Efficacy and Tolerability of High- versus Low-dose Lenalidomide Maintenance Therapy of Multiple Myeloma after Autologous Blood Stem Cell Transplantation.

PURPOSE: For multiple myeloma, high-dose chemotherapy and autologous blood stem-cell transplantation (ASCT) followed by lenalidomide maintenance (LenMT) at 10-15 mg/day is considered standard of care. However, dose reductions due to side effects are common and median LenMT doses achieved over time may remain lower. Dose response during LenMT has never been investigated. PATIENTS AND METHODS: In a multicenter, randomized, open-label trial, patients with multiple myeloma after ASCT and high-dose lenalidomide consolidation therapy (CT) at 25 mg/day were randomized to receive LenMT at either 25 or 5 mg/day. Primary endpoint was progression-free survival (PFS). RESULTS: Ninety-four patients (median age, 58 years) were randomized to either arm, with 22% having International Staging System (ISS) stage 3 and 22% being in complete remission (CR). After median follow-up of 46.7 months, median doses of 14.5 and 5 mg/day were achieved in the two arms; 53% of dose reductions occurring during CT. In the high- and the low-dose arm, median PFS was 44.8 and 33.0 months (HR, 0.65; 95% CI, 0.44-0.97; P = 0.032), 36% and 23% of patients had stringent CR as best response (P = 0.08), and 4-year OS was 79% and 67% (P = 0.16), respectively. Hematologic toxicity, grade ≥3 neutropenia, and infections were initially more common with LenMT 25 mg, but decreased after dose adjustments. SPM incidence and quality-of-life (QoL) scores in both arms were similar. CONCLUSIONS: LenMT dose correlated with efficacy and toxicity. High rates of dose reductions during CT argue against a high starting dose. However, continuous up- and down-titration for each patient to the current maximum tolerated dose is prudent.

Relapse patterns and treatment strategies in patients receiving allogeneic hematopoietic stem cell transplantation for myeloid malignancies.

Allogeneic hematopoietic stem cell transplantation (aHSCT) cures a considerable number of patients with myeloid malignancies, but relapse is the most frequent cause of death. We retrospectively studied relapse rate, kinetics, treatment, and outcome after first aHSCT in 446 patients during a 13-year period. Relapse occurred in 167 patients after a median of 4.6 months (116 hematologic (HR), 38 molecular (MR), and 13 extramedullary relapses (XR)). Median survival after relapse was 8.4 months and 2-year overall survival was 25%. Regarding survival after relapse, type (MR/HR/XR) and timepoint of relapse ( 12 months), age ( 50), diagnosis (MDS/AML and sAML), and remission status at transplant (CR and untreated MDS vs. refractory disease) were relevant in univariate analyses, in multivariate analyses timepoint, and type of relapse, age, and diagnosis. One hundred fifty-six patients were treated, most frequently with hypomethylating agents (HMA, n = 109) or intensive chemotherapy (n = 12). Donor lymphocyte infusion (DLI) was administered to 99 patients. Second aHSCT was performed in three patients as first and in 21 as higher salvage treatment. A complete remission (CR) was achieved in 46 patients (30%). Among CR patients, 65% had received HMA and DLI. Median survival of patients achieving CR was 105 months and 2-year overall survival was 80%. We conclude that with HMA and DLI or second aHSCT, a substantial number of patients, who relapse after aHSCT, can re-achieve remission and long-term survival. Techniques to further improve the detection of minimal residual disease are urgently needed because early treatment of MR results in significantly better survival.

Six versus eight doses of rituximab in patients with aggressive B cell lymphoma receiving six cycles of CHOP: results from the "Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas" (PETAL) trial.

