Gamida Cell Research Articles

A Phase I Study of FT819, a First-of-Kind, Off-the-Shelf, iPSC-Derived TCR-Less CD19 CAR T Cell Therapy for the Treatment of Relapsed/Refractory B-Cell Malignancies

A Phase I Study of FT819, a First-of-Kind, Off-the-Shelf, iPSC-Derived TCR-Less CD19 CAR T Cell Therapy for the Treatment of Relapsed/Refractory B-Cell Malignancies

Combination of Ibrutinib with Rituximab (IR) in Previously Untreated Older Patients with Mantle Cell Lymphoma (MCL) - a Phase II Clinical Trial

Combination of Ibrutinib with Rituximab (IR) in Previously Untreated Older Patients with Mantle Cell Lymphoma (MCL) - a Phase II Clinical Trial

A 3-Question Symptom Assessment Score Can Predict Outcomes in Newly Diagnosed Multiple Myeloma (MM)

A 3-Question Symptom Assessment Score Can Predict Outcomes in Newly Diagnosed Multiple Myeloma (MM)

Preliminary Results of a Phase 1 Dose Escalation Study of the First-in-Class IgM Based Bispecific Antibody Igm-2323 (anti-CD20 x anti-CD3) in Patients with Advanced B-Cell Malignancies

Preliminary Results of a Phase 1 Dose Escalation Study of the First-in-Class IgM Based Bispecific Antibody Igm-2323 (anti-CD20 x anti-CD3) in Patients with Advanced B-Cell Malignancies

Outcomes of Acalabrutinib Failures in Relapsed Mantle Cell Lymphoma

Outcomes of Acalabrutinib Failures in Relapsed Mantle Cell Lymphoma

The Utility of Granulocyte Colony Stimulating Factor in Patients Receiving Chimeric Antigen Receptor T-Cell Therapy with Axicabtagene Ciloleucel

Background: Infection during the period of neutropenia following chemotherapy represents a major cause of morbidity and mortality in patients with malignancy.(Freifeld, et al, 2011, Baden LR, et al, 2012) Several guidelines recommend granulocyte colony stimulating factor (GCSF) to reduce the duration and severity of chemotherapy-induced neutropenia and abate infection risk.(Lyman, et al 2018, Aapro, et al, 2011, Smith, et al, 2015). Optimal GCSF administration following chimeric antigen receptor (CAR) T-cell therapy remains undefined and requires characterization. Methods: The Mayo Institutional Review Board approved this retrospective, single-center study. Electronic medical records for patients prescribed axicabtagene ciloleucel were reviewed until disease relapse, death, or a maximum of 60 days after infusion. Baseline characteristics and laboratory values were abstracted prior to lymphodepleting chemotherapy. GCSF support was originally prescribed when the absolute neutrophil count (ANC) declined below 500 cells/mm3 and discontinued when the ANC exceeded 1000 cells/mm3 (neutropenia) for 2 consecutive days. A practice change was made where GCSF was recommended only in those with febrile neutropenia and an increased concern for infection. The primary endpoint was the difference in the total days of neutropenia for patients receiving and not receiving GCSF. Secondary outcomes compared total days of severe neutropenia, number of neutropenia episodes, infection rates by GCSF use, and outcomes by protocol change. Neutropenia and severe neutropenia were defined as an ANC below 500 cells/mm3 and 100 cells/mm3, respectively. Updated data with more patients will be presented at the conference. Results: The 60 included patients had a median age of 59 (IQR: 44, 63) years, 38 (63%) were male and 53 (88%) were Caucasian. Significantly fewer patients were prescribed GCSF according to infection-related concerns compared to ANC-based indication, 18% vs. 94%, p<0.001. Because only 3 subjects received GCSF based on infection-related concerns, results based on GCSF use versus no use is shown here. GCSF was prescribed to 35 (58%) patients for a median of 8 (IQR: 6, 12) doses with a median cumulative dosage of 3840 mcg (IQR 2100-5400) and median time to first dose of 3 days (IQR: 1, 4) post CAR T-cell infusion. Table 1 displays additional baseline characteristics and laboratory parameters according to GCSF support utilization. GCSF prescribed: Table 2 displays outcomes by GCSF use. Total days of neutropenia were similar between groups (13 vs. 16, p=0.52) with a trend towards significantly fewer days of severe neutropenia when prescribed GCSF (6 vs. 9, p=0.129). Patients prescribed GCSF were more likely to experience multiple episodes of neutropenia (83% vs. 43% p=0.002) with a significantly greater median number of episodes (3 vs. 1, p=0.002) when compared to those not prescribed GCSF. GCSF use significantly decreased the median days of the first neutropenia episode (6 vs. 12, p=0.001). There was a trend for decreased median days of severe neutropenia in the first episode with GCSF (5.0 vs. 8.0, p=0.236). Figure 1 displays a trend towards a lower overall risk of infection (HR 0.55, 95%CI: 0.16-1.87, p=0.34) and lower risk of bacterial infection (HR: 0.49, 95% CI: 0.18-1.31, p=0.15); however, these were not statistically significant. Conclusion: Patients prescribed GCSF according to ANC-based indication were significantly more likely to experience multiple neutropenia episodes; however, duration of first neutropenic episode and days of severe neutropenia during the first neutropenic episode were significantly reduced. Interestingly, the total days of neutropenia and severe neutropenia were similar between groups. It is possible that using the parameter of ANC more than 1000 cells/mm3 for 2 consecutive days is not the optimal criteria for stopping GCSF. Risk of overall and bacterial infection was lower with ANC-based initiation of GCSF, although non-significant likely due to small sample size. The potential benefit for using CSF and the optimal timing after CAR T-cell infusion requires further, rigorous, prospective investigation. Disclosures Ansell: ADC Therapeutics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; AI Therapeutics: Research Funding; Takeda: Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding. Bennani:Purdue Pharma: Other: Advisory Board; Kite/Gilead: Research Funding; Affimed: Research Funding; Verastem: Other: Advisory Board. Lin:Kite, a Gilead Company: Consultancy, Research Funding; Vineti: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gamida Cells: Consultancy; Takeda: Research Funding; Merck: Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding.

