Treatment and prophylaxis of bleeding in patients with haemophilia A (congenital factor VIII deficiency).

ELOCTA can be used for all age groups.

Treatment should be initiated under the supervision of a physician experienced in the treatment of haemophilia.

Treatment monitoring

During the course of treatment, appropriate determination of factor VIII levels (by one-stage clotting or chromogenic assays) is advised to guide the dose to be administered and the frequency of repeated injections. Individual patients may vary in their response to factor VIII, demonstrating different half-lives and recoveries. Dose based on bodyweight may require adjustment in underweight and overweight patients. In the case of major surgical interventions in particular, precise monitoring of the substitution therapy by means of coagulation analysis (plasma factor VIII activity) is indispensable.

When using an in vitro thromboplastin time (aPTT)-based one stage clotting assay for determining factor VIII activity in patients' blood samples, plasma factor VIII activity results can be significantly affected by both the type of the aPTT reagent and the reference standard used in the assay. Also there can be significant discrepancies between assay results obtained by aPTT-based one stage clotting assay and the chromogenic assay according to Ph. Eur. This is of importance particularly when changing the laboratory and/or reagent used in the assay.

Posology

The dose and duration of the substitution therapy depend on the severity of the factor VIII deficiency, on the location and extent of the bleeding and on the patient's clinical condition.

The number of units of factor VIII administered is expressed in IU, which are related to the current WHO standard for factor VIII products. Factor VIII activity in plasma is expressed either as a percentage (relative to normal human plasma) or in IU (relative to an International Standard for factor VIII in plasma).

One IU of recombinant factor VIII Fc activity is equivalent to that quantity of factor VIII in one mL of normal human plasma.

On-demand treatment

The calculation of the required dose of recombinant factor VIII Fc is based on the empirical finding that 1 IU factor VIII per kg body weight raises the plasma factor VIII activity by 2 IU/dL. The required dose is determined using the following formula:

Required units = body weight (kg) × desired factor VIII rise (%) (IU/dL) × 0.5 (IU/kg per IU/dL)

The amount to be administered and the frequency of administration should always be oriented to the clinical effectiveness in the individual case.

In the case of the following haemorrhagic events, the factor VIII activity should not fall below the given plasma activity level (in % of normal or IU/dL) in the corresponding period. Table 1 can be used to guide dosing in bleeding episodes and surgery:

Table 1: Guide to ELOCTA dosing for treatment of bleeding episodes and surgery

¹ In some patients and circumstances the dosing interval can be prolonged up to 36 hours. See section 5.2 for pharmacokinetic data.

Prophylaxis

For long term prophylaxis, the recommended dose is 50 IU of factor VIII per kg body weight at intervals of 3 to 5 days. The dose may be adjusted based on patient response in the range of 25 to 65 IU/kg (see section 5.1 and 5.2).

In some cases, especially in younger patients, shorter dosage intervals or higher doses may be necessary.

Elderly

There is limited experience in patients ≥ 65 years.

Paediatric population

For children below the age of 12, more frequent or higher doses may be required (see section 5.1). For adolescents of 12 years of age and above, the dose recommendations are the same as for adults.

Method of administration

ELOCTA is for intravenous use.

ELOCTA should be injected intravenously over several minutes. The rate of administration should be determined by the patient's comfort level and should not exceed 10 mL/min.

For instructions on reconstitution of the medicinal product before administration, see section 6.6.

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

Hypersensitivity

Allergic type hypersensitivity reactions are possible with ELOCTA. If symptoms of hypersensitivity occur, patients should be advised to discontinue use of the medicinal product immediately and contact their physician. Patients should be informed of the signs of hypersensitivity reactions including hives, generalised urticaria, tightness of the chest, wheezing, hypotension and anaphylaxis.

In case of shock, standard medical treatment for shock should be implemented.

Inhibitors

The formation of neutralising antibodies (inhibitors) to factor VIII is a known complication in the management of individuals with haemophilia A. These inhibitors are usually IgG immunoglobulins directed against the factor VIII procoagulant activity, which are quantified in Bethesda Units (BU) per mL of plasma using the modified assay. The risk of developing inhibitors is correlated to the severity of the disease as well as the exposure to factor VIII, this risk being highest within the first 50 exposure days but continues throughout life although the risk is uncommon.