Standard first-line treatment of aggressive B cell lymphoma comprises six or eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus eight doses of rituximab (R). Whether adding two doses of rituximab to six cycles of R-CHOP is of therapeutic benefit has not been systematically investigated. The Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas (PETAL) trial investigated the ability of [18F]-fluorodesoxyglucose PET scanning to guide treatment in aggressive non-Hodgkin lymphomas. Patients with B cell lymphomas and a negative interim scan received six cycles of R-CHOP with or without two extra doses of rituximab. For reasons related to trial design, only about a third underwent randomization between the two options. Combining randomized and non-randomized patients enabled subgroup analyses for diffuse large B cell lymphoma (DLBCL; n = 544), primary mediastinal B cell lymphoma (PMBCL; n = 37), and follicular lymphoma (FL) grade 3 (n = 35). With a median follow-up of 52 months, increasing the number of rituximab administrations failed to improve outcome. A non-significant trend for improved event-free survival was seen in DLBCL high-risk patients, as defined by the International Prognostic Index, while inferior survival was observed in female patients below the age of 60 years. Long-term outcome in PMBCL was excellent. Differences between FL grade 3a and FL grade 3b were not apparent. The results were confirmed in a Cox proportional hazard regression model and a propensity score matching analysis. In conclusion, adding two doses of rituximab to six cycles of R-CHOP did not improve outcome in patients with aggressive B cell lymphomas and a fast metabolic treatment response.

Wilms' Tumor 1 Gene Expression Using a Standardized European LeukemiaNet-Certified Assay Compared to Other Methods for Detection of Minimal Residual Disease in Myelodysplastic Syndrome and Acute Myelogenous Leukemia after Allogeneic Blood Stem Cell Transplantation.

Overexpression of the Wilms' tumor 1 (WT1) gene is informative in many patients with acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS) and is measurable in peripheral blood (PB). Despite these advantages, WT1 has not broadly been established as a marker for minimal residual disease (MRD) monitoring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to limited patient numbers, differing sample sources, and nonstandardized in-house methods. To estimate the value of WT1 as an MRD marker, we serially quantified PB WT1 expression using a standardized European LeukemiaNet-certified assay in 59 patients with AML and MDS after allo-HSCT. We compared its performance with routine methods such as chimerism, XY-fluorescence in situ hybridization (FISH), disease-specific cytogenetic, and molecular analyses, which were accessible in 100%, 34%, 68%, and 37%, respectively. Twenty-four patients (41%) relapsed within a median of 126 days after allo-HSCT, and 20 of them showed at least 1 elevated WT1 value above the validated cutoff. The other 35 patients (59%) remained in complete remission, and only 1 patient had a transient increase in WT1 expression. This reflects a sensitivity of 83% and a specificity of 97% for WT1 and appears to be favorable compared with the sensitivities and specificities observed for chimerism (33% and 91%), XY-FISH (67% and 73%), cytogenetic (33% and 77%), and molecular (78% and 85%) analyses. Further supporting its predictive impact, elevated WT1 expression prompted an earlier BM biopsy and consecutively the diagnosis of relapse in 62% of patients. The results of this real-life experience imply that PB WT1 expression is measurable by a standardized assay and predicts imminent relapse after allo-HSCT with high sensitivity and specificity in most patients with AML and MDS.

Sorafenib and azacitidine as salvage therapy for relapse of FLT3-ITD mutated AML after allo-SCT.

OBJECTIVE: Patients with acute myeloid leukemia (AML) carrying FLT3-ITD mutations (FLT3-ITD+) who relapse after allogeneic transplantation (allo-SCT) have a very dismal prognosis with the currently available treatment options. METHODS: We treated eight patients with FLT3-ITD+ AML who had relapsed in median 91 d (range, 28-249) following allo-SCT with a combination of the multikinase inhibitor sorafenib and the DNA methyltransferase inhibitor azacitidine (Aza). RESULTS: Patients received a median of five cycles of Aza (range, 2-9) and sorafenib with a median daily dosage of 750 mg (range 400-800) for 129 d (range, 61-221). Six of eight patients received donor lymphocyte infusions (DLI) with a median number of two DLI per patient (range, 1-4). Following this treatment, four patients (50%) achieved a complete remission and three of them a complete molecular remission. Median duration of CR was 182 d (range, 158-406), and two patients remain in ongoing remission for 406 and 168 d. Median overall survival was 322 d (range, 108-574 d) with three patients being currently alive. CONCLUSION: Taken together, the combination of sorafenib, Aza, and DLI shows promising efficacy and deserves further evaluation in larger patient groups.

Lenalidomide consolidation treatment in patients with multiple myeloma suppresses myelopoieses but spares erythropoiesis.

