Plasma-derived human factor X concentrate for the treatment of patients with hereditary factor X deficiency.

INTRODUCTION: Hereditary factor X (FX) deficiency (HFXD) is an autosomal recessive rare bleeding disorder that leads to defects in the FX protein. Depending on the degree of deficiency, patients may be at risk of life-threatening bleeding episodes. Historical treatments for FX deficiency include prothrombin complex concentrates, which can increase the risk of thrombosis, and fresh frozen plasma, which can cause volume overload and transfusion reactions. Plasma-derived FX (pdFX), a single-factor, high-purity, high-potency human FX treatment, was approved in 2015 in the United States and in 2016 in Europe for on-demand treatment and prophylaxis of bleeding episodes and perioperative management of patients with HFXD. METHODS: Five studies that examined the use of pdFX in patients with mild (plasma FX activity [FX:C] ≥5 IU/dL), moderate (FX:C ≥1 and <5 IU/dL), or severe (FX:C < 1 IU/dL) HFXD were reviewed: TEN01, TEN02 and TEN03 were prospective, open-label, multicentre, nonrandomised studies, and TEN05 and TEN06 were multicentre retrospective studies. RESULTS: When used as an on-demand treatment, pdFX was judged by investigators to be successful in treating 41/42 (97.6%), 2/3 (66.6%) and 79/79 (100%) bleeds in TEN01, TEN02 and TEN05, respectively. When used prophylactically, pdFX was judged 'excellent' for the prevention of bleeds in nine (100%) and eight (100%) patients in TEN02 and TEN05, respectively. Perioperative treatment and pharmacokinetics were also assessed. pdFX was safe and well tolerated. CONCLUSIONS: Together, these studies support the use of pdFX for on-demand treatment of bleeding, routine prophylaxis, and perioperative management of bleeding in patients with HFXD.

Five new F10 variants in hereditary factor x deficiency detected by high-throughput sequencing.

INTRODUCTION: Factor X deficiency is a rare inherited bleeding disorder. To date, 181 variants are reported in the recently updated F10-gene variant database. AIM: This study aimed to describe new F10 variants. METHOD: The F10 gene was analysed in 16 consecutive families with FX deficiency by a targeted high-throughput sequencing approach, including F10, F9, F8 genes, and 78 genes dedicated to haematological malignancies. RESULTS: We identified 19 variants (17 missense, one nonsense and one frameshift) and two copy number variations. Two patients presenting a combined FVII-FX deficiency showed a loss of one F10 gene copy (del13q34) associated with a missense variant on the remaining allele, leading to a FX:C significantly lower than the FVII:C level and explaining their unusual bleeding history. We reported five novel variants. Three missense variants (p.Glu22Val affecting the signal peptide cleavage site, p.Cys342Tyr removing the disulphide bond between the FX heavy and light chains, and p.Val385Met located in FX peptidase S1 domain) were detected at compound heterozygosis status in three patients with severe bleeding symptoms and FX:C level below 10 IU/dL. Two truncating variants p.Tyr279* and p.Thr434Aspfs*13 leading to an altered FX protein were found at heterozygous state in two patients with mild bleeding history. CONCLUSION: This study showed the feasibility and the interest of high-throughput sequencing approach for rare bleeding disorders, enabling the report of F10 gene screening in a 3-weeks delay, suitable for clinical use. The description of five new variants may contribute to a better understanding of the phenotype-genotype correlation in FX deficiency.

Acquired factor X deficiency in a multiple myeloma without amyloidosis: a case report.

