Dose individualization of intravenous busulfan in pediatric patients undergoing bone marrow transplantation: impact and in vitro evaluation of infusion lag-time.

OBJECTIVES: To apply therapeutic drug monitoring and dose-individualization of intravenous Busulfan to paediatric patients and evaluate the impact of syringe-pump induced Busulfan infusion lag-time after in vitro estimation. METHODS: 76 children and adolescents were administered 2 h intravenous Busulfan infusion every 6 h (16 doses). Busulfan plasma levels, withdrawn by an optimized sampling scheme and measured by a validated HPLC-PDA method, were used to estimate basic PK parameters, AUC, Cmax, kel, t1/2, applying Non-Compartmental Analysis. In vivo infusion lag-time was simulated in vitro and used to evaluate its impact on AUC estimation. KEY FINDINGS: Mean (%CV) Busulfan AUC, Cmax, clearance and t1/2 for pediatric population were found 962.3 µm × min (33.1), 0.95 mg/L (41.4), 0.27 L/h/kg (33.3), 2.2 h (27.8), respectively. TDM applied to 76 children revealed 6 (7.9%) being above and 25 (32.9%) below therapeutic-range (AUC: 900-1350 µm × min). After dose correction, all patients were measured below toxic levels (AUC < 1500 µm × min), no patient below 900 µm × min. Incorporation of infusion lag-time revealed lower AUCs with 17.1% more patients and 23.1% more younger patients, with body weight <16 kg, being below the therapeutic-range. CONCLUSIONS: TDM, applied successfully to 76 children, confirmed the need for Busulfan dose-individualization in paediatric patients. Infusion lag-time was proved clinically significant for younger, low body-weight patients and those close to the lower therapeutic-range limit.

Low-dose alemtuzumab for GvHD prevention followed by prophylactic donor lymphocyte infusions in high-risk leukemia.

We analyzed the use of low-dose alemtuzumab in a cohort of 158 consecutive patients who underwent allogeneic PBSC transplantation. Patients with high-risk acute leukemia were prospectively screened for prophylactic donor lymphocyte infusion (pDLI). Lymphocytes were administered repeatedly at low and non-escalating doses (0.5-1 × 106/kg). Low-dose alemtuzumab was effective in prevention of acute GvHD after sibling or well-matched unrelated transplantation, whereas a more intensified approach was needed after mismatched transplantation. The cumulative incidence of chronic moderate/severe chronic-GvHD (cGvHD) was 15.6%. In total, 63 high-risk leukemia patients were eligible for pDLI. Only 1 out of the 39 pDLI recipients relapsed as compared with 7 out of the 24 recipients, who did not receive pDLI due to logistical hurdles. In multivariate analysis, the use of adjuvant lymphocyte therapy was significantly associated with reduced incidence of relapse and improved disease-free survival. In summary, low-dose alemtuzumab confers to a low cGvHD incidence and the administration of pDLIs in this context is very likely to reduce relapse risk in high risk leukemia patients. This is translated in an estimated 5-year probability of GvHD-free and relapse-free survival of 43.3% for the 136 leukemia patients.

Relapse of AML after hematopoietic stem cell transplantation: methods of monitoring and preventive strategies. A review from the ALWP of the EBMT.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) remains the therapeutic method with the most potent anti-leukemic activity mediated by the graft versus leukemia effect. However, a significant proportion of patients with AML will relapse after allo-SCT. The prognosis for these patients is dismal, with a probability of long-term survival of <20%. Data from previous studies have shown that disease-specific prognostic factors, are in general, the same as those in patients treated with conventional chemotherapy. Minimal residual disease (MRD) and chimerism status monitoring after allo-SCT may be used as predictors of impending relapse and should be part of routine follow-up for AML patients. A significant number of studies have shown that pre-emptive administration of donor lymphocyte infusion (DLI) based on MRD and chimerism monitoring, as well as prophylactic DLI in AML patients at high risk of relapse is effective in preventing relapse. In this review, we discuss strategies for the identification of high-risk patients, review current therapeutic options and provide our recommendations for the management of post-SCT AML.

Brentuximab vedotin in combination with or without donor lymphocyte infusion for patients with Hodgkin lymphoma after allogeneic stem cell transplantation.

