A phase II study of mitoxantrone, etoposide, and thiotepa with autologous marrow support for patients with relapsed breast cancer

Oncolytic virotherapy for multiple myeloma: past, present, and future

Multiple myeloma (MM) is a B-cell malignancy that is currently felt to be incurable. Despite recently approved novel targeted treatments such as lenalidomide and bortezomib, most MM patients' relapse is emphasizing the need for effective and well-tolerated therapies for this deadly disease. The use of oncolytic viruses has garnered significant interest as cancer therapeutics in recent years, and are currently under intense clinical investigation. Both naturally occurring and engineered DNA and RNA viruses have been investigated preclinically as treatment modalities for several solid and hematological malignancies. Presently, only a genetically modified measles virus is in human clinical trials for MM. The information obtained from this and other future clinical trials will guide clinical application of oncolytic viruses as anticancer agents for MM. This paper provides a timely overview of the history of oncolytic viruses for the treatment of MM and future strategies for the optimization of viral therapy for this disease.

Viral purging of haematological autografts: should we sneeze on the graft?

High-dose cytotoxic chemotherapy followed by autologous haematopoietic stem cell transplantation (ASCT) is extensively used for the treatment of many haematopoietic, as well as several epithelial cancers. Disease relapse may be the result of tumour contamination within autograft as evidenced by gene marking studies. The multiple purging strategies that have been described to date have not proven effective in most ASCT settings. This review addresses the possibility of using oncolytic viruses as a novel purging strategy. DNA viruses such as genetically engineered adenoviral vectors have widely been used to deliver either a prodrug-activating enzyme or express wild-type p53 selectively in tumour cells in ex vivo purging protocols. In addition, conditionally replicating adenoviruses that selectively replicate in tumour cells and herpes simplex virus type 1 are other DNA viruses that have been tested as ex vivo purging agents under laboratory conditions. Vesicular stomatitis virus (VSV) and reovirus are naturally occurring RNA viruses that appear to hold promise as purging agents under ex vivo and in vivo settings. Preclinical data demonstrate reovirus's purging potential against breast, monocytic and myeloma cell lines as well as patient-derived tumours of diffuse large B-cell lymphoma, chronic lymphocytic leukaemia, Waldenstrom macroglobulinemia and small lymphocytic lymphoma. In addition, VSV has shown effective killing of leukaemic cell lines and multiple myeloma patient specimens. Given the increasing interest in the utilization of viruses as purging agents, the following review provides a timely summary of the potential and the challenges of oncolytic viruses as purging modalities during ASCT.

Cytoreduction of lymphoid malignancies and mobilization of blood hematopoietic progenitor cells with high doses of cyclophosphamide and etoposide plus filgrastim

We evaluated the efficiency of high doses of cyclophosphamide (6 g/m2) and etoposide (2 g/m2) plus filgrastim (granulocyte colony-stimulating factor; G-CSF) to mobilize autologous hematopoietic progenitor cells in patients with non-Hodgkin lymphoma, multiple myeloma, and Waldenström macroglobulinemia. We also evaluated the safety of this regimen and the engraftment kinetics after myeloablative chemotherapy. Seventy-nine patients with high-risk or relapsed/primary refractory non-Hodgkin lymphoma, multiple myeloma, or Waldenström macroglobulinemia were treated. The mobilizing regimen was as follows: cyclophosphamide 600 mg/m2 twice daily for 10 doses, etoposide 200 mg/m2 twice daily for 10 doses (continuous; n=57) or 2 g/m2 over 10 hours on day 5 of etoposide (bolus; n=22), and G-CSF 5 microg/kg/d beginning day 14. Fifty-nine percent of patients achieved the primary end point (a CD34 cell dose of 5 million per kilogram with a single leukapheresis). More bolus etoposide patients achieved the primary end point (86%) compared with continuous etoposide patients (47%; P<.0001). The CD34 cell dose collected was greater in bolus etoposide patients (44 million per kilogram) than in continuous etoposide patients (10.9 million per kilogram; P<.0001). Patients took 3 weeks to recover >500/microL neutrophils and >20000/microL platelets after cyclophosphamide and etoposide. The overall response rate was 69% for non-Hodgkin lymphoma patients and 71% for multiple myeloma/Waldenström macroglobulinemia patients. The treatment-related mortality was 2.5%. Sixteen percent of surviving patients experienced grade>or=3 nonhematologic toxicity. Patients receiving bolus etoposide had significantly less grade>or=2 oral mucositis, less use of total parenteral nutrition, and less need for red blood cell and platelet transfusions. Sixty-four patients (81%) underwent autologous hematopoietic progenitor cell transplantation, with prompt engraftment. Four patients (5%) did not undergo autologous hematopoietic progenitor cell transplantation because of toxicity from high-dose cyclophosphamide and etoposide. We conclude that high doses of cyclophosphamide and etoposide combined with G-CSF are an efficient and safe mobilizing regimen for the collection of hematopoietic progenitor cells during aggressive cytoreduction of tumor burden in patients with lymphoid malignancies.

