In vivo effects of horse and rabbit antithymocyte globulin in patients with severe aplastic anemia

We recently reported that rabbit antithymocyte globulin was markedly inferior to horse antithymocyte globulin as a primary treatment for severe aplastic anemia. Here we expand on our findings in this unique cohort of patients. Rabbit antithymocyte globulin was detectable in plasma for longer periods than horse antithymocyte globulin; rabbit antithymocyte globulin in plasma retained functional capacity to bind to lymphocytes for up to 1 month, horse antithymocyte globulin for only about 2 weeks. In the first week after treatment there were much lower numbers of neutrophils in patients treated with rabbit antithymocyte globulin than in patients receiving horse antithymocyte globulin. Both antithymocyte globulins induced a “cytokine storm” in the first 2 days after administration. Compared with horse antithymocyte globulin, rabbit antithymocyte globulin was associated with higher levels of chemokine (C-C motif) ligand 4 during the first 3 weeks. Besides a much lower absolute number and a lower relative frequency of CD4⁺ T cells, rabbit antithymocyte globulin induced higher frequencies of CD4⁺CD38⁺, CD3⁺CD4⁻CD8⁻ T cells, and B cells than did horse antithymocyte globulin. Serum sickness occurred around 2 weeks after infusion of both types of antithymocyte globulin. Human anti-antithymocyte globulin antibodies, especially of the IgM subtype, correlated with serum sickness, which appeared concurrently with clearance of antithymocyte globulin in blood and with the production of cytokines. In conclusion, rabbit and horse antithymocyte globulins have very different pharmacokinetics and effects on neutrophils, lymphocyte subsets, and cytokine release. These differences may be related to their efficacy in suppressing the immune system and restoring hematopoiesis in bone marrow failure. Clinicaltrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT00260689","term_id":"NCT00260689"}}NCT00260689.     

Efficacy of rabbit anti-thymocyte globulin in severe aplastic anemia

Background

A combination of horse anti-thymocyte globulin and cyclosporine produces responses in 60–70% of patients with severe aplastic anemia. We performed a phase II study of rabbit anti-thymocyte globulin and cyclosporine as first-line therapy for severe aplastic anemia.

Design and Methods

Twenty patients with severe aplastic anemia treated with rabbit anti-thymocyte globulin were compared to 67 historical control cases with matched clinical characteristics treated with horse anti-thymocyte globulin.

Results

Response rates at 3, 6 and 12 months were similar for patients treated with rabbit anti-thymocyte globulin or horse anti-thymocyte globulin: 40% versus 55% (P=0.43), 45% versus 58% (P=0.44) and 50% versus 58% (P=0.61), respectively. No differences in early mortality rates or overall survival were observed. We then performed multivariable analyses of response at 6 months and overall survival and identified the presence of a paroxysmal nocturnal hemoglobinuria clone (P=0.01) and a pretreatment absolute reticulocyte count greater than 30×10⁹/L (P=0.007) as independent predictors of response and younger age (P=0.003), higher pretreatment absolute neutrophil (P=0.02) and absolute lymphocyte counts (P=0.03) as independent predictors of overall survival. None of the immunogenetic polymorphisms studied was predictive of response to immunosupressive therapy.

Conclusions

Despite reports suggesting differences in biological activity of different anti-thymocyte globulin preparations, rabbit and horse anti-thymocyte globulin appear to have a similar efficacy for up-front treatment of severe aplastic anemia. Clinicaltrial.gov: {"type":"clinical-trial","attrs":{"text":"NCT01231841","term_id":"NCT01231841"}}NCT01231841)     

Long-term outcome after immunosuppressive therapy with horse or rabbit antithymocyte globulin and cyclosporine for severe aplastic anemia in children

Some prospective studies showed that rabbit antithymocyte globulin was inferior to horse antithymocyte globulin as first-line therapy for patients with severe aplastic anemia. We retrospectively analyzed the clinical outcome of 455 children with severe aplastic anemia who received horse antithymocyte globulin (n=297) or rabbit antithymocyte globulin (n=158) combined with cyclosporine as first-line therapy between 1992 and 2010. The response rates were comparable between the horse and rabbit antithymocyte globulin groups at 3 months [46% (136/294) versus 42% (66/153), P=0.55] and 6 months [60% (178/292) versus 55% (87/143), P=1.0]. Using multivariate analysis, differences in antithymocyte globulin preparations were not associated with response rates. However, 2-year and 10-year overall survival rates in the horse antithymocyte globulin group were significantly better than those in the rabbit antithymocyte globulin group (2-year overall survival: 96% versus 87%, 10-year overall survival: 92% versus 84%, P=0.004). On the basis of multivariate analysis, use of rabbit antithymocyte globulin was a significant adverse factor for overall survival (hazard ratio = 3.56, 95% confidence interval, 1.53 – 8.28, P=0.003). Rabbit antithymocyte globulin caused more profound immunosuppression, which might be responsible for the higher incidence of severe infections. Considering that there are no studies showing the superiority of rabbit antithymocyte globulin over horse antithymocyte globulin, horse antithymocyte globulin should be recommended as a first-line therapy. However, our results justify the use of rabbit antithymocyte globulin as first-line therapy if horse antithymocyte globulin is not available.     

