; 10 micrograms/kg/d, SC), and one received rhIL-6 in combination with recombinant human leukemia inhibitory factor (rhLIF; 10 micrograms/kg/d, SC). All animals were treated for at least 2 weeks with rhIL-6 or the above mentioned combinations. rhIL-6 alone significantly increased the peripheral blood platelet counts (2- to 3.5-fold). The platelets reached a plateau between days 10 and 15 of treatment. No synergistic effects on platelet numbers were observed when rhIL-6 was combined with rhIL-3, rcGM-CSF, rhG-CSF, or rhLIF. In addition to rhIL-6, only rhLIF increased the platelet numbers when administered alone. To test whether rhIL-6 might also protect the animal from thrombocytopenia or shorten the time of thrombocytopenia after irradiation, we treated nine animals with total body irradiation (3.8 Gy). Six of the animals were additional treated with rhIL-6 (4 with 10 micrograms/kg/d; and 2 with 100 micrograms/kg/d) from day -1 or +1 to day 28 post irradiation. In these animals, rhIL-6 at the same dose effective in healthy animals (10 micrograms/kg/d) was not capable of protecting the animals from platelet nadir. However, when pegylated rhIL-6 was used at a dosage of 100 micrograms/kg/d post irradiation, the mean of the nadirs was 71,000/microL as compared with 39,000/microL in control animals and the time of thrombocytopenia was shorter (3 v 5 days). In all animals (healthy and irradiated), rhIL-6 did not increase the number of bone marrow megakaryocytes but induced a right shift of DNA ploidy in megakaryocytes. These data suggest that IL-6 acts as "thrombopoietin"-like activity, but not as "megakaryocyte-CSF"-like activity.     

Very low doses of GM-CSF administered alone or with erythropoietin in aplastic anemia.

PURPOSE AND RATIONALE: There has been no previously published experience with granulocyte-macrophage colony-stimulating factor (GM-CSF) at doses less than 15 micrograms/m2/d in patients with aplastic anemia, and most observations have been made at doses of 100 to 500 micrograms/m2/d (2.5 to 12.5 micrograms/kg/d). The benefits of using considerably lower doses, if effective, should include a decrease in cost and in side effects. We have therefore used very low doses of GM-CSF to treat a group of patients with aplastic anemia. Additionally, since severe anemia is often a problem in these patients, we recently started administering erythropoietin along with the GM-CSF. Herein we report the results of very-low-dose GM-CSF therapy in patients with aplastic anemia and our preliminary findings in those individuals who received combination therapy. PATIENTS AND METHODS: We administered recombinant human GM-CSF subcutaneously at doses of 5 to 20 micrograms/m2/d ("very-low-dose GM-CSF") to 12 patients with aplastic anemia. In addition, a 13th patient received erythropoietin together with the GM-CSF regimen, and three of the 12 individuals who initially received 1 or more months of GM-CSF alone were later also given erythropoietin (4,000 U/d subcutaneously). RESULTS: In five of 12 patients (42%) treated with very-low-dose GM-CSF, an increase in neutrophil counts (2.0- to 6.7-fold) was noted, and one of these subjects attained a bilineage response (neutrophil counts, 0.3 to 1.75 x 10(9)/L; platelet counts, 8 to 169 x 10(9)/L). Moreover, a sixth patient showed a rise in platelet counts (19 to 80 x 10(9)/L) without a concomitant increase in neutrophils. Constitutional side effects were minimal. Combining erythropoietin and very-low-dose GM-CSF produced a bilineage response (neutrophils, 1.0 to 3.0 x 10(9)/L; hemoglobin, 7.4 to 9.4 g/dL) in the one patient who received erythropoietin together with the GM-CSF from the time that GM-CSF was initiated. In one of the other patients who were given combination therapy, the addition of erythropoietin appeared to enhance the response; this patient demonstrated a neutrophil response to GM-CSF alone and a trilineage response (neutrophils, 0.8 to 3.75 x 10(9)/L; hemoglobin, 7.0 to 13.1 g/dL; and platelets, 10 to 34 x 10(9)/L) to the combination. No toxicity was associated with the addition of erythropoietin. CONCLUSIONS: Our observations suggest that (1) very low doses of GM-CSF (5 to 20 micrograms/m2/d subcutaneously) may be used initially in neutropenic patients with aplastic anemia, and the dose subsequently increased only in patients who do not respond; and (2) the administration of erythropoietin together with GM-CSF is well tolerated, can augment responsiveness in some patients, and deserves further study.     

