Abstract: Tocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. Methods A multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival. Results In the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6–24.0, P  = 0.52) and 22.4% (97.5% CI: 17.2–28.3, P   〈  0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Conclusions Tocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline. Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092).

Abstract: Allogeneic stem cell transplantation survivors are at a relevant risk of developing chronic GvHD (cGvHD), which importantly affects quality of life and increases morbidity and mortality. Early identification of patients at risk of cGvHD-related morbidity could represent a relevant tool to tailor preventive strategies. The aim of this study was to evaluate the prognostic power of immune reconstitution (IR) at cGvHD onset through an IR-based score. Methods We analyzed data from 411 adult patients consecutively transplanted between January 2011 and December 2016 at our Institution: 151 patients developed cGvHD (median follow-up 4 years). A first set of 111 consecutive patients with cGvHD entered the test cohort while an additional consecutive 40 patients represented the validation cohort. A Cox multivariate model for OS (overall survival) in patients with cGvHD of any severity allowed the identification of six variables independently predicting OS and TRM (transplant-related mortality). A formula for a prognostic risk index using the β coefficients derived from the model was designed. Each patient was assigned a score defining three groups of risk (low, intermediate, and high). Results Our multivariate model defined the variables independently predicting OS at cGvHD onset: CD4+ & gt;233 cells/mm 3 , NK & lt;115 cells/mm 3 , IgA & lt;0.43g/L, IgM & lt;0.45g/L, Karnofsky PS & lt;80%, platelets & lt;100x10 3 /mm 3 . Low-risk patients were defined as having a score ≤3.09, intermediate-risk patients & gt;3.09 and ≤6.9, and high-risk patients & gt;6.9. By ROC analysis, we identified a cut-off of 6.310 for both TRM and overall mortality. In the training cohort, the 6-year OS and TRM from cGvHD occurrence were 85% (95% CI, 70-92) and 13% (95% CI, 5-25) for low-risk, 64% (95% CI, 44-89) and 30% (95% CI, 15-47) for intermediate-risk, 26% (95% CI, 10-47), and 42% (95% CI, 19-63) for high-risk patients (OS p & lt;0.0001; TRM p = 0.015). The validation cohort confirmed the model with a 6-year OS and TRM of 83% (95% CI, 48-96) and 8% (95% CI, 1-32) for low-risk, 78% (95% CI, 37-94) and 11% (95% CI, 1-41) for intermediate-risk, 37% (95% CI, 17-58), and 63% (95% CI, 36-81) for high-risk patients (OS p = 0.0075; TRM p = 0.0009). Conclusions IR score at diagnosis of cGvHD predicts GvHD severity and overall survival. IR score may contribute to the risk stratification of patients. If confirmed in a larger and multicenter-based study, IR score could be adopted to identify patients at high risk and modulate cGvHD treatments accordingly in the context of clinical trial.