In our study, we evaluated the safety and efficacy of Brentuximab vedotin (BV) with or without the addition of donor lymphocyte infusion (DLI) after allogeneic stem cell transplantation (allo-SCT) in 16 patients with advanced Hodgkin lymphoma (HL). Thirteen patients with relapsed HL after allo-SCT received BV as treatment for active disease. Three patients without progression of HL after allo-SCT received BV as consolidation. Twelve patients had been previously exposed to BV for treatment of relapse after autologous-SCT. Ten out of 16 patients received BV in combination with DLI. Among the 13 patients treated for active disease, CR and PR was observed in 7 and 2 patients, respectively. With a median follow-up of 13 months, 13 out of 16 patients are alive, while 3 died because of disease progression. The median PFS was 6 months. DLI-associated GVHD occurred in seven patients. Five patients with GVHD required immunosuppression, and in all cases, GVHD resolved after a short course of low dose steroids, implying that an anti-GVHD modulating effect could be induced by the concurrent administration of BV. No serious adverse event was observed in any of the patients.

Treatment of Experimental Candida Sepsis with a Janus Kinase Inhibitor Controls Inflammation and Prolongs Survival.

Janus kinases (JAK) are intracellular tyrosine kinases that transduce cytokine-mediated signals to the nucleus, promoting gene expression. Cytokines play a major role in microbial sepsis, which is often associated with uncontrolled inflammation leading to death. JAK inhibitors have been used for the treatment of several autoimmune diseases by modulating immune response, but they have never been tested against microbial sepsis. Ruxolitinib is a small-molecule inhibitor of JAK1/2 proteins, which are involved in the downstream signaling pathway of the vast majority of proinflammatory and anti-inflammatory cytokines. We therefore studied the effect of ruxolitinib in a mouse model of sepsis due to Candida albicans. When ruxolitinib therapy (50 mg/kg [of body weight]/day) was started 1 day before infection, the median survival time was reduced by 3 days, the fungal loads in all organs were higher, the inflammation was significantly less, and serum tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) levels and IL-10/TNF-α ratios were higher than in controls. When ruxolitinib therapy (50 to 1.5 mg/kg/day) was started 1 day after infection, an inverted-U relationship was found, with 6.25 mg/kg/day prolonging median survival time by 6 days, resulting in similar fungal loads, less inflammation, and similar cytokine levels but higher IL-10/TNF-α ratios than the controls. The optimal dose of ruxolitinib controlled infection and prolonged survival with less inflammation than in control animals. Administration of JAK inhibitors may be a promising therapeutic adjunct that needs further investigation.

Incidence and risk factors for moderate-to-severe veno-occlusive disease of the liver after allogeneic stem cell transplantation using a reduced intensity conditioning regimen.

The incidence and outcome of moderate-to-severe veno-occlusive (VOD) disease was analyzed in 271 consecutive patients with hematological malignancies who underwent allogeneic SCT (allo-SCT) using the same reduced intensity regimen (RIC). RIC consisted of fludarabine, BU and antithymocyte globulin (ATG). Twenty-four out of 271 patients (8.8%) developed VOD, which was severe in only 4 (1.4%) out of 24 cases. All four patients with severe VOD finally succumbed to their disease. In multivariate analysis, i.v. administration of BU was associated with significant reduced incidence of VOD as compared with per os administration. In conclusion, VOD remains a serious complication of allo-SCT using RIC regimens containing BU. Although the incidence of severe VOD is very low, the overall mortality rate in the group of patients with severe VOD remains extremely high and therefore novel treatment approaches are needed.

Specific abnormalities versus number of abnormalities and cytogenetic scoring systems for outcome prediction after allogeneic hematopoietic SCT for myelodysplastic syndromes.

