Phase II study of bendamustine combined with rituximab in relapsed/refractory mantle cell lymphoma: efficacy, tolerability, and safety findings.

In most cases of relapsed/refractory mantle cell lymphoma (MCL), patients respond to salvage therapy, though typically responses are partial and/or transient followed by disease progression, even with newer agents (e.g., ibrutinib). In this multicenter, open-label, single-arm, phase II study, patients with relapsed/refractory non-blastoid MCL received bendamustine 90 mg/m(2) (days 1 and 2) and rituximab 375 mg/m(2) (day 1) for 6 planned 28-day cycles. Functional imaging with 18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) was conducted at baseline and after cycle 6. Forty-five patients were enrolled (median age, 70 years; 82 % stage IV disease; median number of prior chemotherapies, 2 [range, 1-4]), showing an overall response rate (ORR; primary efficacy measure) of 82 % (complete response [CR], 40 %; partial response, 42 %). In the 32 patients with complete 18F-FDG PET/CT data, 75 % achieved a complete metabolic response. Median duration of response was 1.6 years, 1-year progression-free survival was 67 %, and 3-year overall survival was 55 %. Main non-hematologic adverse events were nausea (69 %), fatigue (56 %), decreased appetite (42 %), constipation (38 %), diarrhea (36 %), vomiting (36 %), and decreased weight (31 %). Grade 3/4 neutropenia and lymphopenia occurred in 44 and 89 % of patients, respectively. ORR and CR rate compared favorably with single-agent ibrutinib (ORR, 67 %; CR, 23 %); bendamustine-rituximab is an effective therapy with manageable toxicity in relapsed/refractory MCL.

Comparison of pixantrone-based regimen (CPOP-R) with doxorubicin-based therapy (CHOP-R) for treatment of diffuse large B-cell lymphoma.

BACKGROUND: Pixantrone is an aza-anthracenedione with enhanced, preclinical antitumor activity and reduced cardiotoxicity compared with doxorubicin. PATIENTS AND METHODS: We compared the efficacy and toxic effect of CPOP-R (substituting pixantrone for doxorubicin) against CHOP-R in untreated, diffuse large B-cell lymphoma (DLBCL) patients. The primary objective was to demonstrate non-inferiority of CPOP-R by complete response/complete response unconfirmed (CR/CRu) rate. RESULTS: The CR/CRu rate for CPOP-R was 75% versus 84% for CHOP-R. Three-year overall survival was lower for CPOP-R (69% versus 85%) (P = 0.029). Median progression-free survival (PFS) was not reached for CPOP-R and was 40 months for CHOP-R [HR 95% confidence interval (CI) = 1.02 (0.60, 1.76), P = 0.934]. Fewer CPOP-R patients developed congestive heart failure (CHF) (0% versus 6%, P = 0.120), ≥ 20% declines in ejection fraction (2% versus 17%, P = 0.004), or elevations in troponin-T (P = 0.003). CONCLUSIONS: CPOP-R is an active regimen with modestly lower response rates than CHOP-R but similar PFS and event-free survival. This study demonstrates a substantially lower cardiotoxicity of pixantrone compared with doxorubicin when used as first-line therapy in DLBCL.

"Crack lung and heart" presenting after chemotherapy in a 65-year-old man with non-Hodgkin lymphoma.

Crack cocaine can cause a variety of pulmonary and cardiac complications. Pulmonary findings in a 65- year-old man with non-Hodgkin lymphoma who presented with shortness of breath not resolving with antibiotics are presented here. The usual manifestation of "crack lung" in an unusual clinical circumstance underlines the importance of a clinical history in such cases. The finding of "crack lung" preceded the diagnosis of probable "crack heart." No other similar published case reports could be identified in the literature.

Localization of radiolabeled antimyeloid antibodies in a human acute leukemia xenograft tumor model.