High dose chemotherapy and autologous stem cell transplantation as adjuvant therapy for primary breast cancer patients with four or more lymph nodes involved: long-term results of an international randomised trial

BACKGROUND

The purpose of this study was to assess whether a short course of anthracycline containing chemotherapy followed by high dose therapy with autologous stem-cell support improves disease-free and overall survival as compared with conventional, anthracycline containing chemotherapy, in patients with primary breast cancer and four or more histologically involved lymph nodes.

PATIENTS AND METHODS

Two hundred and eighty one patients entered into a randomised clinical trial were allocated to receive standard, conventional treatment (5-fluorouracil, epirubicin and cyclophosphamide-FEC for six cycles) or FEC for three cycles followed by high dose therapy consisting of cyclophosphamide, thiotepa and carboplatin and stem cell rescue (HDT). To be eligible, patients had to be free of overt metastatic disease and be < or =60 years of age. Analyses were according to intention to treat.

RESULTS

At a median follow up of 68 months, 118 patients have experienced a relapse or death from breast cancer (62 in the FEC followed by HDT arm and 56 in the conventional FEC arm) and a total of 100 patients have died (54 in the FEC followed by HDT arm and 46 in the conventional FEC arm). No significant difference was observed in relapse-free survival [hazard ratio 1.06, 95% CI 0.74-1.52, p = 0.76] or overall survival [hazard ratio 1.18, 95% CI 0.80-1.75, p = 0.40]. Five patients died from treatment related causes, three as a consequence of HDT and two in the conventional FEC arm.

CONCLUSIONS

At the present time, no benefit has been observed from replacing three cycles of conventional chemotherapy with the HDT regimen described here. Patients should continue to receive conventional chemotherapy as adjuvant therapy for breast cancer.

Secondary acute leukemia following mitoxantrone-based high-dose chemotherapy for primary breast cancer patients

The incidence of secondary myelodysplasia/acute myeloid leukemia (AML) was retrospectively assessed in an international joint study in 305 node-positive breast cancer patients, who received mitoxantrone-based high-dose chemotherapy (HDCT) followed by autologous stem cell support as adjuvant therapy. The median age of the patients was 57 years (range 22-67). In all, 268 patients received peripheral blood stem cells, and 47 patients received autologous bone marrow. After a median follow-up of 57 months (range 10-125), three cases of secondary AML (sAML) were observed, resulting in a cumulative incidence of 0.94%. One case of sAML developed 18 months after HDCT (FAB M3) The karyotype was translocation 15;17 and, after induction therapy, the patient underwent autologous stem cell transplantation, and is in complete remission (CR) of both breast cancer and AML. The second patient developed AML (FAB M4eo with inversion 16) 5 months after HDCT. This patient achieved CR after induction therapy, but died of infectious complication. A third patient developed AML (FAB M4) 6 months after HDCT. She achieved CR after induction therapy, but relapsed and expired 28 months after diagnosis of AML. sAML after mitoxantrone-based HDCT is a possible, but rare complication in breast cancer patients.

Reovirus oncolysis as a novel purging strategy for autologous stem cell transplantation

Hematologic stem cell rescue after high-dose cytotoxic therapy is extensively used for the treatment of many hematopoietic and solid cancers. Gene marking studies suggest that occult tumor cells within the autograft may contribute to clinical relapse. To date purging of autografts contaminated with cancer cells has been unsuccessful. The selective oncolytic property of reovirus against myriad malignant histologies in in vitro, in vivo, and ex vivo systems has been previously demonstrated. In the present study we have shown that reovirus can successfully purge cancer cells within autografts. Human monocytic and myeloma cell lines as well as enriched ex vivo lymphoma, myeloma, and Waldenström macroglobulinemia patient tumor specimens were used in an experimental purging model. Viability of the cell lines or purified ex vivo tumor cells of diffuse large B-cell lymphoma, chronic lymphocytic leukemia, Waldenström macroglobulinemia, and small lymphocytic lymphoma was significantly reduced after reovirus treatment. Further, [35S]-methionine labeling and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of cellular proteins demonstrated reovirus protein synthesis and disruption of host cell protein synthesis as early as 24 hours. Admixtures of apheresis product with the abovementioned tumor cells and cell lines treated with reovirus showed complete purging of disease. In contrast, reovirus purging of enriched ex vivo multiple myeloma, Burkitt lymphoma, and follicular lymphoma was incomplete. The oncolytic action of reovirus did not affect CD34+ stem cells or their long-term colony-forming assays even after granulocyte colony-stimulating factor (G-CSF) stimulation. Our results indicate the ex vivo use of an unattenuated oncolytic virus as an attractive purging strategy for autologous stem cell transplantations.

