Bevacizumab mitigates codon-specific effects of trifluridine/tipiracil on efficacy outcome parameters in metastatic colorectal cancer

BACKGROUND

Molecular informed therapy changed treatment patterns of metastatic colorectal cancer (mCRC). Recently KRAS G12, the most prevalent RAS mutation in mCRC, was investigated to be a negative predictive marker for the efficacy of trifluridine/tipiracil (FTD/TPI). Whether this proposed selectivity remains when FTD/TPI is combined with bevacizumab remains elusive. We aimed to describe the efficacy of FTD/TPI + bevacizumab depending on the RAS mutational status in a real-world population.

PATIENTS AND METHODS

Patients from five different cancer centers in Austria who received FTD/TPI + bevacizumab in any treatment line having available information on their molecular profile were eligible. Data were retrospectively collected by chart review. Survival data were compared using log-rank test. Multivariate Cox regression models included several established covariates.

RESULTS

One hundred and twenty-three patients with mCRC were included in this study. Median overall survival (OS) was highly similar in the RAS wild type (WT) [9.63 months (95% confidence interval [CI] 8.055-13.775 months)] and the RAS mutant cohorts [8.78 months (95% CI 8.055-11.014 months)], which was confirmed in a multivariable model adjusting for potential confounders; hazard ratio (HR): 1.05 (95% CI 0.618-1.785; P = 0.857). In addition, no effect of KRAS G12 status on patient outcome was observed. In detail, OS was 8.88 months (95% CI 7.332-12.921 months) in patients with KRAS G12 mutation, compared to 9.47 months (95% CI 8.088-11.375 months) in patients with RAS WT/no-KRAS G12 disease [HR: 0.822 (95% CI 0.527-1.282; P = 0.387)].

CONCLUSION

This real-world study indicates that the efficacy of FTD/TPI + bevacizumab is independent of RAS mutational status and that bevacizumab may therefore mitigate the potentially limited efficacy of FTD/TPI monotherapy in the KRAS G12-mutated population.

Adverse impact of a high CD4/CD8 ratio in the allograft may be overcome by methotrexate- but not mycophenolate- or posttransplant cyclophosphamide-based graft versus host disease prophylaxis

INTRODUCTION

A high CD4/CD8 T cell ratio in hematopoietic stem cell transplant (HSCT) allografts was observed to predict graft-versus-host disease (GVHD) and non-relapse mortality (NRM) but has not been comparatively examined in settings of various GVHD-prophylaxis regimens.

METHODS

This retrospective monocentric study included all consecutive HSCT performed with peripheral blood stem cells (PBSC) between January 2000 and June 2021. The impact of the graft CD4/CD8 ratio was analyzed in three cohorts with different GVHD-prophylaxis platforms.

RESULTS

In the cyclosporine/mycophenolate-mofetil (CSA/MMF) cohort (n = 294, HLA-matched HSCT), a high (> 75^th percentile) CD4/CD8 ratio was associated with increased overall mortality (HR 1.56; P=0.01), increased NRM (HR 1.85; P=0.01) and GVHD-associated mortality (HR 2.13; P=0.005). In the post-transplant cyclophosphamide (PTCy)/tacrolimus/MMF cohort (n = 113, haploidentical-related or mismatched-unrelated HSCT), a high CD4/CD8 ratio was associated with increased overall mortality (HR 2.07; P=0.04) and aGVHD3-4 (HR 2.24; P=0.02). By contrast, in the CSA/methotrexate (CSA/MTX) cohort (n = 185, HLA-matched HSCT) the CD4/CD8 ratio had no significant impact on any of the investigated endpoints.

CONCLUSION

A high CD4/CD8 ratio in the allograft has an adverse impact on GVHD and survival in CSA/MMF- and PTCy-based HSCT, while MTX-based prophylaxis may largely alleviate this important risk factor.

Influence of HER2 expression on prognosis in metastatic triple-negative breast cancer-results from an international, multicenter analysis coordinated by the AGMT Study Group

BACKGROUND

Triple-negative breast cancer (TNBC) is associated with poor prognosis, and new treatment options are urgently needed. About 34%-39% of primary TNBCs show a low expression of human epidermal growth factor receptor 2 (HER2-low), which is a target for new anti-HER2 drugs. However, little is known about the frequency and the prognostic value of HER2-low in metastatic TNBC.

PATIENTS AND METHODS

We retrospectively included patients with TNBC from five European countries for this international, multicenter analysis. Triple-negativity had to be shown in a metastatic site or in the primary breast tumor diagnosed simultaneously or within 3 years before metastatic disease. HER2-low was defined as immunohistochemically (IHC) 1+ or 2+ without ERBB2 gene amplification. Survival probabilities were calculated by the Kaplan-Meier method, and multivariable hazard ratios (HRs) were estimated by Cox regression models.