Acute myeloid leukemia is an attractive disease to treat with radiolabeled antibodies because it is radiosensitive and antibody has ready access to the marrow cavity. In order to evaluate potentially useful radiolabeled antibodies against human acute myeloid leukemia, we have developed a nude mouse xenograft model using the human acute leukemia cell line, HEL. Mice with s.c. xenografts of HEL cells received infusions of radioiodinated anti-CD33 antibody. Examination of the biodistribution of the antibody showed that uptake in the s.c. tumor was maximal [16.9% injected dose (ID)/g at 1 h after infusion] following infusion of 1-10 micrograms of antibody and decreased following infusion of 100 micrograms (6.5% ID/g at 1 h) presumably as a result of saturation of antigen sites. The radiolabel was poorly retained in tumor (4.5-8.2% ID/g at 24 h after infusion). These results were consistent with in vitro studies demonstrating rapid internalization and catabolism of the anti-CD33 antibody. Uptake in tumor could be improved by using either a radiolabel that is retained intracellularly, 111In-DTPA (18.5% ID/g at 24 h), or by targeting a surface antigen that does not internalize upon antibody binding, CD45 (20.5% ID/g at 24 h). These results indicate that this model system will be useful in evaluating the interaction of radiolabeled antibodies with human acute myeloid leukemia cells in an in vivo setting.

Rearrangement of BCR genes in malignant lymphoma.

The Philadelphia chromosome, originally thought to be associated solely with chronic myelogenous leukemia (CML), has since been identified in acute leukemias and in some cases of lymphoma. The Philadelphia chromosome results from reciprocal translocation of genetic material between chromosome 9 and 22 involving the c-abl and BCR genes respectively. Southern blot analysis of the BCR genes was carried out on biopsy specimens from 49 patients presenting with malignant lymphoma without a previously documented CML phase. In two patients, BCR gene rearrangements were detected in the malignant lymph nodes but not in the bone marrow samples. A third patient showed BCR gene rearrangements in the bone marrow but not in the lymph node. From this limited study, it seems that the overall incidence of BCR gene rearrangement in malignant lymphoma is similar to that observed in adult AML.

Are therapeutic decisions supported by evidence from health care research?

BACKGROUND: One of the most common decisions physicians face is deciding which therapeutic intervention is the most appropriate for their patients. In recent years much emphasis has been placed on making clinical decisions that are based on evidence from the medical literature. Despite the emphasis on incorporation of evidence-based medicine into the undergraduate curriculum and postgraduate medical training programs, there has been controversy regarding the proportion of interventions that are supported by health care research. OBJECTIVE: To investigate the proportion of major therapeutic interventions at our institution that are justified by published evidence. METHODS: One hundred fifty charts from the internal medicine department were reviewed retrospectively. The main diagnosis, therapy provided, and patient profile were identified and a literature search using MEDLINE was performed. A standardized search strategy was developed with high sensitivity and specificity for identifying publication quality. The level of evidence to support each clinical decision was ranked according to a predetermined classification. In this system there were 6 distinct levels, which are explained in the study. RESULTS: Of the decisions studied, 20.9% could be supported by placebo-controlled randomized trials and 43.9% by head-to-head trials. Half of these were shown to be significantly superior to the treatment against which it was being compared. For 10 of the 150 clinical decisions, evidence was found demonstrating alternative therapies as being more effective than that selected. CONCLUSIONS: Most primary therapeutic clinical decisions in 3 general medicine services are supported by evidence from randomized controlled trials. This should be reassuring to those who are concerned about the extent to which clinical medicine is based on empirical evidence. This finding has potential for quality assurance, as exemplified by the discovery that a literature search could have potentially improved these decisions in some cases.

FK-506 and methotrexate prevent graft-versus-host disease in dogs given 9.2 Gy total body irradiation and marrow grafts from unrelated dog leukocyte antigen-nonidentical donors.

