Summary of the safety profile
Serious adverse reactions reported in patients treated with Nexviadyme were respiratory distress and chills in 1.4% of patients and in 0.7% of patients each were headache, dyspnoea, hypoxia, tongue oedema, nausea, pruritus, urticaria, skin discoloration, chest discomfort, pyrexia, blood pressure increased or decreased, body temperature increased, heart rate increased, and oxygen saturation decreased. Hypersensitivity reactions were reported in 60.6% of patients, anaphylaxis in 2.8%, and IARs in 39.4% in patients. A total of 4.9% of patients receiving Nexviadyme in clinical studies permanently discontinued treatment; 2.8% of patients each discontinued the treatment because of the following events considered to be related to Nexviadyme: respiratory distress, chest discomfort, dizziness, cough, nausea, flushing, ocular hyperaemia, urticaria, and erythema.
The most frequently reported adverse drug reactions (ADRs) (>5%) were pruritus (13.4%), nausea (12%), headache (10.6%), rash (10.6%), urticaria (8.5%), chills (7.7%), fatigue (7.7%), and erythema (5.6%).
The pooled safety analysis from 4 clinical studies (EFC14028/COMET, ACT14132/mini-COMET, TDR12857/NEO, and LTS13769/NEO-EXT) included a total of 142 patients (118 adult and 24 paediatric patients (1 paediatric patient directly enrolled in the open-label extension period of Study 1)) treated with Nexviadyme. ADRs reported in patients treated with Nexviadyme in the pooled analysis of clinical studies are listed in Table 2.
Tabulated list of adverse reactions
Adverse reactions per System Organ Class, presented by frequency categories: 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) and not known (cannot be estimated from the available data).
Due to the small patient population, an adverse reaction reported in 2 patients is classified as common. Within each frequency grouping, adverse reactions are presented in order of decreasing seriousness.
Table 2 – Adverse reactions occurring in patients treated with Nexviadyme in a pooled analysis of clinical studies (N=142)
| System organ class | Frequency | Preferred term |
| Infections and infestations | Uncommon | Conjunctivitis |
| Immune Disorders | Very common Common | Hypersensitivity Anaphylaxis |
| Nervous system disorders | Very common Common Common Common Common Uncommon | Headache Dizziness Tremor Somnolence Burning sensation Paraesthesia |
| Eye Disorders | Common Common Common Common Uncommon | Ocular hyperaemia Conjunctival hyperaemia Eye pruritus Eyelid oedema Lacrimation increased |
| Cardiac Disorders | Common Uncommon | Tachycardia Ventricular extrasystoles |
| Vascular Disorders | Common Common Common Common Common Common | Hypertension Flushing Hypotension Cyanosis Hot flush Pallor |
| Respiratory, thoracic, and mediastinal disorders | Common Common Common Common Common Uncommon Uncommon | Cough Dyspnoea Respiratory distress Throat irritation Oropharyngeal pain Tachypnoea Laryngeal oedema |
| Gastrointestinal disorders | Very common Common Common Common Common Common Common Common Uncommon Uncommon Uncommon | Nausea Diarrhoea Vomiting Lip swelling Swollen tongue Abdominal pain Abdominal pain upper Dyspepsia Hypoaesthesia oral Paraesthesia oral Dysphagia |
| Skin and subcutaneous tissue disorders | Very common Very common Common Common Common Common Common Common Common Uncommon Uncommon | Pruritus Rash Urticaria Erythema Palmer erythema Hyperhidrosis Rash erythematous Rash pruritic Skin plaque Angioedema Skin discolouration |
| Musculoskeletal and connective tissue disorders | Common Common Common Common | Muscle spasms Myalgia Pain in extremity Flank pain |
| General disorders and administration site conditions | Common Common Common Common Common Common Common Common Common Common Common Common Uncommon Uncommon Uncommon Uncommon Uncommon Uncommon Uncommon Uncommon Uncommon | Fatigue Chills Chest discomfort Pain Influenza-like illness Infusion site pain Pyrexia Asthenia Face oedema Feeling cold Feeling hot Sluggishness Facial pain Hyperthermia Infusion site extravasation Infusion site joint pain Infusion site rash Infusion site reaction Infusion site urticaria Localized oedema Peripheral swelling |
| Investigation | Common Common Common Uncommon Uncommon Uncommon Uncommon | Blood pressure increased Oxygen saturation decreased Body temperature increase Heart rate increased Breath sounds abnormal Complement factor increased Immune complex level increased |
Table 2 includes treatment related adverse events that are considered biologically plausibly related to avalglucosidase alfa based on the alglucosidase alfa SmPC.
