A phase II study of bortezomib and gemcitabine in relapsed mantle cell lymphoma from the National Cancer Institute of Canada Clinical Trials Group (IND 172).

Bortezomib and gemcitabine have each shown activity as single agents in mantle cell lymphoma (MCL), which is incurable. The purpose of this phase II study was to determine the efficacy and safety of the previously unstudied combination of bortezomib and gemcitabine in patients with relapsed or refractory MCL. Patients were eligible if they had relapsed MCL with 1-3 prior therapies. Patients were treated with gemcitabine 1000 mg/m(2) on days 1 and 8 and bortezomib 1.0 mg/m(2) IV on days 1, 4, 8, and 11, on a 21-day schedule. Twenty-six patients were evaluable for toxicity and 25 for response. The overall response rate was 60% and the median progression free survival was 11.4 months. The main adverse effects were hematological, with 40% and 48% of patients experiencing grade 3/4 thrombocytopenia and granulocytopenia, respectively. Bortezomib and gemcitabine is an active combination in relapsed and refractory MCL with clinically meaningful results. It offers a chemotherapy backbone to which other agents, less myelosuppressive, may be added.

A randomized phase I clinical and biologic study of two schedules of sorafenib in patients with myelodysplastic syndrome or acute myeloid leukemia: a NCIC (National Cancer Institute of Canada) Clinical Trials Group Study.

Sorafenib is a small molecule inhibitor of RAF kinase, VEGFR-2, c-KIT, and FLT3. In this randomized phase I study, eligible patients had relapsed/refractory acute myeloid leukemia (AML), and one prior induction regimen, or were age >65 with untreated myelodysplastic syndrome (MDS) or secondary AML. Sorafenib was given orally for 28 days (cont) or 14 days (int) every 4 weeks at three dose levels (100, 200, and 400 mg BID); 300 mg cont was also tested. Forty-two patients were enrolled (median age 71 [37-82]; prior chemotherapy: 22). Dose-limiting toxicity (DLT) was: 100 mg BID: 0/7 patients; 200 mg BID: 2/12 patients; 400 mg BID: 1/17 patients. Sorafenib 400 mg cont was not tolerated in this population: 6/8 received <14 days of treatment due to toxicity; no DLT was seen with 300 mg cont. One CR was seen in a patient with AML with FLT3-ITD. Flow cytometry studies suggest that sorafenib inhibits ERK phosphorylation via c-KIT. The recommended phase II dose in AML is 300 mg BID continuously, and testing in combination and in FLT3-ITD AML is warranted.

Impact of high-dose chemotherapy on the ability to deliver subsequent local-regional radiotherapy for breast cancer: analysis of Cancer and Leukemia Group B Protocol 9082.

PURPOSE: To report, from Cancer and Leukemia Group B Protocol 9082, the impact of high-dose cyclophosphamide, cisplatin, and BCNU (HD-CPB) vs. intermediate-dose CPB (ID-CPB) on the ability to start and complete the planned course of local-regional radiotherapy (RT) for women with breast cancer involving >or=10 axillary nodes. METHODS AND MATERIALS: From 1991 to 1998, 785 patients were randomized. The HD-CPB and ID-CPB arms were balanced regarding patient characteristics. The HD-CPB and ID-CPB arms were compared on the probability of RT initiation, interruption, modification, or incompleteness. The impact of clinical variables and interactions between variables were also assessed. RESULTS: Radiotherapy was initiated in 82% (325 of 394) of HD-CPB vs. 92% (360 of 391) of ID-CPB patients (p = 0.001). On multivariate analyses, RT was less likely given to patients who were randomized to HD treatment (odds ratio [OR] = 0 .38, p < 0.001), older (p = 0.005), African American (p = 0.003), postmastectomy (p = 0.02), or estrogen receptor positive (p = 0.03). High-dose treatment had a higher rate of RT interruption (21% vs. 12%, p = 0.001, OR = 2.05), modification (29% vs. 14%, p = 0.001, OR = 2.46), and early termination of RT (9% vs. 2%, p = 0.0001, OR = 5.35), compared with ID. CONCLUSION: Treatment arm significantly related to initiation, interruption, modification, and early termination of RT. Patients randomized to HD-CPB were less likely to initiate RT, and of those who did, they were more likely to have RT interrupted, modified, and terminated earlier than those randomized to ID-CPB. The observed lower incidence of RT usage in African Americans vs. non-African Americans warrants further study.

Randomized trial of high-dose chemotherapy with autologous peripheral-blood stem-cell support compared with standard-dose chemotherapy in women with metastatic breast cancer: NCIC MA.16.

