The effect of endocrine responsiveness on high-risk breast cancer treated with dose-intensive chemotherapy: results of International Breast Cancer Study Group Trial 15-95 after prolonged follow-up

BACKGROUND

The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established.

PATIENTS AND METHODS

Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m(2) plus cyclophosphamide 4 mg/m(2) with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features.

RESULTS

At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58-1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03).

CONCLUSIONS

After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encouraged.

ApoAI-phosphatidylcholine infusion neutralizes the atherothrombotic effects of C-reactive protein in humans

BACKGROUND

High-density lipoprotein (HDL) exerts a variety of anti-atherothrombotic functions, including a potent anti-inflammatory impact. In line, the direct pro-inflammatory effects of C-reactive protein (CRP) can be attenuated by HDL in vitro.

OBJECTIVE

To evaluate whether this also holds true in humans, we assessed the ability of reconstituted HDL to neutralize CRP-mediated activation of coagulation and inflammation.

METHODS

Fifteen healthy male volunteers received an infusion of recombinant human (rh)CRP (1.25 mg kg(-1) body weight). In eight of these volunteers, an infusion of human apoAI reconstituted with phosphatidylcholine (apoAI-PC; 80 mg kg(-1) body weight) preceded rhCRP infusion.

RESULTS

Infusion of rhCRP alone elicited an inflammatory response and thrombin generation. In individuals who received apoAI-PC prior to rhCRP, these effects were abolished. Parallel tests in primary human endothelial cells showed that apoAI-PC preincubation with rhCRP abolished the CRP-mediated activation of inflammation as assessed by IL-6 release. Although we were able to show that rhCRP co-eluted with HDL after size-exclusion chromatography, plasmon surface resonance indicated the absence of a direct interaction between HDL and CRP.

CONCLUSION

Infusion of apoAI-PC prior to rhCRP in humans completely prevents the direct atherothrombotic effects of rhCRP. These findings imply that administration of apoAI-PC may offer benefit in patients with increased CRP.

Treatment with the novel anti-angiogenic agent PI-88 is associated with immune-mediated thrombocytopenia

BACKGROUND

The novel molecule PI-88 is a highly sulfonated oligosaccharide which inhibits heparanase activity and competes with heparan sulfate binding of growth factors such as FGF and VEGF. Preclinical data demonstrates that PI-88 inhibits angiogenesis and has anti-metastatic effects. The aim of this phase I study was to determine the recommended dose and toxicity profile of PI-88.

PATIENTS AND METHODS

PI-88 was given intravenously in increasing duration of administration (0.57 mg/kg for 2 h, 0.57 mg/kg/day for 1 day, 4, 7 and 14 consecutive days) and then increasing dose for 14 consecutive days (1.14 mg/kg/day and 2.28 mg/kg/day) in patients with advanced malignancies until dose-limiting toxicity (DLT) was observed. Fourteen assessable patients with advanced malignancies received PI-88 intravenously.

RESULTS

DLT was thrombocytopenia. The thrombocytopenia appeared to be immunologically mediated with the development of anti-heparin platelet factor 4 complex antibodies. There were no other significant toxicities. At the final dose and schedule (2.28 mg/kg/day for 14 days), there was limited evidence of biological activity as measured by the surrogate marker activated partial thromboplastin time (APTT), although two patients had stabilisation of disease.

CONCLUSIONS

In conclusion, PI-88 at a dose of 2.28 mg/kg/day for 14 days resulted in dose-limiting thrombocytopenia which appeared to be immune related. Limited evidence of biological activity was noted. Alternate scheduling and routes of administration are now being explored.

Failing to live up to the fanfare? A personal perspective on obstacles to the clinical development of thrombopoietic agents

A number of hematopoietic growth factors have been identified that are active on megakaryocytes and platelets, but only 2, interleukin-11 (IL-11) and thrombopoietin, are being actively pursued clinically, with IL-11 approved for treatment of thrombocytopenia. The development of these agents in general has been disappointing, and in part this reflects the inherent biology of these factors with a failure to match clinical need with physiological function. The delayed action of these factors is also a consequence of the intrinsic biology of megakaryocytes and platelets, and thus is likely to be limiting regardless of which factor is employed. In addition, the development of these agents has occurred at a time when there is something of a decreasing demand for platelets, at least in the context of chemotherapy-induced thrombocytopenia. This decrease is the result of increased use of blood stem cells to support intensive chemotherapy procedures, reduced thresholds for platelet transfusion, and a decreasing role for intensive chemotherapy. These issues are discussed.

Early Australian clinical studies with pegylated recombinant human megakaryocyte growth and development factor

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF, an Mpl ligand) is a truncated form of native thrombopoietin currently undergoing clinical development. A series of studies in Australia have examined the safety and biological activities of PEG-rHuMGDF. Administration of PEG-rHuMGDF causes a dose-dependent increase in platelet count but has no effect on white cell count or hematocrit. These platelets are morphologically and functionally normal. When administered following moderately myelosuppressive chemotherapy, PEG-rHuMGDF significantly enhances platelet recovery, although scheduling in relation to chemotherapy may be important in optimizing the full effects. PEG-rHuMGDF mobilizes progenitor cells of multiple hematopoietic lineages, and alters the kinetics of peripheral blood progenitor cell mobilization after chemotherapy and filgrastim. PEG-rHuMGDF is well tolerated and does not cause toxicity similar to that observed with other thrombopoietic cytokines. Numerous studies are underway to help determine the precise role of PEG-rHuMGDF in clinical practice.

The role of platelet growth factors in cancer therapy

The use of myeloid growth factors has markedly reduced the complications of chemotherapy-induced neutropenia, however, abrogation of severe thrombocytopenia remains a major clinical problem. Platelet transfusions remain the standard method of preventing or treating thrombocytopenia but are associated with a variety of complications and are a limited resource. A number of cytokines have been clinically investigated for their thrombopoietic activity, the most promising of which is the recently cloned ligand to the hematopoietic growth factor receptor, c-Mpl. The c-Mpl ligand, also referred to as thrombopoietin, megakaryocyte growth and development factor (MGDF) and megapoietin, is a potent lineage-specific agent that promotes growth and maturation of megakaryocytes and their progenitors. It holds promise for clinical use in the treatment of iatrogenic or disease-associated bone marrow failure states and possibly in syndromes of excessive platelet consumption. Early clinical trials assessing the safety and activity of recombinant human MGDF are now underway.

