Abstract: Mechanisms underpinning the dysfunctional immune response in severe acute respiratory syndrome coronavirus 2 infection are elusive. We analyzed single-cell transcriptomes and T and B cell receptors (BCR) of 〉 895,000 peripheral blood mononuclear cells from 73 coronavirus disease 2019 (COVID-19) patients and 75 healthy controls of Japanese ancestry with host genetic data. COVID-19 patients showed a low fraction of nonclassical monocytes (ncMono). We report downregulated cell transitions from classical monocytes to ncMono in COVID-19 with reduced CXCL10 expression in ncMono in severe disease. Cell–cell communication analysis inferred decreased cellular interactions involving ncMono in severe COVID-19. Clonal expansions of BCR were evident in the plasmablasts of patients. Putative disease genes identified by COVID-19 genome-wide association study showed cell type-specific expressions in monocytes and dendritic cells. A COVID-19-associated risk variant at the IFNAR2 locus (rs13050728) had context-specific and monocyte-specific expression quantitative trait loci effects. Our study highlights biological and host genetic involvement of innate immune cells in COVID-19 severity.

Abstract: Chronic kidney disease (low estimated glomerular filtration rate [eGFR] or albuminuria) affects approximately 14% of adults in the US. Objective To evaluate associations of lower eGFR based on creatinine alone, lower eGFR based on creatinine combined with cystatin C, and more severe albuminuria with adverse kidney outcomes, cardiovascular outcomes, and other health outcomes. Design, Setting, and Participants Individual-participant data meta-analysis of 27 503 140 individuals from 114 global cohorts (eGFR based on creatinine alone) and 720 736 individuals from 20 cohorts (eGFR based on creatinine and cystatin C) and 9 067 753 individuals from 114 cohorts (albuminuria) from 1980 to 2021. Exposures The Chronic Kidney Disease Epidemiology Collaboration 2021 equations for eGFR based on creatinine alone and eGFR based on creatinine and cystatin C; and albuminuria estimated as urine albumin to creatinine ratio (UACR). Main Outcomes and Measures The risk of kidney failure requiring replacement therapy, all-cause mortality, cardiovascular mortality, acute kidney injury, any hospitalization, coronary heart disease, stroke, heart failure, atrial fibrillation, and peripheral artery disease. The analyses were performed within each cohort and summarized with random-effects meta-analyses. Results Within the population using eGFR based on creatinine alone (mean age, 54 years [SD, 17 years]; 51% were women; mean follow-up time, 4.8 years [SD, 3.3 years] ), the mean eGFR was 90 mL/min/1.73 m 2 (SD, 22 mL/min/1.73 m 2 ) and the median UACR was 11 mg/g (IQR, 8-16 mg/g). Within the population using eGFR based on creatinine and cystatin C (mean age, 59 years [SD, 12 years]; 53% were women; mean follow-up time, 10.8 years [SD, 4.1 years] ), the mean eGFR was 88 mL/min/1.73 m 2 (SD, 22 mL/min/1.73 m 2 ) and the median UACR was 9 mg/g (IQR, 6-18 mg/g). Lower eGFR (whether based on creatinine alone or based on creatinine and cystatin C) and higher UACR were each significantly associated with higher risk for each of the 10 adverse outcomes, including those in the mildest categories of chronic kidney disease. For example, among people with a UACR less than 10 mg/g, an eGFR of 45 to 59 mL/min/1.73 m 2 based on creatinine alone was associated with significantly higher hospitalization rates compared with an eGFR of 90 to 104 mL/min/1.73 m 2 (adjusted hazard ratio, 1.3 [95% CI, 1.2-1.3]; 161 vs 79 events per 1000 person-years; excess absolute risk, 22 events per 1000 person-years [95% CI, 19-25 events per 1000 person-years] ). Conclusions and Relevance In this retrospective analysis of 114 cohorts, lower eGFR based on creatinine alone, lower eGFR based on creatinine and cystatin C, and more severe UACR were each associated with increased rates of 10 adverse outcomes, including adverse kidney outcomes, cardiovascular diseases, and hospitalizations.