Results from a clofarabine-busulfan-containing,reduced-toxicity conditioning regimen prior to allogeneic stem cell transplantation: the phase 2 prospective CLORIC trial

We prospectively evaluated the safety and efficacy of a clofarabine, intravenous busulfan and antithymocyte globulin-based reduced-toxicity conditioning (CloB2A2) regimen before allogeneic stem cell transplantation. Thirty high-risk patients (median age: 59 years; acute myeloid leukemia n=11, acute lymphoblastic leukemia n=13; myelodysplastic syndrome n=5, bi-phenotypic leukemia n=1) were included in this phase 2 study. At time of their transplant, 20 and seven patients were in first and second complete remission, respectively, while three patients with myelodysplastic syndrome were responding to chemotherapy or who had not been previously treated. The CloB2A2 regimen consisted of clofarabine 30 mg/m²/day for 4 days, busulfan 3.2 mg/kg/day for 2 days and antithymocyte globulin 2.5 mg/kg/day for 2 days. The median follow-up was 23 months. Engraftment occurred in all patients. The 1-year overall survival, leukemia-free survival, relapse incidence and non-relapse mortality rates were 63±9%, 57±9%, 40±9%, and 3.3±3%, respectively. Comparing patients with acute myeloid leukemia/myelodysplastic syndrome versus those with acute lymphoblastic leukemia/bi-phenotypic leukemia, the 1-year overall and leukemia-free survival rates were 75±10% versus 50±13%, respectively (P=0.07) and 69±12% versus 43±13%, respectively (P=0.08), while the 1-year relapse incidence was 25±11% versus 57±14%, respectively (P=0.05). The CloB2A2 regimen prior to allogeneic stem cell transplantation is feasible, allowing for full engraftment and low toxicity. Disease control appears to be satisfactory, especially in patients with acute myeloid leukemia/myelodysplastic syndrome. The trial was registered at www.clinicaltrials.gov no. {"type":"clinical-trial","attrs":{"text":"NCT00863148","term_id":"NCT00863148"}}NCT00863148.     

Zoledronic acid as compared with observation in multiple myeloma patients at biochemical relapse: results of the randomized AZABACHE Spanish trial

This study analyzed the anti-myeloma effect of zoledronic acid monotherapy by investigating patients at the time of asymptomatic biochemical relapse. One hundred patients were randomized to receive either zoledronic acid (4 mg iv/4 weeks, 12 doses) (n=51) or not (n=49). Experimental and control groups were well balanced for disease and prognostic features. Zoledronic acid did not show an antitumor effect according to changes in M-component. However, there were fewer symptomatic progressions in the experimental group than in the control group (34 versus 41, respectively; P=0.05) resulting in a median time to symptoms of 16 versus 10 months (P=0.161). The median time to next therapy was also slightly longer for the treated group than the untreated, control group (13.4 versus 10.1 months), although the difference was not statistically significant (P=0.360). The pattern of relapses was different for treated versus control patients: progressive bone disease (8 versus 20), anemia (24 versus 18), renal dysfunction (1 versus 2), and plasmacytomas (1 versus 1, respectively). This concurred with fewer skeletal-related events in the treated group than in the control group (2 versus 14), with a projected 4-year event proportion of 6% versus 40% (P<0.001). In summary, zoledronic acid monotherapy does not show an antitumor effect on biochemical relapses in multiple myeloma, but does reduce the risk of progression with symptomatic bone disease and skeletal complications. This trial was registered in the ClinicalTrials.gov database with code {"type":"clinical-trial","attrs":{"text":"NCT01087008","term_id":"NCT01087008"}}NCT01087008     

A phase II multicenter rabbit anti-thymocyte globulin trial in patients with myelodysplastic syndromes identifying a novel model for response prediction

