Hematopoietic stem cell boost for persistent neutropenia after CAR T-cell therapy: a GLA/DRST study.

Hematotoxicity after chimeric antigen receptor (CAR) T-cell therapy is associated with infection and death but management remains unclear. We report results of 31 patients receiving hematopoietic stem cell boost (HSCB; 30 autologous, 1 allogeneic) for either sustained severe neutropenia of grade 4 (<0.5 × 109/L), sustained moderate neutropenia (≤1.5 × 109/L) and high risk of infection, or neutrophil count ≤2.0 × 109/L and active infection. Median time from CAR T-cell therapy to HSCB was 43 days and median absolute neutrophil count at time of HSCB was 0.2. Median duration of neutropenia before HSCB was 38 days (range, 7-151). Overall neutrophil response rate (recovery or improvement) was observed in 26 patients (84%) within a median of 9 days (95% confidence interval, 7-14). Time to response was significantly associated with the duration of prior neutropenia (P = .007). All nonresponders died within the first year after HSCB. One-year overall survival for all patients was 59% and significantly different for neutropenia (≤38 days; 85%) vs neutropenia >38 days before HSCB (44%; P = .029). In conclusion, early or prophylactic HSCB showed quick response and improved outcomes for sustained moderate to severe neutropenia after CAR-T.

Improved Primary Staging of Marginal-Zone Lymphoma by Addition of CXCR4-Directed PET/CT.

PET/CT with 18F-FDG is an integral component in the primary staging of most lymphomas. However, its utility is limited in marginal-zone lymphoma (MZL) because of inconsistent 18F-FDG avidity. One diagnostic alternative could be the targeting of C-X-C motif chemokine receptor 4 (CXCR4), shown to be expressed by MZL cells. This study investigated the value of adding CXCR4-directed 68Ga-pentixafor PET/CT to conventional staging. Methods: Twenty-two newly diagnosed MZL patients were staged conventionally and with CXCR4 PET/CT. Lesions identified exclusively by CXCR4 PET/CT were biopsied as the standard of reference and compared with imaging results. The impact of CXCR4-directed imaging on staging results and treatment protocol was assessed. Results: CXCR4 PET/CT correctly identified all patients with viable MZL and was superior to conventional staging (P < 0.001). CXCR4-directed imaging results were validated by confirmation of MZL in 16 of 18 PET-guided biopsy samples. Inclusion of CXCR4 PET/CT in primary staging significantly impacted staging results in almost half of patients and treatment protocols in a third (upstaging, n = 7; downstaging, n = 3; treatment change, n = 8; P < 0.03). Conclusion: CXCR4 PET/CT is a suitable tool in primary staging of MZL and holds the potential to improve existing diagnostic algorithms.

[68Ga]Pentixafor-PET/CT for imaging of chemokine receptor CXCR4 expression in multiple myeloma - Comparison to [18F]FDG and laboratory values.

Chemokine (C-X-C motif) receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer including multiple myeloma (MM). Proof-of-concept of CXCR4-directed radionuclide therapy in MM has recently been reported. This study assessed the diagnostic performance of the CXCR4-directed radiotracer [68Ga]Pentixafor in MM and a potential role for stratifying patients to CXCR4-directed therapies. Thirty-five patients with MM underwent [68Ga]Pentixafor-PET/CT for evaluation of eligibility for endoradiotherapy. In 19/35 cases, [18F]FDG-PET/CT for correlation was available. Scans were compared on a patient and on a lesion basis. Tracer uptake was correlated with standard clinical parameters of disease activity. [68Ga]Pentixafor-PET detected CXCR4-positive disease in 23/35 subjects (66%). CXCR4-positivity at PET was independent from myeloma subtypes, cytogenetics or any serological parameters and turned out as a negative prognostic factor. In the 19 patients in whom a comparison to [18F]FDG was available, [68Ga]Pentixafor-PET detected more lesions in 4/19 (21%) subjects, [18F]FDG proved superior in 7/19 (37%). In the remaining 8/19 (42%) patients, both tracers detected an equal number of lesions. [18F]FDG-PET positivity correlated with [68Ga]Pentixafor-PET positivity (p=0.018). [68Ga]Pentixafor-PET provides further evidence that CXCR4 expression frequently occurs in advanced multiple myeloma, representing a negative prognostic factor and a potential target for myeloma specific treatment. However, selecting patients for CXCR4 directed therapies and prognostic stratification seem to be more relevant clinical applications for this novel imaging modality, rather than diagnostic imaging of myeloma.