RESULTS

In total, 691 patients, diagnosed between January 2006 and February 2021, were assessable. The incidence of HER2-low was 32.0% [95% confidence interval (CI) 28.5% to 35.5%], with similar proportions in metastases (n = 265; 29.8%) and primary tumors (n = 425; 33.4%; P = 0.324). The median overall survival (OS) in HER2-low and HER2-0 TNBC was 18.6 and 16.1 months, respectively (HR 1.00; 95% CI 0.83-1.19; P = 0.969). Similarly, in multivariable analysis, HER2-low had no significant impact on OS (HR 0.95; 95% CI 0.79-1.13; P = 0.545). No difference in prognosis was observed between HER2 IHC 0/1+ and IHC 2+ tumors (HR 0.89; 95% CI 0.69-1.17; P = 0.414).

CONCLUSIONS

In this large international dataset of metastatic TNBC, the frequency of HER2-low was 32.0%. Neither in univariable nor in multivariable analysis HER2-low showed any influence on OS.

Improvement in colorectal cancer outcomes over time is limited to patients with left-sided disease

PURPOSE

Incidence and mortality of colorectal cancer (CRC) declined over the last decades. However, survival depends on the primary tumor location. It is unknown if all progress in outcomes vary depending on left-sided (LCRC) versus right-sided (RCC) colorectal cancer. We compare incidence and mortality rates over time according to the primary tumor location.

METHODS

Data from the Austrian National Cancer Registry spanning from 1983 to 2018 were used to calculate annual incidence and mortality rates and survival stratified by primary tumor localization and stage. Joinpoint regression with linear regression models were used on different subgroups to identify significant changes of incidence- and mortality slopes.

RESULTS

A total of 168,260 (incidence dataset) and 87,355 cases (mortality dataset) were identified. Survival of disseminated RCC was worse compared to LCRC (HR 1.14; CI 1.106-1.169). Total and LCRC incidence and mortality rates declined steadily over time, whereas the rates of RCC did not. Incidence of disseminated RCC declined significantly less (slope - 0.07; CI - 0.086; - 0.055) than in LCRC (slope - 0.159; CI - 0.183; - 0.136); mortality rate of RCC was unchanged over time. Incidence and mortality of localized RCC remained unchanged over time, whereas both rates declined independently of stage in LCRC.

CONCLUSION

Colorectal cancer outcomes during the last 35 years have preferentially improved in LCRC but not in RCC, indicating that the progress made is limited to LCRC. It is necessary to define RCC as a distinct form of CRC and to focus on specific strategies for its early detection and treatment.

Development and validation of a HPLC electrochemical detection method to measure COMT activity as a tool in drug development

The determination of catechol-O-methyltransferase (COMT) activity is considered valuable for various pharmaceutical and biomedical research projects. A specific high performance liquid chromatography-coulometric electrochemical detection method, for the assay of COMT activity was developed by measuring the formation of normetanephrine from norepinephrine. The chromatographic separation was achieved on a C₁₈ reversed phase column with a mobile phase consisting of 10 mM sodium dihydrogen phosphate buffer, 4 mM sodium 1-octanesulfonate, 0.17 mM ethylenediaminetetra-acetic acid disodium salt, 6 % methanol and 4 % acetonitrile (pH ± 4.0). The detection of normetanephrine was achieved through electrochemical detection, with a coulometric cell potential setting of +450 mV. The flow rate was at 1 ml/min and the total run time was 45 min. The method was validated according to validation guidelines (Shabir 2006; European Medicines Agency 2011; US FDA 2018). The method was found to be linear (R² > 0.99) over the analytical range (100 to 2500 ng/ml) for all the analytes. All the other validation parameters (sensitivity, precision, accuracy, recovery and stability) were acceptable and within range. The method was applied for the determination of COMT activity in rat liver homogenate test samples. The known selective COMT inhibitor entacapone was used as test inhibitor. The results confirmed the ability of entacapone to inhibit COMT activity by decreasing the production of all the metabolites of norepinephrine.

Abstract OT3-07-01: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 trial)

Background:Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with poor prognosis. Recently, the PARP inhibitor olaparib was approved as first targeted treatment beyond antiVEGF therapy for the BRCA1/2 mutated subgroup of TNBC. However, cytotoxic agents still remain the mainstay of treatment for this breast cancer subtype. Ixazomib is a selective and reversible inhibitor of the proteasome, which has been mainly investigated as treatment of multiple myeloma. In a preclinical cell line model for TNBC the first-generation proteasome inhibitor bortezomib showed synergistic efficacy with cisplatin. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity (47% and 38% response rate, respectively) and good tolerability. In solid tumors cytotoxic effect of proteasome inhibitors is thought to be mediated through different mechanisms: (1) Inhibition of the Fanconi Anemia and BRCA1 DNA repair mechanism (2) Inhibition of p53 degradation (3) Inhibition of NF-kappa B signaling cascade. Based on this evidence, the phase I/II MBC-10 trial will evaluate the toxicity profile and efficacy of the oral second-generation proteasome inhibitor ixazomib in combination with carboplatin in patients with advanced TNBC. Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study.Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. The MBC-10 trial is accompanied by a broad biomarker program investigating predictive biomarkers for treatment response and potential resistance mechanisms to the investigational drug combination. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Burgstaller S, Voskova D, Rossmann D, Balic M, Egle D, Rumpold H, Singer CF, Petru E, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 trial) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-07-01.