Immune dysregulation is a mechanism contributing to ineffective hematopoiesis in a subset of myelodysplastic syndrome patients. We report the first US multicenter non-randomized, phase II trial examining the efficacy of rabbit(r)-anti-thymocyte globulin using 2.5 mg/kg/day administered daily for 4 doses. The primary end point was hematologic response; secondary end points included duration of response, time to response, time to progression, and tolerance. Nine (33%;95% confidence interval=17%–54%) of the 27 patients treated experienced durable hematologic improvement in an intent-to-treat analysis with a median time to response and median response duration of 75 and 245 days, respectively. While younger age is the most significant factor favoring equine(e)-anti-thymocyte globulin response, treatment outcome on this study was independent of age (P=0.499). A shorter duration between diagnosis and treatment showed a positive trend (P=0.18), but International Prognostic Scoring System score (P=0.150), karyotype (P=0.319), and age-adjusted bone marrow cellularity (P=0.369) were not associated with response classification. Since activated T-lymphocytes are the primary cellular target of anti-thymocyte globulin, a T-cell expression profiling was conducted in a cohort of 38 patients consisting of rabbit and equine-antithymocyte globulin-treated patients. A model containing disease duration, CD8 terminal memory T cells and T-cell proliferation-associated-antigen expression predicted response with the greatest accuracy using a leave-one-out cross validation approach. This profile categorized patients independent of other covariates, including treatment type and age using a leave-one-out-cross-validation approach (75.7%). Therefore, rabbit-anti-thymocyte globulin has hematologic remitting activity in myelodysplastic syndrome and a T-cell activation profile has potential utility classifying those who are more likely to respond ({"type":"clinical-trial","attrs":{"text":"NCT00466843","term_id":"NCT00466843"}}NCT00466843 clinicaltrials.gov).     

Rituximab maintenance for patients with aggressive B-cell lymphoma in first remission: results of the randomized NHL13 trial

We investigated rituximab maintenance therapy in patients with diffuse large B-cell lymphoma (n=662) or follicular lymphoma grade 3b (n=21) in first complete remission. Patients were randomized to rituximab maintenance (n=338) or observation (n=345). At a median follow-up of 45 months, the event-free survival rate (the primary endpoint) at 3 years was 80.1% for rituximab maintenance versus 76.5% for observation. This difference was not statistically significant for the intent-to-treat population (likelihood ratio P=0.0670). The hazard ratio by treatment arm was 0.79 (95% confidence interval 0.57–1.08; P=0.1433). The secondary endpoint, progression-free survival was also not met for the whole statistical model (likelihood ratio P=0.3646). Of note, rituximab maintenance was superior to observation when treatment arms only were compared (hazard ratio: 0.62; 95% confidence interval 0.43–0.90; P=0.0120). Overall survival remained unchanged (92.0 versus 90.3%). In subgroup analysis male patients benefited from rituximab maintenance with regards to both event-free survival (84.1% versus 74.4%) (hazard ratio: 0.58; 95% confidence interval 0.36–0.94; P=0.0267) and progression-free survival (89.0% versus 77.6%) (hazard ratio: 0.45; 95% confidence interval 0.25–0.79; P=0.0058). Women had more grade 3/4 adverse events (P=0.0297) and infections (P=0.0341). Men with a low International Prognostic Index treated with rituximab had the best outcome. In summary, rituximab maintenance in first remission after R-CHOP-like treatment did not prolong event-free, progression-free or overall survival of patients with aggressive B-non-Hodgkin lymphoma. The significantly better outcome of men warrants further studies prior to the routine use of rituximab maintenance in men with low International Prognostic Index. This trial is registered under EUDRACT #2005-005187-90 and www.clinicaltrials.gov as #{"type":"clinical-trial","attrs":{"text":"NCT00400478","term_id":"NCT00400478"}}NCT00400478.     

Donor lymphocyte count and thymic activity predict lymphocyte recovery and outcomes after matched-sibling hematopoietic stem cell transplant