Effects of interleukin-3 after chemotherapy for advanced ovarian cancer.

To define the maximum tolerated dose and to study whether recombinant human interleukin-3 (rhIL-3) reduced chemotherapy-induced neutropenia and thrombocytopenia, 20 chemotherapy-naive patients with advanced ovarian cancer eligible for treatment with 6 cycles of carboplatin-cyclophosphamide every 4 weeks (day 1) were entered in a phase I/II open, single-center trial. Cohorts of five patients received during 7 days 1, 5, 10, or 15 micrograms/kg/d rhIL-3 (days 5 through 11) in cycles 1, 3, and 5 by continuous intravenous (IV) infusion or once daily subcutaneous (SC) administration. In control cycles 2, 4, and 6, no rhIL-3 was administered. rhIL-3 significantly increased the recovery of leukocyte, neutrophil, and platelet counts, especially at 5, 10, and 15 micrograms/kg rhIL-3. rhIL-3 also increased basophil, eosinophil, monocyte, and lymphocyte counts at this dose steps. Effects on reticulocytes were limited. No difference in efficacy between SC and IV rhIL-3 treatment was found. Chemotherapy postponement for insufficient bone marrow recovery was necessary in 22 of 45 control cycles versus 2 of 49 rhIL-3 cycles (P less than .001). Platelet transfusions were required in 7 of 45 control cycles versus 3 of 50 rhIL-3 cycles (P less than .5). rhIL-3 up to 10 micrograms/kg/d could be administered without severe side effects. At 15 micrograms/kg/d, rhIL-3 headache was dose-limiting. Other side effects were fever, flu-like symptoms, nausea, skin rash, flushing, facial erythema, and urticaria. Liver toxicity occurred in rhIL-3 and control cycles. rhIL-3 slightly increased tumor necrosis factor alpha, C-reactive protein, and serum amyloid A plasma levels, whereas no effect on IL-6 plasma levels was observed. rhIL-3 administered SC appears to be an interesting hematopoietic growth factor for reduction of chemotherapy-induced myelotoxicity.     

Results of a phase I/II trial of recombinant human granulocyte- macrophage colony-stimulating factor in very low birthweight neonates: significant induction of circulatory neutrophils, monocytes, platelets, and bone marrow neutrophils

Neonates, especially those of very low birthweight (VLBW), have an increased risk of nosocomial infections secondary to deficiencies in development. We previously demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) production and mRNA expression from stimulated neonatal mononuclear cells are significantly less than that from adult cells. Recombinant murine GM-CSF administration to neonatal rats has resulted in neutrophilia, increased neutrophil production, and increased survival of pups during experimental Staphylococcus aureus sepsis. In the present study, we sought to determine the safety and biologic response of recombinant human (rhu) GM-CSF in VLBW neonates. Twenty VLBW neonates (500 to 1,500 g), aged < 72 hours, were randomized to receive either placebo (n = 5) or rhuGM-CSF at 5.0 micrograms/kg once per day (n = 5), 5.0 micrograms/kg twice per day (n = 5), or 10 micrograms/kg once per day (n = 5) given via 2-hour intravenous infusion for 7 days. Complete blood counts, differential, and platelet counts were obtained, and tibial bone marrow aspirate was performed on day 8. Neutrophil C3bi receptor expression was measured at 0 and 24 hours. GM-CSF levels were measured by a sandwich enzyme-linked immunosorbent assay at 2, 4, 6, 12, and 24 hours after the first dose of rhuGM-CSF. At all doses, rhuGM-CSF was well tolerated, and there was no evidence of grade III or IV toxicity. Within 48 hours of administration, there was a significant increase in the circulating absolute neutrophil count (ANC) at 5.0 micrograms/kg twice per day and 10.0 micrograms/kg once per day, which continued for at least 24 hours after discontinuation of rhuGM-CSF. When the ANC was normalized for each patient's first ANC, there was a significant increase in the ANC on days 6 and 7 at each dose level. By day 7, all tested doses of rhuGM- CSF resulted in an increase in the absolute monocyte count (AMC) compared with placebo-treated neonates. In those receiving rhuGM-CSF 5.0 micrograms/kg twice per day, there was additionally a significant increase in the day 7 and 8 platelet count. Tibial bone marrow aspirates demonstrated a significant increase in the bone marrow neutrophil storage pool (BM NSP) at 5.0 micrograms/kg twice per day and 10.0 micrograms/kg once per day. Neutrophil C3bi receptor expression was significantly increased 24 hours after the first dose of rhuGM-CSF at 5.0 micrograms/kg once per day. The elimination half-life (T1/2) of rhuGM-CSF was 1.4 +/- 0.8 to 3.9 +/- 2.8 hours.(ABSTRACT TRUNCATED AT 400 WORDS)     

