Mohamed A. Kharfan-Dabaja

A novel therapeutic cytomegalovirus DNA vaccine in allogeneic haemopoietic stem-cell transplantation: a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND Cytomegalovirus reactivation occurs within 6 months in 60-70% of cytomegalovirus-seropositive patients after allogeneic haemopoietic stem-cell transplantation (HSCT), mainly due to immunosuppression associated with the procedure. Pre-emptive antiviral therapy reduces incidence of cytomegalovirus disease but can be toxic. To reduce the potential for disease and subsequent need for such antiviral drugs, we aimed to assess safety and efficacy of a cytomegalovirus therapeutic DNA vaccine compared with placebo. METHODS In this exploratory double-blind, placebo-controlled, parallel group, phase 2 trial, up to 80 donor-recipient pairs and 80 unpaired recipients undergoing allogeneic HSCT were planned for enrolment at 16 transplant centres in the USA. Eligible recipients were cytomegalovirus-seropositive, 18-65 years old, without high-risk primary disease, T-cell depletion, previous vaccination for cytomegalovirus, or autoimmune diseases. We randomly allocated participants in both parallel groups in a 1:1 ratio to receive a cytomegalovirus therapeutic DNA vaccine (TransVax; Vical, San Diego, CA, USA) or placebo before conditioning and at 1, 3, and 6 months after transplantation. The vaccine contains plasmids encoding cytomegalovirus glycoprotein B and phosphoprotein 65 formulated with poloxamer CRL1005 and benzalkonium chloride. Randomisation was done by sequential allocation based on Pocock and Simons method, and stratified by site, donor-recipient HLA matching status, and donors cytomegalovirus serostatus. The primary outcome was the occurrence rate of clinically significant viraemia resulting in initiation of cytomegalovirus-specific antiviral therapy in the per-protocol assessable population. We assessed rates of adverse events in all participants who received at least one dose of vaccine or placebo. This study is registered with ClinicalTrials.gov, number NCT00285259. FINDINGS We randomly allocated 108 participants (94 HSCT recipients and 14 paired donors) between June 29, 2006, and Dec 11, 2009. Enrolment of the paired arm was halted in February 2008 for logistical reasons. Safety was assessed in all participants; the efficacy population was restricted to 74 unpaired recipients. Groups were balanced for demographic and clinical variables. 19 (48%) of 40 vaccine recipients required cytomegalovirus-specific antiviral therapy, compared with 21 (62%) of 34 controls (p=0·145). However, during follow-up vaccine significantly reduced the occurrence and recurrence of cytomegalovirus viraemia and improved the time-to-event for viraemia episodes compared with placebo. The vaccine was well-tolerated; only one participant discontinued after an allergic reaction. Incidence of common adverse events after HSCT (eg, graft-versus-host disease or secondary infections) did not differ between groups. INTERPRETATION We show proof of concept for an immunotherapeutic cytomegalovirus vaccine (TransVax) for clinically significant viraemia in the HSCT setting. The reported safety and efficacy outcomes support further development in a phase 3 trial, notwithstanding a lack of significant reduction in the use of cytomegalovirus-specific antiviral therapy compared with placebo in this phase 2 trial. FUNDING Vical and US National Institute of Allergy and Infectious Diseases.

5-Azacitidine for myelodysplasia before allogeneic hematopoietic cell transplantation

Relapse remains a leading cause for treatment failure after hematopoietic cell transplantation (HCT) in patients with intermediate- or high-risk myelodysplastic syndrome (MDS). To discern the impact of 5-azacitine treatment pretransplant on the risk for relapse after HCT, we analyzed the post transplant outcomes of all 54 consecutive patients with MDS or chronic myelomonocytic leukemia who received HCT from HLA-compatible donors according to pretransplant 5-azacitidine exposure. Thirty patients received a median of four (1–7) cycles of 5-azacitidine, and 24 patients did not receive 5-azacitidine before HCT. The 1-year estimates of overall survival, relapse-free survival and cumulative incidence of relapse were 47, 41 and 20%, for 5-azacitidine patients and 60, 51 and 32%, respectively, for non-5-azacytidine patients. These observations suggest that outcomes are similar in both groups with a trend toward decreased early relapse in patients receiving 5-azacitidine. 5-Azacitidine may be of value in stabilizing the disease, thereby allowing time for patients to reach transplant and does not appear to affect transplant outcomes.