Delayed immune recovery is a characteristic feature of allogeneic hematopoietic stem cell transplantation in adult recipients. Although recipient thymic T-cell neogenesis contributes to T-cell regeneration after transplantation, thymic recovery in the transplant recipient decreases with increasing age, and is diminished by intensive preconditioning regimens and graft-versus-host disease. In adult recipients, most events that determine transplant success or failure occur during the period when the majority of circulating T cells is derived from the donor’s post thymic T-cell repertoire. As a result, the make-up of the donor lymphocyte compartment may strongly influence immune recovery and transplant outcomes. The aim of this study was to examine donor lymphocyte counts in a series of patients undergoing an allogeneic hematopoietic stem cell transplant to identify the potential contribution of donor regulatory and conventional T lymphocyte populations to immune recovery and transplant outcomes. We examined donor lymphocyte subset counts in relation to post-transplant lymphocyte recovery and transplant events in 220 consecutive myeloablative, T-cell-depleted, HLA-identical sibling hematopoietic stem cell transplant recipients with hematologic malignancies. In a multivariate analysis, absolute numbers of donor CD4⁺ recent thymic emigrants were associated with overall survival (P=0.032). The donors’ absolute lymphocyte count and thymic production of regulatory T cells were both associated with extensive chronic graft-versus-host disease (P=0.002 and P=0.022, respectively). In conclusion, these results identify donor immune characteristics that are associated with lymphocyte recovery, extensive chronic graft-versus-host disease, and survival in the recipient following allogeneic hematopoietic stem cell transplantation. The study reported here was performed using peripheral blood samples drawn from donors and patients enrolled in the ClinicalTrials.gov-registered trials {"type":"clinical-trial","attrs":{"text":"NCT00001623","term_id":"NCT00001623"}}NCT00001623, {"type":"clinical-trial","attrs":{"text":"NCT00001873","term_id":"NCT00001873"}}NCT00001873, {"type":"clinical-trial","attrs":{"text":"NCT00353860","term_id":"NCT00353860"}}NCT00353860, NCT00066300, {"type":"clinical-trial","attrs":{"text":"NCT00079391","term_id":"NCT00079391"}}NCT00079391, and NCT00398346.     

High cure rates in Burkitt lymphoma and leukemia: a Northern Italy Leukemia Group study of the German short intensive rituximab-chemotherapy program

We evaluate the long-term results of a prospective clinical study enrolling more than 100 adult patients with Burkitt lymphoma/leukemia. Depending on extent of disease, treatment consisted of six to eight rituximab infusions and four to six courses of intensive chemotherapy (attenuated in patients aged >55 years) with high-dose methotrexate, fractionated ifosfamide/cyclophosphamide, other drugs in rotation, and intrathecal chemoprophylaxis. One-hundred five patients were treated (median age 47 years, range 17–78 years); 48% had Burkitt leukemia, 25% were older than 60 years, 37% had an Eastern Cooperative Oncology Group performance score >1, and 14% were positive for human immunodeficiency virus. The complete response rate and 3-year overall and disease-free survival rates were 79%, 67% and 75%, respectively, ranging from 100% to 45% for survival (P=0.000) and from 100% to 60% for disease-free survival (P=0.01) in patients with low, intermediate and high adapted International Prognostic Index scores. In multivariate analysis, only age (≤ versus >60 years) and performance status (0–1 versus >1) retained prognostic significance, identifying three risk groups with overall and disease-free survival probabilities of 88% and 87.5%, 57% and 70.5%, 20% and 28.5% (P=0.0000 and P=0.0001), respectively. The relapse rate was only 7% in patients treated with an intercycle interval ≤25 days. This regimen achieved 100% curability in patients with low adapted International Prognostic Index scores (21% of total), and very close to 90% in patients aged ≤60 years with performance score 0–1 (48% of total). Rapid diagnosis of Burkitt lymphoma/leukemia with prompt referral of patients to prevent clinical deterioration, and careful supervision of treatment without chemotherapy delay can achieve outstanding therapeutic results. ClinicalTrials.gov ID, {"type":"clinical-trial","attrs":{"text":"NCT01290120","term_id":"NCT01290120"}}NCT01290120     

High CD45 surface expression determines relapse risk in children with precursor B-cell and T-cell acute lymphoblastic leukemia treated according to the ALL-BFM 2000 protocol