BACKGROUND: Multiple myeloma is one of the most common hematologic malignancies. Acquired factor X deficiencies are often observed in primary (AL) amyloidosis and rarely in multiple myeloma. OBJECTIVE: We report a case of an acquired factor X deficiency in a patient with a newly diagnosed IgA lambda multiple myeloma, without any evidence of concomitant amyloidosis. METHODS: We present the patient's medical history, clinical and physical examinations, laboratory analysis, and outcome. RESULTS: A 76-year-old male presented at the emergency department with ongoing gingival bleeding. Several analytical problems with blood sample analysis arose, which eventually led to the diagnosis of a multiple myeloma. Further exploration revealed an acquired factor X deficiency, explaining the ongoing bleeding. There was no evidence of concomitant amyloidosis. The multiple myeloma was treated, leading to complete remission of the malignancy and bleeding tendency. CONCLUSION: While coagulopathy is rarely observed in patients diagnosed with multiple myeloma, considering an acquired factor X deficiency becomes relevant when such patient present with bleeding diathesis.

Postmortem diagnosis of severe factor X deficiency in a fetus with intracranial hemorrhage resulting in intrauterine death.

In patients with severe congenital factor X deficiency, spontaneous intracranial hemorrhage (ICH) is particularly frequent in early childhood. We describe a case of fetal death at 26 weeks due to massive ICH. Gene panel analysis of postmortem samples revealed homozygosity for a pathologic F10 gene variant (c.1210T>C, p.Cys404Arg), which impedes correct folding of the catalytic serine protease domain and, therefore, causes a significant reduction in FX levels. The parents, not consanguineous but of the same ethnic community, were found to be heterozygous for this variant and did not have any personal or family history of abnormal bleeding. To the best of our knowledge, this is the first reported case of severe FX deficiency resulting in ICH diagnosed through postmortem genetic analysis. It illustrates the importance of exploring the etiology of fetal or neonatal ICH, which may impact future pregnancies, and the treatment of a potential coagulopathy in the child.

Preclinical development and characterization of a human plasma-derived high-purity factor X concentrate for therapeutic use.

INTRODUCTION: Hereditary factor X deficiency is a rare bleeding disorder, with limited treatment options. This paper describes the approach to pre-clinical development and characterization of a high-purity plasma-derived factor X concentrate, to achieve orphan drug marketing authorization for the treatment of hereditary factor X deficiency. METHODS: A chromatographic process was developed, to purify factor X from human plasma for fractionation. The product was characterized using in vitro, in vivo and ex vivo tests for potency, purity, thrombogenicity, immunogenicity, toxicity and stability. RESULTS: The production process complied with good pharmaceutical manufacturing practice. It achieved 6000-fold purification and 100-fold concentration of the factor X protein compared to human plasma. The factor X protein was 94%-96% pure. Other residual plasma proteins were well below levels in plasma, minimizing potential interference in hemostasis after therapeutic administration. Effective virus-reduction during manufacture, and the absence of thrombogenicity, toxicity and immunogenic potential were confirmed, addressing the main safety concerns historically associated with plasma-derived therapeutics. The freeze-dried product remained stable between +2°C and +30°C for at least three years. After reconstitution with water for injections, the factor X activity was maintained for at least 48 h at +18°C to +22°C. CONCLUSION: Targeted pre-clinical development of the first highly-purified concentrate to treat hereditary factor X deficiency is described. Following international guidelines for nonclinical safety testing, particular strategies were adopted for unmodified products derived from human blood plasma. This approach may also be relevant to the development of other ultra-orphan medicinal products.

Management of Acquired Factor X Deficiency Caused by In Vitro Non-neutralizing Anti-factor X Autoantibodies with Pre-emptive Corticosteroid Therapy.

Coagulation factor X (FX) deficiency causes severe hemorrhagic symptoms. We herein report a 90-year-old man with hemorrhagic symptoms and prolongation of prothrombin time (PT) and activated partial thromboplastin time (APTT). Cross-mixing tests showed a factor deficiency pattern, but administration of plasma products was not effective. Acquired coagulation factor deficiency was suspected, and immunosuppressive therapy was started. After the intervention, his hemorrhagic symptoms improved. A decrease in FX activity was later confirmed, and anti-FX autoantibody was retrospectively detected by an enzyme-linked immunosorbent assay. Immediate intervention is important for patients suspected of having acquired coagulation factor deficiency.