Immunomodulatory drugs disrupt the cereblon-CD147-MCT1 axis to exert antitumor activity and teratogenicity.

Immunomodulatory drugs (IMiDs), such as thalidomide and its derivatives lenalidomide and pomalidomide, are key treatment modalities for hematologic malignancies, particularly multiple myeloma (MM) and del(5q) myelodysplastic syndrome (MDS). Cereblon (CRBN), a substrate receptor of the CRL4 ubiquitin ligase complex, is the primary target by which IMiDs mediate anticancer and teratogenic effects. Here we identify a ubiquitin-independent physiological chaperone-like function of CRBN that promotes maturation of the basigin (BSG; also known as CD147) and solute carrier family 16 member 1 (SLC16A1; also known as MCT1) proteins. This process allows for the formation and activation of the CD147-MCT1 transmembrane complex, which promotes various biological functions, including angiogenesis, proliferation, invasion and lactate export. We found that IMiDs outcompete CRBN for binding to CD147 and MCT1, leading to destabilization of the CD147-MCT1 complex. Accordingly, IMiD-sensitive MM cells lose CD147 and MCT1 expression after being exposed to IMiDs, whereas IMiD-resistant cells retain their expression. Furthermore, del(5q) MDS cells have elevated CD147 expression, which is attenuated after IMiD treatment. Finally, we show that BSG (CD147) knockdown phenocopies the teratogenic effects of thalidomide exposure in zebrafish. These findings provide a common mechanistic framework to explain both the teratogenic and pleiotropic antitumor effects of IMiDs.

11C-Methionine-PET: a novel and sensitive tool for monitoring of early response to treatment in multiple myeloma.

Multiple myeloma (MM) remains an essentially incurable hematologic malignancy. However, new treatment modalities and novel drugs have been introduced and thus additional tools for therapy monitoring are increasingly needed. Therefore, we evaluated the radiotracers 11C-Methionine (paraprotein-biosynthesis) and 18F-FDG (glucose-utilization) for monitoring response to anti-myeloma-therapy and outcome prediction. Influence of proteasome-inhibition on radiotracer-uptake of different MM cell-lines and patient-derived CD138+ plasma cells was analyzed and related to tumor-biology. Mice xenotransplanted with MM.1S tumors underwent MET- and FDG-µPET. Tumor-to-background ratios before and after 24 h, 8 and 15 days treatment with bortezomib were correlated to survival. Treatment reduced both MET and FDG uptake; changes in tracer-retention correlated with a switch from high to low CD138-expression. In xenotransplanted mice, MET-uptake significantly decreased by 30-79% as early as 24 h after bortezomib injection. No significant differences were detected thus early with FDG. This finding was confirmed in patient-derived MM cells. Importantly, early reduction of MET- but not FDG-uptake correlated with improved survival and reduced tumor burden in mice. Our results suggest that MET is superior to FDG in very early assessment of response to anti-myeloma-therapy. Early changes in MET-uptake have predictive potential regarding response and survival. MET-PET holds promise to individualize therapies in MM in future.

18 FDG-PET/CT for prognostic stratification of patients with multiple myeloma relapse after stem cell transplantation.

The aim of this study was to investigate the prognostic value of 18F-fluoro-deoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT) in 37 patients with a history of multiple myeloma (MM) and suspected or confirmed recurrence after stem cell transplantation (SCT). All patients had been heavily pre-treated. Time to progression (TTP) and overall survival (OS) were correlated to a number of different PET-derived as well as clinical parameters. Impact on patient management was assessed. Absence of FDG-avid MM foci was a positive prognostic factor for both TTP and OS (p<0.01). Presence of >10 focal lesions correlated with both TTP (p<0.01) and OS (p<0.05). Interestingly, presence of >10 lesions in the appendicular skeleton proved to have the strongest association with disease progression. Intensity of glucose uptake and presence of extramedullary disease were associated with shorter TTP (p=0.037 and p=0.049, respectively). Manifestations in soft tissue structures turned out to be a strong negative predictor for both, TTP and OS (p<0.01, respectively). PET resulted in a change of management in 30% of patients. Our data underline the prognostic value of 18F-FDG-PET/CT in MM patients also in the setting of post-SCT relapse. PET/CT has a significant impact on patient management.

Targeting paraprotein biosynthesis for non-invasive characterization of myeloma biology.