The Burkitt Lymphoma International Prognostic Index (BL-IPI)

The Burkitt Lymphoma International Prognostic Index (BL-IPI)

Cytokine Release Syndrome in Patients with Relapsed/Refractory Multiple Myeloma Treated with Ciltacabtagene Autoleucel in the Phase 1b/2 CARTITUDE-1 Study

Cytokine Release Syndrome in Patients with Relapsed/Refractory Multiple Myeloma Treated with Ciltacabtagene Autoleucel in the Phase 1b/2 CARTITUDE-1 Study

Orca-T, a Precision Treg-Engineered Donor Product, Prevents Acute Gvhd with Less Immunosuppression in an Early Multicenter Experience with Myeloablative HLA-Matched Transplants

Orca-T, a Precision Treg-Engineered Donor Product, Prevents Acute Gvhd with Less Immunosuppression in an Early Multicenter Experience with Myeloablative HLA-Matched Transplants

Health-Related Quality of Life in the Cartitude-1 Study of Ciltacabtagene Autoleucel for Relapsed/Refractory Multiple Myeloma

Health-Related Quality of Life in the Cartitude-1 Study of Ciltacabtagene Autoleucel for Relapsed/Refractory Multiple Myeloma

Superiority of Thiotepa-Containing Conditioning Regimens in Patients with Primary Diffuse Large B-Cell Lymphoma (DLBCL) of the Central Nervous System (CNS) Undergoing Autologous Hematopoietic Cell Transplantation (autoHCT)