Abstract: Although cell-free DNA (cfDNA) testing is expected to drive cancer precision medicine, little is known about the significance of detecting low-frequency variants in circulating cell-free tumor DNA (ctDNA) in castration-resistant prostate cancer (CRPC). We aimed to identify genomic profile including low-frequency variants in ctDNA from patients with CRPC and investigate the clinical utility of detecting variants with variant allele frequency (VAF) below 1%. Experimental Design: This prospective, multicenter cohort study enrolled patients with CRPC eligible for treatment with abiraterone or enzalutamide. We performed targeted sequencing of pretreatment cfDNA and paired leukocyte DNA with molecular barcodes, and ctDNA variants with a VAF ≥0.1% were detected using an in-house pipeline. We investigated progression-free survival (PFS) and overall survival (OS) after different ctDNA fraction cutoffs were applied. Results: One hundred patients were analyzed (median follow-up 10.7 months). We detected deleterious ATM, BRCA2, and TP53 variants even in samples with ctDNA fraction below 2%. When the ctDNA fraction cutoff value of 0.4% was applied, significant differences in PFS and OS were found between patients with and without defects in ATM or BRCA2 [HR, 2.52; 95% confidence interval (CI), 1.24–5.11; P = 0.0091] and TP53 (HR, 3.74; 95% CI, 1.60–8.71; P = 0.0014). However, these differences were no longer observed when the ctDNA fraction cutoff value of 2% was applied, and approximately 50% of the samples were classified as ctDNA unquantifiable. Conclusions: Detecting low-frequency ctDNA variants with a VAF & lt;1% is important to identify clinically informative genomic alterations in CRPC.

Abstract: Abstract 3118 Introduction: Elderly patients with myelodysplastic syndromes (MDS) are often lack of suitable human leukocyte antigen (HLA)-matched related donors. Unfortunately, the data on the efficacy of allogeneic transplantation using alternative donor sources are limited. We retrospectively compared the outcomes of HLA 6/6 antigen-matched related bone marrow or peripheral blood progenitor cells (rBM/PBPC) transplantation (6/6rBM/PBPCT), HLA 8/8 allele-matched unrelated bone marrow (uBM) transplantation (8/8uBMT), HLA 7/8 allele-matched uBM transplantation (7/8uBMT), and HLA at least 4/6 antigen-matched single-unit umbilical cord blood (CB) transplantation (sCBT) for elderly patients with MDS. Method: The data were obtained from the Transplant Registry Unified Management Program, which includes data from the Japan Society for Hematopoietic Cell Transplantation, the Japan Marrow Donor Program, and the Japan Cord Blood Bank Network. Patients aged 50–70 years old at transplantation with MDS according to French-American-British (FAB) classification who received first allogeneic transplantation between January 1, 2001 and December 31, 2010 were included. Among 336 rBM/PBPC, 291 uBM, and 215 CB transplantation recipients with complete HLA data, 268 6/6rBM/PBPCT, 147 8/8uBMT, 90 7/8uBMT, and 211 sCBT recipients were included. Cox proportional-hazards regression model was used for adjusted comparisons of the donor sources on overall survival (OS). Fine and Gray proportional-hazards model was used for adjusted comparisons of the donor sources on non-relapse mortality (NRM), relapse, grade 2–4 acute graft-versus-host disease (aGVHD2–4), and neutrophil engraftment. Recipient age at transplantation ( 〉 =60 or 50–59), recipient sex (male or female), performance status (PS) at transplantation (2–4 or 0–1), FAB classification at transplantation (refractory anemia with excess blasts (RAEB) and RAEB in transformation (RAEBt), or refractory anemia (RA) and RA with ringed sideroblasts), latest cytogenetics classification according to International Prognostic Scoring System (good, intermediate, poor, or unevaluable), transplant conditioning regimen (reduced-intensity conditioning or myeloablative conditioning), and the year at transplantation (2001–2005 or 2006–2010) were included in the multivariate