PURPOSE: Multiple myeloma is a hematologic malignancy originating from clonal plasma cells. Despite effective therapies, outcomes are highly variable suggesting marked disease heterogeneity. The role of functional imaging for therapeutic management of myeloma, such as positron emission tomography with 2-deoxy-2-[¹8F]fluoro-D-glucose (¹8F-FDG-PET), remains to be determined. Although some studies already suggested a prognostic value of ¹8F-FDG-PET, more specific tracers addressing hallmarks of myeloma biology, e.g. paraprotein biosynthesis, are needed. This study evaluated the amino acid tracers L-methyl-[¹¹C]-methionine (¹¹C-MET) and [¹8F]-fluoroethyl-L-tyrosine ((¹8F-Fet) for their potential to image myeloma and to characterize tumor heterogeneity. EXPERIMENTAL DESIGN: To study the utility of ¹¹C-MET, ¹8F-Fet and ¹8F-FDG for myeloma imaging, time activity curves were compared in various human myeloma cell lines (INA-6, MM1.S, OPM-2) and correlated to cell-biological characteristics, such as marker gene expression and immunoglobulin levels. Likewise, patient-derived CD138⁺ plasma cells were characterized regarding uptake and biomedical features. RESULTS: Using myeloma cell lines and patient-derived CD138⁺ plasma cells, we found that the relative uptake of ¹¹C-MET exceeds that of ¹8F-FDG 1.5- to 5-fold and that of ¹8F-Fet 7- to 20-fold. Importantly, ¹¹C-MET uptake significantly differed between cell types associated with worse prognosis (e.g. t(4;14) in OPM-2 cells) and indolent ones and correlated with intracellular immunoglobulin light chain and cell surface CD138 and CXCR4 levels. Direct comparison of radiotracer uptake in primary samples further validated the superiority of ¹¹C-MET. CONCLUSION: These data suggest that ¹¹C-MET might be a versatile biomarker for myeloma superior to routine functional imaging with ¹8F-FDG regarding diagnosis, risk stratification, prognosis and discrimination of tumor subtypes.

Reduced-intensity conditioning versus standard conditioning before allogeneic haemopoietic cell transplantation in patients with acute myeloid leukaemia in first complete remission: a prospective, open-label randomised phase 3 trial.

BACKGROUND: Reduced-intensity conditioning regimens have been developed to minimise early toxic effects and deaths after allogeneic haemopoietic cell transplantation. However, the efficacy of these regimens before this procedure has not been investigated in a randomised trial. In this prospective, open-label randomised phase 3 trial we compared a reduced-intensity fludarabine-based conditioning regimen with a standard regimen in patients with acute myeloid leukaemia in first complete remission. METHODS: Patients were aged 18-60 years and had intermediate-risk or high-risk acute myeloid leukaemia (defined by cytogenetics) in first complete remission; an available HLA-matched sibling donor or an unrelated donor with at least nine of ten HLA alleles; and adequate renal, cardiac, pulmonary, and neurological function. Between Nov 15, 2004, and Dec 31, 2009, patients were randomly assigned (1:1, by a computer-based minimisation procedure that balanced patients for age, cytogenetic risk, induction therapy, and donor type) to receive either reduced-intensity conditioning of four doses of 2 Gy of total-body irradiation and 150 mg/m(2) fludarabine or standard conditioning of six doses of 2 Gy of total-body irradiation and 120 mg/kg cyclophosphamide. All patients were given ciclosporin and methotrexate as prophylaxis against graft-versus-host disease. Neither investigators nor patients were blinded to study treatment. Our primary endpoint was the incidence of non-relapse mortality, analysed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00150878. FINDINGS: The trial was stopped early on Dec 31, 2009, because of slow accrual of patients. 99 patients were randomly assigned to receive reduced-intensity conditioning and 96 to receive standard conditioning. The incidence of non-relapse mortality did not differ between the reduced-intensity and standard conditioning groups (cumulative incidence at 3 years 13% [95% CI 6-21] vs 18% [10-26]; HR 0·62 [95% CI 0·30-1·31]). Relapse incidence (cumulative incidence 3 years 28% [95% CI 19-38] vs 26% [17-36]; HR 1·10 [95% CI 0·63-1·90]), disease-free survival (3 year disease-free survival 58% [95% CI 49-70] vs 56% [46-67]; HR 0·85 [95% CI 0·55-1·32]), and overall survival (3 year overall survival 61% [95% CI 50-74] vs 58% [47-70]; HR 0·77 [95% CI 0·48-1·25]) did not differ significantly between groups. Grade 3-4 of oral mucositis was less common in the reduced-intensity group than in the standard conditioning group (50 patients in the reduced-intensity conditioning group vs 73 patients in the standard conditioning group); the frequency of other side-effects such as graft-versus-host disease and increased concentrations of bilirubin and creatinine did not differ significantly between groups. INTERPRETATION: Reduced-intensity conditioning results in a similar incidence of non-relapse mortality and reduced toxic effects compared with standard conditioning without affecting survival outcomes, and thus could be preferentially used in patients younger than 60 years with acute myeloid leukaemia transplanted in first complete remission.