Abstract OT2-07-11: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 trial)

Background: Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with a poor prognosis. Up to now, no targeted treatment beyond anti-VEGF therapy is approved for TNBC so far and cytotoxic agents are the mainstay for the treatment of advanced tumor stages. Ixazomib is a selective, and reversible inhibitor of the proteasome, which has been mainly investigated in the treatment of multiple myeloma. In a preclinical study triple-negative breast cancer cells were treated with bortezomib, a first generation proteaseome inhibitor, alone and in combination with cisplatin, which had a synergistic effect. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity and good tolerability. Based on this rational, the MBC-10 trial will evaluate the toxicity profile and efficacy of ixazomib in combination with carboplatin in patients with advanced TNBC.

Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study. Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Pusch R, Fridrik M, Rossmann D, Balic M, Egle D, Rumpold H, Singer C, Bartsch R, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 trial) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-07-11.

Abstract P5-15-13: Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6)

Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.

Citation Format: Rinnerthaler G, Gampenrieder SP, Voskova D, Petzer A, Hubalek M, Petru E, Hartmann B, Andel J, Balic M, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-15-13.

Abstract P1-13-10: Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Stage 1 results of a phase II trial (AGMT MBC-6)

Background: Although there is no single accepted standard of care after failure of anthracycline and taxane therapy in HER2-negative metastatic breast cancer, capecitabine is a well-established treatment option. Bendamustine is a hybrid cytotoxic drug because of its structural similarity to alkylating agents and purine and it is generally well tolerated. Since bendamustine has already shown anticancer activity in breast cancer we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in 40 patients with advanced breast cancer after anthracycline and/or taxane pretreatment.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative advanced breast cancer (ClinicalTrials.gov identifier: NCT01891227). All patients were pretreated with anthracyclines and/or taxans in the (neo-)adjuvant and/or metastatic setting and measurable disease according to RECIST 1.1. had to be present at baseline. Following a two-stage Green-Dahlberg design, 20 subjects were accrued and treated within stage 1 of the study. The trial was planned to enroll further 20 patients if there were at least four subjects (20%) with a complete (CR) or partial response (PR). Eligible patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle. After a maximum of eight cycles capecitabine was continued as single drug therapy until disease progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression free survival (PFS), clinical benefit rate (CBR), safety profile and quality of life. Here we report the efficacy and safety analysis of stage 1 patients.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age of the stage 1 cohort was 59 years (range 29-77), 80% and 20% of patients had an ECOG performance score of 0 and 1, respectively. Thirty-three percent had triple-negative disease, 85% had had (neo-)adjuvant treatment and 65% patients were pretreated with at least one chemotherapy line for metastatic disease (15% one line, 50% two lines, 40% three lines). In stage 1, ORR was 50% with 9 confirmed PR and 1 confirmed CR, and ORR was comparable between hormone receptor-positive and triple-negative disease (54% vs. 43%). CBR was 55%. At data cut-off on 05/28/15 overall 15 of 20 patients had discontinued treatment: 10 patients (50%) due to progressive disease, 3 (15%) because of adverse events (AEs) and 2 patients on their own decision (10%). Five patients (25%) experienced at least one drug related non-hematological AE ≥ grade 3: 2 diarrhea, 2 fatigue, 3 respiratory or viral infections, 1 dyspnea, 1 thromboembolic event (each grade 3). One grade 4 hematological AE (neutropenia) was observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine has a moderate toxicity profile and the response data of the stage 1 are promising. Final study results are awaited in the first half of 2016.

Citation Format: Rinnerthaler G, Gampenrieder SP, Fridrik M, Petzer A, Hubalek M, Petru E, Jäger T, Andel J, Balic M, Ulmer H, Mlineritsch B, Greil R. Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Stage 1 results of a phase II trial (AGMT MBC-6). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-13-10.