The clinical relevance of inhibitor development will depend on the titre of the inhibitor, with low titre posing less of a risk of insufficient clinical response than high titre inhibitors.

In general, all patients treated with coagulation factor VIII products should be carefully monitored for the development of inhibitors by appropriate clinical observations and laboratory tests. If the expected factor VIII activity plasma levels are not attained, or if bleeding is not controlled with an appropriate dose, testing for factor VIII inhibitor presence should be performed. In patients with high levels of inhibitor, factor VIII therapy may not be effective and other therapeutic options should be considered. Management of such patients should be directed by physicians with experience in the care of haemophilia and factor VIII inhibitors.

Cardiovascular events

In patients with existing cardiovascular risk factors, substitution therapy with FVIII may increase the cardiovascular risk.

Catheter-related complications

If a central venous access device (CVAD) is required, risk of CVAD-related complications including local infections, bacteraemia and catheter site thrombosis should be considered.

Traceability

In order to improve traceability of biological medicinal products, the name and the batch number of the administered product should be clearly recorded.

Paediatric population

The listed warnings and precautions apply both to adults, children and adolescents.

Excipient related considerations

This medicinal product contains less than 1 mmol sodium (23 mg) per vial, that is to say essentially 'sodium-free'.

However, depending on the body weight and posology, the patient could receive more than one vial (see section 2 for information on content per vial). This should be taken into consideration by patients on a controlled sodium diet.

No interactions of human coagulation factor VIII (rDNA) with other medicinal products have been reported. No interaction studies have been performed.

Animal reproduction studies have not been conducted with factor VIII. A placental transfer study in mice was conducted with ELOCTA (see section 5.3). Based on the rare occurrence of haemophilia A in women, experience regarding the use of factor VIII during pregnancy and breast-feeding is not available. Therefore, factor VIII should be used during pregnancy and breast-feeding only if clearly indicated.

ELOCTA has no influence on the ability to drive and use machines.

Summary of the safety profile

Hypersensitivity or allergic reactions (which may include angioedema, burning and stinging at the infusion site, chills, flushing, generalised urticaria, headache, hives, hypotension, lethargy, nausea, restlessness, tachycardia, tightness of the chest, tingling, vomiting, wheezing) have been observed rarely and may in some cases progress to severe anaphylaxis (including shock).

Development of neutralising antibodies (inhibitors) may occur in patients with haemophilia A treated with factor VIII, including with ELOCTA. If such inhibitors occur, the condition will manifest itself as an insufficient clinical response. In such cases, it is recommended that a specialised haemophilia centre be contacted.

Tabulated list of adverse reactions

The Table 2 presented below is according to the MedDRA system organ classification (SOC and Preferred Term Level). Frequencies of adverse reactions are based on clinical studies with a total of 379 patients with severe haemophilia A, of which 276 were previously treated patients (PTPs) and 103 were previously untreated patients (PUPs). See section 5.1 for additional details on the clinical studies.

Frequencies have been evaluated according to the following convention: very common (≥ 1/10); common (≥ 1/100 to <1/10); uncommon (≥ 1/1,000 to <1/100); rare (≥ 1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be estimated from the available data).

Within each frequency grouping, adverse reactions are presented in order of decreasing seriousness.

Table 2: Adverse reactions reported for ELOCTA in clinical trials¹

PTPs= previously treated patients, PUPs= previously untreated patients.

¹ ADRs and frequency are based on occurrence in PTPs only, unless otherwise noted.

²Frequency is based on studies with all FVIII products which included patients with severe haemophilia A.

³ADRs and frequency are based on occurrence in PUPs only.

⁴ Investigator term: vascular pain after injection of ELOCTA

Paediatric population

No age-specific differences in adverse reactions were observed between paediatric and adult subjects. Frequency, type and severity of adverse reactions in children are expected to be the same as in adults.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme.

Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

No symptoms of overdose have been reported.

Pharmacotherapeutic group: antihaemorrhagics, blood coagulation factor VIII, ATC code: B02BD02

Mechanism of action

The factor VIII/von Willebrand factor complex consists of two molecules (factor VIII and von Willebrand factor) with different physiological functions. When infused into a haemophiliac patient, factor VIII binds to von Willebrand factor in the patient's circulation. Activated factor VIII acts as a cofactor for activated factor IX, accelerating the conversion of factor X to activated factor X. Activated factor X converts prothrombin into thrombin. Thrombin then converts fibrinogen into fibrin and a clot can be formed.

