ALBERT

Description: Background: Approximately 25% of patients with newly diagnosed (MM) fail to respond and progress while receiving conventional induction. As a result, these patients have primary refractory disease. Even though these patients still benefit from HD chemotherapy, their PFS ranges from 4–8 months, while OS is approximately 12 months. PCL accounts for approx. 2% of newly diagnosed MM patients and represents the most aggressive form of disase. These patients often do not respond to standard systemic cytotoxic therapies and their median survival is less than 12 months. Therefore, novel treatment approaches are paramount for patients with primary refractory MM and PCL. The proteasome inhibitor BTZ has been shown to sensitize myeloma cells to melphalan both in vitro and in vivo, but the mechanism is not well understood. In this study we examine the effects of BTZ, followed by BTZ and HDMel as conditioning regimen for TanPSCT in this poor-risk group. Methods: Patients with primary refractory MM or PCL received 2 cycles of BTZ at 1.3 mg/m2. followed by HD Mel (200 mg/m2) and one dose of BTZ at 0.7 mg/m2, 1.0 mg/m2 or 1.3 mg/m2, as a conditioning regimen prior to TanPSCT. The dose of BTZ was given immediately after the last dose of HD Mel. Bone marrow(BM) samples were collected at baseline, on day 4 and after 2 cycles of BTZ, and at 3 months after TanPSCT, for GEP and Fanconi anemia(FA) pathway genes assessment. Results: To date, 17 patients have been enrolled and treated, and 11 patients are evaluable for response. Median age is 59 years (46–70) with the following myeloma distribution: 55% IgA and 45% IgG. FISH analysis showed the following: del 13q (44%), t (4; 14) (11%), t (11; 14) (11%), trisomy 11 (11%), and polyploid (11%); standard karyotype was normal in 88% of patients and complex karyotype in 12%. Median time to WBC engraftment (days) was 13 and 12 after the first and second transplant, respectively. Median time to plt engraftment (days) was 20 and 17, after the first and second transplant, respectively. There were no dose limiting toxicities. Observed grade 3 toxicities were related to the conditioning regimen and similar to those observed with HDMel alone. One patient developed diffuse alveolar hemorrhage after the first cycle of BTZ, which resolved, but was removed from study. After 2 cycles of BTZ, 45% of patients achieved PR, and 55% had stable disease. Overall response rate at 3 months from the second transplant increased to 90%(CR=36%,VGPR=27% andPR=27%). Only 1 patient developed progressive disease after the first transplant. Evaluations of BM samples by GEP and FA pathway gene expression are underway. Conclusions: Single agent BTZ induced responses in 45% and the combination of HD Mel and BTZ as conditioning regimen for TanPSCT was well tolerated and improved response rates to 90%. These early results suggest that this regimen is very active in this poor-risk group. Evaluation of collected BM samples for GEP and FA pathway genes may provide important insight into the mechanisms associated with the observed synergy between BTZ and HD Mel. A Phase II study is underway.

Description: Background. T-cell depletion is often used to reduce graft-vs-host disease in haploidentical donor hematopoietic cell transplantation (HCT). However, the absence of adoptively transferred T-cells may increase graft failure, relapse, and infection. Novel methods have been developed to more selectively deplete naïve T cells and preserve memory T cells. Depletion of CD45RA+ cells can provide robust early recovery of diverse memory T-cell populations in haploidentical donor transplantation, and may provide increased immunity against viral infections. Likewise, the provision of additional donor NK cells may reduce viral complications. Patients and Methods. Sixty-seven patients received initial allogeneic HCT on 3 consecutive IRB approved haploidentical donor HCT trials at St. Jude Children's Research Hospital from 2005 to 2015. CD3-depletion was used in 41 recipients, and CD45RA-depletion was used in 26. All patients received similar preparative doses of fludarabine, thiotepa, and melphalan. Patients with CD3-depleted grafts received OKT3 (n=20) or Campath (n=21), and all 41 received rituximab on Day 0 as EBV prophylaxis. Patients with CD45RA-depleted grafts (n=26) did not receive antibody therapy, but instead received total lymphoid irradiation and a dose of cyclophosphamide added to the preparative backbone. Donor NK cells were given Day +6. Peripheral blood was tested for CMV, EBV, and adenovirus using quantitative PCR at least weekly until day +100, and then as indicated. The first 180 days post-HCT were evaluated. Fisher's exact test was used to compare two proportions. Results. Patients with CD3-depletion received a median 0.04 (range: 0.01 - 0.15) x 106 CD3+ cells/kg, and patients with CD45RA-depletion received a median 80.07 (range: 16.08 - 528.52) x 106 CD3+ cells/kg. CMV reactivation occurred in 23 of 41 patients (56.1%) with CD3-depletion and 5 of 26 patients (19.2%) with CD45RA-depletion (p=0.005). Differences occurred predominantly in those CMV seropositive recipients who received grafts from CMV seropositive donors, as CMV was detected in 22 of 24 (91.7%) +/+ patients with CD3-depletion and 4 of 11 (36.4%) +/+ patients with CD45RA-depletion (p=0.001). Of the 23 patients with CMV after CD3-depletion, the peak viral load was a median 4.49 log10 copies/mL blood (range:

Description: Abstract 2235 Poster Board II-212 Acute graft-versus-host disease (aGVHD) remains the major cause of morbidity and mortality in allogeneic hematopoietic cell transplant recipients. There is no consensus in regards to the best therapy for patients who fail to respond to, or do not tolerate, systemic glucocorticoids. We evaluate the efficacy of sirolimus in 34 pts, median age of 49 (23-67) years, with steroid-refractory (N=31) or steroid-intolerant (N=3) aGVHD. The diagnosis of aGVHD was established at a median of 34 (7-1042) days after transplantation, and confirmed by biopsy in all cases. Initial treatment of aGVHD consisted of prednisone up to 2 mg/kg. Sirolimus was initiated at a median of 9 (1-255) days after glucocorticoid initiation. A loading dose of sirolimus was administered to 19 (56%) of 34 pts, median 6 (3-8) mg, followed by maintenance therapy of 1-2 mg per day with doses adjusted to target therapeutic trough levels between 4 and 12 ng/ml; therapeutic levels were achieved in all cases. The overall response rate was 76%. Fifteen (44%) of the 34 pts achieved a CR after sirolimus initiation and without requiring additional immune suppressive agents. CR was achieved in 11/31 (42%) steroid-refractory patients, and in 2/3 (67%) steroid-intolerant patients. The median overall survival (OS) after initiation of sirolimus was 5.6 months, and one year OS was 44% (95% C.I. 27%-60%). Maximum decrease in dose of steroids over 12 weeks following sirolimus was a median of 50% (range 0-100%). Fourteen (42%) of 33 pts reached a dose 〈 20 mg of prednisone at a median of 4 months (95% CI: 3.5-13.5) after initiation of sirolimus. Seven (21%) of 34 pts were free from steroids after a median of 20 months (95% CI: 9.2-20.0) after initiation of sirolimus. Two pts were shown to be successfully liberated from all immunosuppressive agents without recurrent GVHD at 2.7 and 7.1 months after initiation of sirolimus, respectively. These data indicate the sirolimus is effective in controlling steroid-refractory aGVHD. Further studies are needed to determine the most appropriate timing for sirolimus after transplantation, whether prophylaxis, primary or secondary GVHD therapy. Disclosures: Off Label Use: Sirolimus for graft-versus-host disease.