The inhibition of monoamine oxidase by phenformin and pentamidine

A computational study has suggested that phenformin, an oral hypoglycaemic drug, may bind to the active sites of the monoamine oxidase (MAO) A and B enzymes. The present study therefore investigates the MAO inhibitory properties of phenformin. Pentamidine, a structurally related diamidine compound, has previously been reported to be a MAO inhibitor and was included in this study as a reference compound. Using recombinant human MAO-A and MAO-B, this study finds that phenformin acts as a moderately potent MAO-A selective inhibitor with an IC50 value of 41 µM. Pentamidine, on the other hand, potently inhibits both MAO-A and MAO-B with IC50 values of 0.61 μM and 0.22 μM, respectively. An examination of the recoveries of the enzymatic activities after dilution and dialysis of the enzyme-inhibitor complexes shows that both compounds interact reversibly with the MAO enzymes. A kinetic analysis suggests that pentamidine acts as a competitive inhibitor with estimated Ki values of 0.41 μM and 0.22 μM for the inhibition of MAO-A and MAO-B, respectively. Phenformin also exhibited a competitive mode of MAO-A inhibition with an estimated Ki value of 65 µM. This study concludes that biguanide and amidine functional groups are most likely important structural features for the inhibition of the MAOs by phenformin and pentamidine, and compounds containing these and closely related functional groups should be considered as potential MAO inhibitors. Furthermore, the biguanide and amidine functional groups may act as useful moieties in the future design of MAO inhibitors.

Altered Immune Responses during Septicaemia in Patients Suffering from Haematological Malignancies

Septicaemia is a frequent complication in patients with haematological malignancies. In this study we analysed markers of inflammation/immune activation (C- reactive protein, interleukin-6, neopterin), tryptophan metabolites and mannose binding lectin (MBL) levels consecutively in 36 septic patients with haematological malignancies (HM) and “non-haematological” diseases [intensive care unit (ICU) patients]. During septicaemia different chronological sequences for inflammation markers CRP, IL-6 and neopterin were seen in HM and ICU patients. Septic ICU-patients presented with significantly increased tryptophan degradation and higher neopterin and CRP levels at baseline, while MBL levels were lower in this group compared to subjects with HM. Concentrations of inflammation markers Were linked to each other and associated with enhanced tryptophan degradation. Patients who died during follow-up of 28 days tended to have lower baseline MBL concentrations than survivors. Septic patients with HM showed an impaired pro-inflammatory immune response compared to patients with non-haematological diseases.

Clinical evaluation of Aspergillus-PCR for detection of invasive aspergillosis in immunosuppressed patients

We evaluated the utility of Aspergillus PCR as a tool in diagnosing invasive aspergillosis in patients at risk. Aspergillosis was assessed according to the European Organization for Research and Treatment of Cancer (EORTC), Mycosis Study Group definitions. Nine and seven patients with proven and probable aspergillosis respectively were evaluated. Whole blood samples prior (n = 41) and during antifungal treatment (n = 67), and tissue specimens (n = 9) and/or bronchoalveolar lavage fluids (n = 7) were investigated. In patients with proven infections, the sensitivities of PCR of lung samples were 100%, of blood samples prior treatment were 66%, and during treatment 55%. Clearance of fungal DNA from blood was associated with resolution of clinical symptoms in two of four patients with proven infection. Consecutive positive PCR results for Aspergillus are fatal as two of five patients died. In patients with probable infections, the sensitivities of PCR of lung fluids were 85%, of blood samples prior treatment were 57%, and during treatment 42%. The benefits of PCR diagnosing and screening of whole blood are limited if sampling takes place once treatment has started. The performance of Aspergillus PCR from tissue samples should be recommended in addition to microscopic examination and culture technique for sensitive detection of fungal infection.

High-dose cytarabine and mitoxantrone in consolidation therapy for acute promyelocytic leukemia

The objective of our study was to evaluate high-dose cytarabine in consolidation therapy in patients with newly diagnosed acute promyelocytic leukemia (APL). Patients (age 16-60 years) received induction therapy according to the AIDA protocol (all-trans retinoic acid, idarubicin) followed by one cycle of ICE (idarubicin, cytarabine, etoposide) and two cycles of HAM (cytarabine 3 g/m(2) q12h, days 1-3; mitoxantrone 10 mg/m(2), days 2 and 3). From 1995 to 2003, 82 patients were enrolled. In total, 72 patients (88%) achieved a complete remission, and 10 patients (12%) died from early/hypoplastic death (ED/HD). A total of 71 patients received at least one cycle of HAM. Relapse-free survival (RFS) and overall survival (OS) after 46 months were 83 and 82%, respectively. White blood cell count above 10.0 x 10(9)/l at diagnosis and additional chromosomal aberrations were unfavorable prognostic markers for OS, whereas no prognostic markers for RFS were identified including FLT3 mutations. In conclusion, high-dose cytarabine in consolidation therapy for patients with newly diagnosed APL is an effective treatment approach.