Phase I and pharmacokinetic study of photodynamic therapy for high-grade gliomas using a novel boronated porphyrin

PURPOSE

To determine the recommended dose, toxicity profile, and pharmacokinetics of a novel boronated porphyrin (BOPP) for photodynamic therapy (PDT) of intracranial tumors.

PATIENTS AND METHODS

BOPP was administered alone in increasing doses (0.25, 0.5, 1.0, 2.0, 4.0, or 8.0 mg/kg) preoperatively in patients with intracranial tumors undergoing postresection PDT until dose-limiting toxicity (DLT) was observed.

RESULTS

Twenty-nine assessable patients with intracranial tumors received BOPP intravenously 24 hours before surgery. The recommended dose was 4 mg/kg. Dose escalation was limited by thrombocytopenia. The most common nonhematologic toxicity was skin photosensitivity. Pharmacokinetic parameters showed increased area under the plasma concentration-time curve and maximum concentration with increased dose. Tumor BOPP concentrations also increased with increased dose.

CONCLUSION

BOPP at a dose of 4 mg/kg was well tolerated. DLT was thrombocytopenia, and photosensitivity was the only other toxicity of note. The efficacy of PDT using BOPP requires further exploration.

Enhancement of platelet recovery after myelosuppressive chemotherapy by recombinant human megakaryocyte growth and development factor in patients with advanced cancer

PURPOSE

To explore the influence of dose and schedule on the ability of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) to abrogate thrombocytopenia after multiple cycles of chemotherapy and to mobilize peripheral-blood progenitor cells (PBPC).

PATIENTS AND METHODS

In this open-label study, 68 patients with advanced cancer were randomized to receive PEG-rHuMGDF subcutaneously at different doses and durations before administration of carboplatin 600 mg/m(2), cyclophosphamide 1,200 mg/m(2), and filgrastim 5 microgram/kg/d. PEG-rHuMGDF was not given after the first cycle of chemotherapy but was given after the second and subsequent cycles. Chemotherapy was given every 28 days for up to six cycles.

RESULTS

In patients who received the same dose of chemotherapy for at least two cycles, the platelet nadir was significantly higher (47.5 x 10(9)/L v 35.5 x 10(9)/L; P =.003) and duration of grade 3 or 4 thrombocytopenia significantly shorter (0 v 3 days; P =.004) when PEG-rHuMGDF was administered after chemotherapy. There was no evidence of an effect of PEG-rHuMGDF when it was given before chemotherapy. Platelet recovery after the first cycle of chemotherapy was no different for different PEG-rHuMGDF regimens, and there was no difference between patients treated with PEG-rHuMGDF and historical controls treated with identical chemotherapy. There was a modest dose-related increase in progenitor cell levels after administration of PEG-rHuMGDF alone. Peak levels of PBPC occurred later in cycle 2 than in cycle 1 but were not different in magnitude.

CONCLUSION

PEG-rHuMGDF abrogated severe thrombocytopenia after dose-intensive chemotherapy. However, it had only a modest effect on progenitor cell levels and did not enhance progenitor cell mobilization after chemotherapy and filgrastim.

Combination of stem cell factor and granulocyte colony-stimulating factor mobilizes the highest number of primitive haemopoietic progenitors as shown by pre-colony-forming unit (pre-CFU) assay

Fifty-two patients with poor prognosis carcinoma of the breast underwent peripheral blood stem cell (PBSC) mobilization using five different regimens. The yields of primitive haemopoietic progenitors were quantified by a recently described pre-colony-forming unit (pre-CFU) assay using limiting dilution analysis (LDA). Results of days 14 and 35 pre-CFU were also correlated with conventional CD34+ cell enumeration, CFU-GM (granulocyte-macrophage) and long-term culture-initiating cell (LTCIC) assays. The yield of pre-CFUs with the combination of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) was significantly higher than with G-CSF alone, cyclophosphamide (Cyclo) and granulocyte-monocyte colony-stimulating factor (GM-CSF), interleukin (IL)-3 and GM-CSF, or Cyclo alone. No significant correlation between neutrophil engraftment and pre-CFU could be demonstrated. Furthermore, CFU-GM was shown to bear a stronger correlation with pre-CFU and LTCIC than CD34+ cell measurement; thus, CFU-GM remains a useful biological tool for haemopoietic stem cell assay. We conclude that the combination of G-CSF and SCF mobilizes the highest number of pre-CFUs as measured by functional pre-CFU assay, which provides an alternative measurement of primitive haemopoietic progenitors to the LTCIC assay.

Biologic and structural differences of thrombopoietic growth factors

The search for a thrombopoietic agent has resulted in the identification of numerous cytokines and growth factors with thrombopoietic activity. However, with the exception of interleukin (IL)-11 and thrombopoietin (TPO), the megakaryopoietic activity of most of these molecules has not produced clearly identifiable clinical benefits. Despite the relatively modest effect of IL-11 on megakaryocyte and platelet production in vitro and in vivo, it does reduce the need for platelet transfusions in specialized clinical settings. In contrast, the c-Mpl ligand TPO has been shown to be a potent stimulator of megakaryocyte and platelet production both in vitro and in vivo. Clinical studies are being conducted with two different preparations of the c-Mpl ligand: recombinant human thrombopoietin (rhTPO) and pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF). A recombinant form of the complete human molecule, rhTPO is glycosylated and produced in mammalian cells. PEG-rHuMGDF consists of only the receptor-binding domain linked to a polyethylene glycol (PEG) moiety and is generated in Escherichia coil. Although c-Mpl ligands are still being evaluated, preliminary evidence indicates that these molecules can elevate platelet counts and may be useful in a range of clinical contexts. This report discusses aspects of the biology behind the clinical actions of IL-11 and the c-Mpl ligands.

