Roche announced that new data from the ongoing Hemlibra (emicizumab) clinical development programme were presented at the 59th American Society of Hematology (ASH) Annual Meeting. These data include longer-term results from the pivotal HAVEN 1 and HAVEN 2 studies in people with haemophilia A with inhibitors to factor VIII, showing once-weekly subcutaneous Hemlibra prophylaxis demonstrated superior efficacy compared to prior treatment with bypassing agents (BPAs) as prophylaxis or on-demand. These new data from the largest pivotal studies in people with haemophilia A with inhibitors further support Hemlibra as an important new treatment option for these adults, adolescents and children.

In updated results from the HAVEN 2 study with six additional months of data and 40 more children (younger than 12 years of age), 94.7% (95% CI: 85.4; 98.9) of children with haemophilia A with inhibitors who received Hemlibra prophylaxis had zero treated bleeds (n=57). The intra-patient analysis comparing the effects of different therapies in the same child (n=13) showed a 99% reduction in treated bleeds with Hemlibra prophylaxis compared to prior treatment with a BPA, either as prophylaxis (n=12) or on-demand (n=1). Substantial improvements in health-related quality of life and aspects of caregiver burden, measured by the haemophilia-specific quality of life short form (Haemo-QoL-SF) and adapted health-related quality of life in haemophilia patients with inhibitors (Inhib-QoL) questionnaires, were also observed with Hemlibra prophylaxis compared to prior BPA prophylaxis. These data were featured  in the official press programme of the ASH Annual Meeting.

With nearly ten additional months of follow-up, updated results from the HAVEN 1 intra-patient analysis of adults and adolescents showed an 88% (risk rate [RR]=0.12, 95% CI: 0.05; 0.28) reduction in treated bleeds with Hemlibra prophylaxis compared to prior BPA prophylaxis (n=24). The results also showed a 95% (RR=0.05, 95% CI: 0.02; 0.12) reduction in treated bleeds in patients who received Hemlibra prophylaxis compared to prior on-demand BPA treatment (n=24). After more than one year, substantially more patients continued to experience zero bleeds with Hemlibra prophylaxis compared to their prior prophylaxis or on-demand BPA treatment across bleed endpoints, including treated bleeds and all bleeds. The previously reported improvement in health status after 24 weeks, measured by the haemophilia-specific quality of life (Haem-A-QoL) and EuroQol 5-Dimensions 5-level (EQ-5D-5L) questionnaires, was also maintained with longer follow-up.

“These data demonstrate the continued reduction in bleeds over time with Hemlibra prophylaxis and reinforce the potential of this medicine, recently approved by the FDA for haemophilia A with inhibitors, to redefine the standard of care,” said Sandra Horning, MD, Roche’s Chief Medical Officer and Head of Global Product Development. “We are continuing to study Hemlibra in a robust clinical development programme to help advance care for all people with haemophilia A, regardless of age or inhibitor status, and provide even less frequent dosing options.”

Data from the run-in cohort of the ongoing phase III HAVEN 4 study showed that Hemlibra prophylaxis dosed once every four weeks in people 12 years of age or older with haemophilia A, with or without inhibitors, resulted in levels of Hemlibra in the blood (pharmacokinetics) that were consistent with predictions. These data supported opening the expansion cohort of the study to further evaluate this dosing regimen. After a median observation time of eight weeks, 85.7% of patients (six out of seven) had zero bleeds while receiving Hemlibra prophylaxis once every four weeks. These data follow the recent announcement that an interim analysis of the phase III HAVEN 4 study showed a clinically meaningful control of bleeding in people 12 years of age or older with haemophilia A who received Hemlibra prophylaxis once every four weeks.

The most common adverse events (AEs) in the HAVEN 1 and HAVEN 2 studies at the time of these follow-up data were consistent with those observed previously in the studies. No unexpected safety findings were observed in the run-in cohort of the HAVEN 4 study. No new cases of thrombotic microangiopathy (TMA) or thrombotic events were observed in HAVEN 1, and no cases occurred in HAVEN 2 or HAVEN 4.

Based on earlier results from the HAVEN 1 and HAVEN 2 studies, Hemlibra was approved by the US Food and Drug Administration (FDA) for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children with haemophilia A with inhibitors. Data from HAVEN 1 and HAVEN 2 are also being reviewed under accelerated assessment by the European Medicines Agency (EMA) and submissions to health authorities around the world are ongoing. The clinical development programme also includes the ongoing phase III HAVEN 4 study and the phase III HAVEN 3 study, which showed a statistically significant and clinically meaningful reduction in the number of treated bleeds over time in people aged 12 years or older with haemophilia A without inhibitors who received Hemlibra prophylaxis every week or every other week, compared to those receiving no prophylaxis.