INTRODUCTION Primary DLBCL of the CNS (PCNSL) is a rare, extra-nodal non-Hodgkin lymphoma with high risk of relapse without consolidation therapies. AutoHCT has emerged as an accepted consolidation strategy, especially with increasing use of CNS penetrant chemotherapy agents in transplant conditioning. However, studies defining the optimal conditioning regimen for PCNSL have not been performed. The use of two common conditioning regimens in the U.S., thiotepa/busulfan/cyclophosphamide (TBC) and thiotepa/carmustine (TT-BCNU), is supported by phase II trials, but lack comparative data. Extrapolating experience from systemic lymphomas, BEAM (BCNU/etoposide/cytarabine/melphalan) is also prescribed for PCNSL in the U.S. Using the Center for International Blood & Marrow Transplant Research (CIBMTR) registry, we compared outcomes for PCNSL patients undergoing autoHCT using the three most commonly employed conditioning regimens: TBC vs. TT-BCNU vs. BEAM. METHODS Six hundred and eight adult PCNSL patients who underwent a first autoHCT between 2010-2018 were included. Conditioning regimens included TBC (n = 265), TT-BCNU (n = 278), and BEAM (n = 65). The primary endpoint was progression-free survival (PFS). Secondary endpoints included (a) time to hematopoietic recovery, (b) relapse/progression, (c) non-relapse mortality (NRM), and (d) overall survival (OS). Kaplan-Meier method was used to estimate probabilities of PFS and OS. Cox proportional hazard analysis was used to identify prognostic factors for relapse, NRM, PFS, and OS. Variables considered in regression model include patient age, sex, race, performance status, HCT-comorbidity index (HCT-CI), rituximab use during conditioning, interval between diagnosis and HCT, and remission status. Covariates with a p<0.05 were considered significant. RESULTS Baseline characteristics are presented in Table 1. The groups were comparable with regards to median patient age, gender, race, HCT-CI, and remission status. The cumulative incidences of neutrophil recovery at 1-month for the three conditioning regimens were: TBC 96% (95%CI 94-98%), TT-BCNU 100% (95%CI 98-100%), and BEAM 100% (95%CI 100%), (p < 0.001). The cumulative incidence rate of relapse for TBC, TT-BCNU, and BEAM at 1-year were 6% (95%CI 3-9%), 10% (95%CI 7-14%), and 23% (95%CI 14-35%), respectively (p = 0.003). The corresponding cumulative incidence rate of relapse at 3-years were 11% (95%CI 7-16%), 15% (95%CI 10-20%) and 37% (95%CI 25-50%) (p < 0.001) respectively. The adjusted NRM were higher for TBC: 100-day 7% (95%CI 4-10%) and 1-year 11% (95%CI 7-15%), compared to TT-BCNU: 100-day 2% (95%CI 0.2-3%) and 1-year 4% (95%CI 2-6%), and BEAM: 100-day 0% (95%CI 0%) and 1-year 4% (95%CI 0-9%) (1-year p=0.01). The 3-year adjusted PFS across the three conditioning regimens were: TBC 75% (95%CI 69-81%), TT-BCNU 76% (95%CI 70-82%), and BEAM 58% (95%CI 46-70%) (p = 0.03) [Figure 1a]. The adjusted OS at 3-years were: TBC 81% (95%CI 75-86%), TT-BCNU 78% (95%CI 72-85%) and BEAM 69% (95%CI 58-80%), (p = 0.17) [Figure 1b]. Relapse of primary disease was the most common cause of death in all three cohorts: TBC 38% (n=20), TT-BCNU 72% (n=33) and BEAM 76% (n=19). Other significant causes of death in the TBC group included infections 15% (n=8) and organ failure 21% (n=11). CONCLUSIONS In this CIBMTR analysis in patients with PCNSL, we found favorable outcomes with thiotepa-containing conditioning regimens. Adjusted 3-year PFS favored TBC and TT-BCNU over BEAM and suggest that use of BEAM should be discouraged in this specific setting. Whether TBC or TT-BCNU is the optimal conditioning regimen requires further inquiry in a prospective clinical trial. Disclosures Scordo: McKinsey & Company: Consultancy; Omeros Corporation: Consultancy; Kite - A Gilead Company: Other: Ad-hoc advisory board; Angiocrine Bioscience, Inc.: Consultancy, Research Funding. Kharfan-Dabaja:Pharmacyclics: Consultancy; Daiichi Sankyo: Consultancy. Herrera:Pharmacyclics: Research Funding; Karyopharm: Consultancy; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding; Merck: Consultancy, Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Gilead Sciences: Consultancy, Research Funding; AstraZeneca: Research Funding; Immune Design: Research Funding; Seattle Genetics: Consultancy, Research Funding. Hamadani:Janssen R&D; Incyte Corporation; ADC Therapeutics; Celgene Corporation; Pharmacyclics, Omeros, AbGenomics, Verastem, TeneoBio: Consultancy; Sanofi Genzyme, AstraZeneca: Speakers Bureau; Takeda Pharmaceutical Company; Spectrum Pharmaceuticals; Astellas Pharma: Research Funding; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees. Sauter:Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharamaceuticals: Consultancy; Novartis: Consultancy; Genmab: Consultancy; Precision Biosciences: Consultancy, Research Funding; Kite - a Gilead Company: Consultancy; Celgene: Consultancy, Research Funding; Gamida Cell: Consultancy; GSK: Consultancy; Bristol-Myers Squibb: Research Funding; Juno Therapeutics: Consultancy, Research Funding.