Role of individual factor X concentrate pharmacokinetic studies in perioperative management of AL amyloidosis-associated acquired factor X deficiency.

BACKGROUND: AL amyloidosis is associated with acquired factor X (FX) deficiency. Experience related to its management is limited to case reports and series using prothrombin complex concentrate, fresh frozen plasma, plasma exchange, recombinant activated factor seven, and desmopressin with limited and variable efficacy. FX concentrate has not been widely used in its management. STUDY DESIGN AND METHODS: We report our experience with the perioperative use of FX concentrate (Coagadex) in two patients with AL amyloidosis-associated acquired FX deficiency requiring surgery, using their individual pharmacokinetic studies to manage perioperative hemostasis. Pharmacokinetic studies involved obtaining post-infusion FX activity at 10 min, 2, and 4 h following the administration of FX concentrate to calculate the FX half-life. RESULTS: Both patients' plasma FX activity was successfully increased to provide perioperative hemostatic support. Monitoring FX activity post-surgery was also utilized to maintain FX activity levels to prevent post-operative bleeding. CONCLUSION: Pharmacokinetic studies have a useful role in tailoring preoperative FX repletion in patients with AL amyloidosis associated with acquired FX deficiency.

Acquired Factor X Deficiency without Amyloidosis Presenting with Massive Hematuria: A Case Report and Review of the Literature.

Acquired factor X deficiency is a rare diagnosis, especially without the association of other co-existing conditions such as amyloidosis. The authors report the case of a 34-year-old male with severe frank hematuria found to have markedly prolonged prothrombin time and activated partial thromboplastin time. A mixing study showed correction utilizing normal plasma and a coagulation panel testing revealed decreased factor X activity. The patient was treated with multiple blood transfusions, fresh frozen plasma, high-dose pulse steroids, and rituximab. The patient's condition improved during his 21-day hospital stay and was followed up every 2 weeks for 3 months. The patient's factor X level recovered after two weeks of discharge with no other hemorrhagic episodes.

Post-COVID Factor X Deficiency: A Case Report From Pakistan.

Acquired Factor X deficiency is a rare hematological disease, characterized by excessive bleeding, with fewer than 50 cases reported in the literature and practically all being associated with amyloidosis. We describe a case of a 38-year-old man with no known family history of hematologic disorders who had symptoms of a mild COVID-19 infection. Upon resolution, he developed excessive bleeding features, including epistaxis and hematuria. It was later found that while the rest of the coagulation factors were within normal limits, Factor X was 7% of the normal value, which reversed about two months after recovery. Our case highlights the significance of the less-expected post-COVID bleeding complications, in contrast to the classically seen thrombotic ones.

A case report of congenital factor X deficiency in an adult patient.

Factor X deficiency is one of the rarest coagulation disorders representing 10% of all rare bleeding diseases with a frequency of 1:1,000,000. A 39-year-old male patient with no previous medical conditions was admitted to the hospital with a left carpal ganglion for surgical excision. Routine preoperative laboratory examination revealed a high international normalized ratio of 5.4 IU (0.8-1.1) and a prothrombin time of 72.2 s (10.9-13.6), with an isolated factor X level of less than 5%. Genetic testing for congenital factor X deficiency identified a homozygous mutation c.271 > A (p.Glu91). Vitamin K supplementation did not improve his international normalized ratio or increase factor X levels; hence, surgery was delayed. The patient was re-hospitalized to remove a wisdom tooth, during which fresh frozen plasma was administered. An allergic reaction complicated this procedure in the form of a rash on the body. As a result, the tooth was removed without active bleeding. This report presents a unique factor X deficiency case with limited treatment options to improve factor X levels after failed vitamin K administration and an allergic reaction to fresh frozen plasma. A physician's observation and ongoing follow-up were the only reasonable approaches in treating the patient with mild to moderate factor X deficiency due to lack of prothrombin complex concentrates or factor X replacement at the center at the time.