models. Result: Median follow-up was 2.9 years. The unadjusted 3-year OS rates for recipients of 6/6rBM/PBPCT, 8/8uBMT, 7/8uBMT, and sCBT were 50.7%, 58.2%, 46.2%, and 28.4%, respectively. Multivariate analysis revealed that the OS for sCBT recipients was significantly inferior to those for 6/6rBM/PBPCT (relative risk (RR) [95% confidential interval], 1.9 [1.5–2.5] ; P 〈 0.001), 8/8uBMT (RR, 2.3 [1.7–3.2]; P 〈 0.001), and 7/8uBMT (RR, 1.4 [1.0–2.0]; P=0.047) recipients. The OS for 8/8uBMT and 7/8uBMT recipients were comparable with that for 6/6rBM/PBPCT. Other variables associated with significant inferior OS were recipient age 〉 = 60, male sex, PS 〉 1, FAB classification at transplantation as RAEB/RAEBt, and poor cytogenetics. The risk of relapse for sCBT recipients was comparable with that for 6/6rBM/PBPCT but significantly higher than those for 8/8uBMT (RR, 2.4 [1.5–3.8]; P 〈 0.001) and 7/8uBMT (RR, 2.3 [1.3–4.2]; P=0.005) recipients. The risk of NRM for sCBT recipients was significantly higher than that for 6/6rBM/PBPCT recipients (RR, 1.7 [1.1–2.4] ; P=0.009) but comparable with those for 8/8uBMT and 7/8uBMT recipients. The risk for NRM for 7/8uBMT recipients was significantly higher than that for 6/6rBM/PBPCT (RR, 2.1 [1.4–3.1], P 〈 0.001) and 8/8uBMT (RR, 1.6 [1.1–2.5]; P=0.024) recipients. The risk of aGVHD2–4 for 7/8uBMT recipients was significantly higher than those for 6/6rBM/PBPCT (RR, 1.6 [1.1–2.4] ; P=0.008), 8/8uBMT (RR, 1.7 [1.2–2.6], P=0.008), and sCBT (RR, 1.6 [1.0–2.3] ; P=0.032) recipients. Neutrophil engraftment for sCBT recipients was significantly slower than those for 6/6rBM/PBPCT (RR, 0.26 [0.21–0.33]; P 〈 0.001), 8/8uBMT (RR, 0.35 [0.29–0.43]; P 〈 0.001), and 7/8uBMT (RR, 0.40 [0.31–0.51]; P 〈 0.001) recipients. Conclusion: For elderly patients with MDS, the outcome of sCBT recipient was inferior to those of 6/6rBM/PBPCT, 8/8uBMT, and 7/8uBMT recipients. Decreasing the risk of NRM, which would be brought by improving the neutrophil engraftment, and decreasing the risks of relapse are required to improve the outcome of sCBT. Disclosures: No relevant conflicts of interest to declare.

Abstract: Background: Alvocidib is a potent cyclin-dependent kinase 9 inhibitor, which has previously been shown to downregulate the B-cell lymphoma-2 family member MCL-1 (myeloid cell leukemia-1) which, in turn, sensitizes tumor cells to apoptotic signals. Alvocidib has been studied globally in relapsed/refractory (R/R) AML in combination with cytarabine/mitoxantrone, as well as in newly diagnosed AML in combination with cytarabine/daunorubicin, and has demonstrated acceptable clinical activity. However, safety and tolerability in Japanese AML pts are unknown. Aims: To evaluate the safety and tolerability of alvocidib administered as ACM or A+7+3. Methods: This multicenter, open-label, uncontrolled phase 1 study (NCT03563560) included 2 regimens: ACM (in pts R/R to cytarabine/anthracycline based intensive chemotherapy and without a cumulative total exposure of anthracycline [daunorubicin-equivalent dose] exceeding 360 mg/m2 at entry) and A+7+3 (in newly diagnosed, treatment naive pts). Key eligibility criteria for both regimens were age 20-64 years, Eastern Cooperative Oncology Group performance status ≤ 2, a left ventricular ejection fraction ≥ 50%, and no major organ dysfunction. The ACM regimen (cohorts R1 and R2) comprised a fixed dose hybrid regimen of alvocidib (30 mg/m2/day as a 30-minute intravenous [IV] bolus followed by 60 mg/m2/day over 4 hours as a continuous IV infusion on days 1-3), and escalating doses of cytarabine (300 or 667 mg/m2/day by continuous IV infusion on days 6-8) and mitoxantrone (14 or 40 mg/m2/day IV infusion on day 9 or 10 starting 12 hours after completing cytarabine) in a standard 3+3 design. In the A+7+3 regimen (cohort F1) the dose of each component was fixed according to the recommended dose from the ongoing phase 1 study in the US (NCT03298984). Treatment consisted of the alvocidib hybrid regimen on days 1-3, cytarabine 100 mg/m2/day