Response to Bridging Therapy (BT) before CAR-T Cell Infusion Predicts Outcomes for Relapsed/Refractory (R/R) Aggressive B-Cell Non-Hodgkin Lymphoma (NHL)

Background: Real world multi-institutional data of anti-CD19 CAR-T therapy from across the US shows similar response rates and toxicities as that of the registration trials. For axicabtagene ciloleucel (axi-cel), bridging therapy (BT) during CAR-T manufacturing was not allowed. Real world data shows that patients who received BT had lower complete remission (CR) rates, duraiton of response (DOR) and overall survival (OS). Whether the poorer outcome is due to the effect of the BT or the aggressive biology of the disease is unknown. Patients with lower disease burden had higher response rate in the registration study ZUMA-1 for axi-cel. We examined the impact of response to BT on CAR-T outcome. Specifically, we also describe our experience using polatuzumab vedotin, bendamustine and rituximab (Pola-BR), also a recently approved therapy for relapsed/refractory diffuse large B-cell lymphoma (DLBCL), prior to CAR-T as salvage (ST) and BT. Methods: A retrospective review of 63 patients who received axi-cel for NHL from June 2016 - March 2020 at Mayo Clinic, Rochester was performed. ST was defined as the last therapy prior to leukapheresis and grouped into categories - autologous stem cell transplant (ASCT), and non-ASCT (chemotherapy and immunotherapy) . BT was defined as lymphoma-directed therapy given between leukapheresis and CAR-T infusion. Response to all lymphoma-directed therapy was evaluated using 2014 Lugano criteria. Event free survival (EFS) was defined as time from axi-cel infusion to progression, next treatment, or death. Overall survival (OS) was defined as time from axi-cel infusion to death. Results: Patients received BT if there were concerns for symptomatic progression of disease during CAR-T manufacturing that would reduce the likelihood of eligibility to receive CAR-T. The decision and choice of BT was at the discretion of the treating physician. Sixty-eight percent (n=43) of the patients received BT (19 chemo, 24 immunotherapy). Demographics of the patients based on their response to BT are shown in table 1. More patients in the BT responder group had received chemotherapy as type of bridge (58% vs. 33%). With a median follow up of 12-months for those still alive, significant improvement in EFS was seen in patients who had partial response (PR) or stable disease (SD) to BT than patients who continued to progress (median 12 months vs. 3 months, p = 0.01) [Figure 1A]. OS however, was not significant between the two groups (median OS 18 months - responders vs. 12 months non-responders, p = 0.19) [Figure 1B]. We also describe in the case series below 11 patients who received Pola-BR in salvage setting (ST) and/or BT (Table 2). Due to the lymphopenic effects of bendamustine, it was avoided before T-cell collection if possible. Two patients, however, received bendamustine as part of Pola-BR for salvage therapy as its need was determined per the managing physician. Axi-cel was successfully manufactured for all 10 patients. One patient did not have measurable disease after Pola-BR BT and remains on observation. A second patient died before CAR-T infusion from progressive disease. Four of the nine patients treated with CAR-T remained in response. Updated outcome will be presented. Conclusion: While patients who received BT have worse EFS than those who didn't, having some control of lymphoma after BT was associated with better EFS compared to patients who continued to have progressive disease after BT. Preliminary data from Pola-BR case series shows 60% (6/10) patients achieved PR/SD before CAR-T infusion, but requires longer follow up for its impact on survival. Disclosures Bennani: Purdue Pharma: Other: Advisory Board; Kite/Gilead: Research Funding; Affimed: Research Funding; Verastem: Other: Advisory Board. Ansell:AI Therapeutics: Research Funding; Takeda: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; ADC Therapeutics: Research Funding; Trillium: Research Funding. Lin:Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Juno: Consultancy; Legend BioTech: Consultancy; Merck: Research Funding; Takeda: Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy.