Description: Abstract 1891 Background: The risk of acute GVHD after HSCT is increased in male recipients of female grafts. Disparities for the male-associated H-Y and other minor histocompatibility antigens (mHAs) have the capacity to sensitize alloreactive donor T cells and cause GVHD in HLA-matched recipients. These mHAs are polymorphic proteins that differ between donor and recipient and are presented as peptides by HLA molecules on recipient or donor antigen-presenting cells to donor immune cells. Currently, there is no evidence that minor histocompatibility antigen specific Tregs exist. Earlier in our laboratory, we have measured the frequency, growth requirements, and function of human blood Tregs specific for allo-MHC. In the present study, we sought to detect the frequency, expansion kinetics and characteristics of the minor antigens specific Tregs in the blood of HLA-matched sibling pair. Methods: CD4+CD25+CD127− Tregs were isolated by immunoabsorption from sibling donors, and cultured with HLA-matched sibling recipient antigen-presenting cells in the presence of IL-2, IL-15 and rapamycin. We detected 30–50 fold increase in H-TdR uptake at 6 days in Treg cultures stimulated by HLA-identical sibling compared to self DC. The precursor frequency of mHA-specific Tregs are between 7 and 43 (median - 13) cells per one million blood Tregs. The frequency of mHA-specific conventional CD4 T cells among total blood CD4 T cells is similar in HLA-matched sibling donors. Ex vivo expanded mHA-specific Tregs maintained higher levels of Foxp3 expression, retained the lymphoid homing receptor CD62L and a chemokine receptor, CCR7, suggesting that they are functional and are able to migrate to lymphoid tissue in vivo. Split well assay on day 12 demonstrated the mHA specificity, since Treg responded to restimulation with DC from the original HLA-identical sibling, but not self DC. The mHA-specific Tregs expanded to more than 100 fold in vitro, and exhibited antigen specific suppression. When Tregs were cultured at limiting dilution, we obtained 6 mHA-specific Treg clones that retained TGF-beta secretion in response to the sibling's mHA-disparate DC but not self DC. Conclusion: We demonstrated for the first time that it is possible to detect and expand mHA specific Tregs from HLA-matched sibling pairs, immunotherapy with mHA-specific Tregs may prevent GVHD. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 323 Sirolimus/Tacrolimus Facilitates Preferential Recovery of Regulatory T cells (Treg) after Allogeneic Hematopoietic Cell Transplantation (HCT), and is More Effective than Methotrexate/Tacrolimus in Preventing Grade II-IV Acute Graft vs. Host Disease (GVHD) and Moderate to Severe Chronic GVHD Background: Clinical translation of the Treg suppressive potential will require definition of a pharmacologic immune suppressive platform conducive to preferential Treg reconstitution post-HCT. Sirolimus has differential impact on Treg and conventional T cells. Patients and Methods: We performed a prospective, randomized phase II trial of sirolimus (SIR) and tacrolimus (TAC) vs. methotrexate (MTX) and TAC. From 9/2008 to 5/2011, a total of 74 patients were randomized 1:1 to SIR/TAC vs. MTX/TAC, stratified by age (〉 or ≤ 50) and donor relation (related vs. unrelated). SIR was administered as a 9 mg oral loading dose on day -1, followed by maintenance with 4 mg daily adjusted to target 8–12 ng/ml; SIR was continued for at least 1 year. MTX was 15 mg/m2 on day +1, then 10 mg/m2on days +3, 6, and 11. TAC was administered at 0.02 mg/kg/day IV or equivalent oral dosing starting on day -3. Target TAC levels were 3–7 ng/ml for the SIR arm versus 10–15 ng/ml for the MTX arm and were maintained through day 60. TAC was tapered thereafter in the absence of acute GVHD. Patient age for the whole study was 23 to 69 (median 49) years, and disease diagnoses included AML (23), ALL (15), MDS (9), MM (8), NHL (8), CLL (7), CML (2), and MPD (2). Patients received peripheral blood mobilized stem cells from HLA-A, B, C, and DRB1 matched sibling (n=35) or unrelated donors (n=39). Age, diagnosis, disease risk and donor relation were balanced across the two study arms. Serial peripheral blood samples were obtained at baseline pre-HCT, day 0, and days 30, 90, 180, and 360 post-HCT. Treg were defined by the surface CD4+CD25brightCD127negative phenotype. The reciprocal relationship between negative surface CD127 and high intracellular FoxP3 expression was confirmed in a subset (n=15) of day 30 patient samples (r=0.94). Results: Median percent Tregs among blood CD4 T cells at day 30 was 16.3 (range 12.5–17.9) for SIR versus 9.9 (8.6–13.5) for MTX, p 〈 0.0001, and 14.6 (10.8–18.1) for SIR and 9.7 (7.5–11.6) for MTX at day 90 post-HCT, p = 0.0009. SIR-treated patients had increased absolute numbers of Treg, and decreased absolute numbers of non-Treg CD4+ cells on days 30 and 90. The 100-day cumulative incidence of grade 2–4 acute GVHD for SIR was 43% (95% CI 30–63%), and 89% (95% CI 80–100%) for MTX, p