Pharmacokinetic analysis of pegylated megakaryocyte growth and development factor in humans

Phase I studies with pegylated megakaryocyte growth and development factor (PEG-rHuMGDF), a c-Mpl ligand that stimulates megakaryopoiesis, have demonstrated that PEG-rHuMGDF is biologically active alone and causes a dose-related enhancement of platelet recovery when administered after chemotherapy. Here we report the dose-ranging pharmacokinetics of PEG-rHuMGDF. Pre-injection blood samples were drawn daily for pharmacokinetic studies on 43 patients. An ELISA, established using PEG-rHuMGDF as the standard, was able to quantitate Mpl ligand at concentrations > 0.02 ng/mL. Over the dose range 0.03 to 5.0 microg/kg/day, subcutaneous administration produced linear increases in steady-state serum levels. Maximum levels of PEG-rHuMGDF attained after 5.0 microg/kg/day were 5.88 to 10.9 ng/mL. After discontinuation of PEG-rHuMGDF, concentrations of Mpl ligand returned to baseline within 5 days. The pharmacokinetics were best described by a one-compartment model with first-order absorption, an absorption delay, and non linear clearance over the first 48 hours. The mean terminal half-life was 33.3 + 16.7 hours, and the average apparent at steady state was 27.7 + 14.0 mL/h/kg; both were independent of administered dose. The apparent clearance of PEG-rHuMGDF was not predicted by platelet count. Administration of chemotherapy and Filgrastim did not alter the pharmacokinetics of PEG-rHuMGDF.

KRN8602 (MX2-hydrochloride): an active new agent for the treatment of recurrent high-grade glioma

PURPOSE

To assess the efficacy and toxicity of KRN8602 when administered as an intravenous bolus to patients with recurrent high-grade malignant glioma.

PATIENTS AND METHODS

Patients with recurrent or persistent anaplastic astrocytoma or glioblastoma multiforme who had not received recent chemotherapy or radiotherapy and were of good performance status (Eastern Cooperative Oncology Group score < or = 2) were treated with an intravenous bolus of 40 mg/m(2) KRN8602 every 28 days. Tumor responses were assessed radiologically and clinically after every second cycle of therapy. Treatment was continued until documented progression or a total of six cycles.

RESULTS

A median of three cycles (range, one to six cycles) of KRN8602 was administered to 55 patients, 49 of whom received at least two cycles and were, therefore, assessable for response. The overall response rate (disease stabilization or better) was 43% (95% confidence interval, 29% to 58%). There were three complete responses, one partial response, seven minor responses, and 10 patients with stable disease. The median time to progression was 2 months (range, 1.5 to 37 months) and overall survival was 11 months (range, 1.5 to 40 months). Neutropenia was the most common toxicity, although it was generally of brief duration, and there were only seven episodes of febrile neutropenia in 176 cycles delivered. Nonhematologic toxicity was mostly gastrointestinal (nausea and vomiting, diarrhea) and events were grade 2 or lower except for a single episode of grade 3 vomiting.

CONCLUSION

KRN8602 is an active new agent with minimal toxicity in the treatment of relapsed or refractory high-grade glioma. Further studies with KRN8602 in combination with other cytotoxics and in adjuvant treatment of gliomas are warranted.

Prolonged release and c-kit expression of haemopoietic precursor cells mobilized by stem cell factor and granulocyte colony stimulating factor

Mobilization of haemopoietic precursor cells into the circulation by the combination of cytokines, stem cell factor (SCF) and G-CSF in previously untreated patients with carcinoma of the breast resulted in increased yield of collected peripheral blood precursor cells (PBPC). This mobilization of PBPC by SCF with G-CSF lasted several days after ceasing the cytokines in comparison to the rapid fall of PBPC after ceasing G-CSF. Possible mechanisms for this increased and prolonged mobilization were investigated. Immunological phenotyping with CD38, Thy-1 and MDR-1 of the CD34-positive mobilized PBPC detected no difference in maturity compared to PBPC mobilized by G-CSF alone. However, the down-regulation of c-kit, which is associated with the mechanism of mobilization, was much greater in the PBPC mobilized by SCF and G-CSF. The potential clinical implication of increased and prolonged mobilization is increased yield, allowing transplantation of heavily pre-treated patients, transplantation with PBPC from a single apheresis, or PBSC support for multiple courses of high-dose therapy from one mobilization procedure.

New developments in high-dose chemotherapy for breast cancer

High-dose chemotherapy with autologous stem cell support as applied to the treatment of breast cancer has shown promise for over 15 years. Three main approaches have been used: (1) standard-dose induction chemotherapy followed by one or two cycles of myeloablative therapy, (2) multicycle nonablative combination chemotherapy, and (3) high-dose sequential chemotherapy using single agents at the maximum tolerated doses in rapid sequence. Each of these approaches has a strong biological rationale and is being pursued in randomized trials. Unfortunately, comparative data are limited and there is only one fully published randomized trial of the use of high-dose chemotherapy in metastatic breast cancer. This small study from South Africa showed a significant improvement in response rate and survival for women receiving high-dose chemotherapy compared to those given standard dose treatment. It is anticipated that results from larger studies in the USA and Europe evaluating the use of high-dose chemotherapy in metastatic breast cancer and in adjuvant treatment of poor-prognosis early-stage disease will be available within the next 2-3 years. A potentially important and related issue is that of tumor contamination of bone marrow and apheresis collections. Current data suggest that finding epithelial tumor cells with sensitive techniques (such as immunohistochemistry or polymerase chain reaction) gives prognostic information. However, it is not clear whether reinfusion of these cells after high-dose chemotherapy contributes to relapse of breast cancer. Unfortunately, understanding of the data is marred by a lack of standardization of assay methodology. Further work is needed to develop a widely accepted method for the detection of circulating tumor cells before the clinical relevance of such a finding can be meaningfully interpreted.

Cardiac effects of high-dose epirubicin and cyclophosphamide in women with poor prognosis breast cancer

PURPOSE

To prospectively evaluate the long term cardiac effects of high-dose epirubicin and cyclophosphamide given to women with early stage, poor prognosis breast cancer.

