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Immune Reconstitution and Outcomes after Peripheral Blood Haploidentical Transplantation with Novel Conditioning and Post-Transplant Cyclophosphomide (PTCY)
Abstracts / Biol Blood Marrow Transplant 23 (2017) S18–S391
Figure 2. Monocyte recovery during the first 200 days after CBT and BMT. Absolute monocyte counts after CBT are depicted in blue and after BMT in red, black lines show the mean predictions of the logistic cell growth model.
Figure 3. Natural killer {NK} cell recovery during the first 200 days after CBT and BMT. Absolute NK-cell counts after CBT are depicted in blue and after BMT in red, black lines show the mean predictions of the logistic cell growth model.
interactions between innate and adaptive IR for better predictable IR.
205 Immune Reconstitution and Outcomes after Peripheral Blood Haploidentical Transplantation with Novel Conditioning and Post-Transplant Cyclophosphomide (PTCY) Yasser Khaled, Diwura Owolabi, Christy R. Parks, Deborah Lamontagne, Joshua D. Boss, Jason Chandler, Valeh Huseynov. University of Tennessee/Methodist University Hospital, Blood and Marrow Transplant Program-West Cancer Center, Memphis, TN The outcomes after Haploidentical HCT with Flu-CY-TBI and PTCY using BM as a graft source have been associated with high relapse and delayed immune recovery. Additionally, there is limited knowledge regarding immune reconstitution post haploidentical HCT with the use of mobilized peripheral blood. We hypothesized that the immunogenic properties of pretransplant low dose Cyclophosphamide along with immunomodulatory effects of Melphalan would enhance early post-transplant engraftment and early peripheral T cell recovery through enhanced cytokine release and antigen alloreactivity. We examined the clinical outcomes and immune reconstitution recovery of 12 consecutive haploidentical HCT patients with high-risk hematological malignancies. Patients and Graft characteristics is as shown in Table 1. Conditioning regimen
S165
was low dose Cy 14.5 mg/m2 on day -6 & day −5, Flu 30 mg/ m2 day −6 to Day −2 and Mel 70 mg/m2 on day −3 & −2. Graft versus host disease prophylaxis (GVHD) was PTCY 50 mg/ Kg on day +3 and day +4 along with Tacrolimus and Mycophenolate starting at day +5. Immune reconstitution performed on days +60, +120 and +180 post HCT. All the patients treated according to an institutional protocol and records reviewed retrospectively after IRB approval. All patients engrafted with median time to engraftment of 17 days (range 12-23). Chimerism studies revealed enhanced engraftment with 100% donor in bone marrow and peripheral blood at day 30 in all 12 patients. Post HCT immune recovery shown in Table 2. There was significant early recovery at day 60 of all T cell subsets, most pronounced in activated T cells. While we have observed a progressive reduction in the median number of early-activated T cells at day 120 & 180, the number CD4 and NK cells has improved (Figure 1). With median duration of follow up of 323 days, range (123451), the overall survival at day 100 and projected one year is 92% and 81% respectively. Only 2/12 had relapsed at 95 and 321 days post- transplant. Treatment related mortality (TRM) was limited to 1/12 patients. Acute GVHD grade 2-4 developed in six of 12 patients, two of whom were grade 3-4. Chronic GVHD has developed in four patients (1 serositis, 1 pericardial effusion and 2 nephrotic range proteinuria). CMV reactivation occurred in 9/12 patient with no CMV disease. Aspergillus antigen positivity in serum occurred in 4 /12 but only two of them developed clinical fungal infection. Conclusion: In this limited series of patients with high- risk hematological malignancies who underwent haploidentical HCT with Cy/Flu and Melphalan with PTCY, the regimen was well tolerated and resulted in effective disease control. The regimen has also demonstrated enhanced early engraftment and robust immune recovery in comparison to other studies, Table 3. The study provide unavailable knowledge
Table 1
S166
Abstracts / Biol Blood Marrow Transplant 23 (2017) S18–S391
Figure 1. Immune recovery post transplant.