Small interfering RNA targeting HIF-1α reduces hypoxia-dependent transcription and radiosensitizes hypoxic HT 1080 human fibrosarcoma cells in vitro.

BACKGROUND: Hypoxia inducible factor-1 has been identified as a potential target to overcome hypoxia-induced radioresistance The aim of the present study was to investigate whether selective HIF-1 inhibition via small interfering RNA (siRNA) targeting hypoxia-inducible factor 1α (HIF-1α) affects hypoxia-induced radioresistance in HT 1080 human fibrosarcoma cells. MATERIAL AND METHODS: HIF-1α expression in HT 1080 human fibrosarcoma cells in vitro was silenced using HIF-1α siRNA sequence primers. Quantitative real-time polymerase chain reaction assay was performed to quantify the mRNA expression of HIF-1α. HIF-1α protein levels were studied by Western blotting at 20% (air) or after 12 hours at 0.1% O2 (hypoxia). Cells were assayed for clonogenic survival after irradiation with 2, 5, or 10 Gy, under normoxic or hypoxic conditions in the presence of HIF-1α-targeted or control siRNA sequences. A modified oxygen enhancement ratio (OER´) was calculated as the ratio of the doses to achieve the same survival at 0.1% O(2) as at ambient oxygen tensions. OER´ was obtained at cell survival levels of 50%, 37%, and 10%. RESULTS: HIF-1α-targeted siRNA enhanced radiation treatment efficacy under severely hypoxic conditions compared to tumor cells treated with scrambled control siRNA. OER was reduced on all survival levels after treatment with HIF-1α-targeted siRNA, suggesting that inhibition of HIF-1 activation by using HIF-1α-targeted siRNA increases radiosensitivity of hypoxic tumor cells in vitro. CONCLUSION: Inhibition of HIF-1 activation by using HIF-1α-targeted siRNA clearly acts synergistically with radiotherapy and increase radiosensitivity of hypoxic cells in vitro.

DSMM XI study: dose definition for intravenous cyclophosphamide in combination with bortezomib/dexamethasone for remission induction in patients with newly diagnosed myeloma.

A clinical trial was initiated to evaluate the recommended dose of cyclophosphamide in combination with bortezomib and dexamethasone as induction treatment before stem cell transplantation for younger patients with newly diagnosed multiple myeloma (MM). Thirty patients were treated with three 21-day cycles of bortezomib 1.3 mg/m(2) on days 1, 4, 8, and 11 plus dexamethasone 40 mg on the day of bortezomib injection and the day after plus cyclophosphamide at 900, 1,200, or 1,500 mg/m(2) on day 1. The maximum tolerated dose of cyclophosphamide was defined as 900 mg/m(2). At this dose level, 92% of patients achieved at least a partial response. The overall response rate [complete response (CR) plus partial response (PR)] across all dose levels was 77%, with a 10% CR rate. No patient experienced progressive disease. The most frequent adverse events were hematological and gastrointestinal toxicities as well as neuropathy. The results suggest that bortezomib in combination with cyclophosphamide at 900 mg/m(2) and dexamethasone is an effective induction treatment for patients with newly diagnosed MM that warrants further investigation.

Treatment of invasive fungal infections in cancer patients--recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO).

Invasive fungal infections are a main cause of morbidity and mortality in cancer patients undergoing intensive chemotherapy regimens. Early antifungal treatment is mandatory to improve survival. Today, a number of effective and better-tolerated but more expensive antifungal agents compared to the former gold standard amphotericin B deoxycholate are available. Clinical decision-making must consider results from numerous studies and published guidelines, as well as licensing status and cost pressure. New developments in antifungal prophylaxis improving survival rates result in a continuous need for actualization. The treatment options for invasive Candida infections include fluconazole, voriconazole, and amphotericin B and its lipid formulations, as well as echinocandins. Voriconazole, amphotericin B, amphotericin B lipid formulations, caspofungin, itraconazole, and posaconazole are available for the treatment of invasive aspergillosis. Additional procedures, such as surgical interventions, immunoregulatory therapy, and granulocyte transfusions, have to be considered. The Infectious Diseases Working Party of the German Society of Hematology and Oncology here presents its 2008 recommendations discussing the dos and do-nots, as well as the problems and possible solutions, of evidence criteria selection.