PURPOSE: We conducted a multicenter, randomized trial to compare progression-free survival (PFS), overall survival (OS), and quality of life in women with metastatic breast cancer (MBC) receiving high-dose chemotherapy plus autologous stem-cell transplantation (ASCT; HDCT) compared with standard-dose therapy. PATIENT AND METHODS: Between April 1997 and December 2000, 386 women with MBC and no prior chemotherapy for metastatic disease were registered. After initial response to anthracycline- or taxane-based induction chemotherapy, 224 patients were randomly assigned: 112 to high-dose cyclophosphamide, mitoxantrone, and carboplatin chemotherapy and ASCT (HDCT), and 112 to standard therapy (ST). Median age was 47 years (range, 25 to 67 years). Thirty two percent of women randomly assigned had estrogen and progesterone receptor-negative breast cancer, 42% had visceral metastases, and 58% had bone metastases. Complete remission rates before random assignment were 11% for those receiving HDCT and 12% for those receiving ST. RESULTS: After a median follow-up of 48 months, 79 deaths were observed in the HDCT arm and 77 deaths were observed in the ST arm; seven patients (6%) in the HDCT arm died as a result of toxicity. The median OS was 24 months for the HDCT arm (95% CI, 21 to 35 months) and 28 months for ST (95% CI, 22 to 33 months; hazard ratio [HR], 0.9; 95% CI, 0.6 to 1.2; P = .43). PFS was 11 months for HDCT and 9 months for ST (HR, 0.6 in favor of HDCT; 95% CI, 0.5 to 0.9; P = .006). CONCLUSION: HDCT did not improve OS in women with MBC when used as consolidation after response to induction chemotherapy.

Risk of acute leukemia following epirubicin-based adjuvant chemotherapy: a report from the National Cancer Institute of Canada Clinical Trials Group.

PURPOSE: Cyclophosphamide, epirubicin, and fluorouracil (CEF), compared with classical cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy. has lead to an improvement in relapse-free and overall survival in premenopausal women with node-positive breast cancer. We undertook this analysis to more accurately define the estimate of risk of secondary acute leukemia (sAL) following epirubicin-containing chemotherapy regimens. PATIENTS AND METHODS: We assessed the conditional probability of sAL among 1,545 women who received adjuvant (n = 1,477) or neoadjuvant (n = 68) chemotherapy in four National Cancer Institute of Canada Clinical Trials Group trials from 1990 to 1999. The risks associated with epirubicin-containing regimens (CEF or epirubicin and cyclophosphamide [EC]) and other regimens (doxorubicin and cyclophosphamide [AC] or CMF) were determined. RESULTS: A total of 10 cases of sAL were observed (eight acute myelogeneous leukemia, two acute lymphoblastic leukemia): seven among women treated with CEF, two who had received AC, and one following CMF. Using competing risk statistics, the conditional probability of sAL was 1.7% (95% confidence interval [CI], 0.5 to 3.6) among 539 women treated with CEF chemotherapy at a follow-up of 8 years, 0.4% (95% CI, 0% to 1.3%) among the 678 who received CMF, and 1.3% (95% CI, 0% to 4.7%) among the 231 treated with AC. The conditional probability of death from breast cancer at 8 years for the entire group of women treated with epirubicin-containing regimens in all four trials was approximately 34.9%. CONCLUSION: CEF chemotherapy for breast cancer carries a small increased risk of sAL compared with CMF. These estimates of acute leukemia risk are important in discussing treatment with women, especially patients with a lower risk of death from breast cancer, such as those with node-negative breast cancer.

Purging of contaminating breast cancer cells from hematopoietic progenitor cell preparations using activation enhanced cell death.

Activation enhanced cell death (AECD) involves stimulating cells with growth or activation signals while concurrently blocking calcium influx. In this study, we have evaluated the effect of AECD on human breast cancer cells. MCF-7 or MDA-MB-231 cells treated with Ca2+ influx blockers econazole or ketotifen for 24 h underwent a dose-dependent, irreversible loss of viability, and clonogenicity. Two-hour treatment of these cells with higher concentrations of the drugs also resulted in loss of clonogenicity, but morphological indicators of cell death were apparent only after longer incubation. Loss of clonogenicity could be enhanced almost 10-fold by co-stimulation of the cells with the agonists EGF or bombesin. Econazole was also effective in inducing cell death in multi-drug resistant MCF-7adr cells. Human hemopoietic progenitor cell sensitivity to econazole or ketotifen was evaluated by colony assay. Under conditions resulting in 2.5-3 logs of breast cancer cell loss, 60-70% of hemopoietic progenitors could be recovered. We further evaluated the effect of econazole on breast cancer cells present in mobilized hemopoietic cells obtained from patients undergoing high dose chemotherapy with autologous stem cell support. In six of eight samples evaluated, cytokeratin-positive breast cancer cells could be detected by immunofluorescence microscopy and colony formation. Breast cancer colonies were reduced 60-500-fold or more after exposure to econazole while hemopoietic colonies were typically reduced only 2-fold. In all cases, addition of EGF as an activator either had no evaluable effect or enhanced breast cancer cell loss. We conclude that Ca2+ influx blockade with concurrent EGF stimulation is a promising approach for purging breast cancer cells from hemopoietic progenitor cell preparations.