Haemophilia A is an X-linked hereditary disorder of blood coagulation due to decreased levels of functional factor VIII:C and results in bleeding into joints, muscles or internal organs, either spontaneously or as a result of accidental or surgical trauma. By replacement therapy the plasma levels of factor VIII are increased, thereby enabling a temporary correction of the factor deficiency and correction of the bleeding tendencies.

Of note, annualized bleeding rate (ABR) is not comparable between different factor concentrates and between different clinical studies.

ELOCTA (efmoroctocog alfa) is a fully recombinant fusion protein with extended half-life. ELOCTA is comprised of recombinant B-domain deleted human coagulation factor VIII covalently linked to the Fc domain of human immunoglobulin G1. The Fc region of human immunoglobulin G1 binds to the neonatal Fc receptor. This receptor is expressed throughout life and is part of a naturally occurring pathway that protects immunoglobulins from lysosomal degradation by cycling these proteins back into circulation, resulting in their long plasma half-life. Efmoroctocog alfa binds to neonatal Fc receptor thereby utilising this same naturally occurring pathway to delay lysosomal degradation and allow for longer plasma half-life than endogenous factor VIII.

Clinical efficacy and safety

The safety, efficacy, and pharmacokinetics of ELOCTA in previously treated patients (PTPs) were evaluated in 2 multinational, open-label, pivotal phase 3 studies, Study I and Study II (see Paediatric population), and an extension study (Study III) with a duration of up to four years. In total 276 PTPs were followed for a total of 80,848 exposure days with a median of 294 (range 1-735) exposure days per patient. In addition, a phase 3 study (Study IV) was performed to evaluate the safety and efficacy of ELOCTA in previously untreated patients (PUPs) (see Paediatric population).

Study I enrolled 165 previously treated male patients (12 to 65 years of age) with severe haemophilia A. Subjects on prophylaxis regimens prior to entering the study were assigned to the individualised prophylaxis arm. Subjects on on-demand therapy prior to entry either entered the individualised prophylaxis arm or were randomised to the weekly prophylaxis or on-demand arms.

Prophylaxis regimens:

Individualised prophylaxis: 25 to 65 IU/kg every 3 to 5 days. Weekly prophylaxis: 65 IU/kg

Out of 153 subjects who completed Study I, 150 were enrolled onto Study III (extension study). Median total time on Study I+III was 4.2 years and median number of exposure days was 309.

Individualised prophylaxis: Median annual factor consumption was 4212 IU/kg (min. 2877, max. 7943) in Study I and 4223 IU/kg (min. 2668, max 8317) in Study III. Respective median Annualized Bleed Rate (ABR) was 1.60 (min. 0, max. 18.2) and 0.74 (min. 0, max. 15.6).

Weekly prophylaxis: Median annual factor consumption was 3805 IU/kg (min. 3353, max. 6196) in Study I and 3510 IU/kg (min. 2758, max. 3984) in Study III. Respective median ABR was 3.59 (min. 0, max. 58.0) and 2.24 (min. 0, max. 17.2).

On-demand treatment: Median annual factor consumption was 1039 IU/kg (min. 280, max. 3571) for 23 patients randomised to the on-demand treatment arm in Study I and 671 IU/kg (min. 286, max. 913) for 6 patients remaining on on-demand treatment for at least one year in Study III.

Subjects that switched from on-demand treatment to weekly prophylaxis during Study III had a median ABR of 1.67.

Treatment of bleeding: 2490 bleeding events were treated during Study I and III with a median dose of 43.8 IU/kg (min. 13.0, max. 172.8) to control each bleed. 79.2 % of first injections were rated as excellent or good by the patients.

Perioperative management (surgical prophylaxis): A total of 48 major surgical procedures were performed and assessed in 34 subjects in Study I and Study III. The haemostatic response was rated by the physicians as excellent in 41 and as good in 3 of 44 major surgeries. Median dose to maintain haemostasis during surgery was 60.6 IU/kg (min. 38, max. 158).

Paediatric population

Study II enrolled a total of 71 previously treated male paediatric patients <12 years of age with severe haemophilia A. Of the 71 enrolled subjects, 69 received at least 1 dose of ELOCTA and were evaluable for efficacy (35 were <6 years of age and 34 were 6 to <12 years of age). The starting prophylactic regimen consisted of 25 IU/kg on the first day followed by 50 IU/kg on the fourth day. Dosing of up to 80 IU/kg and a dosing interval as short as 2 days was allowed and used in a limited number of patients. Out of 67 subjects having completed Study II, 61 enrolled onto Study III (extension study). Median total time on study II+III was 3.4 years and median number of exposure days was 332.