Table 2
Table 3
this impacts immune responsiveness is of great interest but presently under-characterized. As patients are increasingly treated with BCL-2 family targeting compounds, selective pressure on the immune system will be of paramount significance. To study this, we have replicated long-term selective BCL-2 therapeutic pressure in a genetic model of BIM deletion in T cells. BIM is a master T cell pro-apoptotic “BH3-only” BCL-2 family member able to activate apoptosis through binding all known anti-apoptotic BCL-2 members and through directly activating pro-apoptotic BAX and BAK. The pro-death supremacy of BIM is underscored by a comprehensive BH3 knock-in study demonstrating that only the BH3 domain of BIM can functionally restore the Flox/Flox immune defect in Bim-null mice. Using an Lck-cre Bim murine model where BIM is deleted specifically in T cells we have shown that loss of BIM leads to profound early onset lymphocytosis that normalizes as mice age. In contrast, BIM deletion in B cells (CD19-cre BimFlox/Flox) leads to chronic moderate lymphocytosis indicating differential dependency of Band T-cells on BIM for expansion and survival. While loss of BIM causes early T cell expansion followed by contraction, regulatory T cells (Tregs) increase over time in Lck-cre BimFlox/ Flox/Flox Flox mice. As expected, T cells from young Lck-cre Bim mice were more resistant to ionomycin- and cytokine depravation-induced apoptosis than BIM replete T cells. However, T cells from older mice were less resistant to treatment, corresponding to their lymphocyte normalization. To determine if other BH3-only proteins were compensating for the loss of BIM over time, qRT-PCR analysis of BCL-2 family transcript levels from CD4+ T cells isolated from Lck-cre BimFlox/ Flox mice found increased expression of Noxa and Bmfcompared to normal T cells isolated from similarly aged controls. Interestingly, expression patterns of the BH3-only proteins begin to normalize to wild type levels over time. These findings provide strong evidence that long- and short-term selective BCL-2 pressure can modulate the BCL-2-family repertoire in T cells. In fact, Tregs treated for only 24 hours with the BH3mimetic ABT-737 show significant differences in their BCL-2 repertoire. Establishment of a BCL-2 “targetablility profile” within T cell subpopulations at steady-state and in response to treatment may allow for more timely use of BH3-mimetic compounds in conjunction with burgeoning immunotherapies such as tumor cell vaccines, checkpoint inhibitors, chimeric antigen receptor (CAR) T cells, or following stem cell transplantation.
207 about immune reconstitution post Haplo-identical HCT with PTCY with the use of mobilized peripheral blood.
206 T Cell BCL-2 Family Protein Dependence and Therapeutic Targetability Lindsey M. Ludwig 1,2, Greta Schmitt 1, James L. LaBelle 1,2. 1 Pediatric Hematology, Oncology and Stem Cell Transplantation, University of Chicago, Chicago, IL; 2 Committee on Cancer Biology, University of Chicago, Chicago, IL Elucidation of the BCL-2 repertoire of naïve effector, activated, memory, and regulatory T cells is under greater scrutiny as the ability to correlate BCL-2 expression patterns with functional apoptotic dependency grows. How this repertoire changes in response to BCL-2 family BH3-mimetics, and how
Early Adoptive Transfer of Ex Vivo Generated Multi-Virus Specific T Cells is a Safe Strategy to Prevent Viral Reactivation in Recipients of Allogeneic T Cell Depleted Stem Cell Transplant Pawel Muranski 1, Greg Whitehill 2, Sarah I. Davies 3, Quan Yu 2, Marianna Sabatino 4, Steven Highfill 5, Hanh Khuu 4, Mark Chang 2, Upneet Chawla 2, Prathima Anandi 2, Alexandros Spyridonidis 6, Sawa Ito 2, David F. Stroncek 4, Minocher Battiwalla 2, A. John Barrett 2. 1 Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD; 2 Hematology Branch, NHLBI/NIH, Bethesda, MD; 3 NHLBI/NIH, Bethesda, MD; 4 Department of Transfusion Medicine, National Institutes of Health, Bethesda, MD; 5 Department of Transfusion Medicine, NIH/Clinical Center, Bethesda, MD; 6 BMT Unit, University of Patras, Rio, Greece Background: Reactivation of latent viruses in allogeneic stem cell transplant (SCT) recipients significantly increases the risk
Figure 2. Monocyte recovery during the first 200 days after CBT and BMT. Absolute monocyte counts after CBT are depicted in blue and after BMT in red, black lines show the mean predictions of the logistic cell growth model.
