Faculty Bibliography

Following allogeneic blood and marrow transplantation (BMT), graft-versus-host disease (GvHD) continues to represent a significant cause of treatment failure, despite the routine use of conventional, mainly calcineurin inhibitor-based prophylaxis. Recently, post-transplant cyclophosphamide (PTCy) has emerged as a safe and efficacious alternative. First, omitting the need for ex vivo T-cell depletion in the setting of haploidentical transplantation, growing evidence supports PTCy role in GvHD prevention in matched-related and matched-unrelated transplants. Through improved understanding of GvHD pathophysiology and advancements in drug development, PTCy emerges as a unique opportunity to design calcineurin inhibitor-free strategies by integrating agents that target different stages of GvHD development.

CYAD-01 cells are engineered T-cells expressing a chimeric antigen receptor (CAR) based on the natural full-length human natural killer group 2D (NKG2D) receptor fused to the intracellular domain of CD3zeta. NKG2D binds to 8 ligands (MICA, MICAB, and ULBP1-6) over-expressed by a large variety of malignancies, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Phase I DEPLETHINK study (NCT03466320) evaluates the safety and preliminary efficacy of a single CYAD-01 infusion (inf.) after lymphodepletion with cyclophosphamide and fludarabine in patients with relapsed or refractory (r/r) AML and MDS. A second cycle of 3 CYAD-01 infusions without preconditioning could be administered in absence of progressive disease (PD) following the 1XX infusion. Three dose-levels (DLs; 1x10XX and 1x10XX cells/inf.) are evaluated in the dose escalation segment. The first DL is also evaluated at two different intervals between preconditioning and CYAD-01 infusion (T7: seven days interval; T3: three days interval) in order to mitigate for any potential increased toxicity due to the administration of lymphodepletion. As of end of July 2019, 6 patients (4 AML and 2 MDS) were enrolled in the first 2 cohorts which evaluated DL1 (1x10XX cells/inf. at T3 or T7) and 3 patients (3 AML) were enrolled in the cohort 3 evaluating DL2 (3x10XX cells/inf. at T3). The blasts in the bone marrow of 8 out of 9 patients ranged between 3% and 48% at baseline. Of the 6 patients treated at DL1 (with lymphodepletion administered up to 7 or 3 days before first CYAD-01 infusion), 3 patients experienced grade (G) 1 toxicity (cytokine release syndrome or CRS and diarrhea), or G2 CRS (uncleaned database). The patient with G2 CRS following the first infusion also experienced G4 CRS and G3 CAR T-cell-related encephalopathy syndrome (CRES) during the second inf. at 3x10XX cells/inf. One other patient experienced G1 CRS during the second cycle. At DL2, only 1 patient experienced G1 related AEs (diarrhea and CRS) after the first CYAD-01 infusion. Another patient experienced G3 CRS during the second cycle. All patients recovered with treatment including tocilizumab and, when indicated, steroids. At DL1, two out of 5 evaluable patients reached a stable disease (SD) at day (d) 36, allowing the initiation of the 2XX cycle. At DL2, one patient out of 3 reached SD. The DEPLETHINK study is currently enrolling at DL3 (T3). Preliminary correlative studies show that the area under the curve at d36 (AUC XX) after a single infusion of CYAD-01 with prior lymphodepletion is better than without preconditioning. Furthermore, the T3 interval between the preconditioning and CYAD-01 provides better engraftment than the T7 interval. In conclusion, to date, the results demonstrate the safety and tolerability for CYAD-01 doses 1x10XX cells/infusion with a prior lymphodepletion in patients with r/r AML and MDS. The T3 interval was therefore chosen for further CYAD-01 evaluations. The improved persistence of CYAD-01 with lymphodepletion, in particular 3 days before infusion, could lead to improved clinical responses. The study is ongoing and further data will be provided at the meeting. Disclosures: Al-Homsi: Celyad: Membership on an entity's Board of Directors or advisory committees. Abdul-Hay: Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Pollyea: Diachii Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Forty-Seven: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lequertier: Celyad: Employment. Alcantar-Orozco: Celyad: Employment. Borghese: Celyad: Employment. Lonez: Celyad: Employment. Braun: Celyad: Employment. Renard: Celyad: Employment. Flament: Celyad: Employment.XXCopyright