FK-506 was evaluated either alone or combined with methotrexate (MTX) for prevention of graft-versus-host disease (GVHD) in dogs given 9.2 Gy total body irradiation and dog leukocyte antigen-nonidentical unrelated marrow grafts. Studies with marrow autografts showed gut toxicity and weight loss to be major side effects of FK-506. There was no hematopoietic toxicity with FK-506. In an initial allograft study, 5 dogs were given FK-506 intramuscularly at 0.3 mg/kg/day from days 0 to 8 and then orally at 0.5 mg/kg/day. All 5 died, 3 with intussusception most likely due to FK-506 toxicity, 1 with graft failure, and 1 with GVHD. Subsequently, the FK-506 dose was reduced and these drug schedules were used: FK-506 days 0-8 at 0.15 mg/kg/day i.m. and then orally at 0.5 mg/kg/day until day 90, with or without MTX intravenously at 0.4 mg/kg days 1, 3, 6, and 11. Twenty allografts were done, 10 with FK-506 alone, and 10 with MTX/FK-506. Results were compared with those in concurrent and historical controls given either no immunosuppression (n = 64), MTX (n = 114), CsA (n = 15), or MTX/CsA (n = 17). Five of 20 current dogs died with intussusception, too early to be evaluated for GVHD. The 10 dogs given FK-506 alone survived significantly better than those not given immunosuppression but not differently from those given short-term MTX or CsA alone. Three died from toxicity, 2 with graft failure, and 4 with GVHD. Only 1 dog became a long-term survivor, and this dog inadvertently received a single dose of MTX on day 7. Two of 10 dogs given MTX/FK-506 died from toxicity, 1 died with graft failure, 2 died with GVHD, and 5 became long-term survivors, a result that is significantly better than seen with either drug alone and similar to that seen with MTX/CsA. Four of the 5 survivors had no clinical GVHD. FK-506 blood levels were 15-35 ng/ml between days 8 and 15, when gut toxicity was most severe. Thereafter, levels were approximately 5 ng/ml. In conclusion, FK-506 prolonged survival of recipients of dog leukocyte antigen-nonidentical unrelated marrow grafts. When FK-506 was combined with MTX, graft-host tolerance was induced in 50% of dogs, even though FK-506 was stopped on day 90.

Effect of pentoxifylline on regimen related toxicity in patients undergoing allogeneic or autologous bone marrow transplantation.

An unblinded, historical controlled study of 49 bone marrow transplant (BMT) patients was carried out in our institution to assess the effect of oral pentoxifylline (PTX) on BMT regimen related toxicity (RRT). Twenty-eight consecutively treated BMT patients (17 allogeneic, 11 autologous) were entered into the PTX treatment group and treated with oral PTX 400 mg at intervals of 4 h from day -10 until day +35 or discharge, whichever came sooner. These were compared with a control group of 21 BMT patients (14 allogeneic, 7 autologous). Patient groups were very similar with respect to age, sex, conditioning regimen, graft-versus-host disease (GVHD) prophylaxis and baseline liver and renal function. Compliance with the drug was 85%. Despite this, no significant difference in days of mucositis or hyperalimentation, incidence or severity of renal or hepatic dysfunction, hypertension, GVHD, weight gain > 5%, day 100 mortality or length of hospitalization was observed. Median follow-up is > 2 years in both groups and no difference in relapse or survival was observed. We were unable to confirm an effect of oral PTX on BMT related morbidity or mortality.

Busulfan and cyclophosphamide as a preparative regimen for bone marrow transplantation in patients with prior chest radiotherapy.

In a previous study, we reported that patients with hematologic malignancies who had received prior chest radiotherapy had a 32% risk of developing fatal interstitial pneumonia (IP) when prepared for bone marrow transplantation (BMT) with a regimen containing total body irradiation (TBI). To determine if avoidance of TBI would lessen the incidence of fatal IP, 37 patients who had received prior chest radiotherapy in excess of 2000 cGy were prepared with busulfan (BU, 4 mg/kg x 4 days) and cyclophosphamide (CY, 60 mg/kg x 2 days) followed by autologous (n = 15) or allogeneic (n = 22) BMT. Thirty-five of these patients had recurrent or refractory hematologic malignancies and most were heavily pretreated. Results were compared with the group of similar patients (n = 25) previously treated at our institution with a CY/TBI conditioning regimen. Among those treated with BU/CY, two patients (5%) developed fatal interstitial pneumonia, 12 (32%) died of other transplant related toxicities and 13 (35%) died of relapse. Seven (19%) patients remain alive and well. Among those treated with CY/TBI, eight (32%) died of pneumonia, six (24%) died of relapse, nine (36%) died of other causes and two (8%) remain alive and well. The 5% incidence of fatal interstitial pneumonitis in the chemotherapy conditioned group was significantly less than the 32% incidence in the previously treated CY/TBI group (p = 0.005). However, long-term survival and relapse probabilities were not significantly better than seen previously with CY/TBI, although a trend towards improved survival was observed in the BU/CY group. Avoidance of TBI appeared to lower the incidence of fatal pneumonitis in patients with prior chest radiotherapy.