PATIENTS AND METHODS

Women with stage 2 breast cancer and 10+ nodes or 4+ nodes and estrogen receptor negative tumor, or stage 3 breast cancer received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 gm/m2 with peripheral blood progenitor cell and filgrastim support. Treatment was given every 28 days (n = 79) or 21 days (n = 20). Fifty patients received radiotherapy to the chest wall or breast, 25 of to the left side. Patients were assessed clinically regularly during chemotherapy and at least three times yearly after completion of treatment. Cardiac left ventricular ejection fraction (LVEF) was assessed by radionuclide scan before therapy, after each cycle of chemotherapy, three months and six months after completion of chemotherapy, and yearly thereafter until relapse.

RESULTS

Ninety-nine women were treated, and 92 completed all three cycles of chemotherapy. The median age was 43 years (range 24 to 60 years). All patients were included in this analysis. The median relapse-free survival was 39 months (11 to 68 months). There was a significant fall in LVEF during chemotherapy. In general, there was no further deterioration in cardiac function from the third month after cessation of treatment, however there was substantial variation between individuals. 35 patients had at least one LVEF measure less than normal (< 50%), but the LVEF returned to normal in 20 of these with further follow-up. Cardiac dysfunction was not increased in women who received radiotherapy and was not different between cohorts given chemotherapy every three or every four weeks. One patient died of acute myocardial necrosis following the third cycle of chemotherapy. Two patients developed clinical evidence of cardiac failure, and another had radiological signs but was asymptomatic. One woman died of progressive cardiac failure, one recovered clinically but also developed recurrent breast cancer, while the third recovered after commencement of medical therapy.

CONCLUSIONS

During follow-up after high-dose epirubicin and cyclophosphamide as delivered in this study, the LVEF fell to below normal in approximately one third of patients. However, in over half of these patients the LVEF subsequently recovered to the normal range, and the incidence of clinically evident chronic cardiac failure was low. Further follow-up is required to assess the long-term safety. A randomized comparison with standard-dose anthracycline-based chemotherapy is needed to determine whether this regimen is associated with an increased risk of clinical cardiac toxicity.

Multicycle high-dose chemotherapy and filgrastim-mobilized peripheral-blood progenitor cells in women with high-risk stage II or III breast cancer: five-year follow-up

PURPOSE

To determine the safety and efficacy of multiple cycles of dose-intensive, nonablative chemotherapy in women with poor-prognosis breast cancer.

PATIENTS AND METHODS

Women with stage II breast cancer and 10 or more involved nodes or four or more involved nodes and estrogen receptor-negative tumors and women with stage III disease received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2, with progenitor cell and filgrastim support every 28 days (n = 79) or 21 days (n = 20). Patients were reviewed at least twice yearly thereafter. Twenty-six patients had bone marrow and apheresis collections assessed for the presence of micrometastatic tumor cells.

RESULTS

Ninety-nine women (median age, 43 years; range, 24 to 60 years) were treated. Ninety-two completed all three cycles of chemotherapy. The major toxicity was severe, reversible myelosuppression that was more prolonged with successive cycles, and this did not differ between patients given treatment every 28 days and those treated every 21 days. Febrile neutropenia occurred in 176 (61%) of 287 cycles. Severe mucositis (grade 3 or 4) occurred in 23% of cycles but tended to be short-lived and was reversible. The cardiac ejection fraction fell by a median of 4% during treatment, and three patients developed evidence of cardiac failure after chemotherapy. Two patients (2%) died of acute toxicity. Three of 26 patients had evidence of circulating micrometastatic tumor cells. The actuarial distant disease-free and overall survival rates at 60-month follow-up were 64% (95% confidence interval [CI], 53% to 75%) and 67% (95% CI, 56% to 78%), respectively.

CONCLUSION

Multiple cycles of dose-intensive, nonablative chemotherapy is a feasible and safe approach. Disease control and survival are similar to those in other studies of myeloablative chemotherapy in poor-prognosis breast cancer. The regimen is being evaluated in a randomized trial of the International Breast Cancer Study Group.

Phase I and pharmacokinetic study of KRN8602 alone and with filgrastim in patients with advanced cancer

PURPOSE

To determine the recommended dose, toxicity profile, and pharmacokinetics of KRN8602 (MX2-hydrochloride), a novel morpholino anthracycline with potent cytotoxicity against anthracycline-sensitive and resistant experimental tumors in vitro and in vivo.

PATIENTS AND METHODS

KRN8602 was administered alone in increasing doses to patients with advanced cancer or high-grade gliomas until dose-limiting toxicity (DLT) was observed in three or more of five patients treated in a dose level. Because neutropenia was dose limiting, further escalation was investigated with filgrastim support.

RESULTS

Fifty-six assessable patients completed at least one cycle of chemotherapy. The recommended dose of KRN8602 alone was 40 mg/m2. Dose escalation was limited by neutropenia. The recommended dose of KRN8602 with filgrastim was 70 mg/m2, and limiting toxicities were neutropenia, diarrhea, and vomiting. The most commonly experienced nonhematologic toxicity was nausea and vomiting. Alopecia and mucositis were infrequent and mild. Pharmacokinetic parameters showed substantial variation, although the area under the plasma concentration-time curve (AUC) and maximum concentration both increased with dose. There was no relationship between pharmacokinetic parameters and toxicity.

CONCLUSION

KRN8602 at doses of 40 mg/m2 when administered alone and 70 mg/m2 when administered with filgrastim appeared to be manageable. The major DLTs were neutropenia and, at higher doses, diarrhea and vomiting. The efficacy of this drug is currently being tested in phase II studies.

Rapid hematopoietic recovery after multicycle high-dose chemotherapy: enhancement of filgrastim-induced progenitor-cell mobilization by recombinant human stem-cell factor

PURPOSE

To assess the mobilization potential and safety of recombinant human stem-cell factor (SCF) when coadministered with filgrastim to untreated women with poor-prognosis breast cancer.