HAVEN 1 is a randomised, multicentre, open-label, phase III study evaluating the efficacy, safety and pharmacokinetics of once-weekly subcutaneous administration of Hemlibra prophylaxis compared to no prophylaxis in adults and adolescents with haemophilia A with inhibitors to factor VIII. The study included 113 patients (12 years of age and older) with haemophilia A with inhibitors to factor VIII, who were previously treated with BPAs on-demand or as prophylaxis. Patients previously treated with on-demand BPAs were randomised in a 2:1 ratio to receive Hemlibra prophylaxis (Arm A) or no prophylaxis (Arm B). Patients previously treated with BPAs as prophylaxis received Hemlibra prophylaxis (Arm C). Additional patients previously treated with on-demand BPAs were also enrolled in a separate arm (Arm D). On-demand treatment of breakthrough bleeds with BPAs was allowed per protocol in all arms.

The updated HAVEN 1 intra-patient analysis data presented at ASH comparing treatment with Hemlibra prophylaxis to prior BPAs as prophylaxis or on-demand showed:

No new AEs resulted in treatment discontinuation. No new cases of TMA or thrombotic events were observed. As previously reported, three people experienced TMA events and two people experienced serious thrombotic events in the HAVEN 1 study when on average a cumulative amount of >100 U/kg/24 hours of activated prothrombin complex concentrate (aPCC) was administered for 24 hours or more to patients receiving Hemlibra prophylaxis.

HAVEN 2 is a single-arm, multicentre, open-label, clinical study in children younger than 12 years of age with haemophilia A with inhibitors to factor VIII. The study is evaluating the efficacy, safety and pharmacokinetics of once-weekly subcutaneous administration of Hemlibra prophylaxis.

The updated HAVEN 2 analysis after a median of nine weeks of treatment (range 1.6-41.6 weeks) included 60 children with haemophilia A with inhibitors to factor VIII. The updated data presented at ASH showed:

The most common AEs related to Hemlibra were injection-site reactions. Six patients experienced serious AEs, including bleeding in the muscles (muscle haemorrhage), eye pain, catheter site infection, device-related infection, bleeding of the mouth or gums (mouth haemorrhage) and appendicitis. No cases of TMA or thrombotic events occurred in the study.

HAVEN 4 is a single-arm, multicentre, open-label, phase III study evaluating the efficacy, safety and pharmacokinetics (PK) of subcutaneous administration of Hemlibra dosed every four weeks. The study included 48 patients (12 years of age or older) with haemophilia A with or without inhibitors to factor VIII who were previously treated with either factor VIII or bypassing agents, on-demand or as prophylaxis.

The study was conducted in two parts: a PK run-in; and an expansion cohort. All patients in the PK run-in (n=7) were previously treated on-demand, and received subcutaneous Hemlibra at 6 mg/kg to fully characterise the PK profile after a single dose during four weeks, followed by 6 mg/kg every four weeks for at least 24 weeks. Patients in the expansion cohort (n=41) received subcutaneous Hemlibra prophylaxis at 3 mg/kg/wk for four weeks, followed by 6 mg/kg every four weeks for at least 24 weeks. Episodic treatment of breakthrough bleeds with factor VIII therapy or bypassing agents, depending on a patient’s inhibitor status, was allowed per study protocol.
About Hemlibra (emicizumab)

Hemlibra is a bispecific factor IXa- and factor X-directed antibody. It is designed to bring together factor IXa and factor X, proteins required to activate the natural coagulation cascade and restore the blood clotting process for haemophilia A patients. Hemlibra is a prophylactic (preventative) treatment that can be administered by an injection of a ready-to-use solution under the skin (subcutaneously). The clinical development programme is assessing the safety and efficacy of Hemlibra and its potential to help overcome current clinical challenges: the short-lasting effects of existing treatments, the development of factor VIII inhibitors and the need for frequent venous access. Hemlibra was created by Chugai Pharmaceutical Co., Ltd. and is being co-developed by Chugai, Roche and Genentech. It is marketed in the United States as Hemlibra (emicizumab-kxwh) for patients with factor VIII inhibitors, with kxwh as the suffix designated in compliance with Nonproprietary Naming of Biological Products Guidance for Industry issued by the US Food and Drug Administration.