The rapid evolution of Blood and Marrow Transplant (BMT), coupled with diverse outcomes associated with heterogeneous groups of patients, led to the formation of two important organizations early in the development of the field: the Center for International Blood and Marrow Transplant Research (CIBMTR) and the Foundation for the Accreditation of Cellular Therapy (FACT). These organizations have addressed two of the nine elements identified by the National Quality Strategy (NQS) [1] for achieving better health care, more affordable care, and healthy people and communities: first, a registry that promotes improvement of care and, second, accreditation based on quality standards. More recently, a federally-mandated database in the United States addresses the third element of the NQS: public reporting of treatment results. This paper describes the current process by which FACT incorporates patient outcomes reported by the CIBMTR into standards for accreditation, the requirements for accredited programs whose performance is below expected outcomes to maintain accreditation, and preliminary findings in assessing corrective action plans intended to improve outcomes.

Background: Substrate competitive proteasome inhibitor, bortezomib, has been shown to prevent GvHD in murine models and in early phase clinical trials. However, sustained administration of bortezomib aggravates GvHDrelated intestinal injury, in part due to paradoxical increase in interleukin (IL) 1beta. Imidazoline scaffold TCH-013 compound prevents proteasome cap binding to alpha rings and thus modulates proteasome activity. We aimed to study the effects of TCH-013 on dendritic cell (DC) maturation and cytokine production and on T cell proliferation and differentiation in vitro. We also examined the ability of TCH-013 to protect mice in an MHC-mismatched GvHD model.
Method(s): DCs were isolated from the peripheral blood of healthy volunteers and treated with TCH-013 at different concentrations (12 and 24 muM) for 4 hrs and were then stimulated with lipopolysaccharide (LPS) for 16 hrs. DCs were then stained with antibodies against maturation markers and analyzed by flow cytometry. DC viability was assessed after 7AAD staining. Pro-inflammatory cytokines were measured in the supernatant of DC cultures treated before or after stimulation with LPS. Similarly, the effects of TCH-013 on T cell differentiation was studied in healthy volunteer mononuclear cells stimulated with T cell activating antibodies without and with the addition of TCH-013. Th1, Th17, and regulatory T cells (Tregs) were enumerated after staining with antibodies to IFNy, IL-17, and FOXP3. At a minimum, all experiments were done in triplicate. ANOVA with Tukey post hoc tests was used for statistical analysis. A p value < 0.05 was considered significant. A B6 <- BALB/c pre-clinical GvHD model was adopted to evaluate the effect of TCH-013 on GvHD development. Mice were transplanted in 3 groups with intraperitoneal injection of either a vehicle or TCH-013 250 mg/kg on days 0 to +3 or TCH-013 250 mg/kg on days 0 to +6.
Result(s): TCH-013 inhibited the expression of DC maturation markers including CD40, CD54, CD80, and CD86. DCs viability remained unchanged compared to the control. TCH-013 significantly decreased DC production of IL-1beta and IL-6. TCH-013 decreased TNF-alpha at the higher concentration. Importantly, TCH-013 did not cause paradoxical IL-1beta by pre-stimulated DCs. In mononuclear cell cultures, TCH-013 decreased the percentage of Th1 and Th17 cells and increased the Tregs:Th1 and Tregs:Th17 ratio. In vivo, TCH-013 improved GvHD scores and survival compared to the control. Noticeably, TCH-013 did not cause GvHD exacerbation in mice treated from days 0 to +6.
Conclusion(s): T cell differentiation, by reducing Th1 and Th17 and increasing Tregs ratio to Th1 and Th17; 3) TCH-013 ameliorates GvHD in an aggressive murine model; 4) Contrary to the effects of bortezomib, TCH-013 does not cause a paradoxical surge in IL-1beta in pre-stimulated DCs and does not exacerbate GvHD in mice treated in a sustained fashion