PATIENTS AND METHODS

Eligible women had breast cancer with 10 or more positive axillary nodes, or estrogen receptor-negative tumor with 4 positive nodes, or stage III disease. Patients were randomized to receive SCF plus filgrastim or filgrastim alone. Filgrastim 12 microg/kg daily was administered for 6 days by continuous subcutaneous infusion. SCF was administered by daily subcutaneous injection at 5, 10, or 15 microg/kg concurrent with filgrastim for 7 days, or 10 microg/kg daily starting 3 days before filgrastim for a total of 10 days (SCF pretreatment). Apheresis was performed on days 5, 6, and 7 of filgrastim administration. Patients then had three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2 every 28 days, each supported by one third of the apheresis product.

RESULTS

Sixty-two women were treated. Greater yields occurred in patients who received SCF 10 microg/kg daily plus filgastim than those who received filgrastim alone (P=.013 for CD34+ cells; P=.07 for granulocyte-macrophage colony-forming cells [GM-CFCs]). The difference was more marked with SCF-pretreatment than concurrent SCF. Fewer aphereses were required to reach the predetermined target of peripheral-blood progenitor/stem cells (PBPCs) in women who received SCF. SCF was generally well tolerated. Hematologic recovery was rapid after each of the three cycles of chemotherapy. There was no difference in recovery between the different treatment groups.

CONCLUSION

Mobilization of PBPCs by filgrastim is significantly enhanced by coadministration of SCF, and commencing SCF before filgrastim can optimize this effect. SCF has the potential to reduce the number of aphereses required to collect a target number of PBPCs.

Effect of filgrastim on the pharmacokinetics of MX2 hydrochloride in patients with advanced malignant disease

PURPOSE

To investigate the effect of granulocyte colony-stimulating factor (G-CSF) on the pharmacokinetics and pharmacodynamics of the new morpholino anthracycline drug MX2.

METHODS

A total of 25 patients with advanced malignant disease participated in a dose-escalation study in the first cycle of treatment given i.v. at doses of 50-80 mg/m2 (74-152 mg) with concomitant filgrastim (G-CSF, 5 microg/kg) given daily beginning at 24 h after the dose of MX2.

RESULTS

The mean fast distribution half-life (1.5 +/- 1.0 min) and the mean plasma clearance (2.18 +/- 0.95 l/min) were significantly lower than the respective mean values found in a previous study in which 27 patients had received MX2 (16.8-107.5 mg) alone (3.3 +/- 2.2 min and 2.98 +/- 1.68 l/min, respectively; P < 0.05). There was no correlation between plasma clearance and the delivered dose for the combined MX2-alone and MX2-filgrastim groups, indicating that the lower clearance observed in the G-CSF group was probably not due to the higher dose. Elimination half-lives of the metabolites M1 and M4 were significantly greater in the filgrastim group (19.8 +/- 14.7 and 11.8 +/- 5.0 h for M1 and 14.8 +/- 4.1 and 12.3 +/- 6.3 h for M2, respectively). Unlike the MX2-alone group, there was no relationship in the MX2-filgrastim group between the relative nadir neutrophil count and the dose or between the duration of grade IV neutropenia and the dose of MX2.

CONCLUSIONS

This study shows that filgrastim decreased the plasma clearance of MX2 by approximately 25%, possibly by inhibition of metabolism.

Progress in management of acute myeloid leukaemia (AML) in Australia since 1980: a single institution retrospective study

BACKGROUND

Much research has been conducted into the pathobiology, diagnosis, and management of acute myeloid leukaemia (AML) since 1980, with major contributions from Australian studies in this period.

AIMS

To determine whether advances in basic and clinical research into AML have translated into improved survival for patients in the community.

METHODS

A retrospective survey of records of all patients with AML presenting to the Royal Melbourne Hospital (RMH) over a 16 year period, analysed according to induction therapy and established prognostic factors. Between 1980 and December 1996 223 (98%) of 227 patients were evaluable.

RESULTS

The probability of survival at five years for patients treated since 1990 has improved significantly compared to the cohort treated between 1980-89 (34 +/- 5% vs 4 +/- 2%; mean +/- standard error). This benefit is most evident in patients less than 60 years of age (50 +/- 7% vs 11 +/- 4%). Successive induction protocols in the context of clinical trials conducted since 1985 contributed to improved outcomes. The selective application of bone marrow transplantation, and use of retinoic acid as induction therapy for acute promyelocytic leukaemia has also improved survival. Despite increases in dose-intensity, early death rates for patients undergoing induction therapy fell during the study period.

CONCLUSIONS

Participation in clinical and basic research with the development of more intense and specific treatments for patients with AML has contributed to better outcomes, underpinned by improvements in supportive care.

Isolated pleural effusion with hematopoietic cells of mixed lineage in a patient receiving granulocyte-colony-stimulating factor after high-dose chemotherapy

A 43-yr-old woman with recently diagnosed breast carcinoma presented with a right pleural effusion after a cycle of adjuvant, high-dose chemotherapy supported by peripheral blood progenitor cells (PBPC) and granulocyte-colony-stimulating factor (G-CSF, Filgrastim). Cytologic examination of the pleural aspirate yielded highly cellular material composed predominantly of cells of myeloid and macrophage/monocytic lineages. Despite clinical concern of a malignant effusion, the combination of cytologic and immunophenotypic examination yielded the correct diagnosis of a nonneoplastic effusion related to underlying pleural inflammation and possibly the administration of G-CSF.