Abstract: Introduction Allogeneic stem cell transplantation (allo-HCT) survivors are at a defined relevant risk of developing long-term complications: the prevalence of chronic health conditions approaches 75% among HCT survivors. The endocrine system is one of the most frequent targets of complications, providing justification for a long-term and continuous follow-up (LTFU) to assure a timely and appropriate treatment. The aim of our study is to evaluate the incidence of endocrinopathies in survivors in respect of sex, age, donor type, conditioning regimen and GvHD occurrence. Methods A standardized LTFU is applied at our center. We here analyze data consecutively collected in an Institutional database, starting from 2006, including 402 adult patients (pts) who underwent an allo-HCT between 1992 and 2016 at our Institution. A written consent was given by pts allowing the use of medical records for research in accordance with the Declaration of Helsinki. We considered for the analysis pts with an overall survival 〉 /=1y. We reviewed pts chapters with a focus on occurrence, management and treatment of diabetes, thyroid disfunctions, dyslipidemia and osteopenia / osteoporosis: diagnosis and follow-up were performed according to guidelines for long-term HCT survivors. Results With a median follow-up of 7y (r 2-25y) 328 pts were evaluable; donor was a match unrelated donor in 107 cases, HLA identical sibling in 88, haploidentical relative in 129 and cord blood in 4. The 5y-incidence of diabetes type 2 was 3%, with a median time after allo-HCT of 1138 days (r 5-4181 days); 13/22 developed diabetes after diagnosis of GvHD (median time 884 days, r 30-3753 days). All pts received indication for diet modification, 11 pts were treated with insulin and 8 pts with metformin. Thyroid disfunction was documented in 38 pts (5y-incidence 8,5%): 2 pts were diagnosed with hyperthyroidism and treated with methimazole or radioiodine treatment. Hypothyroidism was documented in 36 pts (median time after allo-HSCT 799 days, r 65-5021 days). Thirteen pts developed hypothyroidism following the diagnosis of GvHD (median time 1236 days, r 166-3540 days). Only 2 pts did not receive a specific treatment, while all the others received substitutive therapy with levothyroxine. Furthermore 1 pt was diagnosed with a papillary thyroid cancer. The 5y-incidende of dyslipidemia was 30% with a median time after allo-HSCT of 1433 days (r 366-7629), 47 pts developed dyslipidemia after the diagnosis of GVHD (median time 1425 days, r 134-7403 days). Diet-therapy was recommended to all the pts, 29 pts received a statin-based pharmacological treatment, 20 pts a polyenoic-fatty-acids based treatment, while a nutraceutical compound was given in 13 pts. Osteopenia was documented in 120 pts (median time after allo-HSCT 994 days, range 31-6605 days) with a 5y-incidence of 36%. Seventy-nine pts presented osteopenia after diagnosis of GvHD (median time after GvHD diagnosis 707 days, r 13-6379 days). Eight pts did not receive a specific treatment. Two pts received treatment with biphosphonates plus oral vitamin D and calcium supplementation, the 110 remaining pts received oral vitamin D +/- calcium supplementation only. Sixty-four pts developed osteoporosis (median time after allo-HSCT 1000 days, r 60-8836 days), the 5y-incidence was 26%. Forty-four pts developed osteoporosis following the diagnosis of GvHD (median time 724 days, r 28-8280 days). Only 4 pts did not receive any specific therapy; 31 pts received therapy with bisphosphonates, 2 pts denosumab and 27 pts oral vitamin D and calcium supplementation. In univariate analysis no relationship between host sex, age at transplant, TBI exposure, donor or history of GvHD and development of diabetes, thyroid disfunction and dyslipidemia was outlined. Otherwise, osteopenia development was strongly associated with GvHD occurrence and osteoporosis was strongly associated with age, sex and GvHD occurrence (table 1). Conclusions Allo-HCT survivors are at relevant risk of endocrinopathies after transplantation, providing justification for specific monitoring to individualize treatment and follow-up. Of note, classical transplant-related variables are not enough to justify the occurrence of endocrinological disfunction: a further deeper evaluation of a misdiagnosed donor-mediated autoimmune predisposition will be essential. Disclosures Bonini: Intellia Therapeutics: Research Funding.

