ALBERT

Beschreibung: Background: Activating mutations of NRAS and KRAS genes are common in newly diagnosed acute myeloid leukemia (AML), occurring in 11-16% and 4-5% of patients, respectively. RAS mutations are frequently acquired at time of progression from MDS to AML and are associated with poor survival. Next generation sequencing (NGS) at diagnosis and during complete remission has shown that RAS mutations have high clearance rates with induction chemotherapy. In the CALGB 8525 study, RAS-mutant younger patients (age

Beschreibung: Novel strategies, such as chemosensitization with targeted agents, that build on the success of standard immunochemotherapy show promise for the treatment of non-Hodgkin lymphoma (NHL). Here, we report a phase 1b study investigating dose escalation of the BCL2 inhibitor, venetoclax, in combination with rituximab or obinutuzumab and cyclophosphamide, doxorubicin, vincristine, and prednisone (R-/G-CHOP) chemotherapy in B-cell NHL. Objectives included safety assessment and determination of a recommended phase 2 dose (RP2D). Fifty-six patients were enrolled, most with follicular lymphoma (43%) or diffuse large B-cell lymphoma (DLBCL; 32%). Dose-limiting toxicities were reported in 3/14 patients at the first venetoclax dose (200 mg/d), after which dosing was changed from daily to 10 days per cycle and escalated to 800 mg. A further reduction to 5 days per cycle occurred at the 800-mg dose level in the G-CHOP arm. Cytopenias were predominant among grade 3/4 events and reported at a higher rate than expected, particularly in the G-CHOP arm; however, safety was manageable. Overall response rates were 87.5% (R-CHOP and G-CHOP combinations); complete response (CR) rates were 79.2% and 78.1%, respectively. Most double-expressor (BCL2+ and MYC+) DLBCL patients (87.5%; n = 7/8) achieved CR. Although the maximum tolerated dose was not reached, the RP2D for venetoclax with R-CHOP was established at 800 mg days 4 to 10 of cycle 1 and days 1 to 10 of cycles 2 to 8; higher doses were not explored, and this dosing schedule demonstrated an acceptable safety profile. This regimen is subsequently being evaluated in first-line DLBCL in the phase 2 portion of the study. This trial was registered at www.clinicaltrials.gov as #NCT02055820.

Beschreibung: Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HCT) provides a potential cure for a multitude of diseases but can result in high rates of morbidity and mortality. These outcomes have been associated with donor choice, with umbilical cord blood (UCB) perceived as an inferior option to matched related or matched unrelated donors (MRD/MUD) due to increased morbidity and mortality the first year after allo-HCT due to delayed engraftment and increased graft versus host disease (GvHD). At the same time, studies have shown that recipients of cells from younger donors do better, and UCB is the youngest donor cell source available. Given that UCB may have long-term benefits, we evaluated long-term survival in recipients of UCB vs. MRD/MUD in patients who had survived at least 1 year. Methods: This is a retrospective analysis of ≥1 year (≥365 days) survivors of first allo-HCT from the Duke Adult Bone Marrow Transplant (ABMT) program over a twenty year period from January 1, 1996 to December 31, 2015. Detailed clinical data was extracted from the Duke ABMT database and electronic medical record. Patients who either died or were lost to follow-up within 1 year of transplant were excluded. Also excluded were those who received an allo-HCT for a disease other than a hematologic malignancy and those who received haploidentical or mismatched adult cells, as these donor sources have been associated with worse outcomes and the goal was to compare UCB to MRD/MUD. Patient characteristics included gender, race, ethnicity, transplant diagnosis, transplant year, hematopoietic cell transplantation-specific comorbidity index (HCT-CI), Karnofsky performance score (KPS) at transplant workup, age at transplant, donor cell characteristics, conditioning regimen, acute GvHD (aGvHD), date of relapse, and date of death. Chi-square tests or Fisher's exact tests were used to compare categorical variables, as appropriate, and Wilcoxon Rank Sum tests or t-tests were used to compare continuous variables, as appropriate. A Kaplan-Meier estimator was used to analyze overall survival. A Cox Proportional Hazard model with stepwise selection with significance of entry=0.1 and significance of stay=0.2 was used to evaluate the patient characteristics of age, gender, race, disease, KPS, conditioning type, history of aGvHD, and decade of transplant and adjusted for selected covariates to compare the two groups. Results: Over the 20-year study period, 848 patients received a first allo-HCT, of whom 456 (54%) survived at least 1 year post-HCT: 102 (22%) UCB and 354 (78%) MRD/MUD. UCB recipients were more likely to be younger (median 42 years vs. 50 years, p=

