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Press Release

Ascension Healthcare Announces Positive Data from Phase 2 Study of XLR8 in Severe Haemophilia A Patients

Injection of an adjuvant PEGylated lipid (PEGLip) following a normal dose of standard half-life FVIII in severe haemophilia A patients lengthened dosing interval to once every 4.9 days, while bleeding events were significantly reduced compared to the pre-trial period

The extended dosing interval which resulted from clotting improvements achieved by a separate PEGLip injection following prior administration of FVIII was accompanied   with an  associated significant reduction in the number of bleeding episodes

Data presented at the 64th American Society of Hematology Annual Meeting

LONDON, 12 December 2022 – Ascension Healthcare plc (“Ascension” or the “Company”), a clinical-stage biopharmaceutical company focused on developing and commercialising innovative therapies for haemophilia and osteoarthritis, today announces positive data from a Phase 2 open-label, multicenter trial of XLR8, in 14 patients with severe haemophilia A without inhibitors to factor VIII. XLR8 involves the intravenous injection of a standard, prophylactic dose (35 IU/kg) of recombinant, standard half-life factor VIII clotting protein (FVIII) followed by an intravenous injection of PEGylated liposomes (PEGLip) 15 minutes later.

Haemophilia A patients lack sufficient factor VIII clotting factors which leaves them at risk of uncontrolled bleeding. This trial was designed to demonstrate that administration of PEGLip, following a normal dose of prophylactic, standard half-life FVIII in severe, non-inhibitor Haemophilia A patients can both enhance clotting activity and extend the dosing interval beyond FVIII administered alone.

Results from the study demonstrated that clotting activity was significantly improved at certain time points over baseline and over injection of FVIII alone. The clotting improvements conferred by the additional PEGLip injection led to an extended dosing interval of once every 4.6 days (min 2.1, max 7.3 days) for a 30IU/kg dose. This compares to the normal prophylactic dosing interval for this standard-half-life FVIII at this dose of once every 2-3 days for long-term prophylaxis. Currently approved extended half-life products approved by the FDA recommend dosing between 2-3 times weekly or every 4 to five days but at a higher dose of 45IU/kg (average). Despite the lower dose rate, the number of bleeding episodes was significantly reduced over the 6-week trial period, compared to the 6 month history preceding the study.

Professor Edward Tuddenham, Emeritus Professor of Haemophilia at University College London and member of Ascension’s Medical and Scientific Advisory Board said: “These are exciting early clinical results which show that the injection of PEGLip after a dose of standard half-life FVIII can enhance the coagulation of the patient to the point where prophylaxis with a standard half-life product can be injection-sparing, with a regimen similar to current extended half-life products but at a lower dose so as to also be FVIII-sparing, which is significant for the treatment of haemophiliacs in poorer countries where the healthcare systems cannot afford the quantity of FVIII normally required for prophylaxis.”

Biresh Roy, Chief Executive Officer at Ascension added: “Haemophilia A patients currently have to  make clinic visits every 2-3 days for prophylactic dosing of FVIII, and this regime places a major burden on them and their families. The results announced today, demonstrate the potential of our PEGLip technology, when administered following intravenous injection of a recombinant factor VIII, to extend the dosing interval offering significant improvements over patient compliance and standard of care. The results also offer  the possibility of making gold standard prophylactic haemophilia care more widely accessible to patients as Professor Tuddenham suggests.”

Full details of the poster presentation are:

Title: The Use of a PEGylated Liposome in a Phase II Trial to Enhance the Potency and Extend the Dosing Interval of Prophylactic Standard Half-Life FVIII, without Increasing the Dose

Publication No: 2464

Session Name: 322. Disorders of Coagulation or Fibrinolysis: Clinical and Epidemiological: Poster II

Session Date: Sunday, December 11, 2022

Presentation Time: 6:00 PM – 8:00 PM

Location: Ernest N. Morial Convention Center, Hall D

– Ends –

About Haemophilia A

Haemophilia A (“HA”) is a congenital bleeding disorder which leaves a patient at risk of uncontrolled bleeding due to a lack of blood clotting Factor VIII (“FVIII”). HA is the most common form of haemophilia with a prevalence rate estimated at 1.7 – 2.5 in 10,000 male births and can be categorised from mild (5-40%of normal circulating FVIII) to moderate (1-5% of normal), to severe (<1% of normal); of these sever HA is prevalent in circa 0.6 to 1 in 10,000 males (World Federation of Haemophilia Global Survey 2021). The global market for haemophilia A treatments was estimated to be worth approximately $11 billion in 2021, (Ascension Healthcare research)

About XLR8

XLR8 is a form of PEGLip administered as an adjuvant to patients who already have some circulating FVIII. The therapy is primarily aimed at f severe patients who are receiving standard of care prophylaxis with intravenous FVIII, where the adjuvant will extend their FVIII dosing interval, thereby improving compliance.

About Ascension Healthcare plc

Ascension Healthcare plc is a clinical-stage biopharmaceutical company focused on developing and commercialising innovative therapies for the treatment of haemophilia and osteoarthritis. The Company has three products in clinical development for the treatment of haemophilia A and also a range of internationally marketed products for osteoarthritis sufferers. For more information please visit:

For more information contact

Ascension Healthcare plc
Biresh Roy, Chief Executive Officer

[email protected] / +44 (0)20 7291 5400

Consilium Strategic Communications
(European Media and Investor Enquiries)
Lindsey Neville, Ashley Tapp

Tel: +44 (0)20 3709 5700 / [email protected]