Chemical fingerprinting for the evaluation of unintended secondary metabolic changes in transgenic food crops.

A common element in designed guidelines for assessment of the food safety of transgenic crops is centred on a comparative analytical analysis with conventionally bred crop plants, assuming that these products have a long history of safe use (i.e. OECD-principle of substantial equivalence). In this study we examine the utility of an off-line combination of 400 MHz proton (1H)-NMR spectroscopy and liquid chromatography (LC) for the multi-component comparison of low-molecular weight compounds (i.e. chemical fingerprinting) in complex plant matrices. The developed NMR-methodology can contribute to the demonstration of substantial equivalence by its ability to compare possible compositional alterations in a novel food crop with respect to related non-transgenic reference lines. In this respect a hierarchical approach is proposed by comparing the chemical fingerprints of the transgenic crop plant to those of: (1) isogenic parental or closely related lines bred at identical and multiple sites; (2) extended ranges of commercial varieties of that plant; and (3) downstream processing effects. This is of importance to assess the likelihood that some of the statistical differences in a transgenic crop plant may be false positives due to chance alone or arose from natural genetic and/or physiologic variations.

The effect of exogenous thyroid hormones on functional recovery of the rat after acute spinal cord compression injury.

The effect of triiodothyronine (T3) or thyroxine (T4) on functional recovery after acute spinal cord compression injury in the rat was assessed. Rats treated with T3 for 14 consecutive days after injury showed significantly improved recovery at 12 and 16 weeks, and rats treated with T4 for 4 days after injury showed significantly improved recovery at 12 weeks as compared with control animals. The possible modes of action of these two hormones on the injured spinal cord are briefly discussed.

Oxygenated fluorocarbon perfusion as treatment of acute spinal cord compression injury in dogs.

Experiments were conducted to determine the therapeutic value of subarachnoid perfusion of the traumatized dog spinal cord with the fluorocarbon, Fluosol-DA (20%). Control dogs without lesions, but which had durotomy, subarachnoid catheter placement, and saline irrigation for 4 hours, did not have any residual neurological deficit. A series of 41 dogs underwent an acute spinal cord compression using an epidural balloon inflated to a pressure of 160 mm Hg and maintained for 1 hour. Treatment included durotomy only (11 dogs), durotomy with saline perfusion at room temperature (15 dogs), and durotomy with oxygenated Fluosol-DA perfusion at room temperature (15 dogs). The dogs underwent daily grading of neurological status for a 60-day period. Dogs undergoing perfusion of the spinal cord with either saline or oxygenated Fluosol-DA had significantly improved motor recovery (p less than 0.004) compared with dogs undergoing durotomy only. Perfusion with oxygenated Fluosol-DA resulted in significantly better motor recovery (p less than 0.05) than did perfusion with normal saline. Microscopic examination of the traumatized spinal cords failed to reveal a substantial difference between the three groups. However, dogs with better functional results tended to have less destruction of the white matter. Hemorrhagic necrosis of the central gray matter was consistently observed in all traumatized spinal cords.

The effect of acute spinal cord compression injury on thyroid function in the rat.

The effect of acute spinal cord injury on thyroid function was studied in rats subjected to severe spinal cord compression at T1. Serum thyroxine (T4), effective thyroxine index (ETI), and thyroid stimulating hormone (TSH) were measured at 1 and 100 minutes at one, three, and seven days after laminectomy and spinal cord injury. Control animals were subjected to laminectomy only. T4 was decreased at 1 minute after laminectomy with or without spinal cord injury, though the animals with cord injury had a much more profound reduction. The effects on TSH at 1 minute were dramatically different: laminectomy alone caused an elevation of TSH, while spinal cord injury produced a marked decline. At the later time intervals both groups showed gradual normalization of T4 and TSH levels, and at seven days there were no significant differences between the groups. Thus, acute spinal cord compression injury produced a major alteration in thyroid function during the acute phase.

A Canadian perspective on bendamustine for the treatment of chronic lymphocytic leukemia and non-Hodgkin lymphoma.