Fungal colonization in neutropenic patients: a randomized study comparing itraconazole solution and amphotericin B solution

We assessed the impact of prophylaxis with the oral itraconazole solution and amphotericin B solution on fungal colonization and infection in a randomized study among patients with hematological malignancies and neutropenia. Infecting and colonizing Candida strains of patients suffering from candidiasis were genotyped by random amplification of polymorphic DNA (RAPD) analysis. A total of 106 patients were evaluated in this study: 52 patients in the itraconazole and 54 in the amphotericin B arm. During neutropenia fungal colonization in the oropharynx occurred in 11 (19.6%) and 24 (40.6%) and in the rectum in 11 (19.6%) and 23 (38.9%) courses in the itraconazole and amphotericin B groups ( P<0.05), respectively. Candida albicans was the most prevalent species in both study groups. Mixed fungal colonization with Candida krusei and Candida glabrata was increased in the amphotericin B group, yet without clinical importance since infections were due to C. albicans. The occurrence of invasive candidiasis was significantly increased in multicolonized compared to monocolonized patients. In the amphotericin B group 20 and in the itraconazole group 2 neutropenic patients showed multicolonization with Candida spp. ( P<0.05). Overall fungal infections were 3.8% in the itraconazole and 14.8% in the amphotericin B group ( P<0.05). RAPD typing showed oropharynx strains involved in superficial infections in four of five patients. In all four patients with deep fungal infections, it appears that the colonizing rectum strains were identical to infecting strains of Candida spp. Itraconazole solution significantly reduced Candida colonization and infection compared to amphotericin B solution. Most patients remained infected with the colonized strains for the entire study period, irrespective of antifungal prophylaxis.

Screening for Aspergillus spp. using polymerase chain reaction of whole blood samples from patients with haematological malignancies

Sensitive screening for Aspergillus spp. using polymerase chain reaction (PCR) of whole blood samples in patients with haematological disorders has not been performed to date. In a 2-year study, 121 patients admitted to the University Hospital of Innsbruck for cancer chemotherapy without clinical signs of fungal infection were prospectively screened for Aspergillus spp. In 28 out of 121 (23%) patients, Aspergillus DNAaemia was detected. Of these patients, 16 (57%) were positive only once for Aspergillus DNA, but positivity was never associated with invasive aspergillosis. PCR positive episodes were short and resolved without antifungal treatment. Five patients (18%) had intermittent PCR positive results. Seven (25%) patients presented at least two consecutive positive PCR results; one of these patients developed invasive aspergillosis and another two were strongly suspected as having aspergillosis. Based on the criteria of the European Organization for Research and Treatment of Cancer case definitions, sensitivity and specificity of serial PCR monitoring were 75% and 96%. Positive PCR results became negative shortly after commencement of antifungal treatment, but the changes did not correlate with clinical responsiveness to treatment in three patients. Our results indicate the potential usefulness of PCR for screening for Aspergillus spp. in patients at risk, but without antifungal treatment.

Changes in the cytokine regulation of stem cell self-renewal during ontogeny

The last 10 years have seen the development of a quantitative assay that is specific for transplantable totipotent murine hematopoietic cells with durable in vivo blood-forming ability. Recently, this assay has been successfully adapted to allow the detection and enumeration of an analogous population of human hematopoietic stem cells using myelosuppressed immunodeficient (nonobese diabetic/severe-combined immunodeficiency) mice as recipients. Characterization of the cells detected by this assay indicates their close relationship in both mice and humans with cells detected in vitro as long-term culture-initiating cells (LTC-IC). Culture conditions have now been identified that support a significant net expansion of these cells from both species. More detailed analyses of the cytokine requirements for this response indicate that the viability, mitogenesis and maintenance of LTC-IC function by human CD34+ CD38- cells can be independently regulated by exogenous factors. Superimposed on this uncoupling of hematopoietic stem cell "self-renewal" and proliferation control is a change during ontogeny in the particular cytokines that regulate their responses. These findings unite stochastic and deterministic models of hematopoietic stem cell control through the concept of a molecular mechanism that actively blocks stem cell differentiation and must be maintained when these cells are stimulated to divide by exposure to certain types and concentrations of cytokines.

Thrombocytes are the major source for soluble vascular endothelial growth factor in peripheral blood

Serum levels of vascular endothelial growth factor (VEGF-S) have been reported to correlate with tumor stage and prognosis in various human malignancies. The source of soluble VEGF in peripheral blood remains obscure. We therefore measured the concentration of immunoreactive VEGF in 241 serum samples and 61 plasma samples (VEGF-P) from 20 subjects undergoing myeloablative chemotherapy and from 3 normal platelet donors. A significant correlation between the peripheral blood platelet count (PC) and VEGF-S (r = 0.86) but not VEGF-P was found. VEGF-S levels were 58.43 +/- 42.50 pg/ml (mean +/- SD) in patients with a PC < 50 x 10(9)/l, 203.29 +/- 176.56 pg/ml for a PC of 50-150 x 10(9)/l, and 457.42 +/- 475.41 pg/ml for a PC > 150 x 10(9)/l. Interestingly, VEGF-P levels were substantially lower than the corresponding VEGF-S values, namely below the detection limit in most cases. Supernatants from platelet-rich plasma contained no VEGF, but after in vitro lysis of the platelets very high VEGF levels were found. The VEGF content per 10(9) platelets was calculated at 2.51 +/- 2.39 pg and was dependent on the mean platelet volume. In summary, VEGF release from platelets during blood clotting was found to be the main source of VEGF in serum samples. Cancer patients in clinical remission have negligible amounts of soluble VEGF in peripheral blood, and myeloablative chemotherapy causes a significant drop in VEGF-S levels corresponding to the decrease in PC. Thus, studies addressing the diagnostic and prognostic value of VEGF-S in cancer patients must be interpreted with caution. Our data provide the basis for predicting VEGF-S in relation to PC in vivo, and for reevaluating former studies of VEGF-S in patients with malignant or nonmalignant disease.