Neoadjuvant Moderately High-Dose Chemotherapy with rh-G-CSF in Locally Advanced Breast Carcinoma

Aims and Background

The poor results of local treatment for locally advanced breast carcinoma (LABC) justify the use of chemotherapy as primary treatment. Retrospective studies have shown a positive correlation between dose and response rate in advanced breast cancer. G-CSF has shown efficacy in achieving optimal dose intensity and ameliorating chemotherapy-induced myelosuppression. The aim of the present study was to assess the efficacy of a moderately high-dose chemotherapy regimen in terms of response rate, disease-free and overall survival and to assess the role of G-CSF in induced neutropenia.

Methods

Inclusion criteria were the following: age <65 years, WHO performance status <2, histologically proven breast carcinoma, adequate hematologic, renal and hepatic function, stage IIIA or IIIB disease, and no metastatic disease. No prior chemotherapy or radiotherapy was allowed. Three cycles of the following chemotherapy were used preoperatively: epirubicin (100 mg/m2 on day 1), cyclophosphamide (400 mg/m2 for 3 consecutive days) and rh-G-CSF (5 μg/kg/die from day 4 to day 12 every 14 days). After mastectomy or quadrantectomy plus radiotherapy, all patients were treated with 4 courses of adjuvant chemotherapy according to the CMF 1-8 schedule (methotrexate, 40 mg/m2; cyclophosphamide, 600 mg/m2; fluorouracil, 600 mg/m2; all on days 1 and 8, with recycle every 4 weeks).

Results

From May 1992 to June 1996, 57 patients with histologically proven LABC were preoperatively treated. Forty-four patients were premenopausal and 13 postmenopausal; the median age was 45 years (range, 29-64). Thirty-five patients had stage IIIA and 22 patients stage IIIB disease (7 with inflammatory disease). Forty-seven patients underwent radical mastectomy and 10 conservative surgery. A clinical response was noted in 93% (95% confidence interval, 83-98%) of patients (12% complete responses and 81% partial responses); 2 pathological complete remissions (3.5%) were obtained. No toxic deaths were observed. All patients had a follow-up of at least 42 months. The overall 5-year survival rate was 76% (standard error - SE), 6%) and the 5-year disease-free survival rate was 68% (SE, 6.3%).

Conclusions

The 14-day regimen was well tolerated and effective in LABC patients, although not superior to standard-dose chemotherapy. To improve results the use of new drugs in controlled clinical trials seems warranted.

Recombinant human thrombopoietin clinical development

Patients undergoing anticancer therapy are often at risk for developing severe and/or prolonged posttreatment thrombocytopenia. This can be associated with significant bleeding; currently, it is treated with supportive platelet transfusions. Frequent platelet transfusions can cause alloimmunization which requires HLA-matched donors and more frequent blood transfusions, and transmission of both viral and bacterial infections via platelet transfusions remains a concern. Furthermore, thrombocytopenia can mandate a decrease in the dose intensity of cytotoxic therapy by causing either delays or dose reductions in therapy administration. An intervention that reduces the risk or shortens the duration of severe thrombocytopenia would represent an important medical advance. Thrombopoietin (TPO), a naturally occurring, glycosylated polypeptide that was cloned by Genentech in 1994, is capable of inducing differentiation of stem cells into megakaryocytes and accelerating the maturation of megakaryocytes, thereby increasing the platelet count. Recombinant human TPO (rHuTPO) is currently undergoing testing in phase 1 and 2 studies in patients receiving myelosuppressive or myeloablative therapy. For the purposes of illustration, preliminary safety and activity data from one ongoing phase 1 myelosuppression trial (rHuTPO in women with advanced gynecologic malignancies receiving carboplatin) and one ongoing phase 1 myeloablation trial (rHuTPO for peripheral blood progenitor cell mobilization prior to myeloablative chemotherapy for high risk breast cancer) will be presented.

High-dose chemotherapy (CTM) for breast cancer

We designed and implemented a new mitoxantrone-based high-dose chemotherapy regimen to minimize pulmonary injury (seen in carmustine-based regimens) in patients with breast cancer. One hundred and ninety-one breast cancer patients (99 stage II/IIIA; 27 stage IIIB; 65 stage IV responsive to conventional-dose chemotherapy) were treated with high-dose chemotherapy (CTM) delivered over 4 days (cyclophosphamide (6 g/m2), thiotepa (600 mg/m2), and mitoxantrone (24-60 mg/m2)) followed by autologous hematopoietic stem cell rescue. Stage II/III patients received chest wall radiation and tamoxifen (if hormone-receptor positive) after CTM. The 5-year event-free survival (EFS) for stage II/IIIA patients with 10 or more involved axillary lymph nodes (n = 80) was 62 +/- 12%. Hormone receptor-positive patients with 10 or more nodes did significantly better than negative patients. The EFS for stage IIIB patients at 5 years was 44 +/- 19%; for stage IV patients at 5 years was 17 +/- 10%. Stage IV patients achieving complete response in viscera and/or soft tissue prior to CTM did significantly better than those achieving a partial response. There were six (3%) treatment-related deaths including two due to diffuse alveolar hemorrhage. There were no episodes of delayed interstitial pneumonitis. There were six severe cardiac events in 91 patients (6.6%) but none after instituting mitoxantrone dose-adjustment in the final 100 patients. We conclude that CTM is associated with a low treatment-related mortality and little pulmonary toxicity. CTM produces excellent outcomes in stage II/IIIA patients with 10 or more involved axillary lymph nodes.