Further improvement of outcome in childhood acute lymphoblastic leukemia could be achieved by identifying additional high-risk patients who may benefit from intensified treatment. We earlier identified PTPRC (CD45) gene expression as a potential new stratification marker and now analyzed the prognostic relevance of CD45 protein expression. CD45 was measured by flow cytometry in 1065 patients treated according to the ALL-BFM-2000 protocol. The 75^th percentile was used as cut-off to distinguish a CD45-high from a CD45-low group. As mean CD45 expression was significantly higher in T-cell acute lymphoblastic leukemia than in B-cell-precursor acute lymphoblastic leukemia (P<0.0001), the analysis was performed separately in both groups. In B-cell-precursor acute lymphoblastic leukemia we observed a significant association of a high CD45 expression with older age, high initial white blood cell count, ETV6/RUNX1 negativity, absence of high hyperdiploidy (P<0.0001), MLL/AF4 positivity (P=0.002), BCR/ABL1 positivity (P=0.007), prednisone poor response (P=0.002) and minimal residual disease (P<0.0001). In T-cell acute lymphoblastic leukemia we observed a significant association with initial white blood cell count (P=0.0003), prednisone poor response (P=0.01), and minimal residual disease (P=0.02). Compared to CD45-low patients, CD45-high patients had a lower event-free survival rate (B-cell-precursor acute lymphoblastic leukemia: 72±3% versus 86±1%, P<0.0001; T-cell acute lymphoblastic leukemia: 60±8% versus 78±4%, P=0.02), which was mainly attributable to a higher cumulative relapse incidence (B-cell-precursor acute lymphoblastic leukemia: 22±3% versus 11±1%, P<0.0001; T-cell acute lymphoblastic leukemia: 31±8% versus 11±3%, P=0.003) and kept its significance in multivariate analysis considering sex, age, initial white blood cell count, and minimal residual disease in B-cell-precursor- and T-cell acute lymphoblastic leukemia, and additionally presence of ETV6/RUNX1, MLL/AF4 and BCR/ABL1 rearrangements in B-cell-precursor acute lymphoblastic leukemia (P=0.002 and P=0.025, respectively). Consideration of CD45 expression may serve as an additional stratification tool in BFM-based protocols. (ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT00430118","term_id":"NCT00430118"}}NCT00430118)     

Combination therapy of hydroxycarbamide with anagrelide in patients with essential thrombocythemia in the evaluation of Xagrid? efficacy and long-term safety study

Available information is limited regarding the use of cytoreductive combination therapy in high-risk patients with essential thrombocythemia. This analysis aims to evaluate the clinical relevance and patterns of cytoreductive combination treatment in European high-risk patients with essential thrombocythemia in the Evaluation of Xagrid^® Efficacy and Long-term Safety study. Of 3643 patients, 347 (9.5%) received combination therapy. Data were recorded at each 6-month update. Of 347 patients who received combination therapy, 304 (87.6%) received hydroxycarbamide + anagrelide. Monotherapies received before this combination were hydroxycarbamide (n=167, 54.9%) and anagrelide (n=123, 40.5%). Median weekly doses of hydroxycarbamide and anagrelide were: 7000 and 10.5 mg when used as prior monotherapy; 3500 and 7.0 mg when used as add-on treatment. Overall, median platelet counts were 581×10⁹/L and 411×10⁹/L before and after starting hydroxycarbamide + anagrelide, respectively. In patients with paired data (n=153), the number of patients with platelet counts less than 400×10⁹/L increased from 33 (21.6%) to 74 (48.4%; P<0.0001), and with platelet counts less than 600×10⁹/L, from 82 (53.6%) to 132 (86.3%; P<0.0001). Hydroxycarbamide + anagrelide was discontinued in 158 patients: 76 (48.1%) stopped hydroxycarbamide, 59 (37.3%) stopped anagrelide, 19 (12.0%) stopped both and 4 (2.5%) had another therapy added. The most frequent reasons for discontinuation were intolerance/side-effects, lack of efficacy, and therapeutic strategy. Combination therapy, usually hydroxycarbamide + anagrelide, is used in approximately 10% of all high-risk patients with essential thrombocythemia and may be a useful approach in treating patients for whom monotherapy is unsatisfactory. (Clinicaltrials.gov identifier:{"type":"clinical-trial","attrs":{"text":"NCT00567502","term_id":"NCT00567502"}}NCT00567502)     

High-dose imatinib induction followed by standard-dose maintenance in pre-treated chronic phase chronic myeloid leukemia patients �C final analysis of a randomized, multicenter, phase III trial

Background

Previous data suggest that the response of chronic myeloid leukemia cells to imatinib is dose-dependent. The potential benefit of initial dose intensification of imatinib in pre-treated patients with chronic phase chronic myeloid leukemia remains unknown.

Design and Methods

Two hundred and twenty-seven pre-treated patients with chronic myeloid leukemia in chronic phase were randomly assigned to continuous treatment with a standard dose of imatinib (400 mg/day; n=113) or to 6 months of high-dose induction with imatinib (800 mg/day) followed by a standard dose of imatinib as maintenance therapy (n=114).

Results

The rates of major and complete cytogenetic responses were significantly higher in the high-dose arm than in the standard-dose arm at both 3 and 6 months (major cytogenetic responses: 36.8% versus 21.2%, P=0.01 and 50.0% versus 34.5%, P=0.018; complete cytogenetic responses: 22.8% versus 6.2%, P<0.001 and 40.4% versus 16.8%, P<0.001) on the basis of an intention-to-treat analysis. At 12 months, the difference between treatment arms remained statistically significant for complete cytogenetic responses (40.4% versus 24.8%, P=0.012) but not for major cytogenetic responses (49.1% versus 44.2%, P=0.462). The rate of major molecular responses was also significantly better at 3 and 6 months in the high-dose arm (month 3: 14.9% versus 3.5%, P=0.003; month 6: 32.5% versus 8.8%, P<0.001). Overall and progression-free survival rates were comparable between arms, but event-free survival was significantly worse in the high-dose arm (P=0.014).