Hematological effect of 14 days treatment of recombinant human granulocyte colony-stimulating factor for neutropenia in myelodysplastic syndromes]

Nineteen patients with myelodysplastic syndromes (MDS) were treated with a glycosylated recombinant granulocyte colony-stimulating factor (rG-CSF) for improvement of neutropenia. rG-CSF was administrated intravenously at a dose of 5 micrograms/kg/day for 14 consecutive days. Most of patients responded to rG-CSF and an approximately 10 fold increase of the peak neutrophil counts was observed. The neutrophil counts were maintained at high level during the treatment period and returned to pretreatment levels several days after stopping rG-CSF. Consistent with the recovery of neutrophil, infectious complications improved in many cases. Effects of rG-CSF were confined to neutrophils, sparing blast cells and other blood cells. Eruption was observed in one patient as toxicity. We conclude that rG-CSF therapy is effective in improving neutropenia with MDS patients.     

Thrombocytopoiesis in normal and sublethally irradiated dogs: response to human interleukin-6.

The response of megakaryocytes and platelets to the administration of recombinant human interleukin-6 (IL-6) was investigated in normal and sublethally irradiated dogs. IL-6 was administered for 2 weeks at doses of 10 to 160 micrograms/kg/d to normal animals to assess dose-response and toxicity. Subsequently, 40, 80, or 160 micrograms/kg/d for 2 weeks was administered to animals treated with 200 cG total body irradiation. Analysis of normal dogs showed a significant increment in the platelet count detectable approximately 11 days after initiation of IL-6 at all administered doses. Large platelets greater than 6.3 microns in diameter were observed 1 day after beginning IL-6, progressively increasing to as many as 19.1% of the total circulating platelets by day 10. The ploidy distribution of the marrow megakaryocytes did not differ from the normal at doses of less than or equal to 80 micrograms/kg/d, but at 160 micrograms/kg/d, a shift toward higher ploidy cells was noted. No change in total white count was noted; however, a decrease in hematocrit was seen at all doses. In the irradiated animals, the platelet count recovered earlier in the IL-6-treated dogs than in the controls, but no consistent change in the ploidy distribution was observed irrespective of dose. Large platelets were also noted in the treated animals, comprising up to 6.9% of the total platelet count. Fibrinogen levels were elevated to greater than 4 times normal. A significant decrease in hematocrit was seen in all animals, while no consistent change was noted in the white count. Elevations in serum cholesterol, triglycerides, and alkaline phosphatase, together with a decline in serum albumin were observed in all the treated animals (both normal and irradiated), but clinical symptoms were observed only in the dogs receiving greater than or equal to 80 micrograms/kg/d. The data show that IL-6 alone is capable of enhancing platelet recovery in dogs with bone marrow suppression.     