Newer cytogenetic scoring systems for myelodysplastic syndromes (MDSs), like cytogenetic stratification of the revised international prognostic scoring system (IPSS-R) or monosomal karyotype, may also improve outcome prediction after hematopoietic SCT (HCT). We compared the prognostic value of specific cytogenetic abnormalities, IPSS-R karyotype and monosomal karyotype for HCT outcome in 98 patients with MDS and AML post MDS. Higher-risk IPSS-R karyotype, 3q21q26 and transformation to AML before HCT were associated with increased cumulative incidence of relapse (CIR), whereas OS was adversely influenced by del 5q/-5, abnormalities of chromosomes 11 and 17 and cytogenetic IPSS-R very poor category. Karyotype with ⩽2 abnormalities and no abnormalities of chromosomes 3, 5, 7, 11 and 17 was an independent prognostic factor of lower CIR (hazard ratio (HR)=0.2, P=0.01) and longer OS (HR=0.5, P=0.03). In conclusion, some specific cytogenetic abnormalities and high cytogenetic complexity, as reflected by IPSS-R very poor karyotype, rather than monosomal karyotype, were associated with higher CIR and shorter OS after HCT. Conversely, results were encouraging in patients lacking those abnormalities, who may be very good candidates for HCT.

Radiotherapy for Hodgkin's lymphoma: too hard to die?

The treatment of Hodgkin's lymphoma (HL) is associated with significant toxicity. The objective of high quality management is to keep the concept of combined modality, while trying to decrease the radiation dose, to diminish to a great extent the irradiated volume and at the same time to reduce the number of chemotherapy courses, introducing the so-called optimisation. New directives should be followed to obtain more effective treatments of HL. Shorter cycles of chemotherapy and the utilization of modern techniques in radiotherapy (RT) constitute fundamental steps to achieve this objective. Analysis of randomized studies supports the inclusion of reduced-field and dose of RT in the radiotherapeutic treatment options for HL. RT is an integral part of the combined-modality therapy (CMT) of HL.

The number of infused CD34+ cells does not influence the incidence of GVHD or the outcome of allogeneic PBSC transplantation, using reduced-intensity conditioning and antithymocyte globulin.

The influence of graft composition on the outcome of reduced-intensity (RIC) allogeneic PBSC transplantation (allo-PBSC) remains controversial. In this study, we analyzed the impact of CD34+ cell dose on the incidence of GVHD, and on the outcome after allo-PBSC, in 103 patients with hematological malignancies, using a uniform RIC regimen. The following variables were included in statistical analysis: (1) number of C34+ cells, (2) high-risk vs low-risk disease status, (3) matched related vs matched unrelated donor, (4) female donor to male recipient vs any other combination, (5) age of recipient (above vs below the median). Univariate and multivariate analysis did not reveal any association between CD34+ cell dose and acute grade-2 to grade-4, cGVHD, non-relapse mortality (NRM), relapse rate (RR) and OS. High-risk disease status was the only variable independently associated with increased NRM (P=0.001), increased RR (P=0.012) and decreased OS (P<0.001). The same results were obtained when analysis was restricted to a subgroup of 55 patients with myeloid neoplasms. The influence of graft composition on the outcome of RIC allo-PBSC should be further investigated via well-controlled randomized prospective studies.

Alefacept treatment for refractory chronic extensive GVHD.

Alefacept (Amevive) is an immunosuppressive dimeric fusion protein that is used for psoriasis control. We recently showed its effect in acute steroid-resistant/dependent GVHD. In this study, we describe the effect of alefacept treatment on chronic extensive GVHD (cGVHD). Twelve patients were included in this study; of these 8 (9 of 13 episodes) showed response. The median time to initial response was 2.25 weeks and the response was marked (n=3), moderate (n=2) or minimal (n=4). In two responding patients, the response was only temporary. Complications that appeared during treatment included infection, pericarditis and squamous cell carcinoma of the lip. All these events may be related to other drugs given simultaneously. With a 30-month median follow-up, 6 of 12 patients are alive, with all but one with stable or improved cGVHD. Six patients died because of GVHD progression, whereas none of the patients experienced relapse of the disease for which the transplantation was done. As reported earlier in psoriatic patients treated with alefacept, we found a consistent increase in the percentage of naive T cells as a consequence of treatment. In conclusion, alefacept is effective for the treatment of cGVHD, and dose and time intervals of treatment should be explored further.

Keratinocyte growth factor is effective in the prevention of intestinal mucositis in patients with hematological malignancies treated with high-dose chemotherapy and autologous hematopoietic SCT: a video-capsule endoscopy study.