A phase III study of high-dose intensification without hematopoietic progenitor cells support for patients with high-risk primary breast carcinoma

Patients with more than nine ipsilateral lymph node involvement or inflammatory breast cancer have a 5-year survival rate of approximately 50%. We studied the efficacy of high-dose intensification, comparing it with the standard dose chemotherapy for patients with high-risk primary breast cancer. Patients with inflammatory breast cancer or more than nine ipsilateral lymph node involvement without evidence of distant metastasis were randomized to receive either standard dose 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) every 3 weeks for nine courses (control) or six courses of FAC followed by two courses of cyclophosphamide (5.25 g/m2), etoposide (1,500 mg/m2), and cisplatin (165 mg/m2) (HDCVP). The study was terminated in 1998 because of slow accrual of patients. Forty-six patients were entered in the study. At 4 years, the overall survival was 72.8% (SE 11.9%) and 61.7% (SE 12.4%), and disease-free survival were 45.5% (SE 12.3%) and 33.7% (SE 11.9%) for the control and HDCVP groups, respectively (p = 0.757 and 0.720). With the small number of patients in our study, a small overall survival benefit of high-dose intensification compared with the standard therapy cannot be excluded. However, any substantial benefit is unlikely.

Phase I/II trial of cyclophosphamide, mitoxantrone, and escalated doses of carboplatin supported by peripheral-blood stem cells in women with metastatic breast cancer

PURPOSE

To intensify a regimen of high-dose cyclophosphamide, mitoxantrone, and carboplatin that had previously produced high complete and overall response rates in metastatic breast cancer (MBC).

PATIENTS AND METHODS

Forty-four patients with a median age of 43 years (range, 25 to 57 years) and previously untreated MBC who were responding to anthracycline-based or single-agent taxane chemotherapy received cyclophosphamide 1.5 g/m(2)/d and mitoxantrone 16 mg/m(2)/d combined with escalating doses of carboplatin 200 to 500 mg/m(2)/d, each given daily from days -6 to -3. Hematopoiesis was supported by mobilized peripheral-blood stem cells infused on day 0 and by use of granulocyte-macrophage colony-stimulating factor 300 microg/d subcutaneously starting on day 1.

RESULTS

A total of six dose levels of carboplatin were examined. Grades 3 and 4 toxicity occurred in 10 patients and one patient, respectively, with grade 3 toxicity occurring in only five of 31 patients treated with < or = 400 mg/m(2) of carboplatin. Major dose-limiting toxicities were cardiac, pulmonary, and renal. Four patients developed congestive heart failure: two had persistently low ejection fraction 11 and 36 months after peripheral-blood stem-cell transplantation (PBSCT), and two recovered. Hematologic recovery to an absolute neutrophil count of greater than 0.5 x 10(9)/L occurred at a median of 11 days (range, 8 to 25 days) and to a platelet count of greater than 20 x 10(9)/L at a median of 10.5 days (range, 6 to 60 days). There were two toxic deaths from sepsis: one on day 27 (level 5) and one from cardiac arrest on day 42 (level 6).

CONCLUSION

The maximum-tolerated dose of carboplatin was 400 mg/m(2)/d in combination with mitoxantrone 16 mg/m(2)/d and cyclophosphamide 1,500 mg/m(2), all drugs given over 4 days. This regimen is being tested in a phase III trial of high-dose chemotherapy and PBSCT versus standard treatment.

Is there a role for intensive therapy in breast cancer?

With reference to survival, polychemotherapy has been demonstrated to be statistically significantly more effective than monochemotherapy both in the adjuvant setting and in the metastatic situation. Breast cancer demonstrates a dose-response relationship. Chemotherapy used in the conventional dose range should be given with adequate dose-intensity both in the adjuvant setting and for metastatic patients. More dose-intensive combinations are almost always associated with a higher response rate in patients' metastatic disease, but these results have seldom been translated into an improved survival. For marrow requiring high-dose therapy, repeated phase II studies have demonstrated the possibility of a survival tail, which may be due to stage migration and patient selection. At present we have at least 13 ongoing phase III studies in the adjuvant setting and at least 5 ongoing studies in the metastatic situation. These studies will give a definite answer on whether marrow-supported high-dose therapy is better than conventional therapy or if alternative approaches using tailored therapy will result in an equivalent outcome. In the future we must make better use of the present arsenal of drugs and examine the marked inter-individual variations in pharmacokinetic profiles for the drugs. We have to tailor the therapy to the tumour biological profile, in both the primary tumour and metastases with appreciation of heterogeneity and tumour progression. Based on these prerequisites, therapy can be either dose-intensive or in some instances continuous using lower doses.