Prophylaxis, age <6 years: Median dose interval was 3.50 days in Study II and Study III. Median annual factor consumption was 5146 IU/kg (min. 3695, max 8474) in Study II and 5418 IU/kg (min. 3435, max. 9564) in Study III. Respective median Annualized Bleed Rate (ABR) was 0.00 (min. 0, max. 10.5) and 1.18 (min. 0, max. 9.2).

Prophylaxis, age 6 up to 12 years: Median dose interval was 3.49 days in Study II and 3.50 days in Study III. Median annual factor consumption was 4700 IU/kg (min. 3819, max. 8230 IU/kg) in Study II and 4990 IU/kg (min. 3856, max. 9527) in Study III. Respective median ABR was 2.01 (min. 0, max. 27.2) and 1.59 (min. 0, max. 8.0).

12 adolescent subjects age 12 up to 18 years were included in the adult study population on prophylactic treatment. Median annual factor consumption was 5572 IU/kg (min. 3849, max. 7035) in Study I and 4456 IU/kg (min. 3563, max. 8011) in Study III. Respective median ABR was 1.92 (min. 0, max. 7.1) and 1.25 (min. 0, max. 9.5).

Treatment of bleeding: During Studies II and III, 447 bleeding events were treated with a median dose of 63 IU/kg (min. 28, max. 186) to control each bleed. 90.2 % of first injections were rated as excellent or good by the patients and their caregivers.

Study IV evaluated 103male previously untreated patients (PUPs) <6 years of age with severe haemophilia A. Patients were followed for a total of 11,255 exposure days with a median of 100 (range 0-649) exposure days per patient. Most subjects started on episodic treatment (N=81) with subsequent transition to prophylaxis (N=69). At any time during the study, 89 PUPs received prophylaxis. The recommended initial dose on prophylaxis was 25– 80 IU/kg at 3– 5-day intervals. For subjects on prophylaxis, the median average weekly dose was 101.4 IU/kg (range: 28.5-776.3 IU/kg) and the median dosing interval was 3.87 days (range 1.1 to 7 days). Median annual factor consumption was 3971.4 IU/kg. Annualized Bleeding Rate was 1.49 (min. 0.0, max. 18.7).

All pharmacokinetic studies with ELOCTA were conducted in previously treated patients with severe haemophilia A. Data presented in this section were obtained by chromogenic and one-stage clotting assays. The pharmacokinetic parameters from the chromogenic assay data were similar to those derived for the one-stage assay.

Pharmacokinetic properties were evaluated in 28 subjects (≥ 15 years) receiving ELOCTA (rFVIIIFc). Following a washout period of at least 96 hours (4 days), the subjects received a single dose of 50 IU/kg of ELOCTA. Pharmacokinetic samples were collected pre-dose and then subsequently at 7 time points up to 120 hours (5 days) post-dose. Pharmacokinetic parameters after 50 IU/kg dose of ELOCTA are presented in Tables 3 and 4.

Table 3: Pharmacokinetic parameters of ELOCTA using the one-stage clotting assay

¹ Pharmacokinetic parameters are presented in Geometric Mean (95% CI)

Abbreviations: CI = confidence interval; C_max= maximum activity; AUC = area under the FVIII activity time curve; t_½ = terminal half-life; CL = clearance; V_ss = volume of distribution at steady-state; MRT = mean residence time.

Table 4: Pharmacokinetic parameters of ELOCTA using the chromogenic assay

¹ Pharmacokinetic parameters are presented in Geometric Mean (95% CI)

Abbreviations: CI = confidence interval; C_max= maximum activity; AUC = area under the FVIII activity time curve; t_½ = terminal half-life; CL = clearance; V_ss = volume of distribution at steady-state; MRT = mean residence time.

The PK data demonstrate that ELOCTA has a prolonged circulating half-life.