Hematopoietic stem cells: inferences from in vivo assays

Mice and humans both contain a population in their marrow which can permanently regenerate all of the hematopoietic lineages. This developmental potential was first demonstrated in myeloablated mice transplanted with genetically marked marrow obtained from congenic donors. More recently, this approach has been used to devise an in vivo limiting dilution assay for "competitive (lymphomyeloid) repopulating units" (CRU) that allows murine hematopoietic stem cells to be quantitated. Measurements of murine CRU have shown that this population expands concomitantly with the total hematopoietic system during ontogeny and to some extent post-transplant. During these periods of expansion, defective c-kit function can be seen to preferentially compromise CRU self-renewal more than early CRU detection (which requires differentiation and amplification of the progeny of CRU, but may not require extensive CRU self-renewal). In humans, a similar cell type with transplantable lymphomyeloid differentiation potential can be identified in cord blood on the basis of its ability to engraft sublethally irradiated immunodeficient nonobese diabetic/severe combined immunodeficient mice. Quantitation of these human CRU by limiting dilution analysis of unseparated, highly purified (CD34+CD38-) and cultured (CD34+CD38-) human cord blood cells indicates that their numbers (like the long-term culture-initiating cell [LTC-IC] population) can be slightly expanded in cytokine-supplemented serum-free media, although not as extensively as anticipated from analogous studies of human marrow LTC-IC cultured under the same conditions. Taken together, the results of our studies suggest that the self-renewal of mitotically activated hematopoietic stem cells can be enhanced by their interactions with particular cytokine combinations whose effectiveness in this regard may change during ontogeny.

[High dose therapy with transplantation of autologous peripheral hematopoietic stem cells. I. Basic principles and clinical development]

High-dose therapy with peripheral stem cell rescue is increasingly being used as a salvage or consolidation therapy for patients with malignant disease. The accelerated hemopoietic recovery and the collection of peripheral stem cells in an outpatient setting are the main advantages. Recent findings on tumor cell contamination of autografts stimulated the development of techniques for tumor cell reduction, based on negative selection (purging) of tumor cells or positive selection of CD34+ progenitor cells. Purging and CD34 selection could probably result in increased cure rates. CD34 selection is also imperative for the successful expansion of progenitor cells in vitro. Using various mixtures of cytokines, different cell lineages may be preferentially expanded. A further area of interest is gene transfer into hematopoietic cells, where a purified cell population is a prerequisite for success. Future directions are the increase of cure rates by sequential administration of chemotherapeutic drugs at their maximum tolerated doses, the evaluation of new antineoplastic drugs and improved supportive care.

[High dose therapy with transplantation of autologous peripheral hematopoietic stem cells. II. Indications and clinical results]

Transplant studies in a variety of malignant diseases suggest that dose intensification with peripheral stem cell support can be safely applied to a wide range of patients. The clinical results are comparable to that after autologous bone marrow transplantation by achieving long lasting remissions, even in advanced disease. Clinical studies evaluating this therapeutic modality in leukemias, Hodgkin's-and non-Hodgkin's lymphoma, myeloma, and in chemotherapy-sensitive solid tumors are in progress. The clinical results compared to conventional chemotherapy are summarized in Table 1. Several approaches are targeted at improved elimination of malignant cells: 1) incorporation of new drugs into preparative conditioning regimens, 2) tandem or multiple cycles of high-dose chemotherapy followed by stem cell rescue, 3) post-transplant immunomodulation aimed at inducing an antitumor effect, and 4) purging techniques to eliminate contaminating tumor cells from the transplant. Improvements in stem cell technology and supportive care will decrease the mortality of the procedure and leed to a substancial cost reduction.

