Efficacy and safety of the neonatal Fc receptor inhibitor efgartigimod in adults with primary immune thrombocytopenia (ADVANCE IV): a multicentre, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Primary immune thrombocytopenia is an autoimmune disorder mediated partly by platelet autoantibodies, resulting in thrombocytopenia, bleeding, and constitutional symptoms. Efgartigimod, a first-in-class novel human IgG1 Fc fragment, binds the neonatal Fc receptor with high affinity and thus reduces serum IgG concentrations, including autoantibodies. The objective of this study was to evaluate the efficacy and safety of efgartigimod in adults with persistent and chronic primary immune thrombocytopenia. METHODS: This phase 3, multicentre, randomised, double-blinded, placebo-controlled, 24-week study evaluated the efficacy and safety of intravenous efgartigimod in adults aged 18 years or older with chronic or persistent primary immune thrombocytopenia who had an average platelet count of less than 30 000, had responded to at least one previous immune thrombocytopenia therapy, and were on a concurrent therapy at baseline or had received at least a second previous immune thrombocytopenia therapy. The study took place in 71 participating sites from Asia, Europe, and North America. Patients were randomly assigned 2:1 to receive either efgartigimod (10 mg/kg) or placebo intravenously for the first 4 weeks, after which the dosing schedule could be altered to once per week or every other week depending on the patients' platelet count. The primary endpoint, evaluated in the chronic population, was sustained platelet count response (≥50 × 109 for at least 4 of the last 6 weeks). This study is registered with ClinicalTrials.gov (NCT04188379) and is completed. FINDINGS: A total of 205 patients were screened from Dec 9, 2019, to Feb 3, 2022, and 131 (86 in the efgartigimod group; 45 in the placebo group) were randomly assigned. These patients represented a population with long-term disease who had a mean time since diagnosis of 10·6 years and 67% (88/131) of whom had received at least three previous immune thrombocytopenia treatments. 22% (17/78) of patients with chronic immune thrombocytopenia receiving efgartigimod reached the primary endpoint compared with 5% (2/40) of those receiving placebo (p=0·032; adjusted difference in response, 16% [95% CI 2·6-26·4]). The median number of weeks of disease control in patients with chronic immune thrombocytopenia was 2·0 (IQR 0·0-11·0) for efgartigimod versus 0·0 (0·0-1·0) for placebo (p=0·0009). Efgartigimod was well tolerated; most adverse events were mild to moderate in severity. The most common adverse events of interest in both groups were headache (16% in efgartigimod and 13% in placebo), haematuria (16% in efgartigimod and 16% in placebo), and petechiae (15% in efgartigimod and 27% in placebo). INTERPRETATION: Efgartigimod significantly increased sustained platelet count responses compared with placebo in patients with chronic immune thrombocytopenia, including those who had received multiple previous immune thrombocytopenia therapies. Upon completion of the ADVANCE IV study, patients could enroll in the ongoing open-label extension. Subcutaneous efgartigimod is currently being evaluated in patients with immune thrombocytopenia in the ADVANCE SC+ trial. FUNDING: argenx.

Pharmacokinetic modeling and simulation of subcutaneous and intravenous IgG dosing in patients with primary immunodeficiency diseases.

A population pharmacokinetic (PK) model for comparing the PK of subcutaneously administered immunoglobulin G (IgG) replacement therapy (SCIG) with Gamunex-C 10% or SCIG 20% formulations in patients with primary immunodeficiency diseases was developed using data from 3 clinical trials (N = 95, 69.5% adults, 30.5% <18 years) of intravenous IG (IVIG) 10% and SCIG 10% or SCIG 20%. Serum IgG exposure following switches from IVIG 10% every 3 or 4 weeks to biweekly SCIG 20% (dose adjustment factor 1.0 or 1.37) and from weekly SCIG 20% to biweekly SCIG 20% or SCIG 20% 2-7 times/week was simulated. The PK of IVIG 10% and SCIG 20% were adequately described by a 2-compartment model with first-order absorption rate constant of exogenous IgG from an SC depot compartment into the central compartment and first-order elimination from the central compartment. Switching from IVIG 10% every 4 weeks to biweekly SCIG 20% produced similar serum IgG exposure, with lower peak and higher trough serum IgG concentrations. Switching from IVIG 10% every 3 or 4 weeks to weekly and biweekly SCIG 20% yielded comparable IgG exposure and clinically effective trough IgG concentrations.