Beschreibung: Introduction: CD19-specific chimeric antigen receptor (CAR) T-cell therapy is FDA approved in patients with relapsed or refractory large B-cell lymphomas. While 35-40% of patients may achieve a durable complete response (CR), the toxicity incurred with CAR-T therapy could impact the ability to receive subsequent treatment in those who progress after CAR-T infusion. Our prior data suggested that patients who experienced early progression had inferior overall survival. We now update our results and evaluate the impact of laboratory abnormalities and comorbidities at the time of progression on overall survival. Methods: Adults with large B-cell lymphomas who received CD19-specific CAR T-cells at the University of Washington/Seattle Cancer Care Alliance were included. Patients who received CAR T-cell therapy with additional concurrent protocol-specified therapy were excluded. Those who exhibited progressive disease (PD) or persistent lymphoma after CAR T-cell therapy were the focus of this study. We defined patients who progressed or received additional lymphoma directed therapy after last CAR-T cell infusion as early PD, with all other patients defined as late PD. We collected laboratory data closest to the date of progression. We defined an absolute neutrophil count 〈 1000, platelet count 〈 75K, Creatinine 〉 upper limit of normal (ULN), INR 〉 ULN, AST/ALT 〉 2.5x ULN, total bilirubin 〉 ULN, and LDH 〉 ULN as abnormal. Primary endpoint of this analysis was overall survival (OS) landmarked to date of progression. Secondary endpoints include sub-group analyses based on early PD as well as lab abnormalities at the time of progression. A multi-variate analysis with select baseline and progression variables was also performed. Results: We identified 66 patients who met the above criteria. Median follow up for the entire cohort is 30.4 months (range 0.1-64 months) by reverse KM method. Median time from last planned CAR infusion to progression was 43.5 days (range 11-658). Median OS of the entire cohort was 5.43 months (95% CI 3.75-12.2). 25 (38%) patients experienced early PD, which was associated with inferior OS (median 3.75 vs. 10.4 months, P=0.02). LDH 〉 ULN at the time of progression defined a group with inferior outcomes (median OS 3.16 vs. 17.5 months, P ULN at progression (7.01, 95% CI 2.89-17.013), and abnormal creatinine at progression (5.32, 95% CI 1.71-16.53), as factors associated with increased risk of death. Conclusions: Patients with PD post CD19-specific CAR T-cell therapy, particularly those with early PD, elevated LDH, or renal failure experience extremely poor outcomes. These data can inform discussion of prognosis for patients who progress after CAR T-cell therapy and may predict which patients may benefit from additional anti-lymphoma therapy. Figure Disclosures Lynch: Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Juno Therapeutics: Research Funding; Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Incyte Corporation: Research Funding; Rhizen Pharmaceuticals S.A: Research Funding. Maloney:A2 Biotherapeutics: Honoraria, Other: Stock options ; Celgene,Kite Pharma: Honoraria, Research Funding; Juno Therapeutics: Honoraria, Patents & Royalties: patients pending , Research Funding; BioLine RX, Gilead,Genentech,Novartis: Honoraria. Turtle:Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Ad hoc advisory board member; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; T-CURX: Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Kite/Gilead: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member. Smith:Portola Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Ignyta (spouse): Research Funding; Genentech: Research Funding; Denovo Biopharma: Research Funding; Ayala (spouse): Research Funding; Bristol-Myers Squibb (spouse): Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma BV: Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; Seattle Genetics: Research Funding; Incyte Corporation: Research Funding. Shadman:TG Therapeutic: Research Funding; Mustang Bio: Research Funding; Atara Biotherapeutics: Consultancy; Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Sunesis: Research Funding; Verastem: Consultancy; Astra Zeneca: Consultancy; ADC Therapeutics: Consultancy; Sound Biologics: Consultancy; Celgene: Research Funding; Gilead: Consultancy, Research Funding; BeiGene: Research Funding; Acerta Pharma: Research Funding. Ujjani:Pharmacyclics: Honoraria; Atara: Consultancy; Gilead: Consultancy; Genentech: Honoraria; Astrazeneca: Consultancy; AbbVie: Honoraria, Research Funding; PCYC: Research Funding. Cassaday:Amgen: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Kite/Gilead: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Other: Spouse's disclosure: employment, stock and other ownership interests. Till:Mustang Bio: Patents & Royalties, Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. Gopal:Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding.