Despite the success of standard treatments in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL), patients are often unable to tolerate aggressive regimens, and they require effective alternatives. Bendamustine is a bifunctional alkylator with unique properties that significantly distinguish it from other agents in its class. In untreated CLL, bendamustine has demonstrated rates of response and progression-free survival (PFS) that are superior to those with chlorambucil, with an acceptable toxicity profile. In the relapsed setting, combination treatment with bendamustine-rituximab (BR) has demonstrated promising activity in high-risk patients such as those refractory to fludarabine or alkylating agents. In untreated patients with indolent NHL and mantle cell lymphoma, BR has demonstrated a PFS significantly longer than that achieved with R-CHOP (rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone), with significantly reduced toxicity. In the relapsed setting, br has demonstrated rates of response and PFS superior to those with fludarabine-rituximab, with comparable toxicity. In the United States and Europe, bendamustine has been approved for the treatment of CLL and indolent NHL; its approval in Canada is pending and eagerly awaited. Once available, bendamustine will benefit many Canadian patients with NHL and CLL.

The introduction of evidence-based medicine as a component of daily practice.

Evidence-based medicine is an increasingly important concept in continuing medical education and medical school curricula. To cope with the rapid evolution of medicine, physicians need to remain abreast of the many new therapies and diagnostic tools that affect their practices. Unfortunately, along with the many changes there is also a surplus of relevant written material. Physicians are unable to read all of this information due to time constraints. Instead, they must choose information efficiently. Tools are needed to facilitate this process. Over a two-month period, a demonstration model was carried out at the Ottawa General Hospital to encourage faculty, residents, and students to incorporate evidence-based medicine into their daily practice. A study was conducted to investigate the level and type of information required by these individuals in a clinical setting. A literature searching service was introduced six months after the formal introduction of evidence-based medicine in the Department of Medicine. The logistics of and recommendations for providing such a service are presented in this paper.

Inactivation of the Moloney murine leukemia virus long terminal repeat in murine fibroblast cell lines is associated with methylation and dependent on its chromosomal position.

The expression of a retroviral vector with the Moloney murine leukemia virus (Mo-MuLV) long terminal repeat (LTR) promoter after integration into the genome of murine fibroblast cell lines was monitored with the Escherichia coli-derived beta-galactosidase (beta-gal) gene as the reporter. Monoclonal cell lines derived after retroviral infection exhibited a marked heterogeneity in their expression of the reporter gene. We studied two monoclonal cell lines with a single unrearranged copy of the vector provirus integrated into their genome. The first, BB10, expressed the marker enzyme in only 8% of its cell population, whereas in the second, BB16, beta-gal expression could be detected in over 98% of the cells. Treatment of BB10 with the DNA-demethylating agent 5-azacytidine raised the number of beta-gal-positive cells to over 60%. Transfection experiments showed that the Mo-MuLV LTR promoter-enhancer is potentially fully functional in both the BB10 and BB16 cell lines. The inactivated provirus from BB10 cells was cloned and subsequently used to generate retrovirus stocks. The promoter-enhancer activity of its LTR after infection with these BB10-derived viruses showed a variation similar to that of the original virus stocks. Our data showed that (1) inactivation of the Mo-MuLV LTR is a frequent event in murine fibroblast cell lines, (2) inactivation is associated with de novo methylation of cytidine residues, (3) the frequency of inactivation of the provirus must be determined by its chromosomal position, (4) the process of methylation of sequences within the LTR is not necessarily the same as the transcription-repression mechanism that is operating in undifferentiated embryonal carcinoma cells.

Phenotype-associated env gene variation among eight related human immunodeficiency virus type 1 clones: evidence for in vivo recombination and determinants of cytotropism outside the V3 domain.

