Long-term outcomes of patients treated with rituximab as second-line treatment for adult immune thrombocytopenia - Follow-up of the RITP study
Br J Haematol. 2020
RITP was a double-blind randomized, 78-week follow-up trial in which 109 adults with immune thrombocytopenias (ITP) who failed to achieve adequate response to steroids, were randomized to receive rituximab or placebo. Here, we provide the duration of response, splenectomy and mortality rates based on extended follow-up after completion of the RITP study. Extended follow-up data were retrospectively collected for 72 (83%) patients out of the 84 patients who were not splenectomized during the initial RITP study. For the present analysis, median [interquartile range] duration of follow-up after randomization was 72 [62-82] months. Median duration of response among patients who achieved an initial response was significantly longer in patients who received rituximab (8.2 [5.5-16.7] months) as compared to placebo (1.8 [1.3-3.6] months), P = 0.036. Overall, 35 patients underwent splenectomy (13 in the rituximab, and 22 in the placebo arm, P = 0.12). Eleven patients (10%) died during the study: five in the rituximab and six in the placebo arms, including four deaths from severe bleeding. Although most rituximab-treated patients eventually relapsed, a longer duration of response and a trend towards lower splenectomy rate were observed in rituximab-treated patients.
Pharmacokinetics and pharmacodynamics of a recombinant fusion protein linking activated coagulation factor VII with human albumin (rVIIa-FP) in patients with congenital FVII deficiency
Hematology (Amsterdam, Netherlands). 2020;25(1):17-25
Objectives: Recombinant fusion protein linking activated factor VIIa to human albumin (rVIIa-FP) is a therapeutic option designed to prevent and treat bleeding events in patients with congenital FVII deficiency with reduced infusion frequency compared to current FVII treatments. This study characterized the pharmacokinetics (PK) and pharmacodynamics (PD) of rVIIa-FP.Methods: A phase I multicenter, randomized, open-label, parallel-arm, single-dose study (NCT02470871) was conducted in nine patients with severe congenital FVII deficiency. Patients received their routine FVII product (30 IU/kg plasma-derived FVII [pdFVII] or 25 mug/kg recombinant activated FVII (rFVIIa) [eptacog alfa]), and were then randomly assigned to receive 100 or 300 mug/kg of rVIIa-FP. Blood samples for PK and PD assessments were drawn up to 48 hr after administration. FVIIa activity was determined using a one-stage clotting assay. PD parameters were derived from thrombin generation testing, using the Nijmegen hemostasis assay.Results: rVIIa-FP showed improved PK compared to rFVIIa, with 2- to 3-fold longer t1/2 and 4- to 8-fold lower clearance. Analysis of PD data showed a sustained suppression of lag time below 4.5 min (upper limit of healthy people) for rVIIa-FP compared to rFVIIa. AUEC and ECmax were similar across the two dose groups of rVIIa-FP and rFVIIa.Discussion: rVIIa-FP was well tolerated in patients with congenital FVII deficiency, showed a longer half-life and lower clearance compared to rFVIIa, and lag time remaining within healthy ranges for ≥8 hr.Conclusion: These results warrant further investigation into the efficacy of rVIIa-FP to control and prevent bleeding in patients with FVII deficiency.
Pharmacodynamics of recombinant activated factor VII and plasma-derived factor VII in a cohort of severe FVII deficient patients
Thrombosis Research. 2013;132((1):):116-22.
Recombinant activated factor VII (rFVIIa) and plasma-derived factor VII (pdFVII) are used to prevent bleedings in severe FVII deficient patients, despite their short half-lifes. It is suggested that FVII levels of 15-20IU/dL are sufficient to maintain hemostasis. We analyzed the pharmacodynamic effects of FVII substitution therapy in the Nijmegen Hemostasis Assay (NHA) that simultaneously measures thrombin and plasmin generation. Ten severe FVII deficient patients were treated with 20mug/kg rFVIIa or 25IU/kg pdFVII in a cross-over design. Thrombin generation lag-time (TG-LT) was identified as an effect-response parameter. Pharmacodynamic analysis using a maximum effect model showed 50% reduction of the TG-LT effect at ~2IU/dL FVII activity for both rFVIIa and pdFVII. The FVII activity to obtain TG-LT comparable to the upper limit of normal range in healthy controls (4min) was given by the effective concentration (ECnormal), showing sufficient hemostasis at 3-4IU/dL FVII activity. No association was seen between FVII activity and other thrombin or plasmin generation parameters as measured by NHA. In conclusion, 3-4IU/dL FVII activity seems sufficient to maintain hemostasis in patients with severe FVII deficiency during prophylaxis. These data may suggest a potential value for measurement of TG-LT in the monitoring of FVII(a) therapy. Copyright 2013 Elsevier Ltd. All rights reserved.
Increased volume of distribution for recombinant activated factor VII and longer plasma-derived factor VII half-life may explain their long lasting prophylactic effect
Thrombosis Research. 2013;132((2):):256-62.
INTRODUCTION Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study. MATERIALS AND METHODS Ten factor VII deficient patients were treated with either recombinant activated (20mug/kg) or plasma-derived (25IU/kg) factor VII in a cross-over design. Pharmacokinetic parameters were analyzed through activated factor VII activity, factor VII clotting activity, and factor VII antigen levels on depicted time points. RESULTS Factor VII activity half-lifes, determined by non-compartmental and one-compartmental analysis (results in brackets), were shorter for recombinant activated (1.4h; 0.7h) than for plasma-derived factor VII (6.8h; 3.2h); both recombinant activated (5.1h; 2.1h and plasma-derived factor VII (5.8h; 3.2h) resulted in longer half-lives of factor VII antigen. Activated factor VII half-lives (based on activated factor VII activity levels) were significantly higher compared to factor VII clotting activity (1.6h; 0.9h). Volumes of distribution were significantly higher for activated factor VII (236ml/kg; 175ml/kg, measured by activated factor VII) as compared to plasma-derived factor VII (206ml/kg; 64ml/kg, measured by factor FVII activity), suggesting a plasma- and extracellular fluid distribution for recombinant activated factor VII. CONCLUSIONS Recombinant activated factor VII showed significantly shorter half-lifes than plasma-derived factor VII. Volumes of distribution were significantly higher for treatment with recombinant activated factor VII. The longer half-life for plasma-derived factor VII, compared to recombinant activated factor VII, and the increased volume of distribution for recombinant activated factor VII, compared to plasma-derived factor VII may further elucidate the beneficial effect of prophylactic treatment of both products. Copyright 2013 Elsevier Ltd. All rights reserved.