Abstract: Background: The clinical spectrum of COVID-19 ranges from pauci-symptomatic forms to severe disease characterized by respiratory failure requiring mechanical ventilation and intensive care unit (ICU) management, as well as multisystem involvement characterized by sepsis, organ dysfunction and death. Treatment of COVID-19 is not standardized, and respiratory failure from ARDS is the leading cause of mortality; in-hospital mortality at 28-days in our tertiary care center in Lombardia, northern Italy was 23% during the first wave in 2020(Ciceri et al. 2020). Endothelial damage and thrombo-inflammation have been identified as common to both COVID-19 pathophysiology and veno-occlusive disease (VOD/SOS). Defibrotide (DF) has endothelial-protective properties, with pro-fibrinolytic, anti-thrombotic, anti-ischemic, anti-inflammatory, and anti-adhesive activity, but no significant systemic anticoagulant effects and is approved for the treatment of severe VOD/SOS. Aim: A prospective, multicenter, phase II, single-arm, open label trial (DEFI-VID19, NCT04335201) was conducted in patients (pts) with COVID-19 ARDS to evaluate the efficacy of DF in addition to best available therapy per institutional guidelines. The primary endpoint was respiratory-failure rate (RFR) defined as progression of respiratory failure, i.e. severe gas transfer deficit (PaO2/FiO2 & lt;200 mmHg), need of ICU or death at day+14 from treatment start. Secondary endpoints included overall survival (OS) at 28 days, duration of hospitalization and safety. A sample size of 50 pts was calculated to detect an absolute reduction of 20% in RFR at day+14, assuming a failure rate in non-treated pts of 70% (alpha=5%, power=90%, two-sided test). Pts received DF intravenously at 6.25 mg/kg/dose by 2-hour infusion repeated every 6 hours. Expected treatment duration was 14 days, with earlier discontinuation if clinical improvement occurred. LMWH at prophylactic dose was allowed. Approval was provided by the National IRB for COVID-19 trials at Institute Spallanzani (Rome) and by the Italian Agency for Drug (AIFA). All patients provided written informed consent. Results: Overall, 52 pts were enrolled from September 2020 to April 2021; 48 were evaluated for efficacy and safety; 4 pts were excluded due to screen failure (n=2) or withdrawal of informed consent at day 2 after defibrotide was initiated (n=2). Median age was 60.5 years (range 53-71); 35 pts (73%) were male and 65% had comorbidities, with high blood pressure, obesity and COPD most common. Two pts had pre-existing diagnoses of non-Hodgkin lymphoma. Median time from onset of COVID-19 symptoms and from Sars-COV2 PCR by nasal swab to enrollment were 8 (range 7-10) and 3 days (range 1-6), respectively. All pts were hospitalized and scale 5 of 8-category ordinal scale by WHO criteria, requiring noninvasive ventilation with CPAP or high-flow oxygen, with a median P/F ratio of 211 (range 134-275) mmHg. At treatment start, the median and (range) lymphocyte counts, LDH, CRP, ferritin, D-dimer and IL-6 were 0.7 (0.5-0.9) x 10e9/L; 404 (291-491) U/L; 49 (22-97) mg/L; 823 (363-1088) ng/ml; 0.44 (0.28-1.29) µg/mL and 20 (11-32), respectively. Median treatment duration was 8.5 days (range 6-11). Overall, 13/48 pts (27%) discontinued the treatment due to clinical worsening and/or need of further therapies: 9 pts experienced progressive respiratory failure and 6 of those were transferred to ICU for IOT (one pt required ECMO), and 4 required full anticoagulation due to pulmonary embolism (n=1), ischemic stroke (n=1), and femoral deep venous thrombosis (n=2). All pts who completed the treatment 35/48 (73%) were discharged with no need of oxygen support. Overall, 14 SAEs have been reported in a median time of 6 days (range 2-10): all unrelated to DF. No pts experienced hemorrhagic events. The incidence of RFR at day 14 was 25 (+/- 6)%, and at day 28, 27 (+/- 6) %. Probability of OS at day 28 was 89 (+/-4) %, at day 60 83 (+/- 5)%. Overall, 8 pts died from COVID-19 -related complications. No pts required re-admission after hospital discharge (median 14 days) or died after discharge. Conclusion: Treatment with DF in pts with grade 5 WHO COVID 19 ARDS does not induce bleeding, and is associated with rapid restoration of respiratory function (73% of pts). Notably, no oxygen support was needed at discharge and a 1-month OS rate of 89% was observed, which is higher than historical controls (77%) treated in the same setting. Disclosures Richardson: Takeda: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; AstraZeneca: Consultancy; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; Regeneron: Consultancy; Celgene/BMS: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Sanofi: Consultancy. Ciceri: IRCCS Ospedale San Raffaele: Current Employment. Carlo-Stella: Incyte: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Research Funding; AstraZeneca: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Oncology: Honoraria; Karyopharm Therapeutics: Membership on an entity's Board of Directors or advisory committees.

