ALBERT

Description: Functional control of CMV reactivation is profoundly influenced by CMV serostatus after nonmyeloablative hematopoietic cell transplantation following a TLI-ATG preparative regimen Joanna M. Schaenman1,2, Marcy L. Vana2, Chanu Rhee2, Jonathan Wong1, Shelly Navato2, Laura Johnston2, Ruby M. Wong2, Dora Y. Ho1, and Janice M. Brown1,2 Divisions of Infectious Diseases1 and Blood and Marrow Transplantation2, Stanford University Medical Center, Stanford, California 94305-5623, USA. A substantial body of data supports the importance of recapitulation of effective immune function for control of cytomegalovirus (CMV) following hematopoietic cell transplantation (HCT). However, many questions remain regarding immune reconstitution of functional viral control after nonmyeloablative (NMA) HCT, especially with preparative regimens containing total lymphoid irradiation and antithymocyte globulin (TLI-ATG). We analyzed 197 patients who underwent NMA HCT at Stanford University Hospital between 2001 and 2007; 126 patients had either donor or recipient seropositivity for CMV. TLI was administered 11 days prior to transplant, and ATG on D-11 to -7. Nine patients were eliminated from analysis for either participation in a CMV prophylaxis trial or for insufficient data. HCT recipients were screened weekly for CMV reactivation using the Amplicor CMV test (Roche Molecular Diagnostics) on peripheral blood for the first 100 days after HCT. Any positive result led to preemptive treatment with intravenous ganciclovir or valganciclovir. Statistical analysis was performed using SAS Enterprise Guide. There were no significant differences between groups with respect to sex, age, race, underlying hematologic disease, or donor type. 35% had acute leukemia as their underlying diagnosis, 18% chronic leukemia, 32% lymphoma, and 15% myelodysplastic syndrome. 63 patients received HCT from siblings including one partially matched related donor (53%), 6 patients received haplo-identical transplants (5%), and 48 patients had unrelated donors (41%). Data regarding reactivation by serogroup Serogroup No. patients Patients with CMV reactivation (%) Median days to first reactivation No. patients with multiple reactivations (%)* Average no. reactivations per patient Max. no. reactivations * Patients included if there was less than one month of missing data: D+/R− 15 patients, D+/R+ 55 patients, D−/R+ 35 patients evaluated. D+/R− 15 2 (13.3) 56 0 (0) 0.1 1 D+/R+ 57 27 (47.4) 17 5 (9.1) 0.6 3 D−/R+ 45 29 (64.4) 12 5 (14.3) 0.9 5 Analysis by logistic regression with correction for age, diagnosis, donor type, and steroid use was statistically significant (p=0.005) for the comparison of all three serogroups. Other covariates reaching statistical significance were diagnosis (increased reactivation with acute leukemia and lymphoma) and donor type (OR 2.7 for unrelated versus related donors (95% confidence interval 1.2–6.1, p=.016). There was no difference in the degree of chimerism in whole blood on day 28 with a mean of 80% for the D+/R+ and 79% for the D−/R+ patients (t test, pooled p-value 0.90). The incidence and severity of acute graft versus host disease (GVHD) (Grade 〉 II) were not statistically different between groups, with 0 D+/R− patients, 2 D+/R+ patients, and 4 D−/R+ patients with acute GVHD. Sustained CMV viral load was significantly greater in the D−/R+ group based on analysis by a mixed effect model with correction for the covariates listed above (p=.0006 for serogoup*time). None of the other covariates analyzed had a statistically significant effect in this model. CMV serostatus of both donor and recipient had a significant effect on CMV reactivation over the first 100 days after NMA HCT following a TLI-ATG preparative regimen. The relative paucity of reactivation and the longer time to first reactivation in the D+/R− group is predicted by previously published observations. Donor CMV serology did not influence the timing of CMV reactivation in the D+/R+ compared with the D−/R+ group, however, donor seropositivity did play an important role in the reconstitution of effective antiviral immune function as manifested by an increased burden of detectable CMV in the D−/R+ as compared with the D+/R+ group. These observations have led us to an ongoing exploration of the kinetics of the antiviral immune response in an animal model in an attempt to refine our understanding of the interaction between the magnitude and timing of CMV exposure and the reconstitution of functional immunologic control after HCT.

Description: Abstract 2224 Poster Board II-201 Although acyclovir (ACV)-resistant herpes simplex virus (HSV) occurs in healthy patients, higher rates have been reported in 7-27% of immunocompromised patients, particularly in the setting of acyclovir prophylaxis. Infection due to ACV-resistant HSV (ACV-R HSV) is frequently severe and poses challenges to treatment, particularly following hematopoietic cell transplantation (HCT). Unfortunately, currently available alternative therapies including foscarnet, cidofovir, and ganciclovir are frequently limited by their toxicity profile. We present a series of five HCT patients from 1997-2008 with severe infections due to ACV-R HSV who were successfully treated with continuous infusion of high dose acyclovir. A Pubmed search of published literature from 1948-2009 confirmed this as the first report of ACV-R HSV in HCT patients treated with this regimen. The characteristics of the patients are summarized in the table. Patients ranged in age from 24 to 55 and had undergone an allogeneic HCT following a myeloablative preparative regimen. All grafts were composed of peripheral blood hematopoietic cells. Underlying diseases included acute myelogenous leukemia, myelodysplastic syndrome, and essential thrombocytosis. Four of the five patients were receiving treatment for GVHD of the skin (grades 2-4), with regimens that included varying doses of prednisone. Infection was due to HSV-1 in three patients and HSV-2 in two. In vitro testing revealed that high median inhibitory concentrations were necessary to inhibit viral replication by 50% (MIC50) for all five isolates consistent with resistance to acyclovir, ganciclovir, and foscarnet. Failed HSV treatment regimens included standard, intermittent doses of acyclovir (5-10 mg/kg IV every eight hours), foscarnet, cidofovir, and/or famciclovir. Adverse reactions to these agents included severe renal insufficiency, hyponatremia, and neutropenia. The doses of ACV administered via continuous infusion ranged from 30 to 50 mg/kg per day, and time to resolution of lesions ranged from 1 week to 2 months. No patients experienced toxicity associated with continuous infusion of high dose acyclovir and therapy could be continued as an outpatient when appropriate. Conclusions: Continuous infusion of high dose acyclovir for acyclovir resistant HSV is an attractive and more tolerable alternative for patients failing standard dose intermittent infusion acyclovir or intolerant of alternative standard therapies such as foscarnet, cidofovir, or ganciclovir. At this time it is not clear how the altered pharmacokinetics that results from continuous infusion of high doses of acyclovir overcomes viral resistance. We are currently investigating the mechanisms by which the sustained levels of ACV provide this therapeutic advantage. Disclosures: No relevant conflicts of interest to declare.