Expansion in vitro of transplantable human cord blood stem cells demonstrated using a quantitative assay of their lympho-myeloid repopulating activity in nonobese diabetic-scid/scid mice

Human hematopoiesis originates in a population of stem cells with transplantable lympho-myeloid reconstituting potential, but a method for quantitating such cells has not been available. We now describe a simple assay that meets this need. It is based on the ability of sublethally irradiated immunodeficient nonobese diabetic-scid/scid (NOD/SCID) mice to be engrafted by intravenously injected human hematopoietic cells and uses limiting dilution analysis to measure the frequency of human cells that produce both CD34(-)CD19(+) (B-lymphoid) and CD34(+) (myeloid) colony-forming cell progeny in the marrow of such recipients 6 to 8 weeks post-transplant. Human cord blood (CB) contains approximately 5 of these competitive repopulating units (CRU) per ml that have a similar distribution between the CD38(-) and CD38(+) subsets of CD34(+) CB cells as long-term culture-initiating cells (LTC-IC) (4:1 vs. 2:1). Incubation of purified CD34(+)CD38(-) human CB cells in serum-free medium containing flt-3 ligand, Steel factor, interleukin 3, interleukin 6, and granulocyte colony-stimulating factor for 5-8 days resulted in a 100-fold expansion of colony-forming cells, a 4-fold expansion of LTC-IC, and a 2-fold (but significant, P < 0.02) increase in CRU. The culture-derived CRU, like the original CB CRU, generated pluripotent, erythroid, granulopoietic, megakaryopoietic, and pre-B cell progeny upon transplantation into NOD/SCID mice. These findings demonstrate an equivalent phenotypic heterogeneity amongst human CB cells detectable as CRU and LTC-IC. In addition, their similarly modest response to stimulation by a combination of cytokines that extensively amplify LTC-IC from normal adult marrow underscores the importance of ontogeny-dependent changes in human hematopoietic stem cell proliferation and self-renewal.

Quantitation and characterization of human megakaryocyte colony-forming cells using a standardized serum-free agarose assay

Human progenitors of the megakaryocyte (Mk) lineage were detected by their ability to generate colonies-containing from 3 to > 100 Mk, detectable as glycoprotein IIb/IIIa+ cells in APAAP-stained whole mount agarose cultures. Optimal growth conditions were achieved through the use of a defined serum substitute and a suitable cocktail of recombinant cytokines. Under these culture conditions, the smallest Mk-containing colonies (CFC-Mk) were detectable within a week followed by colonies containing larger numbers of Mk over the ensuing 2 weeks. The total number of CFC-Mk at 18-21 d was linearly related to the number of cells plated. Variation in the cytokines added showed that thrombopoietin (TPO) or IL-3 alone would support the formation of large numbers of CFC-Mk. However, optimal yields of colonies containing cells of both Mk and non-Mk lineages required the addition of other growth factors, of which a combination of IL-3, IL-6, GM-CSF and Steel factor (SF) +/- TPO was the best of those tested. The further addition of erythropoietin to this combination reduced the number of large "pure' Mk colonies seen and in their place a corresponding number of mixed erythroid-Mk colonies became detectable. Flt3-ligand alone was unable to support the growth of CFC-Mk nor did it enhance their growth when combined with other factors. Plating of FACS-sorted sub-populations of CD34+ marrow cells in both serum-free agarose and methylcellulose assays demonstrated that most CFC-Mk are generated from CD34+ cells that are CD45RA- and CD71+, approximately half of which are CD41+. Thus, CFC-Mk are more similar to primitive clonogenic erythroid progenitors than to their granulopoietic counterparts in their expression of CD34, CD45RA and CD71. Taken together, these findings support the concept that some erythroid and Mk progenitors may share a common developmental pathway. The availability of sensitive and reproducible procedures for isolating and detecting human Mk progenitors should facilitate future investigations of their biology and role in a variety of haematological conditions.

Minimal residual disease in hairy-cell leukemia after treatment with 2-chlorodeoxyadenosine

Some patients in apparent complete remission of hairy cell leukemia (HCL) after 2-chlorodeoxyadenosine (2-CdA) treatment may have minimal residual disease (MRD). This study examines detection of minimal residual disease by immunohistological staining using the monoclonal antibody (MoAb) B-ly 7 in 11 patients with complete remission of hairy cell leukemia (HCL) after 2-CdA therapy administered between 1990 and 1993. In all 11 cases, residual hairy cells could be detected by MoAb B-ly 7 (0.1 to 7.5%, median 0.65%). At a follow-up period of 7 - 29 months (median 19.3), 9 of these patients remained in complete remission, whereas 2 patients relapsed 22 and 27 months after 2-CdA therapy. To determine whether flow-cytometric analysis of hairy-cells in bone marrow aspirates and peripheral blood cells are comparable with results obtained by immunostaining with B-ly 7 in bone marrow biopsies, available data using CD-19/CD-11c double-staining were analyzed. In 5 of 10 cases no hairy-cells could be detected in bone marrow aspirates, and in 6 partly different cases no hairy-cells were detectable in peripheral blood using flow-cytometry, although immunostaining of bone marrow biopsies using B-ly 7 revealed hairy-cells (ranging form 0.1 to 7.5%) in these cases. These results indicate that therapy with 2-CdA does not eradicate hairy cell leukemia despite complete remission according to conventional criteria. Minimal residual disease might be responsible for subsequent relapse. We conclude that routine immunohistological examination of bone marrow biopsies with B-ly 7 should be performed for assessment of MRD. Flow cytometric investigations of mononuclear cells of bone marrow aspirate or peripheral blood seem valuable for regular long term monitoring of MRD, but does not substitute for immunostaining of bone marrow biopsies.