Abstract: Introduction Allogeneic stem cell transplantation (HCT) survivors are at a relevant risk of developing long-term complications such as chronic GvHD (cGvHD), which importantly affects their quality of life and increases their morbidity and mortality. Being able to early identify high risk patients would enable us to tailor preventive strategies. Current approach on prophylaxis of GvHD is lacking of predictive biomarkers that could guide patient-tailoring of drugs choice, tapering and treatment schedules. Immune system is the cause of cGvHD but is also a target of it, and cGvHD patients are characterized by lymphoid hypocellularity. Moreover, immune reconstitution (IR) is a good candidate biomarker being it an easily-available and reproducible parameter. We investigated IR variables as predictive biomarker of cGvHD. Methods A standardized follow-up of HCT-survivors is applied at our center. We analyzed 307 adult patients consecutively undergoing first allogeneic HCT transplant between July 2012 and December 2016 at our Institution. A written consent was given for the use of medical records for research in accordance with the Declaration of Helsinki. Median follow-up for surviving patients was 2.8 years (range 1.1-5.5). We prospectively collected IR data of our entire cohort at specific time-points (+30, +60, +90, +180, +365 days) and followed patients up recording events. IR variables were CD3+, CD3+CD4+, CD3+CD8+, CD19+, CD56+ cell counts, measured by flow-citometry, and immunoglobulins IgG, IgA and IgM levels, measured by immunoturbidimetric assays. Time as a continuous parameter could not be studied since the number of events would have been too low for the analysis. For this reason, a series of landmark analyses were performed at 3, 6 and 12 months post-HCT in order to identify predictive factors of cGvHD, transplant-related mortality (TRM), progression-free survival (PFS) and overall survival (OS) for patients alive and in good conditions at the beginning of each time interval. Factors predicting cGvHD incidence and survival endpoints were studied using multivariate analysis by Cox regression model. Variables included in the model were patient and donor age and Sorror-Comorbidity Index (according to median values), disease-related index, type of donor, stem cell source, IR values at the timepoint according to landmark cut-off for cell counts and median values for immunoglobulin levels. A backward stepwise procedure was used for variable selection with a p-value 〈 0.05. All statistical analyses were performed with R (R Development Core Team, Vienna, Austria) software package. Results Chronic-GvHD of any grade and severity was diagnosed in 111 patients. Immune recovery in our cohort was in line with the current knowledge: CD3+CD8+ and NK (CD56+) cells normalized first, followed by CD3+ and CD3+CD4+ cell. B cells (CD19+) took at least 1 year to normalize in terms of absolute counts. IgM levels were the first to rise among immunoglobulins, followed by IgG and then IgA which can also be subnormal for a long time after transplant. Results of multivariate analysis are shown in Table 1. Single lymphocyte subset counts did not prove to be associated to cGvHD onset significantly; conversely, immunoglobulins were strongly predictive of cGvHD in our multivariate model. Median time to GvHD onset was 198 days, thus the most important analysis was the one performed at +90 days as the majority of patients had still not developed cGvHD. IgG, IgA and IgM at +90 days from HCT below the median value were found before the onset of GvHD and could predict its onset. This data were confirmed on the analysis at later time-points in which low IgG levels predicted cGvHD diagnosis. Conclusions Day-90 low immunoglobulin levels predict cGvHD, confirming that subclinical immune dysregulation mechanisms could be already present before overt clinical onset of cGvHD symptoms. Early prediction of subsequent cGvHD will be operationally translated into patient-tailored preventive measures. Disclosures Bonini: Intellia Therapeutics: Research Funding.