Current options in treatment of anthracycline-resistant breast cancer

Breast cancer is a chemosensitive tumour and anthracyclines are one of the most active cytotoxic agents in chemotherapy treatment. Failure after anthracycline-containing chemotherapy is a poor prognostic factor because of low response rate to salvage chemotherapy. Several factors like P-glycoprotein mediated drug resistance (MDR-1 or MRP), glutathione or amplification of topoisomerase II have been found to be involved in anthracycline resistance. No clear benefit for patients treated with 'resistance-modifier' agents like verapamil, dexverapamil or quinidine has yet been demonstrated. Most clinical studies with non-cross resistant cytotoxic agents are lacking a strict definition of anthracycline resistance. A strict definition of anthracycline resistance implies progressive disease during anthracycline chemotherapy. Among the cytotoxic drugs only 5-Fluorouracil (given as 24 h continuous infusion with folinic acid) and the taxanes produce more than 20% objective remission (RR) in case of anthracycline resistance, whereas the highest response rate was reported for docetaxel (32-57%). Only few randomized studies were performed: docetaxel showed higher anti-tumor activity than methotrexat/5-FU (RR: 42% vs 19%, P<0.001) or mitomycin/vinblastine (RR: 30% vs 12%;P<0.001) and treatment with paclitaxel (175 mg/m(2)) was in favour to mitomycin (RR 17% vs 6%). In combination chemotherapy most activity have been reported for paclitaxel plus high-dose 5-fluorouracil (given as 24 h continuous infusion with folinic acid) (RR: 58%) or for docetaxel plus cisplatinum (RR: 46%). High-dose regimens with growth factor or stem cell support seems to be active in anthracycline-resistant disease but the toxicity is considerable. In conclusion, the taxanes, especially docetaxel as single agent or paclitaxel plus high-dose 5-FU, are the most promising therapeutic options in treatment of anthracycline resistant disease. Further clinical phase II/III studies in breast cancer should include exact definition of anthracycline pretreatment and resistance.

High-dose chemotherapy and autologous stem cell transplantation as treatment for high-risk breast cancer

High-dose chemotherapy with autologous stem cell transplantation has emerged as a common treatment for patients with breast cancer who have a poor prognosis. The success of this approach appears to depend on the tumor burden and the sensitivity of the disease to chemotherapy because treatment techniques have been refined and treatment-related mortality has declined. Phase II studies in patients with stage II and III disease are encouraging and suggest that treatment with high-dose chemotherapy before the development of metastatic disease may provide an advantage in terms of relapse-free and overall survival. However, tumor cells may contaminate stem cell collections and contribute to relapse after transplantation. Therefore it may be important to separate and select purified CD34+ cells which are not contaminated. It has been suggested that selection bias contributes to the favorable preliminary results observed in phase II studies of high-risk patients. Such issues, together with patient and physician bias regarding the benefits of this strategy, emphasize the need to complete the prospective randomized trials now underway.

High-dose therapy with peripheral blood stem cell (PBSC) support using an innovative mobilization regimen in patients with high-risk primary or chemoresponsive metastatic breast cancers

High-dose therapy followed by peripheral blood stem cell (PBSC) support was performed in 29 patients with primary high-risk (Group I) or chemoresponsive metastatic (Group II) breast cancer patients. Group I patients had received PBSC mobilization within 4 weeks of modified radical mastectomy. Group II patients had to achieve minimal residual disease (MRD) by induction chemotherapy before being considered eligible for PBSC mobilization and high-dose therapy. An innovative FE120C regimen (5-FU 600 mg/m2, i.v., day 1; epirubicin 120 mg/m2, i.v., day 1; cyclophosphamide 600 mg/m2, i.v., day 1) plus G-CSF (300 microg/day, subcutaneous injection for 9 days, from day 4 post-FE120C) was used to mobilize PBSCs. After high-dose CTCb (cyclophosphamide 6,000 mg/m2, thiothepa 500 mg/m2, carboplatin 800 mg/m2, in 4 days), patients received PBSC infusion and daily C-CSF 300 microg subcutaneous injection. There were 19 and 16 patients enrolled into Group I and Group II, respectively. Ten of the Group II patients had achieved minimal residual disease (MRD) after induction chemotherapy. The median numbers of mobilized total CD34 + cells for Group I and Group II patients were 27.3 (9.2 to 114.1) x 10(6)/kg and 17.1 (5.9 to 69.1) x 10(6)/kg respectively. The median time to neutrophil recovery (ANC > or = 500/microL) was 8 and 9 days in Group I and II, respectively. The median time to platelet recovery (> or = 50,000/microL) was 10 and 15 days in Group I and II, respectively. No major treatment-related toxicities were noted. In Group I, 13 out of 19 patients (68.4%; 43-87%, 95% C.I.) remained recurrence-free with a median follow-up of 31 months (6 + to 55 + months). In Group II, 3 out of 10 patients (30%; 7-65%, 95% C.I.) remained progression-free at 33 +, 35 +, 39 + months from induction therapy. We suggest that the FE120C plus G-CSF is an effective and innovative regimen for PBSC mobilization in breast cancer patients, and high-dose CTCb therapy with PBSC support is a safe and well-tolerated treatment modality.