Conclusions

Standard-dose imatinib remains the standard of care for pre-treated patients with chronic phase chronic myeloid leukemia (Clinicaltrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT00327262","term_id":"NCT00327262"}}NCT00327262).Key words: CML, chronic phase, pre-treated, imatinib, high-dose, phase III study     

Rituximab plus gemcitabine and oxaliplatin in patients with refractory/relapsed diffuse large B-cell lymphoma who are not candidates for high-dose therapy. A phase II Lymphoma Study Association trial

A previous pilot study with rituximab, gemcitabine and oxaliplatin showed promising activity in patients with refractory/relapsed B-cell lymphoma. We, therefore, conducted a phase II study to determine whether these results could be reproduced in a multi-institutional setting. This phase II study included 49 patients with refractory (n=6) or relapsing (n=43) diffuse large B-cell lymphoma. The median age of the patients was 69 years. Prior treatment included rituximab in 31 (63%) and autologous transplantation in 17 (35%) patients. International Prognostic Index at enrollment was >2 in 34 patients (71%). The primary endpoint was overall response rate after four cycles of treatment. Patients were planned to receive eight cycles if they reached at least partial remission after four cycles. After four cycles 21 patients (44%) were in complete remission and 8 (17%) in partial remission, resulting in an overall response rate of 61%. Factors significantly affecting overall response rate were early (<1 year) progression/relapse (18% versus 54%; P=0.001) and prior exposure to rituximab (23% versus 65%; P=0.004). Five-year progression-free and overall survival rates were 12.8% and 13.9%, respectively. Rituximab, gemcitabine and oxaliplatin were well tolerated with grade 3–4 infectious episodes in 22% of the cycles. These results are the first confirmation from a multicenter study that rituximab, gemcitabine and oxaliplatin provide a consistent response rate in patients with refractory/relapsed diffuse large B-cell lymphoma. This therapy can now be considered as a platform for new combinations with targeted treatments. This trial was registered at clinicaltrial.gov under #{"type":"clinical-trial","attrs":{"text":"NCT00169195","term_id":"NCT00169195"}}NCT00169195.     

A phase II trial of sequential ribonucleotide reductase inhibition in aggressive myeloproliferative neoplasms

Myeloproliferative neoplasms are a varied group of disorders that can have prolonged chronic phases, but eventually accelerate and can transform into a secondary acute myeloid leukemia that is ultimately fatal. Triapine is a novel inhibitor of the M2 subunit of ribonucleotide reductase. Sequential inhibition of ribonucleotide reductase with triapine and an M1 ribonucleotide reductase inhibitor (fludarabine) was noted to be safe, and led to a 29% complete plus partial response rate in myeloproliferative neoplasms. This article reports the findings of a phase II trial of triapine (105 mg/m²/day) followed by fludarabine (30 mg/m²/day) daily for 5 consecutive days in 37 patients with accelerated myeloproliferative neoplasms and secondary acute myeloid leukemia. The overall response rate was 49% (18/37), with a complete remission rate of 24% (9/37). Overall response rates and complete remissions were seen in all disease subsets, including secondary acute myeloid leukemia, in which the overall response rate and complete remission rate were 48% and 33%, respectively. All patients with known JAK2 V617F mutations (6/6) responded. The median overall survival of the entire cohort was 6.9 months, with a median overall survival of both overall responders and complete responders of 10.6 months. These data further demonstrate the promise of sequential inhibition of ribonucleotide reductase in patients with accelerated myeloproliferative neoplasms and secondary acute myeloid leukemia. This study was registered with clinicaltrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT00381550","term_id":"NCT00381550"}}NCT00381550).     