Figure 3. Natural killer {NK} cell recovery during the first 200 days after CBT and BMT. Absolute NK-cell counts after CBT are depicted in blue and after BMT in red, black lines show the mean predictions of the logistic cell growth model.
interactions between innate and adaptive IR for better predictable IR.
205 Immune Reconstitution and Outcomes after Peripheral Blood Haploidentical Transplantation with Novel Conditioning and Post-Transplant Cyclophosphomide (PTCY) Yasser Khaled, Diwura Owolabi, Christy R. Parks, Deborah Lamontagne, Joshua D. Boss, Jason Chandler, Valeh Huseynov. University of Tennessee/Methodist University Hospital, Blood and Marrow Transplant Program-West Cancer Center, Memphis, TN The outcomes after Haploidentical HCT with Flu-CY-TBI and PTCY using BM as a graft source have been associated with high relapse and delayed immune recovery. Additionally, there is limited knowledge regarding immune reconstitution post haploidentical HCT with the use of mobilized peripheral blood. We hypothesized that the immunogenic properties of pretransplant low dose Cyclophosphamide along with immunomodulatory effects of Melphalan would enhance early post-transplant engraftment and early peripheral T cell recovery through enhanced cytokine release and antigen alloreactivity. We examined the clinical outcomes and immune reconstitution recovery of 12 consecutive haploidentical HCT patients with high-risk hematological malignancies. Patients and Graft characteristics is as shown in Table 1. Conditioning regimen
S165
was low dose Cy 14.5 mg/m2 on day -6 & day −5, Flu 30 mg/ m2 day −6 to Day −2 and Mel 70 mg/m2 on day −3 & −2. Graft versus host disease prophylaxis (GVHD) was PTCY 50 mg/ Kg on day +3 and day +4 along with Tacrolimus and Mycophenolate starting at day +5. Immune reconstitution performed on days +60, +120 and +180 post HCT. All the patients treated according to an institutional protocol and records reviewed retrospectively after IRB approval. All patients engrafted with median time to engraftment of 17 days (range 12-23). Chimerism studies revealed enhanced engraftment with 100% donor in bone marrow and peripheral blood at day 30 in all 12 patients. Post HCT immune recovery shown in Table 2. There was significant early recovery at day 60 of all T cell subsets, most pronounced in activated T cells. While we have observed a progressive reduction in the median number of early-activated T cells at day 120 & 180, the number CD4 and NK cells has improved (Figure 1). With median duration of follow up of 323 days, range (123451), the overall survival at day 100 and projected one year is 92% and 81% respectively. Only 2/12 had relapsed at 95 and 321 days post- transplant. Treatment related mortality (TRM) was limited to 1/12 patients. Acute GVHD grade 2-4 developed in six of 12 patients, two of whom were grade 3-4. Chronic GVHD has developed in four patients (1 serositis, 1 pericardial effusion and 2 nephrotic range proteinuria). CMV reactivation occurred in 9/12 patient with no CMV disease. Aspergillus antigen positivity in serum occurred in 4 /12 but only two of them developed clinical fungal infection. Conclusion: In this limited series of patients with high- risk hematological malignancies who underwent haploidentical HCT with Cy/Flu and Melphalan with PTCY, the regimen was well tolerated and resulted in effective disease control. The regimen has also demonstrated enhanced early engraftment and robust immune recovery in comparison to other studies, Table 3. The study provide unavailable knowledge
Table 1
S166
Abstracts / Biol Blood Marrow Transplant 23 (2017) S18–S391
Figure 1. Immune recovery post transplant.