Prevalence, clinical characteristics and treatment outcome of factor X deficiency in a consecutive cohort of primary light-chain amyloidosis.

Factor X (FX) deficiency is prevalent in light-chain (AL) amyloidosis but its clinical significance was not investigated deeply. We conducted a retrospective analysis of a consecutive cohort with 207 primary AL amyloidosis patients. FX deficiency was present in 129 patients (62.3%). Those with FX deficiency had higher dFLC (299.6 mg/L vs. 102.3 mg/L, P < 0.001), higher cardiac troponin I (0.05 µg/L vs. 0.02 µg/L, P < 0.001) and N-terminal pro-brain natriuretic peptide (3115 ng/L vs. 392 ng/L, P < 0.001), and more patients with bone marrow plasma cells > 10% (18.0% vs. 4.3%, P = 0.008). The prevalence of FX deficiency increased with the Mayo 2004 stage. FX-deficient patients exhibited inferior overall survival (P < 0.001) and progression-free survival (P < 0.001) than others. Fifty-five patients with FX deficiency received retesting of FX activity after anti-plasma cell therapy. The median variation in FX activity was + 6.8% (range, -24.5% ~ +73.4%). Better improvement of FX activity was observed in patients with complete hematologic response (+18.2% vs. +4.0%, P = 0.036) and at least one organ response (+14.4% vs. +3.4%, P = 0.024). FX deficiency is associated with a heavier disease burden and poorer survival in primary AL amyloidosis. Improvement of FX activity tends to appear in patients with better hematologic and organ responses after chemotherapy.

A review of the pharmacokinetics, efficacy and safety of high-purity factor X for the prophylactic treatment of hereditary factor X deficiency.

INTRODUCTION: Hereditary factor X (FX) deficiency (FXD) is a rare autosomal recessive bleeding disorder. Plasma-derived FX (pdFX) is a high-purity FX concentrate approved in the United States and Europe for the treatment and prophylaxis of bleeding episodes and for peri-operative management in patients with hereditary FXD (HFXD). AIM: To review pharmacokinetic dosing, efficacy, and safety data for pdFX as routine prophylaxis for HFXD. METHODS: Summary of the published pharmacokinetic and safety data from TEN01, TEN02, TEN05, and real-world publications of pdFX for prophylaxis. RESULTS: Pharmacokinetic modelling data from the phase 3 TEN01 study supported administration of pdFX 25 IU/kg twice weekly for routine prophylaxis in adolescents/adults (aged ≥12 years). Results from nine paediatric patients in the phase 3 TEN02 study and eight adolescents/adults (aged ≥12 years) in the retrospective data-collection TEN05 study, along with real-world evidence, showed that routine prophylaxis with pdFX ≈40 IU/kg twice weekly in patients aged <12 years and pdFX ≈25 IU/kg twice weekly in patients aged ≥12 years was effective in bleeding prevention. CONCLUSIONS: pdFX was well tolerated in clinical studies, with no new safety signals identified during routine prophylactic use. Based on current evidence, it is recommended that routine prophylaxis with pdFX be initiated at 25 IU/kg twice weekly in adults/adolescents ≥12 years of age, and at a dosage of 40 IU/kg twice weekly in children <12 years of age. Thereafter, FX levels should be closely monitored, and dosages should be adjusted according to clinical response and to maintain trough levels ≥5 IU/dl.

The 13-year bleed: Exuberant amyloid angiopathies, angiodysplasias, and acquired coagulopathies of the gut.

Amyloidosis is a disorder characterized by extracellular deposits of proteins that are prone to aggregate and form insoluble fibrils. Amyloid deposits limited to a single organ or tissue without the involvement of any other site in the body is uncommon. We report a 75-year-old man with previously treated non-Hodgkin's lymphoma who presented with recurrent gastrointestinal hemorrhage. Histopathology showed amyloid deposition within vascular malformations. His bleeding continued with the cause rooted in the fundamental building blocks-clotting factors. We discuss the interplay of the pathophysiology of lymphoma, amyloidosis, and factor X deficiency in a patient with preexisting angiodysplasias leading to refractory gastrointestinal bleeding. To our knowledge, there are only 3 reported cases of concomitant amyloidosis and angiodysplasia in the colon, and none involving the small bowel.