Multilineage mobilization of peripheral blood progenitor cells in humans following administration of PEG-rHuMGDF

The most important physiological regulator of megakaryocytopoiesis is the ligand for the c-mpl receptor (thrombopoietin/megakaryocyte growth and development factor, MGDF). We examined the effect of pegylated-recombinant human MGDF (PEG-rHuMGDF): patients received PEG-rHuMGDF at doses of 0.03, 0.1, 0.3 or 1.0 microg/kg/d or placebo for 10d maximum in a double-blinded randomized study. There was a dose-dependent elevation in circulating platelet counts but no alteration in erythrocyte or total leucocyte counts. The number of bone marrow megakaryocytes was increased approximately 2-fold. The frequency of bone marrow progenitor cells was not altered. In contrast, both to the bone marrow results and to published pre-clinical data, there was a dose-dependent mobilization into the blood of progenitor cells of multiple cell lineages. Increased levels of Meg-CFC (maximum increase 30-fold), day 7 and day 14 GM-CFC and BFU-E were demonstrated at doses of 0.3 and 1.0 microg/kg/d PEG-rHuMGDF. At 0.1 microg/kg/d, mobilization of Meg-CFC alone occurred in two-thirds of patients. Maximum blood levels of progenitor cells occurred at day 12. Thus, administration of PEG-rHuMGDF to humans resulted in mobilization of progenitor cells of multiple lineages despite its 'lineage-specific' activity on mature cell development.

Randomized, blinded, placebo-controlled phase I trial of pegylated recombinant human megakaryocyte growth and development factor with filgrastim after dose-intensive chemotherapy in patients with advanced cancer

Thrombocytopenia caused by chemotherapy is an important cause of morbidity and mortality in the treatment of malignant disease. Recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is a potent stimulator of megakaryocytopoiesis and prevents chemotherapy-induced thrombocytopenia in preclinical studies. We administered PEG-rHuMGDF with filgrastim after dose-intensive chemotherapy to 41 patients with advanced cancers to determine its safety and effects on hematologic recovery. Carboplatin 600 mg/m2 and cyclophosphamide 1,200 mg/m2 were administered to patients with advanced cancer. Patients were randomly assigned to receive blinded study drug, either PEG-rHuMGDF or placebo (3-to-1 ratio), commencing the day after chemotherapy. PEG-rHuMGDF was given at doses of 0.03, 0.1, 0.3, 1.0, 3.0, and 5.0 microg per kilogram body weight by daily subcutaneous injection for between 7 and 20 days. All patients received concurrent filgrastim 5 microg per kilogram body weight per day until neutrophil recovery. Fifteen patients had received PEG-rHuMGDF alone in a previous phase I study. Platelet function and peripheral blood progenitor cells (PBPC) were assessed. PEG-rHuMGDF enhanced platelet recovery in a dose-related manner when compared with placebo. The platelet nadir occurred earlier in patients given PEG-rHuMGDF (P = .002) but there was no difference in the depth of the nadir. Recovery to baseline platelet count was achieved significantly earlier following PEG-rHuMGDF administration compared with placebo (median, 17 days for PEG-rHuMGDF 0.3 to 5.0 microg/kg versus 22 days for placebo, P = .014). In addition, platelet recovery was faster in patients who had previously received PEG-rHuMGDF, suggesting that pretreatment might be beneficial. Platelet function did not change during or after administration of PEG-rHuMGDF. Levels of PBPC on day 15 after chemotherapy were significantly greater in patients administered PEG-rHuMGDF 0.3 to 5.0 microg/kg and filgrastim compared with those given placebo plus filgrastim. PEG-rHuMGDF was well tolerated at all doses. Two patients given PEG-rHuMGDF had a thrombotic episode. PEG-rHuMGDF accelerates platelet recovery after moderately dose-intensive carboplatin and cyclophosphamide, and is likely to be clinically useful in treatment of chemotherapy-induced thrombocytopenia. Because it enhances mobilization of PBPC by filgrastim, PEG-rHuMGDF might also allow more efficient collection of stem cells for autologous or allogeneic transplantation.

Pharmacokinetics and pharmacodynamics of MX2 hydrochloride in patients with advanced malignant disease

The purpose of the present study was to investigate the pharmacokinetics and pharmacodynamics of the new morpholino anthracycline drug MX2. A total of 27 patients with advanced cancer participated in a dose-escalation study in the first cycle of treatment with drug given i.v. at doses of 10-50 mg/m2 (total dose 16.8-107.5 mg). The mean total systemic plasma clearance (CL) of MX2 was 2.98 +/- 1.68 l/min, the mean volume of distribution at steady state was 1460 +/- 749 l and mean elimination half-life was 10.8 +/- 5.1 h. The area under the plasma concentration-time curve (AUC) of MX2 was linearly related to the dose per kilogram and the dose per body surface area (r2 = 0.43, P < 0.01 and r2 = 0.44, P < 0.01, respectively). CL did not correlate with total body weight, lean body mass or body surface area. The mean elimination half-lives of the metabolites M1, M2, M3 and M4 were 11.8 +/- 5.0, 21.9 +/- 11.8, 19.0 +/- 11.3 and 12.3 +/- 6.3 h, respectively. The fractional Emax model produced a much better fit to the relative nadir neutrophil count versus dose data (r2 = 0.42) than to the relative nadir neutrophil count versus AUC or peak concentration (Cmax) data (r2 = 0.15 and 0.09, respectively). There seemed to be a threshold dose of about 65 mg of MX2 at or above which a large proportion of patients had a nadir neutrophil count of less than 0.5 x 10(9)/l. This study shows that the pharmacokinetics of MX2 are similar to those of other anthracyclines. With other anthracyclines the degree of myelosuppression seems to depend more on the AUC and Cmax than on the delivered dose; however, with MX2 the degree of myelosuppression depends more on the dose given than on drug exposure expressed as the AUC or Cmax.

A risk-benefit assessment of anthracycline antibiotics in antineoplastic therapy

The anthracycline antibiotics comprise a group of cytotoxic compounds with wide-ranging activity against human malignancies. They are used extensively for curative, adjuvant and palliative therapy, both as single agents and in combination regimens. They produce a number of adverse effects, some of which are shared by other cytotoxic drugs. The most important adverse effect is cardiotoxicity, which is unique to this class of compounds. Strategies have been devised to circumvent these adverse effects, including the development of less toxic analogues, alterations in scheduling, the addition of cardioprotectant agents and methods of monitoring for cardiac abnormalities.

Thrombopoietic effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) in patients with advanced cancer

BACKGROUND

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is a potent stimulator of megakaryocyte colony formation and platelet production. It is likely to be useful in the management of severe thrombocytopenia. To determine its clinical activity and safety, we gave it to patients with advanced cancer before chemotherapy.