Description: Abstract 4226 There has been reluctance to collect apheresis HPC grafts from donors of age 60 and beyond. This is predicated on concern over relative frailty, poor venous access, reduced potential for HPC mobilization, and reduced potential for stable engraftment of HPC transplant. We have expanded our transplant eligibility into patients beyond the age of 60, with the concomitant acceptance of matched sibling donors of similar age. We have reviewed 96 consecutive sibling donors, 19 of whom were of age ≥60 years at the time of collection. All donors were collected using Gambro Spectra apheresis instruments, and the volume of blood pheresed was gauged to target a CD34 dose of 5-10 million per Kg of recipient weight. We have found the following: Age 〈 60 (n=77) Age ≥ 60 (n=19) p Blood volumes (Mean±Std) 4.9±3.3 6.1±3.1 .85 CD34/RecipKg E6 (Mean±Std) 8.1±2.8 5.8±1.7 .02 CD34/Blood vol E7. (Mean±Std) 18.0±11.7 10.9±7.8 .06 〈 5E6 CD34/Kg Collected (n) 5 3 .21 〉 1 collection (n) 12 7 .04 Catheter required (n) 23 6 .54 Grade 3+ pheresis complications 2 3 .47 ANC500 Median days (Min-Max) 16 (10-28) 16 (13-75) .14 Plt20K Median days (Min-Max) 16 (8-77) 16 (13-89) .30 These results suggest that donors of age ≥60 years may be successfully collected, and that the resultant grafts can be expected to produce successful transplants. There is not a higher toxicity rate or need for catheter insertion associated with the collections in the older age group. There is a clear trend, however, to reduced mobilization of CD34+ cells, as reflected in the need for more collections, and fewer CD34+ cells per blood volume leukopheresed. In spite of this, sufficient cells to produce functional grafts were collected from all donors, although a limited number of donors in both age categories failed to collect a full 5e+6 CD34/Kg. We conclude that in the context of an aging demographic, allograft donors of age ≥60 may be successfully employed for HPC collection. Further, we propose that the application of plerixafor in ≥60 year old donors should be investigated in the context of a growing need to collect allografts from donors in this age group. Disclosures: Off Label Use: sirolimus for graft-versus-host disease.

Description: Abstract 4060 Study Purpose and Methods: Following FDA approval of plerixafor, our institution developed practice guidelines using a risk-based algorithm to optimize the use of plerixafor for CD34 cell mobilization in autologous hematopoietic cell transplant (HCT) candidates. We defined patients (pts) at high risk for mobilization failure and eligible to receive G-CSF 10 mcg/kg/day for 4 days with plerixafor 0.24 mg/kg added on day 4 if they met any of the following criteria: 1) 3 or more lines of prior chemotherapy; 2) 2 or more lines of prior chemotherapy plus a radioimmunoconjugate or extensive field radiation therapy (XRT); 3) 4 or more cycles of hyper-CVAD, 4) 4 or more cycles of lenalidomide; or 5) hypocellular bone marrow (

Description: Autologous stem cell transplantation (ASCT) has been demonstrated to prolong survival of Multiple Myeloma (MM) patients, but the benefit of this therapy for elderly patients has not been well established. Randomized data is available for patients up to 65 years of age; however, older patients have been offered autologous SCT provided they fulfill criteria for fitness at different institutions. We conducted a retrospective analysis of 214 MM patients treated with ASCT at our institution from 2001–2006. The objective of this study is to determine if age is a prognostic factor for overall survival (OS) and progression-free survival (PFS) in this patient population. Eight potential risk factors along with 3 age variables (≥65, ≥70 or age in years) were studied using backward elimination (BE) Cox model for the age terms. Age ≥ 65 was the best variable for OS and PFS, with the other two age terms dropping out. We examined 8 parameters [e.g gender, stage at diagnosis, lines of therapy, disease status at the time of transplant, conditioning regimen, time from diagnosis to transplant, and HSCT-comorbidity index and CIRS-G index, to account for co-morbidity] and clinical outcomes [e.g. length of hospital stay (LOS), time to neutrophil engraftment, PFS, and OS]. PFS and OS were calculated from the time of transplant to the time of event occurrence. One-hundred and ten patients (45 female, 65 male), with median age 68 (range 65–77) were ≥65 years (old cohort). One hundred and four patients (46 female, 58 male) with a median age 55 (range 36–64) were 0.5 × 109/L was 12 days (range 6–40 and 9–21) for both cohorts. Transplant-related mortality was (4.7 vs 1.9%) and response to transplant was [CR + VGPR (33 vs 40%), PR (31 vs 24%), SD+ PD (28 vs 29%)]. Median PFS was 14.8 months (range 12.3–20.3) and median OS was 36.8 months (range 29.4–46.8) for the old cohort. Median PFS was 24.4 months (range 16.6–31.5) and median OS was 47.9 months (range 43.8–74.3) for the young cohort. Male gender (HR1.8, 95%CI 1.7–2.8, p=0.0075), HSCT co-morbidity score (HR 1.11, 95%CI 0.9–1.2 p=0.06) were negative prognostic factor for OS, and age ≥65 was found to be the strongest negative prognostic factor influencing OS (HR 2.03, 95%CI 1.3–3.1, p=0.0014) and PFS (HR 1.86, 95%CI 1.3–2.7, p=0.0008). CONCLUSION: ASCT remains a feasible and safe therapy for elderly for multiple myeloma patients, but our experience suggests that age significantly influences PFS and OS in this population.