Graft-versus-host disease (GVHD) hampers the utility of allogeneic hematopoietic stem cell transplantation (AHSCT). The purpose of this study was to determine the feasibility, safety, and efficacy of a novel combination of post-transplantation cyclophosphamide (PTC) and bortezomib for the prevention of GVHD. Patients undergoing peripheral blood AHSCT for hematological malignancies after reduced-intensity conditioning with grafts from HLA-matched related or unrelated donors were enrolled in a phase I/II clinical trial. Patients received a fixed dose of PTC and an increasing dose of bortezomib in 3 cohorts, from .7 to 1 and then to 1.3 mg/m², administered 6 hours after graft infusion and 72 hours thereafter, during phase I. The study was then extended at the higher dose in phase II for a total of 28 patients. No graft failure and no unexpected grade ≥3 nonhematologic toxicities were encountered. The median times to neutrophil and platelet engraftment were 16 and 27 days, respectively. Day +100 treatment-related mortality was 3.6% (95% confidence interval [CI], .2% to 15.7%). The cumulative incidences of grades II to IV and grades III and IV acute GVHD were 35.9% (95% CI, 18.6% to 53.6%) and 11.7% (95% CI, 2.8% to 27.5%), respectively. The incidence of chronic GVHD was 27% (95% CI, 11.4% to 45.3%). Progression-free survival, overall survival, and GVHD and relapse-free survival rates were 50% (95% CI, 30.6% to 66.6%), 50.8% (95% CI, 30.1% to 68.2%), and 37.7% (95% CI, 20.1% to 55.3%), respectively. Immune reconstitution, measured by CD3, CD4, and CD8 recovery, was prompt. The combination of PTC and bortezomib for the prevention of GVHD is feasible, safe, and yields promising results. The combination warrants further examination in a multi-institutional trial.

There is an abiding need for innovative approaches to the prevention of graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation (HSCT). Interest in prevention of GvHD by dendritic cell (DC) suppression has re-emerged since the introduction of proteasome inhibitors into clinical practice. Ixazomib is an orally bioavailable proteasome inhibitor with a rapid proteasome dissociation rate. We studied the effects of ixazomib on human DC maturation, viability, and cytokine production in vitro. We also determined the effects of ixazomib in a murine GvHD model. Although ixazomib suppressed naive human DC maturation, it had only a limited effect on cell viability. Ixazomib decreased pro-inflammatory cytokine production of resting DCs. This effect was diminished or reversed when DCs were pre-stimulated. In vivo, ixazomib administered post-transplantation on days +1 and +4 or days -1, +2, and +5 ameliorated GvHD in comparison to the GvHD group. Although a fraction of mice treated according to the prolonged schedule died abruptly after the day +5 treatment, both schedules resulted in improved overall survival. When we examined the effects of ixazomib on splenic cells and serum cytokines, we found that ixazomib exerted complex schedule-dependent immunomodulatory effects. Our study provides a rationale for the potential use of ixazomib in the prevention of GvHD.

Lapses in the prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) warrant novel approaches. Such approaches include, among others, the use of post-transplantation cyclophosphamide (PTC) and proteasome inhibitors. Although PTC alone consistently produces low rates of chronic GVHD, the incidence of acute GVHD remains significant. Inversely, prolonged post-transplantation administration of proteasome inhibitors carries a risk of paradoxical aggravation of GVHD. We examined whether the combination of cyclophosphamide and ixazomib addresses the limitations of each of these agents when used alone to prevent GVHD in mice subjected to allogeneic HSCT across MHC barriers. We chose ixazomib, an orally bioavailable proteasome inhibitor, because of its favorable physiochemical characteristics. The combination of cyclophosphamide and ixazomib improved overall survival of mice in comparison to an untreated control group and to groups receiving either cyclophosphamide alone or ixazomib alone. Furthermore, cyclophosphamide prevented the surge of IL-1beta, GVHD aggravation, and sudden death associated with prolonged administration of ixazomib after HSCT. Finally, we demonstrated that although ixazomib was administered before cyclophosphamide, it did not impair the preferential depletion of proliferating as opposed to resting donor T cells. Our data suggest that the combination of cyclophosphamide and ixazomib for the prevention of GVHD after allogeneic HSCT is promising and merits further investigation in clinical trials.