Table 2
Table 3
this impacts immune responsiveness is of great interest but presently under-characterized. As patients are increasingly treated with BCL-2 family targeting compounds, selective pressure on the immune system will be of paramount significance. To study this, we have replicated long-term selective BCL-2 therapeutic pressure in a genetic model of BIM deletion in T cells. BIM is a master T cell pro-apoptotic “BH3-only” BCL-2 family member able to activate apoptosis through binding all known anti-apoptotic BCL-2 members and through directly activating pro-apoptotic BAX and BAK. The pro-death supremacy of BIM is underscored by a comprehensive BH3 knock-in study demonstrating that only the BH3 domain of BIM can functionally restore the Flox/Flox immune defect in Bim-null mice. Using an Lck-cre Bim murine model where BIM is deleted specifically in T cells we have shown that loss of BIM leads to profound early onset lymphocytosis that normalizes as mice age. In contrast, BIM deletion in B cells (CD19-cre BimFlox/Flox) leads to chronic moderate lymphocytosis indicating differential dependency of Band T-cells on BIM for expansion and survival. While loss of BIM causes early T cell expansion followed by contraction, regulatory T cells (Tregs) increase over time in Lck-cre BimFlox/ Flox/Flox Flox mice. As expected, T cells from young Lck-cre Bim mice were more resistant to ionomycin- and cytokine depravation-induced apoptosis than BIM replete T cells. However, T cells from older mice were less resistant to treatment, corresponding to their lymphocyte normalization. To determine if other BH3-only proteins were compensating for the loss of BIM over time, qRT-PCR analysis of BCL-2 family transcript levels from CD4+ T cells isolated from Lck-cre BimFlox/ Flox mice found increased expression of Noxa and Bmfcompared to normal T cells isolated from similarly aged controls. Interestingly, expression patterns of the BH3-only proteins begin to normalize to wild type levels over time. These findings provide strong evidence that long- and short-term selective BCL-2 pressure can modulate the BCL-2-family repertoire in T cells. In fact, Tregs treated for only 24 hours with the BH3mimetic ABT-737 show significant differences in their BCL-2 repertoire. Establishment of a BCL-2 “targetablility profile” within T cell subpopulations at steady-state and in response to treatment may allow for more timely use of BH3-mimetic compounds in conjunction with burgeoning immunotherapies such as tumor cell vaccines, checkpoint inhibitors, chimeric antigen receptor (CAR) T cells, or following stem cell transplantation.
207 about immune reconstitution post Haplo-identical HCT with PTCY with the use of mobilized peripheral blood.
206 T Cell BCL-2 Family Protein Dependence and Therapeutic Targetability Lindsey M. Ludwig 1,2, Greta Schmitt 1, James L. LaBelle 1,2. 1 Pediatric Hematology, Oncology and Stem Cell Transplantation, University of Chicago, Chicago, IL; 2 Committee on Cancer Biology, University of Chicago, Chicago, IL Elucidation of the BCL-2 repertoire of naïve effector, activated, memory, and regulatory T cells is under greater scrutiny as the ability to correlate BCL-2 expression patterns with functional apoptotic dependency grows. How this repertoire changes in response to BCL-2 family BH3-mimetics, and how
Early Adoptive Transfer of Ex Vivo Generated Multi-Virus Specific T Cells is a Safe Strategy to Prevent Viral Reactivation in Recipients of Allogeneic T Cell Depleted Stem Cell Transplant Pawel Muranski 1, Greg Whitehill 2, Sarah I. Davies 3, Quan Yu 2, Marianna Sabatino 4, Steven Highfill 5, Hanh Khuu 4, Mark Chang 2, Upneet Chawla 2, Prathima Anandi 2, Alexandros Spyridonidis 6, Sawa Ito 2, David F. Stroncek 4, Minocher Battiwalla 2, A. John Barrett 2. 1 Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD; 2 Hematology Branch, NHLBI/NIH, Bethesda, MD; 3 NHLBI/NIH, Bethesda, MD; 4 Department of Transfusion Medicine, National Institutes of Health, Bethesda, MD; 5 Department of Transfusion Medicine, NIH/Clinical Center, Bethesda, MD; 6 BMT Unit, University of Patras, Rio, Greece Background: Reactivation of latent viruses in allogeneic stem cell transplant (SCT) recipients significantly increases the risk