Efficacy of Rituximab in the Setting of Steroid-Refractory Chronic Graft-versus-Host Disease: A Systematic Review and Meta-Analysis

Increased insight into the role of B lymphocytes in the pathophysiology of graft-versus-host disease has led to a number of studies assessing the efficacy of the anti-CD20 monoclonal antibody (mAb) rituximab in treating steroid-refractory chronic graft-versus-host disease (cGVHD). Findings vary greatly among these studies, however. We conducted a systematic review to summarize the totality of evidence on the efficacy of rituximab in steroid-refractory cGVHD. We performed a PubMed search and contacted experts in the field to identify relevant studies. Endpoints included overall response rate (including organ-specific) and ability of rituximab to allow dosage reduction of immunosuppressive therapies. Data were pooled under a random-effects model. Seven studies (3 prospective and 4 retrospective, with a total of 111 patients) met the inclusion criteria. The pooled proportion of overall response was 0.66 (95% confidence interval=0.57 to 0.74). There was no heterogeneity among the pooled studies. Response rates were 13% to 100% for cGVHD of the skin, 0 to 83% for cGVHD of the oral mucosa, 0 to 66% for cGVHD of the liver, and 0 to 38% for cGVHD of the lung. Common adverse events were related to infusion reactions or infectious complications. The relatively small number of patients and the varying criteria for reporting organ response and dosage reduction of steroids, among other limitations, hinders our ability to reach definitive conclusions on the overall efficacy of rituximab for cGVHD involving other organs.

Reduced-intensity transplantation for lymphomas using haploidentical related donors vs HLA-matched unrelated donors

We evaluated 917 adult lymphoma patients who received haploidentical (n = 185) or HLA-matched unrelated donor (URD) transplantation either with (n = 241) or without antithymocyte globulin (ATG; n = 491) following reduced-intensity conditioning regimens. Haploidentical recipients received posttransplant cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis, whereas URD recipients received calcineurin inhibitor-based prophylaxis. Median follow-up of survivors was 3 years. The 100-day cumulative incidence of grade III-IV acute GVHD on univariate analysis was 8%, 12%, and 17% in the haploidentical, URD without ATG, and URD with ATG groups, respectively (P = .44). Corresponding 1-year rates of chronic GVHD on univariate analysis were 13%, 51%, and 33%, respectively (P < .001). On multivariate analysis, grade III-IV acute GVHD was higher in URD without ATG (P = .001), as well as URD with ATG (P = .01), relative to haploidentical transplants. Similarly, relative to haploidentical transplants, risk of chronic GVHD was higher in URD without ATG and URD with ATG (P < .0001). Cumulative incidence of relapse/progression at 3 years was 36%, 28%, and 36% in the haploidentical, URD without ATG, and URD with ATG groups, respectively (P = .07). Corresponding 3-year overall survival (OS) was 60%, 62%, and 50% in the 3 groups, respectively, with multivariate analysis showing no survival difference between URD without ATG (P = .21) or URD with ATG (P = .16), relative to haploidentical transplants. Multivariate analysis showed no difference between the 3 groups in terms of nonrelapse mortality (NRM), relapse/progression, and progression-free survival (PFS). These data suggest that reduced-intensity conditioning haploidentical transplantation with posttransplant cyclophosphamide does not compromise early survival outcomes compared with matched URD transplantation, and is associated with significantly reduced risk of chronic GVHD.

Two cases of progressive multifocal leukoencephalopathy after allogeneic hematopoietic cell transplantation and a review of the literature

Progressive multifocal leukoencephalopathy (PML) is a rare subacute demyelinating disorder of the central nervous system (CNS) caused by the DNA JC human polyomavirus. In immunocompromised hosts, PML is caused by reactivation of a latent infection rather than de novo primary exposure. PML in the setting of hematopoietic cell transplantation (HCT) is exceedingly rare. PML should be considered in the differential diagnosis of HCT recipients, autologous or allogeneic, presenting with worsening of neurological symptoms, especially associated with post-transplant neurodegenerative findings. Although DNA polymerase chain reaction (PCR) of the cerebrospinal fluid (CSF) has emerged as a promising tool for detecting JC virus, a negative result does not rule out PML. Brain biopsy remains the most reliable and accurate method for diagnosing JC virus-associated PML. Presently, there is no universally effective antiviral therapy against JC virus and outcome is fatal in the majority of cases. We hereby describe two cases of PML developing after allogeneic HCT and provide a comprehensive review of the literature.

A Randomized Phase II Trial Comparing Tacrolimus and Mycophenolate Mofetil to Tacrolimus and Methotrexate for Acute Graft-versus-Host Disease Prophylaxis

Tacrolimus (Tac) plus methotrexate (MTX) is a standard regimen for graft-versus-host disease (GVHD) prophylaxis. Mycophenolate mofetil (MMF) is sometimes used instead of MTX to minimize toxicity, despite the lack of controlled studies demonstrating efficacy. We conducted a single-center, randomized phase II trial comparing Tac + MMF to Tac + MTX. Intent-to-treat analyses included 42 patients randomized to Tac + MMF and 47 to Tac + MTX. Patient characteristics were not different between the study arms. Patients in the Tac + MMF arm were less likely to experience severe mucositis, require narcotic analgesia and parenteral nutrition, and had earlier hospital discharge. The Tac + MMF arm had the same time to neutrophil recovery, but earlier platelet recovery. The cumulative incidence of grade II-IV acute GVHD (aGVHD) at 100 days was similar (P = .8), but grade III-IV aGVHD was higher in the Tac + MMF arm (19% versus 4%; P = .03); this was predominantly seen in unrelated donor transplants (26% versus 4%; P = .04), and less in related donor transplants (11% versus 4%; P = n.s.). Moderate or severe chronic GVHD was similar (P = .71). There were no significant differences between the arms in relapse, nonrelapse mortality, or overall and relapse-free survivals. MMF was associated with less early toxicity than MTX but was not as effective in preventing severe aGVHD, especially in unrelated donor transplants.