Waldenstrom macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL) is characterized by lymphoplasmacytic proliferation, lymph node and spleen enlargement, bone marrow involvement, and IgM production. Treatment varies based on the extent and biology of disease. In some patients, the use of allogeneic hematopoietic cell transplantation (alloHCT) may have curative potential. We evaluated long-term outcomes of 144 patients who received adult alloHCT for WM/LPL. Data were obtained from the Center for International Blood and Marrow Transplant Research database (2001 to 2013). Patients received myeloablative(n = 67) or reduced-intensity conditioning (RIC; n = 67). Median age at alloHCT was 53 years, and median time from diagnosis to transplantation was 41 months. Thirteen percent (n = 18) failed prior autologous HCT. About half (n = 82, 57%) had chemosensitive disease at the time of transplantation, whereas 22% had progressive disease. Rates of progression-free survival, overall survival, relapse, and nonrelapse mortality at 5 years were 46%, 52%, 24%, and 30%, respectively. Patients with chemosensitive disease and better pretransplant disease status experienced significantly superior overall survival. There were no significant differences in progression-free survival based on conditioning (myeloablative, 50%, versus RIC, 41%) or graft source. Conditioning intensity did not impact treatment-related mortality or relapse. The most common causes of death were primary disease and graft-versus-host disease (GVHD). AlloHCT yielded durable survival in select patients with WM/LPL. Strategies to reduce mortality from GVHD and post-transplant relapse are necessary to improve this approach.

BACKGROUND: Chimeric antigen receptor (CAR)-modified "designer" T cells (dTc, CAR-T) against PSMA selectively target antigen-expressing cells in vitro and eliminate tumors in vivo. Interleukin 2 (IL2), widely used in adoptive therapies, was proven essential in animal models for dTc to eradicate established solid tumors. METHODS: Patients under-went chemotherapy condi-tion-ing, followed by dTc dosing under a Phase I escalation with continuous infusion low dose IL2 (LDI). A target of dTc escalation was to achieve >/=20% engraftment of infused activated T cells. RESULTS: Six patients enrolled with doses prepared of whom five were treated. Patients received 10(9) or 10(10) autologous T cells, achieving expansions of 20-560-fold over 2 weeks and engraftments of 5-56%. Pharmacokinetic and pharmacodynamic analyses established the impact of conditioning to promote expansion and engraftment of the infused T cells. Unexpectedly, administered IL2 was depleted up to 20-fold with high engraftments of activated T cells (aTc) in an inverse correlation (P < 0.01). Clinically, no anti-PSMA toxicities were noted, and no anti-CAR reactivities were detected post-treatment. Two-of-five patients achieved clinical partial responses (PR), with PSA declines of 50% and 70% and PSA delays of 78 and 150 days, plus a minor response in a third patient. Responses were unrelated to dose size (P = 0.6), instead correlating inversely with engraftment (P = 0.06) and directly with plasma IL2 (P = 0.03), suggesting insufficient IL2 with our LDI protocol to support dTc anti-tumor activity under optimal (high) dTc engraftments. CONCLUSIONS: Under a Phase I dose escalation in prostate cancer, a 20% engraftment target was met or exceeded in three subjects with adequate safety, leading to study conclusion. Clinical responses were obtained but were suggested to be restrained by low plasma IL2 when depleted by high levels of engrafted activated T cells. This report presents a unique example of how the pharmaco-dynamics of "drug-drug" interactions may have a critical impact on the efficacy of their co-application. A new Pilot/Phase II trial is planned to test moderate dose IL2 (MDI) together with high dTc engraftments for anticipated improved therapeutic efficacy. Prostate 76:1257-1270, 2016. (c) 2016 Wiley Periodicals, Inc.

Allogeneic hematopoietic stem cell transplantation is the standard treatment for a variety of benign and malignant conditions. However, graft-versus-host disease (GvHD) continues to present a major barrier to the success and wide applicability of this procedure. Although current GvHD prevention and treatment regimens exclusively target T cells, bortezomib, a reversible proteasome inhibitor, possesses unique immune regulatory activities that span a wide variety of cellular processes of T and dendritic cells essential for the development of GvHD. Herein, we review the current understanding of the effects of bortezomib in vitro and in animal models and summarize the clinical data relevant to its use in the prevention and treatment of GvHD. We conclude with an outline of the remaining challenges and opportunities to optimize bortezomib's potential role in this setting.