Beschreibung: Introduction: Geriatric assessment (GA) is a multidimensional evaluation of patient health and function that may detect impairments not identified as part of routine care, predict treatment-related morbidity and mortality, and inform treatment plans. Given evidence of these benefits, the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology (NCCN Guidelines®) recommend GA for older candidates of hematopoietic stem cell transplantation (HCT). However, both older and younger HCT candidates will often receive multiple rounds of chemotherapy before HCT, leading to functional impairments in all age groups. Furthermore, HCT patients often experience a significant gap between when they are first evaluated and actually proceed to transplant (e.g., while a donor search is conducted), creating an opportunity to identify impairments and optimize function prior to transplant. Methods: To address this opportunity, we created a clinical pre-HCT optimization program (C-POP) to evaluate physical function, cognitive function, nutritional status, and mental health in all adults who were deemed potential candidates for allogeneic HCT by a HCT physician. We applied this standard of care program to all adult candidates for HCT, regardless of age, with the goal of identifying functional impairments and then referring patients to services to optimize those impairments prior to HCT. We defined impairments using validated measures and compared results to established norms or scoring, controlling for age and gender where appropriate (e.g., the cut-off for six-minute walk distance was adjusted for age, gender, height, and weight, while the cut-off for falls was any fall regardless of characteristics). Patients with impairments were referred to the appropriate supportive care (e.g., physical function impairment -〉 referral to physical therapy). Results were prospectively analyzed at new patient evaluation (NPE), which was the first time the patient met a HCT physician and sign-off, which occurred within a week before starting transplant. While the program is ongoing, we present here the results of patients evaluated between October 16th, 2017 and July 1st, 2019. Patients are divided into three pre-specified age groups: =60 years old, with results compared using a chi-squared test. Results: We evaluated 115 patients: 21 (18%) =60 years). There were no differences between the age groups in other demographics (gender, race, and ethnicity). At NPE, 93 (81%) met criteria for at least 1 impairment in physical function, cognitive function, nutritional status, or mental health; 62 (54%) met criteria for impairments in 2 or more areas. Surprisingly, patients =60 years (36/54, 67%) (p=0.03). Of those 115 patients, 52 (45%) proceeded to HCT, including 12 (57%) =60 years (p=0.75); of those patients who have not proceeded to HCT, 40 (35%) will never proceed to HCT (e.g., deemed not a candidate after functional evaluation or died of disease prior to HCT) while 23 (20%) are still awaiting HCT (e.g., donor search ongoing). Patients who proceeded to HCT were less likely to have mental health impairments (2/52, 4% vs. 9/40, 23%, p=0.006). Of the 52 who were seen at new patient evaluation and proceeded to transplant, 40 (77%) were seen at sign off. Of those who had impairments at NPE, 12/23 (52%) improved their physical function to normal limits, 4/9 (44%) improved their cognitive function, and 9/13 (69%) improved their nutritional status by the time of sign-off (of those who were seen at sign-off, none had mental health impairments at NPE). Discussion: These results demonstrate that younger as well as older candidates for HCT exhibit a high degree of functional impairment. However, this impairment could be amenable to improvement prior to HCT. These findings support application of GA to all HCT candidates regardless of age. We will investigate the effect of referred interventions (e.g., physical therapy, seeing a dietician) in improving functional impairments in future studies, as well as look at the effect of these findings on HCT outcomes. Disclosures Wiggins: Incyte, Inc.: Speakers Bureau. Gasparetto:Janssen: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Celgene: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; BMS: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed . Rizzieri:Millennium: Speakers Bureau; Novartis: Consultancy; AbbVie: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Incyte: Consultancy, Speakers Bureau; TEVA: Consultancy; Spectrum: Consultancy; Kite Pharma: Consultancy; Gilead Sciences: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau. Horwitz:Abbvie Inc: Membership on an entity's Board of Directors or advisory committees. Sung:Novartis: Research Funding; Merck: Research Funding; Seres: Research Funding.