Microbial contamination of hematopoietic progenitor cell grafts—incidence, clinical outcome, and cost-effectiveness: an analysis of 735 grafts

BACKGROUND: Screening of progenitor cell grafts (marrow, peripheral blood, and cord blood) for microbial contamination is required by the standards of AABB. Clinical sequelae from infusion of these contaminated grafts, however, is uncommon.

Human immunodeficiency virus (HIV)-negative plasmablastic lymphoma: A single institutional experience and literature review

Plasmablastic lymphoma (PBL) is a rare aggressive B-cell lymphoproliferative disorder. HIV-negative PBL has not been extensively reported. Nine HIV-negative PBL patients evaluated at Moffitt Cancer Center were studied. Eight patients had extranodal diseases. All patients were treated with CHOP or hyper-CVAD. Responses were observed in 8 cases (7 complete, 1 partial responses). Four patients underwent consolidation with autologous hematopoietic stem cell transplant (HSCT) in first complete remission (CR1). At median follow-up of 23.9 months, 7 patients were alive and 5 were disease-free. Aggressive induction chemotherapy and consolidation with autologous HSCT in CR1 might be considered for patients with HIV-negative PBL.

Reduced-Intensity Transplantation for Lymphomas Using Haploidentical Related Donors Versus HLA-Matched Sibling Donors: A Center for International Blood and Marrow Transplant Research Analysis

PURPOSE Related donor haploidentical hematopoietic cell transplantation (Haplo-HCT) using post-transplantation cyclophosphamide (PT-Cy) is increasingly used in patients lacking HLA-matched sibling donors (MSD). We compared outcomes after Haplo-HCT using PT-Cy with MSD-HCT in patients with lymphoma, using the Center for International Blood and Marrow Transplant Research registry. MATERIALS AND METHODS We evaluated 987 adult patients undergoing either Haplo-HCT (n = 180) or MSD-HCT (n = 807) following reduced-intensity conditioning regimens. The haploidentical group received graft-versus-host disease (GVHD) prophylaxis with PT-Cy with or without a calcineurin inhibitor and mycophenolate. The MSD group received calcineurin inhibitor-based GVHD prophylaxis. RESULTS Median follow-up of survivors was 3 years. The 28-day neutrophil recovery was similar in the two groups (95% v 97%; P = .31). The 28-day platelet recovery was delayed in the haploidentical group compared with the MSD group (63% v 91%; P = .001). Cumulative incidence of grade II to IV acute GVHD at day 100 was similar between the two groups (27% v 25%; P = .84). Cumulative incidence of chronic GVHD at 1 year was significantly lower after Haplo-HCT (12% v 45%; P < .001), and this benefit was confirmed on multivariate analysis (relative risk, 0.21; 95% CI, 0.14 to 0.31; P < .001). For Haplo-HCT v MSD-HCT, 3-year rates of nonrelapse mortality (15% v 13%; P = .41), relapse/progression (37% v 40%; P = .51), progression-free survival (48% v 48%; P = .96), and overall survival (61% v 62%; P = .82) were similar. Multivariate analysis showed no significant difference between Haplo-HCT and MSD-HCT in terms of nonrelapse mortality (P = .06), progression/relapse (P = .10), progression-free survival (P = .83), and overall survival (P = .34). CONCLUSION Haplo-HCT with PT-Cy provides survival outcomes comparable to MSD-HCT, with a significantly lower risk of chronic GVHD.

Sirolimus for treatment of steroid-refractory acute graft-versus-host disease

Acute GVHD (aGVHD) is a major cause of morbidity and mortality in hematopoietic allograft recipients. The best therapy for patients failing to respond, or not tolerating, systemic glucocorticoids remains undefined. We evaluated the efficacy of sirolimus in 34 patients, median age of 49 (23–67) years, with steroid-refractory (n=31) or steroid-intolerant (n=3) aGVHD. aGVHD was diagnosed at a median of 34 (7–1042) days post allografting, and confirmed by biopsy in all cases. Initial aGVHD treatment consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1–255) days after glucocorticoid initiation. A sirolimus loading dose was administered to 19 (56%) of 34 patients, median 6 (3–8) mg, followed by maintenance of 1–2 mg/day to target therapeutic trough levels between 4 and 12 ng/ml. Overall response rate was 76%. Fifteen (44%) of 34 patients achieved CR, defined as complete resolution of aGVHD sustained for at least 1 month, after sirolimus initiation without additional immunosuppressive agents. CR was achieved in 11 (42%) of 31 steroid-refractory and 2 (67%) of 3 steroid-intolerant patients. Median OS after initiation of sirolimus was 5.6 months, and 1-year OS was 44% (95% CI: 27–60%). Sirolimus is effective in controlling steroid-refractory aGVHD.