Oral and/or intestinal mucositis is a severe complication of hematopoietic SCT. Keratinocyte growth factor (KGF) has proven activity in the prevention of oral mucositis. We examined the efficacy of KGF in the prevention of intestinal mucositis. From January 2006 until December 2007, 35 consecutive patients underwent autologous SCT (auto-SCT) in our institution. A total of 15 consecutive patients who underwent auto-SCT from March 2007 to December 2007 received KGF for the prevention of mucositis and were included in the study group A, whereas 20 consecutive patients treated from January 2006 to March 2007, were included in the historical control group B. Oral and intestinal mucositis were significantly less severe in group A (P=0.002 and P<0.001, respectively). These results were confirmed with the use of video-capsule endoscopy. Patients in group A had a significantly lower incidence of neutropenic fever (P=0.026). Severe intestinal mucositis was significantly associated with a higher incidence of documented infections too (P=0.019). KGF is effective in the prevention of intestinal mucositis in patients undergoing auto-SCT. Patients with severe intestinal mucositis run a higher risk to develop infections.

Peliosis hepatis following treatment with androgen-steroids in patients with bone marrow failure syndromes.

Androgens widely used in the treatment of bone marrow failure syndromes can in rare cases cause hepatic peliosis, a pathological entity characterized by multiple blood-filled cavities in the liver parenchyma. Bone marrow failure syndromes per se are associated with a low coagulation status, which is further magnified by bone marrow transplantation for aplastic anaemia due to deep thrombocytopenia. Both these conditions can cause bleeding; their combination is especially dangerous. We describe two cases of aplastic anaemia due to paroxysmal nocturnal hemoglobinuria and Fanconi syndrome, in which patients developed peliosis hepatis after prolonged treatment with androgens. One patient developed severe subcapsular bleeding, successfully treated with catheterization of the right hepatic artery and embolization of the bleeding site. The second patient bridged over deep post-transplant aplasia with high frequency platelet transfusions, and demonstrated an uncomplicated post-BMT course. We suggest avoiding or interrupting treatment with androgens in patients preparing for BMT.

Allogeneic stem cell transplantation from matched related and unrelated donors in thalassemia major patients using a reduced toxicity fludarabine-based regimen.

The only radical cure for thalassemia major patients today is the replacement of the defective hematopoietic system by allogeneic stem cell transplantation (allo-SCT). The major obstacles for the application of allo-SCT even from matched family members have been the transplant-related morbidity and mortality and graft failure that is usually associated with the recurrence of the thalassemia hematopoiesis. The outcome of allo-SCT from HLA-identical family donors is largely dependent on the age of the recipient as well as on pretransplant parameters reflecting the degree of organ damage from iron overload. In this study we report our experience of allo-SCT from matched related and unrelated donors, using a reduced toxicity conditioning consisting of fludarabine, busulfan or more recently busulfex and antithymocyte globulin, in a cohort of 20 patients with thalassemia major. The regimen-related toxicity was minimal, while the incidence of acute grade II-IV and chronic GVHD was 25 and 25%, respectively. With a median follow-up period of 39 months (range: 5-112 months) the overall survival was 100%, while thalassemia-free survival was 80%. Although the results of our study look promising, larger cohorts of patients and prospective clinical trials are required to confirm the benefits of our approach as a possible better alternative to the existing protocols.

Allogeneic hematopoietic stem cell transplantation in the elderly.

The development of reduced intensity or non-myeloablative conditioning (NST) in preparation for allogeneic stem cell transplantation (SCT) revolutionized the field and led to reconsideration of the dogma of upper age limit that was set up by the transplant centers as an eligibility parameter. Analysis of the literature data showed that NST regimens are associated with decreased transplant related mortality, and graft-versus-host disease, in comparison with standard myeloablative conditioning, in patients above the age of 50-55 years, or in younger patients with significant comorbidities. However we have to mention, that our considerations are based on the retrospective analysis of the literature data, and that well controlled prospective randomized studies are needed in order to definitely assess the role of NST. Comorbidity indices might be proved as the most important parameters for the choice of the most proper regimen for each patient in need and should be included in future trials.

Safety and efficacy of donor lymphocyte infusions following mismatched stem cell transplantation.