Outcomes of HMA and Venetoclax in Relapsed AML Post-Allogenic Hematopoietic Stem Cell Transplant

Background: There is no standard of care treatment for Acute Myeloid Leukemia (AML) in relapse post-allogeneic hematopoietic stem cell transplant (post-HSCT), with overall 5-year survival about 5-10%. Venetoclax (Ven) is a novel BCL2 inhibitor approved by the FDA for treatment of newly diagnosed AML in combination with hypomethylating agents (HMA) or low dose cytarabine for patients unfit for intensive induction. However, data in relapsed/refractory AML are limited, especially in the post-HSCT setting. In this retrospective study, we reviewed outcomes of patients with AML relapse post-HSCT who received Ven in combination with HMA in a single center. Methods: Charts of 17 patients who had AML relapse post-HSCT treated with combination of Ven and HMA between November 2018 - March 2020 at the University of Kansas Medical Center were reviewed. We utilized descriptive statistics for baseline characteristics and outcomes, and Kaplan-Meier log-rank test for calculating overall survival. Results Seventeen patients received Ven+HMA for AML relapse post-HSCT in our center. At the time of SCT, patients were in first complete remission (CR) (n=15); second CR (n=1) and primary failure induction (1). Median age was 62 at time of relapse (31-71) years, and 8 patients were female (47%). 9 patients (53%) had adverse risk AML (ELN 2017) 8 of them were in CR1 and 1 with primary induction failure. Common mutations included DNMT3a, ASLX-1, TET2 (3); TP53 (2); IDH1/2 (2); NPM1/FLT3 (1); NPM1/IDH2 (1); NPM1 (1 transplanted in CR2); FLT3 (1). 2/17 had received Ven+HMA prior to SCT; 4 patients received HMA alone prior to SCT. 11 patients (65%) were naïve to either Ven or HMA prior to relapse. Median time to relapse was 181 (44-851) days post-HSCT. 9 (53%) patients received Azacitidine+Ven and 8 (47%) received Decitabine+Ven. HMA+Ven was the first line of therapy post-HSCT relapse in 14 patients. 2 had donor lymphocyte infusion (DLI) after either MEC or dacogen but relapsed prior to Ven+HMA. 1 had IDH (2) inhibitor. Patients received median of 2 (1-10) cycles of HMA+Ven. Six (35%) patients achieved complete remission/complete remission with incomplete hematologic recovery (CR/CRi), and 2/6 patients had negative measurable residual disease by multiparameter flow cytometry. Median overall survival was 361 days from relapse (Figure 1). 3/14 patients received subsequent DLI with Ven+HMA. Disease progression was the most common cause of death in 8/9 of patients who died during the follow up period. Most common side effects included neutropenic fever (n=8, 47%) and acute graft versus host disease (aGVHD) (n=5, 30%). 2/5 developed new aGVHD on HMA+Ven with no prior history of aGVHD. However, aGVHD was mainly grade I-II and responsive to therapy. Discussion HMA+Venetoclax demonstrates potential activity in patients with AML relapse post-HSCT with a CR/CRi rate of 35%, comparable to other salvage therapies. There were no unexpected side effect in this high-risk population. Larger studies are needed to confirm efficacy and toxicity in this setting. Disclosures McGuirk: Pluristem Ltd: Research Funding; Kite Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gamida Cell: Research Funding; Bellicum Pharmaceutical: Research Funding; Allo Vir: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Astellas: Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding. Lin:Aptevo: Research Funding; Abbvie: Research Funding; Bio-Path Holdings: Research Funding; Celgene: Research Funding; Gilead Sciences: Research Funding; Incyte: Research Funding; Jazz: Research Funding; Mateon Therapeutics: Research Funding; Ono Pharmaceutical: Research Funding; Pfizer: Research Funding; Prescient Therapeutics: Research Funding; Seattle Genetics: Research Funding; Tolero Pharmaceuticals: Research Funding; Trovagene: Research Funding; Genetech-Roche: Research Funding; Celyad: Research Funding; Astellas Pharma: Research Funding.