METHODS

Patients were randomly assigned to receive either PEG-rHuMGDF or placebo in a three to one ratio. PEG-rHuMGDF was given at a dose of 0.03, 0.1, 0.3, or 1.0 microgram/kg body weight. The study drug or placebo were administered daily by subcutaneous injection for up to 10 days or until a target platelet count was reached.

FINDINGS

17 patients, median age 59 years, received either PEG-rHuMGDF (13 patients) or placebo (four patients). PEG-rHuMGDF produced a dose-dependent increase in platelet counts. Patients given placebo. 0.03, and 0.1 microgram/kg of PEG-rHuMGDF had median increases in platelet counts of 16%, 12%, and 39%. Those receiving 0.3 and 1.0 microgram/kg of PEG-rHuMGDF had an increase in blood platelets of between 51% and 584%. Platelets rose from day 6 of PEG-rHuMGDF administration and continued to rise after stopping the drug. The platelet count peaked between days 12 and 18 and remained above 450 x 10(9)/L for up to 21 days. There were no alterations in white-blood-cell count or haematocrit, and low toxicity. Platelets taken from patients during PEG-rHuMGDF administration and at the time of peak platelet count were morphologically and functionally normal.

INTERPRETATION

The potency with which PEG-rHuMGDF stimulates platelet production and its low toxicity indicate that this is likely to be a useful agent for the management of thrombocytopenia.

Administration of pegylated recombinant human megakaryocyte growth and development factor to humans stimulates the production of functional platelets that show no evidence of in vivo activation

This report describes the effect of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet production and platelet function in humans. Subjects with advanced solid tumors received PEG-rHuMGDF daily for up to 10 days. There was no increase in circulating platelet count at doses of 0.03 or 0.1 microgram/kg/d by day 12 of study. At doses of 0.3 and 1.0 microgram/kg/d there was a threefold median increase (maximum 10-fold) in platelet count by day 16. The platelets produced in vivo in response to PEG-rHuMGDF showed unchanged aggregation and adenosine triphosphate (ATP)-release responses in in vitro assays. Tests included aggregation and release of ATP in response to adenosine diphosphate (ADP) (10, 5, 2.5, and 1.25 mumol/L), collagen (2 micrograms/mL), thrombin-receptor agonist peptide (TRAP, 10 mumol/L) and ristocetin (1.5 mg/mL). Administration of aspirin to an individual with platelet count of 1,771 x 10(3)/L resulted in the typical aspirin-induced ablation of the normal aggregation and ATP-release response to stimulation with arachidonic acid (0.5 mg/mL), collagen, and ADP (2.5 and 1.25 mumol/L). There was no change in the expression of the platelet-surface activation marker CD62P (P-selectin) nor induction of the fibrinogen binding site on glycoprotein IIb/IIIa as reported by the monoclonal antibody, D3GP3. An elevation of reticulated platelets was evident after 3 days of treatment with PEG-rHuMGDF and preceded the increase in circulating platelet count by 5 to 8 days; this reflected the production of new platelets in response to PEG-rHuMGDF. At later time points, the mean platelet volume (MPV) decreased in a manner inversely proportional to the platelet count. Levels of plasma glycocalicin, a measure of platelet turnover, rose 3 days after the initial increase in the peripheral platelet count. The level of plasma glycocalicin was proportional to the total platelet mass, suggesting that platelets generated in response to PEG-rHuMGDF were not more actively destroyed. Thus, the administration of PEG-rHuMGDF, to humans, increased the circulating platelet count and resulted in fully functional platelets, which showed no detectable increase in reactivity nor alteration in activation status.

Adjuvant treatment of high-risk breast cancer using multicycle high-dose chemotherapy and filgrastim-mobilized peripheral blood progenitor cells

Women with primary breast cancer associated with extensive axillary node involvement or large primary tumors have a very poor prognosis despite treatment with standard-dose adjuvant chemotherapy. In an attempt to improve the outlook of these patients, we investigated the safety and feasibility of delivering three cycles of high-dose epirubicin and cyclophosphamide supported with filgrastim-mobilized peripheral blood progenitor cells (PBPC). Fifteen previously untreated women, median age 50 (range, 30-58) years, with poor prognosis early stage breast cancer received filgrastim (12 microgram/kg daily for 6 days) prior to chemotherapy to mobilize progenitor cells. Patients were then given three cycles of epirubicin (200 mg/m2) and cyclophosphamide (4 g/m2) at planned 28-day intervals, each followed by infusion of one third of the PBPC collected and daily administration of filgrastim (5 microgram/kg s.c.). Three leukaphereses collected a median of 114.9 (range, 22.7-273.5) x 10(4) granulocyte-macrophage-colony-forming cells/kg body weight. Hemopoietic recovery was rapid after each cycle, and there was no correlation between the rate of recovery and the number of granulocyte-macrophage-colony-forming cells infused. There was a small but significant progressive delay in recovery from hematological and nonhematological toxicities across the three cycles. Left ventricular ejection fraction fell to below 50% in eight (53%) patients, but none developed congestive cardiac failure. Two patients did not complete three cycles because of insufficient PBPC for a third cycle (n = 1) and 2-mercaptoethane sodium sulfonate- related drug reaction during the second cycle (n = 1). There were no deaths during the study or during the follow-up period (median, 70 weeks; range, 50-85 weeks), and no late toxicities occurred. Therefore, we concluded that the delivery of multiple cycles of nonmyeloablative, dose-intensive chemotherapy supported by PBPC and filgrastim is safe, and may be widely applicable to a variety of common chemosensitive cancers with a poor prognosis. The efficacy of three cycles of high-dose epirubicin and cyclophosphamide is to be compared with standard-dose chemotherapy in a randomized trial in patients with high-risk, operable stage II and III breast cancer.