Beschreibung: Introduction: Allogeneic hematopoietic stem cell transplant (allo-HCT) remains the only curative treatment for many hematologic conditions. However, significant mortality risk and risk of severe graft-vs-host disease (GvHD) limit its usefulness. Some patient characteristics such as performance status are used routinely as prognostic markers for poor outcomes after transplant. Steatohepatitis is a metabolic dysfunction manifesting as increased hepatic adiposity and resulting inflammation. A pre-clinical murine study suggests steatohepatitis is associated with GvHD. We assessed whether pre-HCT hepatic steatosis was associated with risk of developing GvHD and post transplant mortality. Methods: This retrospective study reviewed adult patients who underwent allogeneic stem cell transplants at Duke University over a 10-year period between 2008 and 2017 and had a computed tomography scan (CT) of the abdomen and pelvis with contrast within a 1-year period preceding the transplant. Patients with an acute illness as the indication for CT were excluded. We measured the attenuation of the liver vs. spleen as an estimate of hepatic steatosis. We used the widely accepted definition of hepatic steatosis as present when the difference in average attenuation between the spleen and liver was greater than or equal to 10 Hounsfield units and as absent when the difference was less than 10 Hounsfield units. Baseline pre-HCT factors as well as post-HCT outcomes were abstracted from the medical record. Results: We identified 80 patients with pre-HCT CT scans; of those, 59 (74%) had hepatic steatosis as defined above. Patients with hepatic steatosis tended to be older (median 52 vs. 38 years, p=0.0522); there were no statistically significant differences in gender, race, ethnicity, height, weight, Karnofsky Performance Status, HCT Comorbidity Index, history of diabetes, history of coronary artery disease, history of elevated liver function tests, primary disease, conditioning regimen, or stem cell source. Hepatic steatosis did not predict acute GvHD grade II-IV (OR 1.003, 95% CI 0.259 - 3.888, p=0.997). However, it was significantly associated with chronic GvHD on both univariate as well as multivariate analysis (Table 1, multivariate OR 3.83, 95% CI 1.11 - 13.28, p=0.023). There was no difference in overall survival or non-relapse mortality between the two groups. Conclusions: This study suggests that hepatic steatosis may predict chronic GvHD but does not predict acute GvHD or overall/non-relapse mortality. This study can be improved by using other imaging techniques such as a noncontrast CT, which is more accurate for assessment of hepatic steatosis. It is also important to note that imaging can only be used to predict the existence of hepatic steatosis; lobular inflammation, which is required to diagnose steatohepatitis, can only be proven on biopsy. Larger studies with liver biopsy or other noninvasive imaging measures of liver stiffness and steatosis will be needed to confirm the above results. Disclosures Gasparetto: Celgene: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Janssen: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; BMS: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed . Horwitz:Abbvie Inc: Membership on an entity's Board of Directors or advisory committees. Rizzieri:Gilead Sciences: Consultancy, Speakers Bureau; Pfizer: Consultancy; Novartis: Consultancy; Millennium: Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau; AbbVie: Consultancy; Spectrum: Consultancy; Kite Pharma: Consultancy; Incyte: Consultancy, Speakers Bureau; TEVA: Consultancy; Seattle Genetics: Consultancy, Speakers Bureau; Amgen: Consultancy. Bashir:Metacrine, Inc.: Research Funding; ProSciento, Inc.: Research Funding; Pinnacle Clinical Research: Research Funding; CymaBay Therapeutics: Research Funding; Siemens Healthcare: Research Funding; NGM Biopharmaceuticals: Research Funding; Madrigal Pharmaceulticals: Research Funding. Sung:Novartis: Research Funding; Merck: Research Funding; Seres: Research Funding.