New drugs for the treatment of multiple myeloma (MM) comprise immunomodulatory substances such as lenalidomide and related compounds. While lenalidomide has found its way into first-line treatment as well as into relapse therapy, little is known about lenalidomide effects on normal hematopoietic stem and progenitor cells (HSPCs). In this study, we investigated whether HSPCs are influenced by lenalidomide on a phenotypic, functional and gene expression level. For that purpose, samples from patients with MM were obtained who underwent equivalent first-line treatment including induction therapy, cytotoxic stem cell mobilization and high-dose melphalan therapy followed by autologous blood stem cell transplantation and a subsequent uniform lenalidomide consolidation treatment within a prospective clinical trial. We found that after six months of lenalidomide therapy, the number of CD34(+) HSPCs decreased. Additionally, lenalidomide affects the numerical composition of hematopoietic cells in the bone marrow while it does not affect long-term HSPC proliferation in vitro. We found a significant amplification of fetal hemoglobin (HbF) expression on a transcriptional level and can confirm a stimulated erythropoiesis on a phenotypic level. These effects were accompanied by silencing of the TGF-ß signaling pathway on the gene expression and protein level that is known to be amplified in active MM. However, these pleiotropic effects gave no evidence for mutagenic potential. In conclusion, lenalidomide does not exert long-term effects on proliferation of HSPCs but instead promotes erythropoiesis by shifting hemoglobin expression toward HbF and by silencing the TGF-ß signaling pathway.

Treatment of acute myeloid leukemia or myelodysplastic syndrome relapse after allogeneic stem cell transplantation with azacitidine and donor lymphocyte infusions--a retrospective multicenter analysis from the German Cooperative Transplant Study Group.

To expand the current knowledge about azacitidine (Aza) and donor lymphocyte infusions (DLI) as salvage therapy for relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and to identify predictors for response and survival, we retrospectively analyzed data of 154 patients with acute myeloid leukemia (AML, n = 124), myelodysplastic (MDS, n = 28), or myeloproliferative syndrome (n = 2). All patients received a median number of 4 courses of Aza (range, 4 to 14) and DLI were administered to 105 patients (68%; median number of DLI, 2; range, 1 to 7). Complete and partial remission rates were 27% and 6%, respectively, resulting in an overall response rate of 33%. Multivariate analysis identified molecular-only relapse (hazard ratio [HR], 9.4; 95% confidence interval [CI], 2.0 to 43.5; P = .004) and diagnosis of MDS (HR, 4.1; 95% CI, 1.4 to 12.2; P = .011) as predictors for complete remission. Overall survival (OS) at 2 years was 29% ± 4%. Molecular-only relapse (HR, .14; 95% CI, .03 to .59; P = .007), diagnosis of MDS (HR, .33; 95% CI, .16 to .67; P = .002), and bone marrow blasts <13% (HR, .54; 95% CI, .32 to .91; P = .021) were associated with better OS. Accordingly, 2-year OS rate was higher in MDS patients (66% ± 10%, P = .001) and correlated with disease burden in patients with AML. In summary, Aza and DLI is an effective and well-tolerated treatment option for patients with relapse after allo-HSCT, in particular those with MDS or AML and low disease burden. The latter finding emphasizes the importance of stringent disease monitoring and early intervention.

Treatment of poor-risk myelodysplastic syndromes and acute myeloid leukemia with a combination of 5-azacytidine and valproic acid.