Conservative management of squamous cell carcinoma of the anal canal

The treatment of anal carcinoma with concurrent chemo/radiotherapy has largely replaced abdominoperineal resection as the primary management. This report details the outcome of 62 patients with anal carcinoma treated at a single institution over a 10 year period, during which this approach has become the mainstay of therapy. Of the 34 patients treated with combination radiotherapy and chemotherapy (5-fluorouracil and mitomycin-C), 31 were evaluable and a complete response was achieved in 77%. The estimated 5 year failure-free survival was 67% and the overall survival was 81%. The overall survival was superior to that in patients treated with radiotherapy alone. Eighty-four per cent of patients received the treatment as planned, while the remainder had a reduction in the dose of radiation or chemotherapy due to acute toxicity. The use of combination therapy for primary management of anal carcinoma is generally well tolerated, appears to provide a treatment outcome at least equivalent to surgery, and allows preservation of anal function. Concurrent chemo/radiotherapy should be considered in the initial management of patients with anal carcinoma.

Comparative study of the pharmacokinetics and toxicity of high-dose epirubicin with or without dexrazoxane in patients with advanced malignancy

PURPOSE

We evaluated the toxicity and pharmacokinetics of the combination of dexrazoxane with epirubicin at dexrazoxane/epirubicin dose ratios of 5 to 9:1 in a controlled, crossover phase I study in patients with advanced malignancy.

PATIENTS AND METHODS

Thirty-eight patients with a variety of malignancies were enrolled. Assessable patients received two cycles of chemotherapy consisting of epirubicin alone and in combination with dexrazoxane. Comparisons were made between the toxicity and pharmacokinetics of epirubicin in the two treatment arms, using each patient as his or her own control. Dexrazoxane and epirubicin were delivered at dose levels of 600/120 mg/m2, 900/120 mg/m2, 900/135 mg/m2, 900/150 mg/m2, and 1,200/135 mg/m2, respectively. Twenty-six patients completed two cycles of chemotherapy and were therefore assessable.

RESULTS

The maximum-tolerated doses (MTDs) of dexrazoxane/epirubicin were 1,200/135 mg/m2, with the dose-limiting toxicities being neutropenia, infection, and stomatitis. There was no difference in the nadir neutrophil or platelet counts between single-agent and combination treatment at any of the dose levels. Severe vomiting and stomatitis occurred less frequently following administration of epirubicin and dexrazoxane when compared with epirubicin alone (P = .01 and .02, respectively). Prior administration of higher doses (900 mg/m2 and 1,200 mg/m2) of dexrazoxane increased the systemic clearance of epirubicin, resulting in a decrease in the area under the curve (AUC). Elimination half-life, maximum plasma concentration (Cmax), and apparent volume of distribution of epirubicin were not significantly affected by dexrazoxane. Left ventricular ejection fraction (LVEF) decreased by greater than 10% in two patients, but neither developed clinical or radiologic evidence of cardiac failure.

CONCLUSION

This study demonstrates that dexrazoxane can be safely combined with escalating doses of epirubicin at dose ratios of 5 to 9:1 without having an adverse impact on toxicity. Studies are need to determine the optimal dose ratio for cardioprotection and to explore further the pharmacokinetic interactions of the two drugs at increasing doses of epirubicin supported by hematopoietic growth factors.

Pilot study of escalating doses of carboplatin and cyclophosphamide in patients with advanced cancer

In all, 18 patients with histologically proven advanced cancer received 400 mg/m2 carboplatin (CBDCA) plus 800 mg/m2 cyclophosphamide (level 1), and 14 others received 550 mg/m2 CBDCA plus 1100 mg/m2 cyclophosphamide (level 2). A maximum of six cycles was given if a response occurred. The dose-limiting toxicity was myelosuppression, with neutropenia being more marked than thrombocytopenia. At level 2, patients experiencing a febrile-neutropenic event showed a mean 24-h urinary creatinine clearance value of 1.1 ml/s (95% confidence limits 0.8-1.4 ml/s), whereas in those who remained afebrile it was 1.7 ml/s (95% confidence limits, 1.3-2.0 ml/s). This difference was significant (P less than 0.01). Other toxicities were only mild. Creatinine clearance is a predictor of febrile episodes after treatment with high doses of CBDCA and cyclophosphamide. We are now conducting a study using human granulocyte colony-stimulating factor to reduce the incidence of neutropenia with escalating doses of these drugs in an attempt to prevent febrile events.

Recombinant alpha-2b interferon in patients with malignant carcinoid tumour

Seventeen patients with malignant carcinoid tumour, ten of whom had the malignant carcinoid syndrome, were treated with recombinant alpha-2b interferon by subcutaneous injection (3 MU per dose) three times per week for a median of 12 weeks (range 4-48). No objective tumour responses were observed; however, there was a greater than 50% reduction in 24-hour urinary 5-hydroxyindolacetic acid (5-HIAA) excretion in four of ten patients (40%) with elevated pretreatment levels. Five of ten patients (50%) with flushing, five of seven patients (71%) with diarrhoea and both patients with wheezing experienced relief of symptoms. Three of four patients (75%) with weight loss as their only problem experienced weight gain. Responses occurred within the first eight weeks of treatment, but were generally of short duration. Toxicity occurred in all patients, and consisted mainly of fever, chills, anorexia, fatigue and weight loss. Four patients ceased therapy due to toxic reactions. Although interferon has activity against carcinoid tumours, its benefits are short-lived and toxicity limits its use with increasing dose. Patients with carcinoid syndrome appear to achieve the best therapeutic response, and it is likely that low doses (9-20 million IU weekly) are as effective as higher doses (36-72 million IU weekly).

Recent advances in carcinoids and gastrointestinal neuroendocrine tumors

The main advances in the management of carcinoid and gastrointestinal neuroendocrine tumors have been in the areas of imaging and therapy. New techniques have been developed to detect and identify the sites of tumor so that correct therapeutic decisions can be made. Although surgery remains the mainstay of treatment of localized and some cases of advanced disease, the use of biologic agents and new drugs has proven valuable in those patients in whom surgery is not indicated. These include interferon-alpha, the somatostatin analogue octreotide, omeprazole. Different methods of delivery have been investigated with mixed success. Future progress in the understanding and management of neuroendocrine tumors is likely to be slow due to their rarity and long natural history.