Pharmacokinetics, surrogate efficacy and safety evaluations of a new human plasma-derived fibrinogen concentrate (FIB Grifols) in adult patients with congenital afibrinogenemia.

BACKGROUND AND AIMS: Congenital afibrinogenemia is a rare coagulation disorder resulting from a deficiency in fibrinogen. This study assessed the pharmacokinetics, surrogate efficacy and safety of FIB Grifols, a new human plasma-derived fibrinogen concentrate, to treat congenital afibrinogenemia. METHODS: Eleven adult patients from a multinational, phase 1-2, prospective, open-label, single-arm, uncontrolled clinical study received a single infusion of FIB Grifols, 70 mg/kg bw. Fibrinogen pharmacokinetics (fibrinogen activity: Clauss method; antigen plasma concentrations: ELISA) and efficacy parameters were determined over 14 days after infusion. Efficacy endpoints were the mean change on plasma maximum clot firmness (MCF) on viscoelastic testing and coagulation tests 1-hour post-infusion, and correlation with fibrinogen levels throughout. Safety parameters were also assessed. RESULTS: For the Clauss method, (mean [standard deviation]) baseline adjusted Cmax was 1.99 (0.40) g/L, reached 1.76 (1.00) h after infusion, and half-life was 76.94 (20.21) h. Using ELISA, Cmax after FIB Grifols infusion was 2.88 (0.86) mg/mL, with a tmax of 3.06 (2.24) h. Fibrinogen activity and antigen concentrations showed statistically significant correlation of 0.9120 (P < 0.001). Surrogate efficacy was demonstrated by a significant increase of 12.35 (3.85) mm in MCF. Prothrombin time, activated partial thromboplastin time and thrombin time, returned to normal ranges over time, indicating restoration of functionally active fibrinogen. There were no treatment-related adverse events, allergic reactions, serious adverse events, or discontinuations. CONCLUSIONS: The pharmacokinetic profile of functionally active FIB Grifols was established, hemostasis was restored, and FIB Grifols was safe and well tolerated in fibrinogen-deficient patients.

A Phase 3 Multicenter, Prospective, Open-Label Efficacy and Safety Study of Immune Globulin (Human) 10% Caprylate/Chromatography Purified in Patients with Myasthenia Gravis Exacerbations.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular transmission. Exacerbations may involve increasing bulbar weakness and/or sudden respiratory failure, both of which can be critically disabling. Management of MG exacerbations includes plasma exchange and intravenous immunoglobulin (IVIG); they are equally effective, but patients experience fewer side effects with IVIG. The objective of this study was to assess the efficacy and safety of immune globulin caprylate/chromatography purified (IGIV-C) in subjects with MG exacerbations. METHODS: This prospective, open-label, non-controlled 28-day clinical trial was conducted in adults with MG Foundation of America class IVb or V status. Subjects received IGIV-C 2 g/kg over 2 consecutive days (1 g/kg/day) and were assessed for efficacy/safety on Days 7, 14, 21, and 28. The primary efficacy endpoint was the change from Baseline in quantitative MG (QMG) score to Day 14. Secondary endpoints of clinical response, Baseline to Day 14, included at least a 3-point decrease in QMG and MG Composite and a 2-point decrease in MG-activities of daily living (MG-ADL). RESULTS: Forty-nine subjects enrolled. The change in QMG score at Day 14 was significant (p < 0.001) in the Evaluable (-6.4, n = 43) and Safety (-6.7, n = 49) populations. Among evaluable subjects, Day 14 response rates were 77, 86, and 88% for QMG, MG Composite, and MG-ADL, respectively. IGIV-C showed good tolerability with no serious adverse events. CONCLUSIONS: The results of this study show that IGIV-C was effective, safe, and well tolerated in the treatment of MG exacerbations.

Prospective, Randomized, Phase II, Non-Inferiority Study to Evaluate the Safety and Efficacy of Topical Thrombin (Human) Grifols as Adjunct to Hemostasis During Vascular, Hepatic, Soft Tissue, and Spinal Open Surgery.