Hematopoietic progenitor cell transplantation in breast cancer: current status and future directions

Breast cancer remains the second leading cause of cancer death despite numerous advances in medical science. In vitro, preclinical, and clinical trials have shown that chemotherapy dose intensity is an important component of therapy. Many clinical trials addressing the use of high-dose chemotherapy and hematopoietic cellular rescue have been conducted over the past decade. Early trials undertaken in heavily pretreated patients who had metastatic disease were associated with high treatment-related mortality rates; good response rates were noted but overall survivals were short. Subsequent technological advances, including the use of recombinant hematopoietic growth factors and peripheral blood progenitor cells as the source of cellular rescue, have dramatically lowered the morbidity and mortality of the procedure, as well as shortened hospital stay and markedly reduced cost. As a result, the high-dose chemotherapy approach has been used earlier in the disease course, both in patients with metastatic disease who were responding and in the adjuvant setting in patients at high risk for relapse. Results of many of these phase II trials are extremely encouraging, and phase III prospective, randomized trials comparing autotransplant to conventional approaches are currently under way. This review discusses past, current, and future initiatives of this modality. Included is a discussion of new preparative regimens, the addition of agents such as biochemical modifiers to enhance antitumor activity, and issues regarding timing of autotransplant, stem cell technology, use of allogeneic stem cells, and posttransplantation therapies.

High-dose mitoxantrone with peripheral blood progenitor cell rescue: toxicity, pharmacokinetics and implications for dosage and schedule

The optimal use of mitoxantrone (NOV) in the high-dose range requires elucidation of its maximum tolerated dose with peripheral blood progenitor cell (PBPC) support and the time interval needed between drug administration and PBPC reinfusion in order to avoid graft toxicity. The aims of this study were: (1) to verify the feasibility and haematological toxicity of escalating NOV up to 90 mg m(-2) with PBPC support; and (2) to verify the safeness of a short (96 h) interval between NOV administration and PBPC reinfusion. Three cohorts of ten patients with breast cancer (BC) or non-Hodgkin's lymphoma (NHL) received escalating doses of NOV, 60, 75 and 90 mg m(-2) plus melphalan (L-PAM), 140-180 mg m(-2), with PBPC rescue 96 h after NOV. Haematological toxicity was evaluated daily (WHO criteria). NOV plasma pharmacokinetics was also evaluated, as well as NOV cytotoxicity against PBPCs. Haematological recovery was rapid and complete at each NOV dose level without statistically significant differences, and there were no major toxicities. NOV plasma concentrations at the time of PBPC reinfusion were below the toxicity threshold against haemopoietic progenitors. It is concluded that, when adequately supported with PBPCs, NOV can be escalated up to 90 mg m(-2) with acceptable haematological toxicity. PBPCs can be safely reinfused as early as 96 h after NOV administration.

Autologous stem cell transplantation in breast cancer

High-dose chemotherapy with autologous stem cell support is an investigational treatment for patients with breast cancer who have a high risk of recurrence or who have metastatic disease. In the adjuvant setting, there is a lack of survival data from randomized studies comparing high-dose to conventional-dose therapy. High-dose adjuvant chemotherapy was found to result in as high as 71% 5-year event-free survival in patients with more than nine metastatic axillary lymph nodes in one nonrandomized study, which appears to be superior to those achieved with conventional-dose therapy. In metastatic breast cancer the great majority of patients die of cancer despite high-dose therapy with the current regimens, and it is unclear whether survival of these patients is improved with high-dose therapy as compared to conventional-dose therapy. However, a few patients with breast cancer with distant metastases have enjoyed a disease-free interval lasting for several years after high-dose therapy, which is rarely seen with conventional-dose therapy, and one small randomized trial showed improved survival in the high-dose arm of the study. The more extensive patient selection for high-dose chemotherapy needs to be taken into account when comparing the results achieved with different dose levels, and therefore a high priority should be given for randomized studies where high-dose therapy is compared with conventional-dose therapy.