Beschreibung: Our group previously showed that B cells signal aberrantly through the B cell receptor (BCR) in allogeneic hematopoietic stem cell transplant (HCT) patients with active chronic graft-versus-host disease (cGVHD). Preclinical mouse studies have demonstrated the importance of the proximal BCR molecule, spleen tyrosine kinase (SYK), in cGVHD development. Hypothesizing that the oral small molecule SYK inhibitor, fostamatinib, would safely target aberrant BCR-activated B cells in HCT patients, we are conducting a single-center, investigator-initiated phase 1 trial (NCT02611063). Our primary objective is to evaluate the safety and tolerability of fostamatinib in patients early after HCT and in those with refractory active cGVHD. Secondary objectives include assessment of cGVHD manifestations, B cell activation, and immune recovery. Methods: All patients receive HCT treatment per program standards at Duke University. Prophylaxis (P-cGVHD) subjects enroll 80-150 days after HCT and have no evidence of cGVHD. P-cGVHD subjects receive drug for up to 1 year post-transplant (215-285 fostamatinib days). Steroid-refractory cGVHD (SR-cGVHD) subjects enroll with active cGVHD that persists despite systemic high-dose steroids. SR-cGVHD subjects receive drug for up to 365 days total. For all enrollees, modified continual reassessment criteria are used to determine starting dose (100mg daily, 150mg daily, or 100mg twice BID) and any needed dose modifications. We monitor for drug-limiting toxicities (DLTs), adverse events (AEs), and cGVHD manifestations using NIH cGVHD consensus criteria at up to 12 follow-up visits. Results: 15 of a planned 18 total patients have enrolled. In the P-cGVHD group (n=5), of the 4 patients who completed treatment (mean 239 fostamatinib days), 1 patient developed cGVHD while enrolled and 2 patients subsequently developed cGVHD, 4 and 6 weeks after study completion. The fifth P-cGVHD subject discontinued therapy on study day 155 (provider decision to initiate donor lymphocyte infusion for low CD3+ chimerism). In the SR-cGVHD group (n=10), 2 patients completed treatment (mean 365 fostamatinib days); 3 patients withdrew (mean 132 fostamatinib days), for non-cardiac chest pain, progression of cGVHD, and moved away; and 5 patients are actively enrolled (mean 207 fostamatinib days). Both SR-cGVHD patients who completed the study clinically improved while on fostamatinib and requested continuation of drug. A total of 2, 9, and 4 patients have been initiated on 100mg daily, 150mg daily, and 100mg BID, respectively. At the 100mg daily dose, no DLTs were noted. At the 150mg daily dose, 1 patient developed liver function test (LFT) elevation. At the 100mg BID dose, 2 patients developed LFT elevation and 1 patient developed non-cardiac chest pain. One patient required dose adjustment: 100mg BID to 150mg daily, for LFT elevation. Two serious AEs possibly related to fostamatinib occurred: 1 patient developed non-cardiac chest pain and 1 patient developed a deep venous thrombosis. No probably- or definitely-related serious AEs occurred. To assess whether fostamatinib effectively targets aberrantly activated B cells, we examined subjects' whole blood using flow cytometry. When comparing CD19+ B cells on study day 1 versus study day 60 in the SR-cGVHD group (n=7), we found the relative proportion of CD19+CD38+IgDlow plasmablast-like cells was decreased (p=0.03, Fig 1A-B), suggesting