Interleukin-1 alpha administered after autologous transplantation: a phase I/II clinical trial

Interleukin-1 alpha (IL-1 alpha) can act as both a hematopoietic growth factor and a stimulant of cellular and humoral immune responses. To promote acceleration of hematologic recovery and induce immune antitumor activity, we initiated a phase I/II dose escalation trial of 6-hour daily infusions of recombinant human IL-1 alpha after autologous transplantation. Forty patients with Hodgkin's disease (n = 9) and non- Hodgkin's lymphoma (n = 31) transplanted with unmobilized autologous peripheral blood stem cells or bone marrow stem cells received daily 6- hour infusions of IL-1 alpha (day 0 to day +13) at daily doses between 0.1 to 10 micrograms/m2/d; 7 patients received only 7 planned days of IL-1 alpha (day 0 through 6). Most patients received all 14 days of therapy, although 5 patients discontinued treatment early (after 1 to 6 doses) because of fever and severe chills. Toxicity included IL-1 alpha- related fever (occurring on a median of 9 of 14 treatment days), fatigue, and severe chills. Hypotension was dose-limiting and led to discontinuation of IL-1 alpha in both patients receiving 10 micrograms/m2/d. IL-1 alpha-treated patients receiving 3.0 micrograms/m2/d (the maximum tolerated dose) achieved neutrophil recovery (absolute neutrophil count greater than 500/microL) significantly earlier (median, 12 days; range, 11 to 27) than untreated control patients or those receiving IL-1 alpha at 0.1 to 1.0 micrograms/m2/d (median, 27; range, 9 to 63; P < .0001). In addition, the IL-1 alpha patients' bone marrows at day +14 were significantly enriched with committed myeloid progenitor cells. Strong trends to earlier freedom from red blood cell (P = .06) and platelet (P = .09) transfusions were also noted after IL-1 alpha treatment. This earlier hematopoietic engraftment after 3.0 micrograms/m2/d IL-1 alpha allowed earlier hospital discharge (median, 25 v 37 days for control or low- dose IL-1 alpha patients [P < .0001]) and a concomitant reduction (by $38,000) in median hospital charges (P = .01). The clinical toxicities of IL-1 alpha infusion are substantial, though not life-threatening. The accelerated hematopoiesis and immune response activation observed in this trial suggest the value of its further investigation in controlled trials and perhaps in combination with other hemopoietins after transplantation.     

A randomized placebo-controlled trial of recombinant human interleukin- 11 in cancer patients with severe thrombocytopenia due to chemotherapy

Thrombocytopenia is a complication of cancer treatment that can limit dose intensity. Interleukin-11 (IL-11) is a growth factor that increases platelet production. We conducted a multicenter, randomized, placebo-controlled trial of recombinant human IL-11 (rhIL-11) in 93 patients with cancer who had already been transfused platelets for severe thrombocytopenia resulting from chemotherapy. The patients had received platelet transfusions for nadir platelet counts of < or = 20,000/microL during the chemotherapy cycle immediately preceding study entry. Chemotherapy was continued during the study without dose reduction. Patients were randomized to receive placebo or rhIL-11 at 50 or 25 micrograms/kg subcutaneously once daily for 14 to 21 days beginning 1 day after chemotherapy. Eight of 27 (30%) evaluable patients treated with rhIL-11 at a dose of 50 micrograms/kg did not require platelet transfusions versus 1 of 27 (4%) patients who received placebo (P < .05). Five of 23 (18%) patients treated with rhIL-11 at 25 micrograms/kg avoided platelet transfusions (P = .23). Side effects were fatigue and cardiovascular symptoms, including a low incidence of atrial arrhythmias and syncope. There were no differences among treatment groups in the incidence of neutropenic fever, days of hospitalization, or number of red blood cell transfusions. This study shows that rhIL-11 treatment of a dose of 50 micrograms/kg significantly increases the likelihood that patients who have already been transfused platelets for severe chemotherapy-induced thrombocytopenia will not require platelet transfusions during a subsequent chemotherapy cycle.     

Sequential in vivo treatment with two recombinant human hematopoietic growth factors (interleukin-3 and granulocyte-macrophage colony-stimulating factor) as a new therapeutic modality to stimulate hematopoiesis: results of a phase I study.