BACKGROUND: Thrombin-based formulations have been used for topical hemostasis in surgery for decades. However, the number of randomized clinical trials comparing bovine vs human thrombin is limited. STUDY DESIGN: A randomized, double-blind, non-inferiority phase II study evaluated the hemostatic efficacy and safety of plasma-derived topical thrombin (human) Grifols (TTH-Grifols; Instituto Grifols SA) vs bovine THROMBIN JMI (BT-JMI; GenTrac Inc) (2:1 ratio) in vascular, hepatic, soft tissue, and spinal operations. The primary efficacy end point was the percentage of patients achieving hemostasis at target bleeding sites with mild to moderate bleeding (response) within 5 minutes (T5) of treatment application. Non-inferiority was met if the lower limit of the 95% CI of the response ratio of TTH-Grifols relative to BT-JMI by T5 exceeded 0.8. Secondary efficacy variables were the cumulative response by 3 and 4 minutes (T3 and T4), and the number of treatment failures. Safety parameters were assessed. RESULTS: Randomized patients in TTH-Grifols and BT-JMI groups were n = 137 and n = 68, respectively. In modified intention-to-treat population, rates of hemostasis by T5 were 78.3% (94 of 120) in TTH-Grifols and 80.3% (49 of 61) in BT-JMI (response ratio: 0.973; 95% CI 0.833 to 1.135). Rates of hemostasis in vascular, hepatic, soft tissue, and spinal operations ranged from 75.0% to 82.5% for TTH-Grifols and from 54.5% to 91.7% for BT-JMI. No significant differences in adverse events were observed between treatment groups. Antibodies to bovine factor V antigen were detected in 2 patients exposed to BT-JMI and in none exposed to TTH-Grifols. CONCLUSIONS: The TTH-Grifols was safe and well tolerated as a local hemostatic agent and was non-inferior to BT-JMI. No antibodies to thrombin developed in TTH-Grifols-treated patients.

A prospective, single-blind, randomized, phase III study to evaluate the safety and efficacy of Fibrin Sealant Grifols as an adjunct to hemostasis compared with manual compression in vascular surgery.

OBJECTIVE: New formulations and applications of hemostatic adjuncts such as fibrin sealant (FS) to support local hemostasis and sutures continue to be developed. In a pivotal, confirmatory, controlled, prospective, single-blinded, randomized, multicenter phase III clinical trial, the efficacy and safety of FS Grifols during vascular surgeries were evaluated. METHODS: Patients undergoing a nonemergency, open, peripheral vascular surgical procedure with moderate arterial bleeding were recruited. In an initial preliminary part of the study, all patients were treated with FS Grifols. In a subsequent primary part, patients were randomized (2:1) to FS Grifols or manual compression (MC). The primary efficacy end point was the proportion of the primary part patients achieving hemostasis by 4 minutes after the start of treatment. Cumulative proportion and time to hemostasis were secondary efficacy end points. Safety end points (in pooled preliminary and primary parts) included adverse events (AEs), vital signs, physical assessments, clinical laboratory tests, viral markers, and immunogenicity. RESULTS: The primary efficacy end point was met by 76.1% of patients (83/109) for the FS Grifols group versus 22.8% of patients (13/57) for the MC group (P < .001). The cumulative proportion of patients at 5, 7, and 10 minutes was 80.7%, 84.4%, and 88.1%, respectively, in the FS Grifols treatment group, and 28.1%, 35.1%, and 45.6% in the MC treatment group (P < .001). The median time to hemostasis was shorter in the FS Grifols group (4 minutes vs ≥10 minutes in the MC group; P < .001). The nature of AEs reported were those expected in the study patient profile. The percentage of patients experiencing treatment-emergent AEs were similar in both the FS Grifols (pooled n = 59 + 109) and MC groups (81.0% and 77.2%, respectively), most recurrent being procedural pain (34.5% and 36.8%, respectively) and pyrexia (11.3% and 10.5%, respectively). CONCLUSIONS: FS Grifols was superior in efficacy and similar in safety to MC as an adjunct local hemostatic agent in patients undergoing open vascular surgeries.

Safety and efficacy of intravenous immunoglobulin (Flebogamma® 10% DIF) in patients with immune thrombocytopenic purpura.