Mixed colony formation in vitro by the heterogeneous compartment of multipotential progenitors in human bone marrow

The physiology of the human haemopoietic primitive progenitor populations can be studied in normal and disease states by clonal in vitro cultures in which the primitive progenitor cells proliferate and differentiate to form mixed colonies. For many applications it is essential that such assays detect a high proportion of primitive progenitor cells. We describe an in vitro assay which detects a high incidence of human CD34+ multipotential progenitor cells. Bone marrow mononuclear cells (MNC) or selected CD34+ cells were plated at low cell concentrations in semisolid agar cultures with synergizing growth factor combinations. The optimum growth factor combination of conditioned medium from Mia PaCa-2 cells (Mia-CM), recombinant granulocyte-macrophage colony-stimulating factor and recombinant stem cell factor (SCF) supported the formation of macroscopic (> or = mm) colonies (97% of which were multilineage), at an average incidence of 250/10(5) MNC. The colony-forming cells (human colony-forming unit, type A) detected, showed a low cycling status (7.3%) and the macroscopic colonies had a high replating efficiency (46%), reflecting their probable primitive nature. This assay should prove invaluable, for studies on the regulation of proliferation of the multipotential compartment and in studies involving the assessment of these cells in transplantation and neoplastic disease.

Stimulation of human early and late erythropoietic progenitor cells by insulin: evidence for different mechanisms

In order to investigate cellular mechanisms involved in insulin stimulation of erythropoiesis, we have studied the response of early (BFU-e) and late (CFU-e) erythroid progenitor cells in a serum-free agar culture system. In this assay system, CFU-e proliferation occurred in media containing low-density lipoproteins, bovine serum albumin, transferrin and recombinant erythropoietin (rEPO). Insulin in physiological concentrations as low as 10(-12)M, added directly to cultures, augmented CFU-e colony formation. This stimulatory effect was also seen when monocyte- and T lymphocyte-depleted cells from normal donors were cultured. In contrast, BFU-e was not stimulated by media devoid of insulin. Occurrence of BFU-e colonies required the presence of insulin in concentrations higher than 10(-8)M. This insulin effect was not dependent on the presence of monocytes and T lymphocytes. Delayed addition studies of rEPO to insulin containing cultures revealed a slight but significant survival rate of CFU-e. A similar survival rate was found for BFU-e. From this, we conclude that insulin stimulates CFU-e by an EPO-like activity. For BFU-e, however, the decline in the number of bursts caused by EPO deprivation implies that insulin does not act directly as a burst-promoting activity but that it probably induces the release of this activity from non-adherent and T lymphocyte-depleted bone marrow cells.

Involvement of complement in B-cell, T-cell and monocyte/macrophage activation

In the early 70's it had been shown, that for the immune response against T-dependent antigens C3 was necessary, while T-independent antigens, although activating the alternative pathway of complement, triggered antibody formation also in C-deficient mice. During recent years functional and biochemical knowledge about complement binding structures on B-cells and monocytes/macrophages continuously increased and, also, on T-cells C3 binding entities have been detected. In the case of B-cells and, at least in special experimental conditions, in the case of T-cells C3 can exert a proliferative response as long as the cells are prestimulated (excited) by anti-Ig or IL-2, respectively. Monocytes can bind C3b- or iC3b-carrying particles, but only when progressed to macrophages can they phagocytose such particles. Thus the concept evolves that B-cells, T-cells and monocytes can acquire competence for a C3-driven response when excited properly. The involvement of molecules such as CR1, CR2, factor H, IL-2-receptor and others with a basic structure of repeating units of 61 amino acids in the triggering processes is a surprising finding and certainly suggests their functional importance. In the case of T-independent antigens the structures triggering the alternative pathway of complement are the structures triggering monocytes directly. Whether these two functions have a causal relationship has to be shown.

Enzyme-linked immunoassay to monitor the purification of, and to screen for monoclonal antibodies against, C3b receptor

An enzyme-linked immunosorbent assay both to screen for monoclonal anti-bodies to the C3b receptor and to monitor its purification was developed. The test requires only purified C3, converted to either the hemolytically no longer active iC3 or C3b. An NP-40 lysate of tonsil cells can be used as a source of CR1 in this test which works best under hypotonic conditions facilitating the interaction of iC3/C3b and CR1. Two monoclonal antibodies to CR1 were produced using this test for the screening of hybridomas. The identity of the molecule recognized by these antibodies with CR1 is demonstrated by immunoprecipitation and Western blot studies, as well as immunofluorescence and immunoperoxidase staining of cells and tissues known to contain CR1. Fractions from lentil-lectin and DEAE-Sephadex columns containing CR1 can be identified using this test.