Randomized placebo-controlled trial of granulocyte-macrophage colony-stimulating-factor support for dose-intensive cyclophosphamide, etoposide, and cisplatin

This is a double-blind randomized placebo-controlled trial to evaluate the efficacy and safety of granulocyte-macrophage colony-stimulating-factor (GM-CSF) after dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP). Fifty-six patients with lymphoma or breast carcinoma were randomized to receive GM-CSF 250 microg/m2 or placebo subcutaneously (SC) every 12 hr after each course of DICEP until recovery of absolute neutrophil count (ANC) of 1.5 x 10(9)/L. Each patient was to receive three courses of DICEP. There were 28 patients in each group. The median duration of ANC below 0.5 x 10(9)/L was 10 versus 12 days for Course 1 (P = 0.010), 10 versus 12 days for Course 2 (P = 0.248), and 16.5 versus 15 days for Course 3 (P = 0.126); platelet counts below 20 x 10(9)/L was 4 versus 4 days for Course 1 (P = 0.586), 8.5 versus 7 days for Course 2 (P = 0.013), and 23.5 versus 10.5 days for Course 3 (P = 0.104); hospitalization for patients readmitted with cytopenic fever were 4 versus 8 days for Course 1 (P = 0.035); 7 versus 6 days for Course 2 (P = 0.692); and 8 versus 12 days for Course 3 (P = 0.884) in the GM-CSF and placebo group, respectively. GM-CSF significantly shortens the duration of neutropenia and readmission only during the first course of DICEP. There was a delay in platelet recovery and an increase in transfusion requirement during subsequent courses in the GM-CSF group. The result cautions the routine use of lineage specific hematopoietic growth factors in supporting repeated cycles of dose-intensive chemotherapy.

High-dose therapy for breast cancer

The high incidence of breast cancer in young women, and the unfavorable prognosis for those who present with a high number of lymph nodes involved with cancer, has encouraged the development and evaluation of new treatment strategies. The use of dose intensification is supported by laboratory and clinical models. In this review article, the use of dose intensification supported by hemopoietic growth factors, and also by hemopoietic stem cells, is discussed. The results of published studies of high-dose chemotherapy in Stage II, III, and IV breast cancer are discussed and summarized, including those randomized comparisons with more conventional therapy. Improvements in supportive care continue to reduce the risks from neutropenia and thrombocytopenia, and these and other toxicities are likely to decrease as side-effects are anticipated and experience increases.

High-dose therapy with autologous bone marrow stem cell support in primary and metastatic human breast cancer. A review

A dose-response relationship has been demonstrated for metastatic human breast cancer. This increased response using moderately increased doses is generally not translated into an improved survival. The use of high-dose therapy to selected patients with metastases/recurrence responding to conventional doses of polychemotherapy may lead to an improved survival tail. Conventional doses of polychemotherapy in the adjuvant setting will reduce the relative mortality by around 25% 10 years after primary diagnosis. The use of high-dose therapy supported by autologous bone marrow stem cells may be markedly more effective in the adjuvant setting, especially to high-risk patients, compared with standard polychemotherapy. Several randomized studies are being planned or have already started in order to answer different aspects of this issue.

High-dose chemotherapy of solid tumours

The use of high-dose chemotherapy (HDC) in the range requiring autologous haematopoietic stem cell support can produce very high rates of response in patients with a variety of solid tumours but it remains controversial. The solid tumour in which HDC has been most extensively studied is breast cancer, and this disease is used as a model for the current discussion. Comparisons are made with ovarian, testicular and small-cell lung cancers and random assignment trials are suggested to demonstrate and to quantitate any survival advantages associated with therapy. Further development work is indicated.

High-dose chemotherapy of metastatic breast cancer: a review

Very-high-dose chemotherapy produces frequent complete responses in patients with metastatic breast cancer. These responses are transient in patients with disease that had relapsed following, or was refractory to, prior conventionally dosed therapy, but when used as first chemotherapy for metastatic disease or as consolidation for patients with responding cancer, a minority achieve durable complete remissions. Improvements in supportive care, especially in hematopoietic support, have resulted in a considerable reduction in the toxicity of this therapy and may allow further intensification through the use of multiple, rapidly cycled courses.

Potential strategies for improving the results of high-dose chemotherapy in patients with metastatic breast cancer

High-dose chemotherapy (HDC) is the most effective approach for inducing complete remissions in patients with metastatic breast cancer, and although most patients will relapse, a small percentage (10%-15%) achieve durable remissions beyond five years. Additionally, HDC has produced five-year relapse-free survival rates in excess of 70% in patients with stage II breast cancer with > 10 nodes. The use of HDC in breast cancer remains controversial and randomised trials are required to assess the survival impact of this approach. The introduction of haematopoietic growth factors (HGF) and peripheral blood progenitor cells (PBPC) has advanced the use of HDC by reducing treatment-related mortality (from 20% to 5%) and by allowing the development of multiple cycles of intensive therapy. Based on tumour kinetic models we have hypothesised that multiple, rapidly cycled courses of high-dose therapy may improve the rate of durable remission in metastatic breast cancer. The feasibility of this approach has been shown in a series of pilot studies in which one or more courses of high-dose cyclophosphamide and recombinant granulocyte colony-stimulating factor (G-CSF) (filgrastim) were given to obtain PBPC which were then used to support one or more courses of HDC. In successive studies the HDC component consisted of: a single course of carboplatin, etoposide and cyclophosphamide; four courses of carboplatin; tandem courses of thiotepa; or a sequence of melphalan and thiotepa. Promising response rates have been produced in advanced breast and ovarian cancer with the later generation of regiments. These results justify the conduct of prospective randomised trials.