Description: Background: B cells are implicated in the pathophysiology of chronic GVHD. We hypothesize that prophylactic anti-B cell therapy delivered two months after reduced intensity conditioning (RIC) transplantation would prevent or reduce chronic GVHD incidence from the historical 50%. Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) were the target diseases as they are B cell malignancies with clear allogeneic GVL benefit. Methods: CLL and MCL patients were conditioned with total lymphoid irradiation (TLI) 80 cGy in 10 fractions, d-11 to d-1 and anti-thymocyte globulin (ATG) 1.5mg/kg/day, d-11 to d-7 (total 7.5mg/kg). PBPC were infused on day 0. Primary GVHD prophylaxis was cyclosporine (CSA) on d-3 with taper by 6 months, and MMF from day 0 until d28 for related donors, d100 for unrelated donors. Rituximab (375 mg/m2/week ×4) was infused on days 56, 63, 70, and 77 post-transplant. Results: 36 patients accrued to the study (median age 57, range 31–66 yrs), with 34 patients completing the 4 rituximab infusions. All 22 CLL patients were high risk (fludarabinerefractory, unmutated VH-IgG, or P53 deletion). The 14 MCL patients included 4 patients in PR and 10 patients in CR status at transplant. Median follow-up is 20 months. Twenty patients had sibling donors; 16, unrelated donors. Median CD34 cell dose was 7.5 CD34/kg. All patients had donor cell engraftment except for one patient who had graft failure with stable autologous recovery. Full donor chimerism (PB CD3〉95%) was achieved in 14 out of 31 patients (45%) by day 90. However, all but 5 patients had achieved full donor chimerism at 1 year. The incidence of grade 2–4 acute GVHD was 6%. The incidence of chronic GVHD was 18%. Day 100 NRM was 0% and 1-year NRM was 3%. Ten relapses have occurred (5 CLL, 5 MCL). Estimated FFP and OS at 2 years for CLL patients is 82%(CI +/−16%) and 73% (CI +/−33%), respectively; for MCL patients, 64% and 68%, respectively Full donor chimerism was associated with persistent disease remission. Twelve of 19 VHIg mutated CLL patients have achieved minimal residual disease (MRD) by quantitative allele-specific oligonucleotide-IgH PCR (ASO-Q-PCR). DLI was given to 5 CLL patients and 1 MCL who had relapsed and had not achieved full donor chimerism.. There were no infusional toxicities with rituximab. Transient rituximab related neutropenia occurred in 10 patients d100–150. Post-transplant infections included influenza B, RSV, fungal sinusitis, pseudomonas, klebsiella infection, VZV reactivation, and one PTLD before day 56 rituximab. All recovered Of 22 patients at risk for CMV reactivation, 10 reactivated ( range 4 to 56 days post-HCT). Therefore, rituximab did not contribute to the CMV reactivation or increase infection incidence. Conclusion: Prophylactic rituximab infusion post RIC transplantation is well tolerated, provides safe donor B cell depletion without detrimental effect on engraftment or infection incidence, and is associated with a low incidence of chronic GVHD while maintaining GVL. A randomized trial of rituximab prophylaxis after allogeneic HCT is warranted.

Description: B cells are involved in the pathogenesis of chronic GVHD (cGVHD). We hypothesized that prophylactic anti–B-cell therapy delivered 2 months after transplantation would decrease allogeneic donor B-cell immunity and possibly the incidence of cGVHD. Therefore, in the present study, patients with high-risk chronic lymphocytic leukemia (n = 22) and mantle-cell lymphoma (n = 13) received a total lymphoid irradiation of 80 cGy for 10 days and antithymocyte globulin 1.5 mg/kg/d for 5 days. Rituximab (375 mg/m2) was infused weekly on days 56, 63, 70, and 77 after transplantation. The incidence of acute GVHD was 6%. The cumulative incidence of cGVHD was 20%. Nonrelapse mortality was 3%. Rituximab treatment after allogeneic transplantation significantly reduced B-cell allogeneic immunity, with complete prevention of alloreactive H-Y Ab development in male patients with female donors (P = .01). Overall survival and freedom from progression at 4 years for chronic lymphocytic leukemia patients were 73% and 47%, respectively; for mantle-cell lymphoma patients, they were 69% and 53%, respectively. This study is registered at www.clinicaltrials.gov as NCT00186628.