Plasma-derived factor X concentrate compassionate use for hereditary factor X deficiency: Long-term safety and efficacy in a retrospective data-collection study.

BACKGROUND: Coagadex is a high-purity plasma-derived factor X concentrate (pdFX) developed to treat hereditary factor X deficiency (FXD). OBJECTIVE: Evaluate the efficacy and safety of pdFX administered to patients with hereditary FXD. METHODS: This was an open-label, multicenter, retrospective analysis of patients receiving pdFX for compassionate use. Efficacy end points included treatments administered, the number and treatment of bleeds, and investigator assessments. Adverse drug reactions (ADRs) were monitored. RESULTS: Fifteen patients were included: seven received routine prophylaxis, seven received on-demand treatment, and one alternated. Most were aged ≥12 years (n = 13) and had severe hereditary FXD (n = 12). The median follow-up time was 19.2 months (range, 3.5-48.8). The number of infusions per patient per month was higher for the routine prophylaxis group (median [range], 5.4 [1.4-10.1]) than for the on-demand group (0.8 [0.1-2.3]), as was the dose per infusion (27.9 [21.9-53.6] IU/kg vs 20.0 [13.6-27.7] IU/kg). Patients experienced 88 bleeds (34 minor, 7 major, 47 unclassified). The monthly bleed rate per patient was 0.04 in the routine prophylaxis group (based on 17 bleeds in four patients) and 0.8 in the on-demand group (based on 71 bleeds in eight patients). pdFX was used to treat 79 bleeds and was rated effective in all instances. In an overall assessment, investigators rated pdFX as excellent for 14 patients (93.3%) and good for 1 patient (6.3%). No ADRs or safety concerns were reported. CONCLUSIONS: This analysis supports the use of pdFX as a safe, effective treatment for hereditary FXD. Routine prophylaxis with pdFX may reduce bleed frequency.

Diagnosis, therapeutic advances, and key recommendations for the management of factor X deficiency.

Factor X deficiency is a rare coagulation disorder that can be hereditary or acquired. The typology and severity of the associated bleeding symptoms are highly heterogeneous, adding to the difficulties of diagnosis and management. Evidence-based guidelines and reviews on factor X deficiency are generally limited to publications covering a range of rare bleeding disorders. Here we provide a comprehensive review of the literature on factor X deficiency, focusing on the hereditary form, and discuss the evolution in disease management and the evidence associated with available treatment options. Current recommendations advise clinicians to use single-factor replacement therapy for hereditary disease rather than multifactor therapies such as fresh frozen plasma, cryoprecipitate, and prothrombin complex concentrates. Consensus in treatment guidelines is still urgently needed to ensure optimal management of patients with factor X deficiency across the spectrum of disease severity.

Occurrence and management of severe bleeding episodes in patients with hereditary factor X deficiency.

Vitamin K-dependent factor X (FX) plays an important role in thrombin formation, and a deficiency in FX can cause impaired coagulation, the severity of which is usually correlated with the degree of deficiency. Due to the critical role that FX plays in the coagulation cascade, FX deficiency is associated with a higher risk of bleeding than deficiencies in other coagulation factors. Patients with the hereditary autosomal-recessive homozygous form of FX deficiency, which occurs in approximately 1:1,000,000 individuals worldwide, are often diagnosed when they present with spontaneous life-threatening haemorrhage (most often intracranial haemorrhage) during the first month of life. In addition to central nervous system bleeds, other severe bleeding types experienced by such patients may include umbilical cord bleeding, gastrointestinal or pulmonary haemorrhage, intramuscular haematomas and/or haemarthrosis. Delayed treatment or inadequate replacement of FX may result in developmental delays, musculoskeletal disabilities or death. The high risk of recurrent severe bleeding necessitates prophylactic replacement therapy for many individuals with severe FX deficiency. Available products for replacement therapy include plasma-derived FX concentrate and prothrombin complex concentrates. Fresh-frozen plasma may be used when concentrates are not available but is a less efficient means of FX replacement. This article reviews the literature on severe bleeding in individuals with hereditary FX deficiency and discusses current treatment options.

