Perioperative haemostasis with full-length, PEGylated, recombinant factor VIII with extended half-life (rurioctocog alfa pegol) in patients with haemophilia A: Final results of a multicentre, single-arm phase III trial.

INTRODUCTION: Rurioctocog alfa pegol (BAX 855, TAK-660) is a PEGylated, full-length, recombinant factor VIII (rFVIII) with extended half-life developed from unmodified rFVIII (antihaemophilic factor [recombinant]). AIM: To determine the perioperative haemostatic efficacy and safety of rurioctocog alfa pegol in male previously treated patients (PTPs) with severe haemophilia A. METHODS: This multicentre, single-arm, phase III study included PTPs who were to undergo major or minor elective or minor emergency surgical, dental or other invasive procedures. Rurioctocog alfa pegol dose and frequency were individualized based on patients' pharmacokinetic profiles for major surgeries and by rurioctocog alfa pegol incremental recovery for minor surgeries. Haemostatic efficacy was assessed using the Global Haemostatic Efficacy Assessment score. RESULTS: Twenty-one patients aged 16-61 years underwent 21 major and five minor surgeries. For all 24 evaluable surgeries, overall haemostatic efficacy was rated as excellent and blood loss comparable to that expected in non-haemophilic patients. No blood transfusions were required intraoperatively but were administered postoperatively for four surgeries in three patients. Five injury-related postoperative bleeding episodes occurred in five patients, of which two required additional rurioctocog alfa pegol treatment. Two non-serious adverse events of mild severity (increased ALT level and headache) were considered possibly related to rurioctocog alfa pegol. There were no deaths or treatment-related serious adverse events. No patients developed inhibitory antibodies to FVIII or persistent IgG- or IgM-binding antibodies to FVIII, PEG-FVIII or PEG. CONCLUSION: Rurioctocog alfa pegol was well tolerated and effective for perioperative use in patients with haemophilia A and showed no signs of immunogenicity.

Safety of PEGylated recombinant human full-length coagulation factor VIII (BAX 855) in the overall context of PEG and PEG conjugates.

INTRODUCTION: BAX 855 is a PEGylated human full-length recombinant factor VIII (rFVIII) based on licensed rFVIII (ADVATE). The applied PEGylation technology has been optimized to retain functionality of the FVIII molecule, improve its pharmacokinetic properties and allow less frequent injections while maintaining efficacy. AIM: The aim of this study was to confirm that the excellent safety profile of ADVATE remains unchanged after PEGylation. METHODS: Non-clinical safety studies with BAX 855 and its respective unbound polyethylene glycol (PEG) were conducted in several species. The distribution of a single dose of radiolabelled BAX 855 was further investigated in rats. Publically available safety data on PEG alone and PEGylated biomolecules were summarized and reviewed for specific safety findings attributable to PEG or PEGylated biopharmaceuticals. RESULTS: Safety pharmacology studies in rabbits and macaques and repeated dose toxicity studies in rats and macaques identified no safety issues. Results of a distribution study in rats administered radiolabelled BAX 855 showed that radioactivity was completely excreted; urine was the major elimination route. A 28-day study in rats dosed with the unbound PEG constituent (PEG2ru20KCOOH) of BAX 855 showed no adverse or non-adverse effects. Safety data for PEG and PEG-protein conjugates indicate no safety concerns associated with PEG at clinically relevant dose levels. Although vacuolation of certain cell types has been reported in mammals, no such vacuolation was observed with BAX 855 or with the unbound PEG constituent. CONCLUSION: Non-clinical safety evaluation of PEG and BAX 855 identified no safety signals; the compound is now in clinical development for the treatment of patients with haemophilia A.

The biological efficacy profile of BAX 855, a PEGylated recombinant factor VIII molecule.

Prophylaxis prevents joint and other bleeding episodes in patients with haemophilia A. Development of new factor concentrates with longer circulating half-lives may encourage patients to start, continue or resume prophylaxis. The aim of this study was to compare the pharmacodynamic effect of a PEGylated full-length recombinant factor VIII (rFVIII) concentrate with that of an unmodified rFVIII concentrate with respect to the duration of prophylactic efficacy in a murine model of haemophilic joint bleeding. Mice were pretreated with BAX 855 or unmodified rFVIII at specified times before right knee puncture to induce haemarthrosis; left knee joints served as controls. Joint bleeding was evaluated using a combination of visual and histological assessments. Administration of a single dose of unmodified rFVIII before joint puncture prevented haemarthrosis in mice up to 24 h, whereas pretreatment with BAX 855 protected the joint from bleeding up to 48 h. This pharmacodynamic study showed prolonged efficacy of BAX 855 compared to ADVATE in a haemophilia A mouse joint bleeding model. This finding supports the possibility of using BAX 855 to increase FVIII trough levels and/or extend the dosing interval in patients with haemophilia A on prophylaxis, which may potentially improve prophylactic efficacy and long-term adherence.

Subgroup analysis of a phase 2/3 study of rurioctocog alfa pegol in patients with severe hemophilia A: efficacy and safety in previously treated Korean patients.

BACKGROUND: The efficacy and safety of extended half-life, full-length, pegylated recombinant factor VIII rurioctocog alfa pegol [BAX 855, ADYNOVATE (USA)/ADYNOVI (Europe); Baxalta US Inc., a Takeda company, Lexington, MA, USA] was investigated in previously treated Korean patients with severe hemophilia A (HA). METHODS: A post hoc data analysis from the international, multicenter, phase 2/3 PROLONG-ATE study of rurioctocog alfa pegol in patients with severe HA (NCT01736475) determined annualized bleeding rates (ABRs) and rates of adverse events (AEs) in Korean patients treated in this study. RESULTS: All 10 enrolled Korean patients receiving rurioctocog alfa pegol (9 prophylaxis, 1 on-demand) completed the study [median (range) age, 28.0 (12-50) yr; weight, 64.8 (45-90) kg; 8 patients had ≥1 target joint at screening]. Median (range) ABR was 1.9 (0.0-14.5) for patients on prophylaxis and 62.2 for the patient receiving on-demand treatment. The hemostatic efficacy of rurioctocog alfa pegol was rated "excellent" or "good" and only single infusions were required per bleeding episode. ABRs improved in most patients compared with prestudy values. No dose adjustments were required for prophylaxis, and the dosing frequency was reduced in 8 patients, compared with their previous prophylaxis regimen. No serious AEs were reported; all 9 nonserious AEs (in 3 patients) were mild in severity and unrelated to the study treatment. CONCLUSION: This post hoc analysis of a small group of Korean patients with severe HA indicated that rurioctocog alfa pegol was effective, and no serious AEs were observed. For most patients, the dosing frequency was also reduced compared with their previous regimen.