The nucleotide sequences of the env genes of eight phenotypically heterogeneous human immunodeficiency virus type 1 (HIV-1) clones recovered from a single individual within a 3-week period were compared. In addition, the accessory gene sequences for four of these clones were obtained. Variation among most accessory genes was limited. In contrast, pronounced phenotype-associated sequence variation was observed in the env gene. At least three of these clones most likely resulted from genetic recombination events in vivo, indicating that this phenomenon may account for the emergence of proviruses with novel phenotypic properties. Within the env genes of the eight clones, four domains could be defined, the sequence of each of which clustered in two groups with high internal homology but 11 to 30% cluster variation. The extensive env gene variation among these eight clones could largely be explained by the unique manner in which the alleles of these four domains were combined in each clone. Experiments with chimeric proviruses demonstrated that the HIV-1 env gene determined the capacity to induce syncytia and tropism for T-cell lines. Amino acids previously shown to be involved in gp120-CD4 and gp120-gp41 interaction were completely conserved among these eight clones. The finding of identical V3 sequences in clones differing in tropism for primary monocytes and T-cell lines demonstrated the existence of determinants of tropism outside the env V3 region.

Expression of functional factor VIII in primary human skin fibroblasts after retrovirus-mediated gene transfer.

We have developed a retroviral-vector system for the transfer and expression of a cloned blood clotting factor VIII cDNA. Since inclusion of the complete cDNA into existing vectors is precluded by its large size, we deleted most codons for the B-domain, which is also excised during in vivo maturation of factor VIII. When inserted into the retroviral vector M5-neoR (Laker, C., Stocking, C., Bergholtz, V., Hess, N., DeLamarter, J. F., and Ostertag, W. (1987) Proc. Natl. Acad. Sci. U. S. A. 84, 8458-8462), the sequence was shown to be efficiently expressed in murine fibroblast cell lines, as well as in primary human skin fibroblasts. Upon infection of murine fibroblast cell lines, clones containing only a single copy of the integrated vector-provirus secreted up to 125 milliunits of factor VIII antigen/10(6) cells/day. Equivalent amounts were found in a factor VIII activity assay, which signifies that the factor VIII protein secreted by the infected fibroblasts is fully functional. Primary human skin fibroblasts infected with the vector virus secreted up to 30 milliunits/10(6) cells/day.

Phase III study comparing methotrexate and tacrolimus (prograf, FK506) with methotrexate and cyclosporine for graft-versus-host disease prophylaxis after HLA-identical sibling bone marrow transplantation.

We report the results of a phase III open-label, randomized, multicenter trial comparing tacrolimus/methotrexate to cyclosporine/methotrexate for graft-versus-host disease (GVHD) prophylaxis after HLA-identical sibling marrow transplantation in patients with hematologic malignancy. The primary objective of this study was to compare the incidence of moderate to severe (grade II-IV) acute GVHD. Secondary objectives were to compare the relapse rate, disease-free survival, overall survival, and the incidence of chronic GVHD. Patients were stratified according to age (<40 v >/=40) and for male recipients of a marrow graft from an alloimmunized female. There was a significantly greater proportion of patients with advanced disease randomized to tacrolimus arm (P = . 02). The incidence of grade II-IV acute GVHD was significantly lower in patients who received tacrolimus than patients in the cyclosporine group (31.9% and 44.4%, respectively; P = .01). The incidence of grade III-IV acute GVHD was similar, 17.1% in cyclosporine group and 13.3% in the tacrolimus group. There was no difference in the incidence of chronic GVHD between the tacrolimus and the cyclosporine group (55.9% and 49.4%, respectively; P = .8). However, there was a significantly higher proportion of patients in the cyclosporine group who had clinical extensive chronic GVHD (P = . 03). The relapse rates of the two groups were similar. The patients in the cyclosporine arm had a significantly better 2-year disease-free survival and overall survival than patients in the tacrolimus arm, 50.4% versus 40.5% (P = .01) and 57.2% versus 46.9% (P = .02), respectively. The significant difference in the overall and disease-free survival was largely the result of the patients with advanced disease, 24.8% with tacrolimus versus 41.7% with cyclosporine (P = .006) and 20.4% with tacrolimus versus 28% with cyclosporine (P = .007), respectively. There was a higher frequency of deaths from regimen-related toxicity in patients with advanced disease who received tacrolimus. There was no difference in the disease-free and overall survival in patients with nonadvanced disease. These results show the superiority of tacrolimus/methotrexate over cyclosporine/methotrexate in the prevention of grade II-IV acute GVHD with no difference in disease-free or overall survival in patients with nonadvanced disease. The survival disadvantage in advanced disease patients receiving tacrolimus warrants further investigation.