Hematopoietic recovery and immune reconstitution after axicabtagene ciloleucel in patients with large B-cell lymphoma

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 may be associated with long-term adverse effects such as cytopenia and immune deficiency. In order to characterize these late events, we analyzed 31 patients with relapsed or refractory large B-cell lymphoma treated with axicabtagene ciloleucel at our institution on two clinical trials, ZUMA-1 (clinicaltrials gov. Identifier: {"type":"clinical-trial","attrs":{"text":"NCT02348216","term_id":"NCT02348216"}}NCT02348216) and ZUMA-9 (clinicaltrials gov. Identifier: {"type":"clinical-trial","attrs":{"text":"NCT03153462","term_id":"NCT03153462"}}NCT03153462). Complete blood counts, lymphocyte subsets, and immunoglobulin levels were measured serially until month 24 or progression. Fifteen (48%) patients had grade 3-4 cytopenia, including anemia (five, 16%), neutropenia (nine, 29%), or thrombocytopenia (13, 42%) at day 30. Cytopenia at day 30 was not significantly associated with later diagnosis of myelodysplasia. Among patients with ongoing remission, grade 3-4 cytopenia was observed in one of nine (11%) at 2 years. While peripheral CD8⁺ T cells recovered early, CD4⁺ T-cell recovery was delayed with a count of <200/mL in three of nine (33%) patients at 1 year and two of seven (29%) at 2 years. Immunoglobulin G levels normalized in five of nine (56%) patients at 2 years. Thirteen (42%) patients developed grade 3-4 infectious complications, including herpes zoster and Pneumocystis jiroveci pneumonia. These results suggest the need for prolonged monitoring and prophylaxis against opportunistic infections in these patients, to improve the longterm safety of axicabtagene ciloleucel therapy.     

Role of antithymocyte globulin in matched sibling donor peripheral blood stem cell transplantation for hematologic malignancies

Background:High incidence of chronic graft-versus-host disease (GVHD) has been a major drawback of matched sibling donor peripheral blood stem cell transplantation (MSD -PBSCT). This study aimed to investigate the safety and efficacy of antithymocyte globulin (ATG) as a standardized part of GVHD prophylaxis in patients receiving MSD -PBSCT.Methods:A total of 72 patients with hematological malignancies receiving MSD -PBSCT who displayed similar baseline characteristics were either given rabbit ATG ( n = 42) or no ATG (n = 30), in addition to cyclosporine, methotrexate, and mycophenolate mofetil as a standard GVHD prophylaxis regimen. Either patients or donors aged ≥40 years were included in the study. Thymoglobulin was administered at a daily dose of 1.5 mg/kg on day −5 and 3.5 mg/kg on day −4 prior to transplant (the total dose was 5 mg/kg)Results:After a median follow-up of 874 days, the 3-year cumulative incidence of chronic GVHD (cGVHD) was 37.3% in the ATG group and 52.1% in the non -ATG group. The 3-year overall and disease-free survival probability were 71.0% and 62.0% (ATG versus non -ATG, P = .262) and 66.7% and 58.4% (ATG versus non -ATG, P = .334). No difference was found in the 2-year cumulative incidence of nonrelapse mortality and relapse between the ATG and non -ATG groups. This significant reduction in the incidence of cGVHD without increased relapse risk and nonrelapse mortality led to a 3-year GVHD-free, relapse-free survival probability of 66.7% and 40.0% in the ATG and non-ATG groups, respectively.Conclusions:These data suggested that rabbit antithymocyte globulin in the current protocol for GVHD prophylaxis was well tolerable and efficacious.The clinical trial was registered on January 1, 2016 (ClinicalTrials.gov Identifier {"type":"clinical-trial","attrs":{"text":"NCT02677181","term_id":"NCT02677181"}}NCT02677181). https://clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT02677181","term_id":"NCT02677181"}}NCT02677181.     

The genotype of MLH1 identifies a subgroup of follicular lymphoma patients who do not benefit from doxorubicin: FIL-FOLL study

Though most follicular lymphoma biomarkers rely on tumor features, the host genetic background may also be relevant for outcome. Here we aimed at verifying the contribution of candidate polymorphisms of FCγ receptor, DNA repair and detoxification genes to prognostic stratification of follicular lymphoma treated with immunochemotherapy. The study was based on 428 patients enrolled in the FOLL05 prospective trial that compared three standard-of-care regimens (rituximab-cyclophosphamide-vincristine-prednisone versus rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone versus rituximab-fludarabine-mitoxantrone) for the first line therapy of advanced follicular lymphoma. Polymorphisms were genotyped on peripheral blood DNA samples. The primary endpoint was time to treatment failure. Polymorphisms of FCGR2A and FCGR3A, which have been suggested to influence the activity of rituximab as a single agent, did not affect time to treatment failure in the pooled analysis of the three FOLL05 treatment arms that combined rituximab with chemotherapy (P=0.742, P=0.252, respectively). These results were consistent even when the analysis was conducted by intention to treat, indicating that different chemotherapy regimens and loads did not interact differentially with the FCGR2A and FCGR3A genotypes. The genotype of MLH1, which regulates the genotoxic effect of doxorubicin, significantly affected time to treatment failure in patients in the rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone arm (P=0.001; q<0.1), but not in arms in which patients did not receive doxorubicin (i.e., the rituximab-cyclophosphamide-vincristine-prednisone and rituximab-fludarabine-mitoxantrone arms). The impact of MLH1 on time to treatment failure was independent after adjusting for the Follicular Lymphoma International Prognostic Index and other potential confounding variables by multivariate analysis. These data indicate that MLH1 genotype is a predictor of failure to benefit from rituximab-cyclophosphamide-doxorubicin-vincristine-prednisone treatment in advanced follicular lymphoma and confirm that FCGR2A and FCGR3A polymorphisms have no impact when follicular lymphoma is treated with rituximab plus chemotherapy (clinicaltrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT00774826","term_id":"NCT00774826"}}NCT00774826).     