In a phase I study, the sequentially administered combination of recombinant human interleukin-3 (rhIL-3) and rhGM-CSF was compared with treatment with rhIL-3 alone in 15 patients with advanced tumors but normal hematopoiesis. Patients were initially treated with rhIL-3 for 15 days. After a treatment-free interval, the patients received a second 5-day cycle of rhIL-3 at an identical dosage, immediately followed by a 10-day course of rhGM-CSF, to assess the toxicity and biologic effects of this sequential rhIL-3/rhGM-CSF combination. rhIL-3 doses tested were 125, and 250 micrograms/m2, whereas rhGM-CSF was administered at a daily dosage of 250 micrograms/m2. Both cytokines were administered by subcutaneous (SC) bolus injection. rhIL-3/rhGM-CSF treatment was more effective than rhIL-3 but equally effective to each other in increasing peripheral leukocyte counts, especially neutrophilic and eosinophilic granulocyte counts. In contrast, both modes of cytokine therapy raised the platelet counts to the same degree. rhIL-3/GM-CSF treatment was more effective than rhIL-3 in increasing the number of circulating hematopoietic progenitor cells BFU-E and CFU-GM. High-dose rhIL-3, but not low-dose rhIL-3, was as effective as the rhIL-3/rhGM-CSF combinations in increasing the number of circulating CFU-GEMM. The increase in absolute neutrophil counts correlated with the increase in the number of circulating CFU-GM. Side effects, mainly fever, headache, flushing, and sweating, were generally mild, but in two patients the occurrence of chills, rigor, and dyspnea after initiation of GM-CSF treatment necessitated dose reduction and discontinuation, respectively. These results indicate that sequential treatment with rhIL-3 and rhGM-CSF is as effective as single-factor treatment with rhIL-3 in stimulating platelet counts, whereas the effect of combination therapy on neutrophil counts and circulating progenitor cells is superior.     

Long-term interleukin-6 administration stimulates sustained thrombopoiesis and acute-phase protein synthesis in a small primate-- the marmoset

Interleukin-6 (IL-6) has been ascribed significant roles in both hematopoiesis and the immune response, although its contribution to host defence as a whole is poorly understood. Because short-term IL-6 treatment was previously shown to stimulate megakaryocytopoiesis, we investigated the effect of long-term administration of IL-6 on megakaryocytopoiesis and other systemic parameters in nonhuman primates. We chose a small primate, the marmoset (Callithrix jacchus), which enabled long-term administration at high doses. Recombinant human IL-6 (rhIL-6) administered at doses of up to 1,000 micrograms/kg/d over 4 and 9 weeks caused a sustained twofold to threefold increase of thrombocyte counts, peaking at 4 weeks. Thrombocyte counts declined thereafter, despite continuing IL-6 administration. The number of bone marrow megakaryocytes at 4 and 9 weeks was not increased compared with controls, but the ploidy grade was augmented, suggesting that IL-6 effects are restricted to mature megakaryocytes in vivo. An acute-phase protein response was observed within 24 hours after the first IL-6 administration and reached a maximum after 1 week of IL-6 administration at 25 micrograms/kg. Serum C-reactive protein, haptoglobin, and ceruloplasmin were increased, whereas albumin and transferrin levels declined. The acute-phase protein response was not associated with any morphologic evidence of hepatocellular damage. The increased levels of Ig and soluble IL-2 receptor in the serum levels reflected systemic immunostimulation. There was no evidence of renal mesangioproliferative pathology. Antibodies against rhIL-6 developed within 2 weeks, continuously increasing during the course of the study. High titers of neutralizing antibodies appeared concomitantly with the decrease in platelet counts and decline in acute-phase proteins. Therefore, despite the pleiotropic effects of IL-6 observed in vitro, long-term administration of IL-6 caused a selective and sustained stimulation of thrombopoiesis in marmosets that was only ablated by the appearance of neutralizing antibodies, and high doses were well tolerated in marmosets. A long-term targeting of IL-6 to cells of the megakaryocytic lineage, without evoking general toxicity, confirms the potential therapeutic usefulness of rhIL-6 for the chronic treatment of thrombocytopenic patients.