fostamatinib 'hit target.' Importantly, in the P-cGVHD group, total lymphocyte and B cell counts did not decrease during day 1 to day 225 (Fig 1C-D), suggesting fostamatinib did not affect immune recovery when given early after HCT. Further investigations with functional assays are underway. Conclusions: This study demonstrates for the first time that fostamatinib is safe and tolerated in HCT recipients both early after transplant and in those with active cGVHD. Importantly, fostamatinib does not appear to hinder lymphocyte or B cell recovery when initiated between days 80-150 after HCT. Additionally, fostamatinib may effectively target aberrantly activated B cells in patients with active SR-cGVHD. Fostamatinib, now FDA-approved for treatment of immune thrombocytopenia, merits a phase 2, randomized controlled trial to assess efficacy as a prophylactic agent against cGVHD. This work was supported by a National Institutes of Health grant, NIH (NHLBI) R01 HL 129061. Fostamatinib was supplied by Rigel. Disclosures Horwitz: Abbvie Inc: Membership on an entity's Board of Directors or advisory committees. Gasparetto:BMS: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Celgene: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Janssen: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed . Sung:Novartis: Research Funding; Merck: Research Funding; Seres: Research Funding. Rizzieri:Celgene, Gilead, Seattle Genetics, Stemline: Other: Speaker; AbbVie, Agios, AROG, Bayer, Celgene, Gilead, Jazz, Novartis, Pfizer, Sanofi, Seattle Genetics, Stemline, Teva: Other: Advisory Board; AROG, Bayer, Celgene, Celltron, Mustang, Pfizer, Seattle Genetics, Stemline: Consultancy; Stemline: Research Funding.

Beschreibung: Factor VII (FVII) is an important component of the coagulation cascade. Few genetic loci regulating FVII activity and/or levels have been discovered to date. We conducted a meta-analysis of 9 genome-wide association studies of plasma FVII levels (7 FVII activity and 2 FVII antigen) among 27 495 participants of European and African ancestry. Each study performed ancestry-specific association analyses. Inverse variance weighted meta-analysis was performed within each ancestry group and then combined for a trans-ancestry meta-analysis. Our primary analysis included the 7 studies that measured FVII activity, and a secondary analysis included all 9 studies. We provided functional genomic validation for newly identified significant loci by silencing candidate genes in a human liver cell line (HuH7) using small-interfering RNA and then measuring F7 messenger RNA and FVII protein expression. Lastly, we used meta-analysis results to perform Mendelian randomization analysis to estimate the causal effect of FVII activity on coronary artery disease, ischemic stroke (IS), and venous thromboembolism. We identified 2 novel (REEP3 and JAZF1-AS1) and 6 known loci associated with FVII activity, explaining 19.0% of the phenotypic variance. Adding FVII antigen data to the meta-analysis did not result in the discovery of further loci. Silencing REEP3 in HuH7 cells upregulated FVII, whereas silencing JAZF1 downregulated FVII. Mendelian randomization analyses suggest that FVII activity has a positive causal effect on the risk of IS. Variants at REEP3 and JAZF1 contribute to FVII activity by regulating F7 expression levels. FVII activity appears to contribute to the etiology of IS in the general population.