Ibrutinib Plus Rituximab (IR) Followed By Short Course R-Hypercvad/MTX in Patients (age ≤ 65 years) with Previously Untreated Mantle Cell Lymphoma - Phase-II Window-1 Clinical Trial

Ibrutinib Plus Rituximab (IR) Followed By Short Course R-Hypercvad/MTX in Patients (age ≤ 65 years) with Previously Untreated Mantle Cell Lymphoma - Phase-II Window-1 Clinical Trial

Nonmyeloablative Allogeneic Stem Cell Transplantation with or without Inotuzumab Ozogamicin for Lymphoid Malignancies

Nonmyeloablative Allogeneic Stem Cell Transplantation with or without Inotuzumab Ozogamicin for Lymphoid Malignancies

Characterization of Cytokine Release Syndrome in the KarMMa Study of Idecabtagene Vicleucel (ide-cel, bb2121) for Relapsed and Refractory Multiple Myeloma

Characterization of Cytokine Release Syndrome in the KarMMa Study of Idecabtagene Vicleucel (ide-cel, bb2121) for Relapsed and Refractory Multiple Myeloma

Idecabtagene Vicleucel (ide-cel, bb2121), a BCMA-Directed CAR T Cell Therapy, in Patients with Relapsed and Refractory Multiple Myeloma: Updated Results from Phase 1 CRB-401 Study

Idecabtagene Vicleucel (ide-cel, bb2121), a BCMA-Directed CAR T Cell Therapy, in Patients with Relapsed and Refractory Multiple Myeloma: Updated Results from Phase 1 CRB-401 Study

A Phase II Study of Pembrolizumab in Combination with Romidepsin Demonstrates Durable Responses in Relapsed or Refractory T-Cell Lymphoma (TCL)

A Phase II Study of Pembrolizumab in Combination with Romidepsin Demonstrates Durable Responses in Relapsed or Refractory T-Cell Lymphoma (TCL)