Paediatric population

Pharmacokinetic parameters of ELOCTA were determined for adolescents in study I (pharmacokinetic sampling was conducted pre-dose followed by assessment at multiple time points up to 120 hours (5 days) post-dose) and for children in study II (pharmacokinetic sampling was conducted pre-dose followed by assessment at multiple time points up to 72 hours (3 days) post-dose). Tables 5 and 6 present the pharmacokinetic parameters calculated from the paediatric data of subjects less than 18 years of age.

Table 5: Pharmacokinetic parameters of ELOCTA for paediatrics using the one- stage clotting assay

¹ Pharmacokinetic parameters are presented in Geometric Mean (95% CI)

Abbreviations: CI = confidence interval; AUC = area under the FVIII activity time curve; t_½ = terminal half-life;

CL = clearance; MRT = mean residence time; V_ss = volume of distribution at steady-state

*Pharmacokinetic parameters in 12 to <18 years included subjects from all the arms in Study I with different sampling schemes

Table 6: Pharmacokinetic parameters of ELOCTA for paediatrics using the chromogenic assay

¹ Pharmacokinetic parameters are presented in Geometric Mean (95% CI) Abbreviations: CI = confidence interval; AUC = area under the FVIII activity time curve; t_½ = terminal half-life;

CL = clearance; MRT = mean residence time; V_ss = volume of distribution at steady-state

* Pharmacokinetic parameters in 12 to <18 years included subjects from all the arms in Study I with different sampling schemes

In comparison with adolescents and adults, children less than 12 years of age may have a higher clearance and a shorter half-life which is consistent with observations of other coagulation factors. These differences should be taken into account when dosing.

Non-clinical data reveal no special hazard for humans based on acute and repeated dose toxicity studies (which included assessments of local toxicity and safety pharmacology). Studies to investigate genotoxicity, carcinogenicity, toxicity to reproduction or embryo-foetal development have not been conducted. In a placental transfer study, ELOCTA has been shown to cross the placenta in small amounts in mice.

Powder

Sucrose

Sodium chloride

Histidine

Calcium chloride dihydrate

Polysorbate 20

Sodium hydroxide (for pH adjustment)

Hydrochloric acid (for pH adjustment)

Solvent

Water for injections

In the absence of compatibility studies, this medicinal product must not be mixed with other medicinal products.

Only the provided infusion set should be used because treatment failure can occur as a consequence of coagulation factor VIII adsorption to the internal surfaces of some injection equipment.

Unopened vial

4 years

During the shelf-life, the product may be stored at room temperature (up to 30° C) for a single period not exceeding 6 months. The date that the product is removed from refrigeration should be recorded on the carton. After storage at room temperature, the product may not be returned to the refrigerator. Do not use beyond the expiry date printed on the vial or six months after removing the carton from refrigeration, whichever is earlier.

After reconstitution

After reconstitution, chemical and physical stability has been demonstrated for 6 hours when stored at room temperature (up to 30° C). Protect product from direct sunlight. After reconstitution, if the product is not used within 6 hours, it must be discarded. From a microbiological point of view, the product should be used immediately after reconstitution. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user.

Store in a refrigerator (2° C - 8° C). Do not freeze. Keep the vial in the outer carton in order to protect from light.

For storage conditions after reconstitution of the medicinal product, see section 6.3.

Each pack contains:

- powder in a type 1 glass vial with a chlorobutyl rubber stopper

- 3 mL solvent in a type 1 glass pre-filled syringe with a bromobutyl rubber plunger stopper

- a plunger rod

- a sterile vial adapter for reconstitution

- a sterile infusion set

- two alcohol swabs

- two plasters

- one gauze pad.

Pack size of 1.

The vial of lyophilised product powder for injection must be reconstituted with the supplied solvent (water for injections) from the pre-filled syringe using the sterile vial adapter for reconstitution.

The vial should be gently swirled until all of the powder is dissolved.

Reconstituted medicinal product should be inspected visually for particulate matter and discoloration prior to administration. The solution should be clear to slightly opalescent and colourless. Do not use solutions that are cloudy or have deposits.

Additional information on reconstitution and administration:

ELOCTA is administered by intravenous (IV) injection after dissolving the powder for injection with the solvent supplied in the pre-filled syringe. ELOCTA pack contains:

ELOCTA should not be mixed with other solutions for injection or infusion. Wash your hands before opening the pack

Preparation:

Administration (Intravenous injection):

ELOCTA should be administered using the infusion set (E) provided in this pack.

Any unused medicinal product or waste material should be disposed of in accordance with local requirements.