High-dose imatinib improves cytogenetic and molecular remissions in patients with pretreated Philadelphia-positive, BCR-ABL-positive chronic phase chronic myeloid leukemia: first results from the randomized CELSG phase III CML 11 ��ISTAHIT�� study

Background

Imatinib 400 mg/day is the standard treatment for patients with chronic phase chronic myeloid leukemia. Recent reports suggested higher and more rapid cytogenetic and molecular responses with higher doses of imatinib.

Design and Methods

In this prospective international, multicenter phase III study, 227 patients with pre-treated Philadelphia chromosome-positive, BCR-ABL-positive chronic myeloid leukemia were randomized to a standard-dose imatinib arm (400 mg/day) or a high-dose imatinib arm (800 mg/day for 6 months followed by 400 mg/day as maintenance therapy). In this planned interim analysis hematologic, cytogenetic and molecular responses as well as toxicity were evaluated.

Results

Compared to the standard-dose, high-dose imatinib led to higher rates of major and complete cytogenetic responses at both 3 months (major: 21% versus 37%, P=0.01; complete: 6% versus 25%, P<0.001) and 6 months (major: 34% versus 54%, P=0.009; complete: 20% versus 44%, P<0.001). This was paralleled by a significantly higher major molecular response rate at 6 months in the high-dose imatinib arm (11.8% versus 30.4%; P=0.003). At 12 months, the rates of major cytogenetic response (the primary end-point) were comparable between the two arms (57% versus 59%). In contrast to non-hematologic toxicities, grade 3/4 hematologic toxicities were more common in the high-dose arm. Cumulative complete cytogenetic response rates were higher in patients without dose reduction in the high-dose arm (61%) than in the patients with no dose reduction in the standard-dose arm (36%) (P=0.014).

Conclusions

This is the first randomized phase III trial in patients with pre-treated chronic phase chronic myeloid leukemia demonstrating improvements in major cytogenetic response, complete cytogentic response and major molecular response rates with high-dose imatinib therapy (ClinicalTrials.gov Identifier: {"type":"clinical-trial","attrs":{"text":"NCT00327262","term_id":"NCT00327262"}}NCT00327262).     

Isatuximab plus carfilzomib and dexamethasone versus carfilzomib and dexamethasone in relapsed multiple myeloma patients with renal impairment: IKEMA subgroup analysis

Renal impairment (RI) is common in patients with multiple myeloma (MM) and new therapies that can improve renal function are needed. The phase III IKEMA study (clinicaltrials gov. Identifier: {"type":"clinical-trial","attrs":{"text":"NCT03275285","term_id":"NCT03275285"}}NCT03275285) investigated isatuximab (Isa) with carfilzomib and dexamethasone (Kd) versus Kd in relapsed MM. This subgroup analysis examined results from patients with RI, defined as estimated glomerular filtration rate <60 mL/min/1.73 m². Addition of Isa prolonged progression-free survival (PFS) in patients with RI (hazard ratio: 0.27; 95% confidence interval [CI]: 0.11–0.66; median PFS not reached for Isa-Kd versus 13.4 months for Kd [20.8-month follow-up]). Complete renal responses occurred more frequently with Isa-Kd (52.0%) versus Kd (30.8%) and were durable in 32.0% versus 7.7% of patients, respectively. Treatment exposure was longer with Isa-Kd, with median number of started cycles and median duration of exposure of 20 versus 9 cycles and 81.0 versus 35.7 weeks for Isa-Kd versus Kd, respectively. Among patients with RI, the incidence of patients with grade ≥3 treatment-emergent adverse events was similar between the two arms (79.1% in Isa-Kd vs. 77.8% in Kd). In summary, the addition of Isa to Kd improved clinical outcomes with a manageable safety profile in patients with RI, consistent with the benefit observed in the overall IKEMA study population.