Phase I trial of mitoxantrone and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with advanced solid malignancies

PURPOSE

To determine the maximally tolerated dose (MTD) and pharmacokinetics of high-dose mitoxantrone and document the toxicities and side effects of mitoxantrone when administered with GM-CSF.

PATIENTS AND METHODS

Twenty-three patients with advanced solid tumors were entered into a phase I and pharmacokinetic study. Mitoxantrone was administered at doses of 12, 21, 28, 32, 37, and 48 mg/m2 on day 1; GM-CSF (5 micrograms/kg once or twice daily) was administered on days 2 to 14. Therapy was repeated every 3 weeks. Dose escalation continued in sets of three patients until the dose limiting toxicity (DLT) was observed. The DLT was based on hematologic, non-hematologic, and cardiac toxicity, and delay of therapy by more than 1 week due to toxicity. Plasma samples were assayed for mitoxantrone concentrations using high performance liquid chromatography (HPLC).

RESULTS

Twelve patients required either mitoxantrone dose reductions or delays. DLT of neutropenia was observed at a mitoxantrone dose of 48 mg/m2/day. Therefore, we conclude the MTD was 37 mg/m2/day. Myelosuppression appeared to be cumulative. Two patients were withdrawn from the study due to a drop in left ventricular ejection fraction (LVEF). Two of 23 patients experienced a partial response. The mean area under the curve (AUC) and peak mitoxantrone levels increased linearly with dose; triexponential elimination of mitoxantrone was observed. No statistically significant correlation was observed between either peak mitoxantrone level or AUC and duration of absolute neutrophil count (ANC) < 500/mm3.

CONCLUSION

The use of GM-CSF allows administration of mitoxantrone at a dose greater than three times that given in standard therapy; treatment is well tolerated. Further studies are needed to determine whether mitoxantrone has cumulative cardiac or hematologic toxicity.

Design of preparative regimens for stem cell transplantation in breast cancer

We have evaluated tandem cycles of a tri-drug combination, termed CVP (cyclophosphamide, etoposide [VP-16], and cisplatin [Platinol]), at four levels in more than 300 patients with various types of tumors. Tandem CVP appears to be at least therapeutically equivalent to alternatives. A second potentially non-cross-resistant combination of mitoxantrone and thiotepa (MT), with or without etoposide, has been used in sequence following CVP to improve long-term, disease-free survival in patients who have multiple metastatic sites, who relapse shortly after adjuvant therapy, or who show other unfavorable clinical features. A combination of MT and etoposide (MVT) achieved an overall response rate of 61% in 32 patients with metastatic or refractory breast cancer. The etoposide was then eliminated to decrease the major toxicities of this regimen. MT was subsequently given to 37 evaluable patients prior to bone marrow infusion. The overall response rate was 48.5% Thirty patients with metastatic breast cancer were then treated with induction therapy, a cycle of CVP, and then a cycle of MT. Given the low complete remission (CR) rate to induction therapy in these patients, the CR rate achieved with CVP-MT was encouraging. Further studies are ongoing.

Immunologic purging of marrow assessed by PCR before autologous bone marrow transplantation for B-cell lymphoma

BACKGROUND

The use of autologous bone marrow transplantation is increasing in the management of advanced cancers. Many investigators have attempted to "purge" autologous marrow of residual tumor cells because of concern that reinfused tumor cells might contribute to relapse. The efficacy of purging remains unproved.

METHODS

We performed clonogenic assays in a tumor cell line in culture to determine the efficiency of immunologic purging. Amplification by the polymerase chain reaction (PCR) was used to detect residual lymphoma cells before and after purging of bone marrow from 114 patients with B-cell non-Hodgkin's lymphoma in whom a translocation (t(14;18] that could be amplified by PCR was detected at the time of their initial evaluation.

RESULTS

Immunologic purging in vitro resulted in a 3-to-6-log destruction of cells in the tumor cell line. Residual lymphoma cells were detected by PCR in the bone marrow of all patients before purging. No lymphoma cells could be detected in the marrow of 57 patients after purging. Disease-free survival was increased in these 57 patients as compared with those whose marrow contained detectable residual lymphoma (P less than 0.00001). The ability to purge residual lymphoma cells was not associated with the degree of bone marrow involvement (P = 0.4494) or the previous response to therapy (P = 0.1298).

CONCLUSIONS

The inability to purge residual lymphoma cells was the most important prognostic indicator in predicting relapse. These results provide evidence of the clinical usefulness of ex vivo purging of autologous bone marrow in the treatment of patients with lymphoma and suggest that the reinfusion of malignant cells in autologous marrow contributes to relapse