Predictors and Outcomes of Flares in Chronic Graft-Versus-Host Disease

Introduction: Chronic Graft-versus-Host Disease (cGvHD) frequently requires prolonged immune suppressive therapy (IST) with > 50% still on IST at 5 years. The IST typically involves a slow taper of steroids often with flare of cGvHD, necessitating augmentation of previous therapy or addition of new IST. Studies describing cGvHD flares are limited. We analyzed patients with cGvHD who flared during the treatment with systemic IST, their overall survival (OS) and non-relapse mortality (NRM). Methods: This study included all adult patients with cGvHD (n=145) following an allogeneic transplant (2010 - 2017) from a matched sibling donor peripheral blood stem cell transplant (MSD, n=104 (72%) or double/single umbilical cord blood transplant (UCBT, n=41 (28%). The 2014 NIH Consensus Criteria were used to classify organ/overall cGvHD severity. Flare of cGvHD was defined as progression in cGvHD manifestations (after initial response), which was less severe than at diagnosis. Multivariate regression of flares was based on the Prentice, Williams and Peterson model for ordered multiple events (flares). Time-dependent effects on OS and NRM were analyzed by Cox and Fine and Gray regression with propensity scoring to control for confounding. Results: Flares occurred in 87 patients; the cumulative incidence of flares was 60% (95% CI: 51-70%) at a median of 188 days (range 16-751) after diagnosis of cGvHD. The median dose of prednisone was 1 mg/kg/day (range 0-4.2) at diagnosis of cGvHD. At the diagnosis of flare, 36 (41%) of the patients were off prednisone, 50 (57%) were receiving 0.1-0.5 mg/kg /day, and 2 patients > 0.5 mg/kg /day. Thirty two of the 87 (36%) patients experienced multiple flares (2 to 4). The most common organs involved at cGvHD flare were skin (n=45; 51%), mouth (n=27; 31%), GI tract (n=22; 25%) and liver (n=12; 14%); often in combinations of skin/mouth in 11 cases (13%), skin/GI in 6 (7%) and liver/mouth in 4 (5%) cases. Treatment for flare was mostly increase in dose of prednisone to 0.5 mg/kg/day (range 0.3-1.0) in 77 patients (88%) plus the addition of another line of IST in 48 patients (55%). In multiple regression analysis, only donor type was significant predictor of flare in cGvHD. UCBT was associated with 2-fold lower probability of flaring (HR 0.5; 95% CI: 0.3-0.9; p=0.03) compared to MSD. cGvHD severity, organ involvement, platelet count at diagnosis and type of onset were not significant predictors of cGvHD flares. At 2 years after the initial flare, the OS was 77% (95% CI: 66-84%) and NRM 19% (95% CI: 11-28%). Multiple regression analysis evaluating OS and NRM from onset of cGvHD comparing flare to non-flare were performed using flare as a time dependent variable. Compared to cGvHD patients without flare at 2 years, those with flare of cGvHD had a similar risk of NRM (HR 1.2; 95% CI: 0.2-6.1, p=0.86) and OS (HR 0.9; 95% CI: 0.4-2.3, p=0.85). At 2 years from cGvHD onset, the cumulative incidence of resolved cGvHD (durable discontinuation of steroids for ≥ 6 consecutive months) was 31% (95% CI: 21-41%) in those who flared vs. 86% (95% CI: 75-96%) in those without flare. Conclusions: Though cGvHD patients with flare had similar risk of NRM and OS as those without a flare, patients with flare required extended steroids, along with clinical monitoring and intensified IST. cGvHD after UCBT was associated with significantly lower risk of flaring compared to MSD. The ongoing burden of IST, risk of infection and morbidity of cGvHD is substantial and needs better approaches than chronic slow taper of steroids. Disclosures Weisdorf: Incyte: Research Funding; FATE Therapeutics: Consultancy. Wagner:Novartis: Research Funding; Rocket Pharmaceuticals, Inc.: Consultancy, Current equity holder in publicly-traded company; Magenta Therapeutics: Consultancy, Research Funding; BlueRock: Research Funding; Gadeta: Membership on an entity's Board of Directors or advisory committees. Blazar:Fate Therapeutics Inc.: Research Funding; Childrens' Cancer Research Fund: Research Funding; BlueRock Therapeutics: Research Funding; BlueRock Therapeuetic: Consultancy; Magenta Therapeutics: Consultancy; KidsFirst Fund: Research Funding; Tmunity: Other: Co-founder. MacMillan:Mesoblast: Consultancy; Angiocrine Biosciences, Inc.: Consultancy; Equillium, Inc.: Consultancy; Talaris Therapeutics, Inc: Consultancy; Fate Therapeutics, Inc.: Consultancy. Holtan:Generon: Consultancy; BMS: Consultancy; CSL Behring: Other: Clinical trial data adjudication; Incyte: Consultancy. Brunstein:AlloVir: Other: Advisory board; Gamida: Research Funding; Astex: Research Funding; Magenta: Research Funding. Betts:Patent Pending: Patents & Royalties: Dr. Betts has a pending patent WO2017058950A1: Methods of treating transplant rejection. This includes the use of JAK inhibitors. Neither he nor his institution have received payment related to claims described in the patent.. Bachanova:FATE: Research Funding; Karyopharma: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding; Gamida Cell: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding. Rashidi:Synthetic Biologics: Other: DSMC member (1 trial) and related honorarium. Arora:Fate Therapeutics: Consultancy; Kadmon: Research Funding; Pharmacyclics: Research Funding; Syndax: Research Funding.

A Single-Arm, Open-Label Phase 1 Study of Itacitinib (ITA) with Calcineurin Inhibitor (CNI)-Based Interventions for Prophylaxis of Graft-Versus-Host Disease (GVHD; GRAVITAS-119)

A Single-Arm, Open-Label Phase 1 Study of Itacitinib (ITA) with Calcineurin Inhibitor (CNI)-Based Interventions for Prophylaxis of Graft-Versus-Host Disease (GVHD; GRAVITAS-119)