by continuous IV infusion on days 5-11, and daunorubicin 60 mg/m2/day IV on days 5-7. The primary study objective was to determine the safety and tolerability of alvocidib in combination with each type of chemotherapy, via the assessment of dose-limiting toxicities (DLTs) and treatment-emergent adverse events (TEAEs; graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events v4.03). Secondary objectives were to evaluate the pharmacokinetics (including maximum plasma concentration [Cmax] and area under the concentration-time curve up to the last measurable concentration [AUC0-last] ) and clinical activities of these regimens. Results: Between April 2018 to October 2019, 10 pts were enrolled, with a median (range) age of 45.0 (25-64) years. Of these, 6 pts (2 with relapsed disease and 4 with refractory disease) received ACM and 4 pts received A+7+3 (Table). Alvocidib was tolerated and DLTs were not observed in either of the two regimens. The most common TEAEs were hematologic events. The most common Grade ≥ 3 non-hematologic TEAEs occurring in ≥ 2 pts in the ACM regimen were diarrhea (50%), hepatic function abnormal (33%), sepsis (33%), cardiac failure (33%) and hypokalemia (33%). The most common Grade ≥ 3 non-hematologic TEAEs noted in ≥ 2 pts in the A+7+3 regimen were diarrhea (100%), tumor lysis syndrome (50%), and vomiting (50%). In the ACM regimen in R/R AML, all 6 pts were evaluable, of whom 5 (83%) achieved an objective response, including 4 complete remissions (CRs) and 1 morphologic leukemia-free state. The mean duration of CR was 13.6 months. In the A+7+3 regimen in newly diagnosed AML, 3 out of 4 pts were evaluable. All 3 evaluable pts achieved CR. One pt did not complete the A+7+3 regimen due to tumor lysis syndrome and was discontinued from the study prior to disease assessment. Overall, the mean Cmax of alvocidib in plasma was 1241 ng/mL on day 1 and 1217 ng/mL on day 3. The mean AUC0-last was 6555 h*ng/mL on day 1 and 7998 h*ng/mL on day 3. WSummary: Alvocidib in combination with cytarabine 667 mg/m2/day and mitoxantrone 40 mg/m2/day IV infusion in Japanese pts with R/R AML or cytarabine/daunorubicin (7+3) induction in Japanese pts with newly diagnosed AML showed an acceptable safety profile similar to previously investigated regimens in other studies. These data suggest that future studies of alvocidib in hematological malignancies are warranted, and planned directions for alvocidib development include phase 1/2 efficacy and safety studies in combination with other agents. Disclosures Ando: Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Kiguchi:SymBio Pharmaceuticals., Ltd.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Research Funding; Daiichi Sankyo Pharmaceutical Co., Ltd.: Research Funding; Eisai Co., Ltd.: Honoraria; Mochida Pharmaceutical Co., Ltd.: Honoraria; Taiho Pharmaceutical Co., Ltd.: Research Funding; Teijin Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria; Pfizer Co., Ltd.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Novartis Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Sumitomo Dainippon Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Janssen Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene Co., Ltd.: Honoraria, Research Funding; Celltrion, Inc.: Research Funding; Bristol-Myers Squibb Co., Ltd.: Honoraria, Research Funding; MSD Co., Ltd.: Honoraria, Research Funding; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Ono Pharmaceutical Co., Ltd.: Honoraria; Sanofi K.K., Ltd.: Research Funding; Nippon Shinyaku Co., Ltd.: Honoraria, Research Funding; Astellas Pharmaceutical Co., Ltd.: Honoraria, Research Funding. Kasai:Sumitomo Dainippon Pharma Co., Ltd.: Current Employment. Sugimoto:Sumitomo Dainippon Pharma Co., Ltd.: Current Employment. Miyazaki:NIPPON SHINYAKU CO.,LTD.: Honoraria; Otsuka Pharmaceutical: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria; Novartis Pharma KK: Honoraria; Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; Astellas Pharma Inc.: Honoraria; Celgene: Honoraria.