Mechanical valve replacement without anticoagulation: a case report.

BACKGROUND: For patients who undergo mechanical valve replacement, the greatest disadvantage is that they require long-term or permanent use of anticoagulant therapy to prevent thromboembolism. To date, mechanical valve replacement without anticoagulation has been published in the literature. CASE SUMMARY: We present the case of a 75-year-old female who underwent mechanical mitral valve replacement (MVR) on mid-June, 2007. However, this patient had not been taking anticoagulant medication since she experienced warfarin overdose in the first month after the operation. She had been well without using any anticoagulation, and there were no complications of the mechanical valve. DISCUSSION: There was no thrombosis for such a long period of time because she suffered from FX deficiency. To the best of our knowledge, she may be the only patient who has been well without any anticoagulation since not taking warfarin 12 years ago.

A Case Report of Acquired Factor X Deficiency in a Patient With Multiple Myeloma.

Multiple myeloma is a plasma cell neoplasm characterized by clonal proliferation of immunoglobulin producing terminally differentiated B cells. Classically patients are described to present with bone pain, hypercalcemia, anemia, and/or renal impairment. A less described clinical manifestation related to the myeloma is acquired coagulation abnormalities including paraprotein interfering with the coagulation cascade or exhibiting specific antibody activity. Factor X deficiency is reported in patients with secondary amyloidosis. We describe a patient who presented with bleeding tendency and an abnormal prothrombin and activated partial thromboplastin times (PT/PTT) due to factor X deficiency. A thorough workup revealed the diagnosis of multiple myeloma with the presence of monoclonal lambda light chain restricted plasma cells with qualifying end-organ damage without evidence of amyloidosis. Prior to the ultimate diagnosis, the patient succumbed to septic shock and acute respiratory distress syndrome due to Streptococcus Pneumonia infection.

A Compound Heterozygosis of Two Novel Mutations Causes Factor X Deficiency in a Chinese Pedigree.

BACKGROUND: Mutations in the F10-coding gene can cause factor X (FX) deficiency, leading to abnormal coagulation activity and severe tendency for hemorrhage. Therefore, identifying mutations in F10 is important for diagnosing congenital FX deficiency. METHODS: We studied a 63-year-old male patient with FX deficiency and 10 of his family members. Clotting and immunological methods were used to determine activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen levels, FX activity, and FX antigen levels. The platelet count was determined. A mixing study was performed to eliminate the presence of coagulation factor inhibitors and lupus anticoagulant. Mutations were searched using whole-exome sequencing and certified by Sanger sequencing. RESULTS: Genetic analysis of the proband identified two single-base substitutions: c.1085G>A (p.Ser362Asn) and c.1152C>A (p.Tyr384Ter, termination codon, caused by the DNA sequence TAA). His FX activity and antigen levels were 1.7% and 408.53 pg/mL, respectively; aPTT and PT were 52.3 and 48.0 s, respectively. One brother had the same compound heterozygous mutations, and his FX activity and antigen levels were 1.3% and 465.47 pg/mL, respectively; his aPTT and PT were 65.2 and 54.5 s, respectively. His mother, another brother, and one sister were heterozygous for c.1085G>A (p.Ser362Asn), and his daughter and grandson (6 years old) were heterozygous for c.1152C>A (p.Tyr384Ter). CONCLUSION: The heterozygous variants p.Ser362Asn or p.Tyr384Ter indicate mild FX deficiency, but the compound heterozygous mutation of the two causes severe congenital FX deficiency and bleeding. Genetic analysis of these two mutations may help characterize the bleeding tendency and confirm congenital FX deficiency.