The use of a mismatched allograft necessitates T cell depletion for prevention of uncontrolled graft-versus-host disease (GVHD), thus impairing a graft-versus-leukemia effect. Data on donor lymphocyte infusion (DLI) after mismatched stem cell transplantation are lacking. Our experience with 28 patients (treated with 59 mismatched DLIs; range, 1-7) is described. The procedure was prophylactic in 6 patients (9 DLIs) and therapeutic in 22 (50 DLIs). DLI dose ranged from 10(2) to 1.5 x 10(9) T cells/kg. In the 6 patients receiving prophylactic DLI, complete remission was maintained in 5; however, 2 died from GVHD. Clinical response to therapeutic DLI was seen in 6 of 22 (27.3%) patients; a greater tumor burden produced a lower response. GVHD appeared in 13 of 28 patients. Surprisingly, a greater HLA mismatch was associated with a lower risk of GVHD, with 3 of 19 DLIs in 3/6 matching and 16 of 29 DLIs in 5/6 matching with similar follow-up. Nevertheless, no correlation between efficacy and HLA mismatching was noted. Death was frequent and usually related to the basic disease rather than to DLI complications. We conclude that mismatched DLI is feasible and may be effective, especially if given soon after transplantation. Future developments using cell therapy with selective or targeted anticancer activity are warranted, with special attention to prophylactic treatment of T cell depleted mismatched allografts recipients.

Treatment of post-hematopoietic stem cell transplantation hemorrhagic cystitis with intravesicular sodium hyaluronate.

Hemorrhagic cystitis (HC) is a well-known complication of HSCT. Its overall incidence has been reported to vary from 7-68%. The spectrum of clinical presentation varies from asymptomatic microhematuria to life-threatening bleeding. Sodium hyaluronate is a glycosaminoglycan present on the bladder mucosa, which serves as an important protective substance against uroepithelial damage. Preparations of this component have been shown to be effective in the treatment of interstitial cystitis. We report our experience in the treatment of post-transplant HC with intravesical instillation of sodium hyaluronate. Five out of the seven patients included in this study achieved complete response, while one patient had only partial response. Sodium hyaluronate administration was not associated with any local or systemic adverse effects. We consider that the results of our study are promising and the efficacy of sodium hyaluronate in the treatment of post-transplant HC should be tested in larger cohorts of patients.

Rapid response to alefacept given to patients with steroid resistant or steroid dependent acute graft-versus-host disease: a preliminary report.

We evaluated the effect of alefacept (Amevive), a novel dimeric fusion protein, in steroid resistant/dependent acute graft-versus-host-disease (aGVHD). Seven patients were treated in eight aGVHD episodes. GVHD grade at treatment initiation and at peak ranged 2-4 (median 2.5) and 2-4 (median 4), respectively. System involvement at GVHD peak included skin (n=7), gastrointestinal tract (n=5) and liver (n=3). All patients responded. However, one patient with skin GVHD and two with gastrointestinal GVHD featuring an early initial response (IR) exacerbated and CR was not achieved. Skin GVHD responded rapidly with a median of 1 day to IR and 7 days to CR. Intestinal response was slower with median 7.5 days to IR. Of the four patients that achieved IR, CR was achieved in only one (40 days to CR). None of the patients had significant hepatic GVHD before treatment so no hepatic effect of alefacept could be determined. No immediate alefacept-related side effects were observed. Late side effects included infections (aspergillus sinusitis, pneumonia, bacteremia, pharyngeal thrush), pancytopenia and hemorrhagic cystitis. Three patients had CMV reactivation while on alefacept. We conclude that alefacept may have a beneficial effect in controlling aGVHD. Further investigations in larger cohorts of patients and controlled studies are warranted.

A novel p27 gene mutation in a case of unclassified myeloproliferative disorder.

P27 encodes a member of Cip/Kip family of cyclin dependent kinase inhibitors, the inactivation of which has been implicated in the pathogenesis of various hematological neoplasias. We report on a novel point mutation of this gene identified in a case of unclassified myeloproliferative syndrome consisting of a T --> C transversion at 821bp of p27 exon 1, resulting in a Ile --> Thr substitution at codon 119. The analysis of larger number of cases as well as the effect of this mutation on protein's function will help to clarify its significance in the pathogenesis of myeloproliferative syndromes.