5-azacytidine (AZA) has become standard treatment for patients with higher-risk myelodysplastic syndrome (MDS). Response rate is about 50% and response duration is limited. Histone deactylase (HDAC) inhibitors are attractive partners for epigenetic combination therapy. We treated 24 patients with AZA (100 mg/m(2), 5 days) plus valproate (VPA; continuous dosing, trough serum level 80-110 µg/ml). According to WHO classification, 5 patients had MDS, 2 had MDS/MPD, and 17 had acute myeloid leukemia (AML). Seven patients (29%) had previously received intensive chemotherapy, and five had previous HDAC inhibitor treatment. The overall response rate was 37% in the entire cohort but significantly higher (57%) in previously untreated patients, especially those with MDS (64%). Seven (29%) patients achieved CR (29%) and two PR (8%), respectively. Hematological CR was accompanied by complete cytogenetic remission according to conventional cytogenetics in all evaluable cases. Some patients also showed complete remission according to FISH on bone marrow mononuclear cells and CD34(+) peripheral blood cells, as well as by follow-up of somatic mitochondrial DNA mutations. Four additional patients achieved at least marrow remissions. Factors influencing response were AML (vs. MDS), marrow blast count, pretreatment, transfusion dependency, concomitant medication with hydroxyurea, and valproic acid (VPA) serum level. This trial is the first to assess the combination of AZA plus VPA without additional ATRA. A comparatively good CR rate, relatively short time to response, and the influence of VPA serum levels on response suggest that VPA provided substantial additional benefit. However, the importance of HDAC inhibitors in epigenetic combination therapy can only be proven by randomized trials.

Specific occlusion of murine and human tumor vasculature by VCAM-1-targeted recombinant fusion proteins.

BACKGROUND: The tumor vasculature is increasingly recognized as a target for cancer therapy. We developed and evaluated recombinant fusion proteins targeting the coagulation-inducing protein soluble tissue factor (sTF) to the luminal tumor endothelial antigen vascular cell adhesion molecule 1 (VCAM-1, CD106). METHODS: We generated fusion proteins consisting of sTF fused to antibody fragments directed against mouse or human VCAM-1 and characterized them in vitro by flow cytometry, surface plasmon resonance, and two-stage coagulation assays. Their therapeutic effects were tested in three human xenograft tumor models: L540rec Hodgkin lymphoma, Colo677 small-cell lung carcinoma, and Colo677/HDMEC small-cell lung carcinoma with human vasculature. Toxicity was analyzed by histologic examination of organs and determination of laboratory blood parameters. RESULTS: The fusion proteins bound VCAM-1 with nanomolar affinities and had the same coagulation activity as an sTF standard. Xenograft tumor-bearing mice treated with fusion protein (FP) alone or in combination with lipopolysaccharide (FP/L) or doxorubicin (FP/D) exhibited tumor-selective necrosis (L540rec tumors: 74% tumor necrosis [95% confidence interval {CI} = 55% to 93%] with FP/L versus 13% tumor necrosis [95% CI = 4% to 22%] with vehicle; Colo677 tumors: 26% [95% CI = 16% to 36%] with FP versus 8% [95% CI = 2% to 14%] with vehicle); tumor growth delay (Colo677/HDMEC: mean tumor weights after 3 days = 42 mg in FP-treated mice versus 71 mg in vehicle-treated mice, difference = 29 mg, 95% CI = 8 to 100, Mann-Whitney P = .008); and some tumor regressions (one of seven FP-treated Colo677 tumor-bearing mice and two of seven FP/D-treated mice). The fusion protein was well tolerated. CONCLUSIONS: Recombinant tissue factor-based fusion proteins directed against an intraluminal tumor endothelial cell marker induce tumor-selective intravascular coagulation, tumor tissue necrosis, and tumor growth delay.

Soluble tissue factor induces coagulation on tumor endothelial cells in vivo if coadministered with low-dose lipopolysaccharides.

OBJECTIVE: This study was performed to evaluate the mechanisms leading to tumor vessel occlusion by tissue factor-based drugs, which are used in vascular targeting approaches for the treatment of malignant tumors. METHODS AND RESULTS: The effects of nontargeted soluble tissue factor were evaluated in vitro and in vivo. Tumor-bearing mice were treated with (1) the extracellular portion of tissue factor (soluble tissue factor), (2) low nontoxic doses of lipopolysaccharides, or (3) a combination thereof. The combination treatment showed the best effects and resulted in selective thrombosis of tumor vessels. On the basis of our data from subsequent in vitro analyses, including surface plasmon resonance measurements and endothelial cell based coagulation assays, we propose a model on how soluble tissue factor, although lacking its membrane anchor, can promote selective tumor vessel occlusion. CONCLUSIONS: To our knowledge, this is the first report to describe the molecular mechanisms of coagulation induction by untargeted soluble tissue factor in vivo. Combination treatments including soluble tissue factor might represent an alternative vascular targeting approach for the treatment of malignant tumors.