AIM: To evaluate the safety and efficacy of 10% intravenous immunoglobulin (IVIG; Flebogamma® 10% DIF) in individuals with chronic immune thrombocytopenic purpura (ITP). PATIENTS & METHODS: Patients aged 3-70 years, diagnosed with chronic ITP, received 1 g/kg IVIG over two consecutive days. RESULTS: 64 evaluable patients (51 adults, 13 children) with chronic ITP received IVIG. The primary efficacy end point (increased platelet counts from ≤20 × 109/l to ≥50 × 109/l by day 8) was achieved by 81.3% of patients; mean time to response was 1.7 days (all responders). Adverse events, mostly mild or moderate, were reported in 59 patients (92.2%). CONCLUSION: Flebogamma® 10% DIF administered over two consecutive days was safe and effective in adults and children with chronic ITP.

A Prospective, Randomized, Phase III Study to Evaluate the Efficacy and Safety of Fibrin Sealant Grifols as an Adjunct to Hemostasis as Compared to Cellulose Sheets in Hepatic Surgery Resections.

BACKGROUND: Local hemostatic agents have a role in limiting bleeding complications associated with liver resection. METHODS: In this randomized, phase III study, we compared the efficacy and safety of Fibrin Sealant Grifols (FS Grifols) with oxidized cellulose sheets (Surgicel®) as adjuncts to hemostasis during hepatic resections. The primary efficacy endpoint was the proportion of patients achieving hemostasis at target bleeding sites (TBS) within 4 min (T4) of treatment application. Secondary efficacy variables were time to hemostasis (TTH) at a later time point if re-bleeding occurs and cumulative proportion of patients achieving hemostasis by time points T2, T3, T5, T7, and T10. RESULTS: The rate of hemostasis by T4 was 92.8% in the FS Grifols group (n = 163) and 80.5% in the Surgicel® group (n = 162) (p = 0.01). The mean TTH was significantly shorter (p < 0.001) in the FS Grifols group (2.8 ± 0.14 vs. 3.8 ± 0.24 min). The rate of hemostasis by T2, T5, and T7 was higher and statistically superior in the FS Grifols group compared to Surgicel®. No substantial differences in adverse events (AE) were noted between treatment groups. The most common AEs were procedural pain (36.2 vs. 37.7%), nausea (20.9 vs. 23.5%), and hypotension (14.1 vs 6.2%). CONCLUSIONS: FS Grifols was safe and well tolerated as a local hemostatic agent during liver resection surgeries. Overall, data demonstrate that the hemostatic efficacy of FS Grifols is superior to Surgicel® and support the use of FS Grifols as an effective local hemostatic agent in these surgical procedures.

SPARTA clinical trial design: exploring the efficacy and safety of two dose regimens of alpha1-proteinase inhibitor augmentation therapy in alpha1-antitrypsin deficiency.

BACKGROUND: Alpha1-antitrypsin deficiency (AATD) is an underdiagnosed genetic disorder that results in early-onset emphysema due to low serum levels of alpha1-proteinase inhibitor (alpha1-PI), leading to increased activity of tissue-damaging neutrophil elastase. Clinical outcomes of AATD may be improved by administering alpha1-PI augmentation therapy. Here, we describe the design of the ongoing Study of ProlAstin-c Randomized Therapy with Alpha-1 augmentation (SPARTA), a phase 3 trial designed to evaluate progression of lung tissue loss in patients with severe AATD receiving human alpha1-PI (Prolastin(®)-C) versus placebo, using whole-lung computed tomography (CT) densitometry. STUDY DESIGN: SPARTA is a randomized, placebo-controlled trial assessing the efficacy and safety of two separate doses of Prolastin-C (60 and 120 mg/kg) administered weekly over 3 years in patients aged 18-70 years with a diagnosis of AATD and clinical evidence of pulmonary emphysema. The primary measure of efficacy (change from baseline whole-lung 15th percentile lung density [PD15]) will be determined by CT lung densitometry measured at total lung capacity. Secondary efficacy variables will be the evaluation of severe chronic obstructive pulmonary disease exacerbations, as defined by American Thoracic Society/European Respiratory Society criteria, and PD15 of the basal lung region using CT densitometry. Adverse events will be collected and documented. CONCLUSIONS: The SPARTA trial is designed to evaluate the long-term (3-year) efficacy of 2 separate doses of Prolastin-C for the treatment of emphysema in patients with AATD. Protocol number: GTi1201. CLINICAL TRIALS IDENTIFIER: NCT01983241.