In a comparative study, EFC14028/COMET, 100 LOPD (late-onset Pompe disease) patients aged 16 to 78 naïve to enzyme replacement therapy were treated either with 20 mg/kg of Nexviadyme (n=51) or 20 mg/kg of alglucosidase alfa (n=49). During the double-blind active-controlled period of 49 weeks, serious adverse reactions were reported in 2% of patients treated with Nexviadyme and 6.1% of those treated with alglucosidase alfa. A total of 8.2% patients receiving alglucosidase alfa in the study permanently discontinued treatment due to adverse reactions; none of the patients from the Nexviadyme group permanently discontinued the treatment. The most frequently reported ADRs (>5%) in patients treated with Nexviadyme were headache, nausea, pruritus, urticaria, and fatigue.
The 95 patients who entered open-label extension period of EFC14028/COMET consisted of 51 patients who continued treatment with Nexviadyme and 44 patients who switched from alglucosidase alfa to Nexviadyme.
During the open-label extension period, serious adverse reactions were reported by 3 (5.8%) patients continuing Nexviadyme treatment throughout the study and by 3 (6.8%) patients who switched to Nexviadyme. The most frequently reported adverse reactions (>5%) by patients continuing Nexviadyme treatment throughout the study were nausea, chills, erythema, pruritus, and urticaria. The most frequently reported adverse reactions (>5%) by patients who switched to Nexviadyme were pruritis, rash, headache, nausea, chills, fatigue, and urticaria.
No adverse reaction or IAR was reported by the additional paediatric patient directly enrolled in the open-label extension period.
Description of selected adverse reactions
Hypersensitivity (including anaphylaxis)
In a pooled safety analysis, 86/142 (60.6%) patients experienced hypersensitivity reactions including 7/142 (4.9%) patients who reported severe hypersensitivity reactions and 4/142 (2.8%) patients who experienced anaphylaxis. Some of the hypersensitivity reactions were IgE mediated. Anaphylaxis signs and symptoms included tongue oedema, hypotension, hypoxia, respiratory distress, chest pressure, generalised oedema, generalised flushing, feeling hot, cough, dizziness, dysarthria, throat tightness, dysphagia, nausea, redness on palms, swollen lower lip, decreased breath sounds, redness on feet, swollen tongue, itchy palms and feet, and oxygen desaturation. Symptoms of severe hypersensitivity reactions included tongue oedema, respiratory failure, respiratory distress, generalized oedema, erythema, urticaria, and rash.
Infusion-associated reactions (IARs)
In a pooled safety analysis, IARs were reported in approximately 56/142 (39.4%) of patients treated with avalglucosidase alfa in clinical studies. Severe IARs were reported in 6/142 (4.2%) of patients including symptoms of respiratory distress, hypoxia, chest discomfort, generalized oedema, tongue oedema, dysphagia, nausea, erythema, urticaria, and increased or decreased blood pressure. IARs reported in more than 1 patient included respiratory distress, chest discomfort, dyspnoea, cough, oxygen saturation decreased, throat irritation, dyspepsia, nausea, vomiting, diarrhoea, lip swelling, swollen tongue, erythema, palmar erythema, rash, rash erythematous, pruritus, urticaria, hyperhidrosis, skin plaque, ocular hyperaemia, eyelid oedema, face oedema, increased or decreased blood pressure, tachycardia, headache, dizziness, tremor, burning sensation, pain (including pain in extremity, abdominal pain upper, oropharyngeal pain, and flank pain), somnolence, sluggishness, fatigue, pyrexia, influenza like illness, chills, flushing, feeling hot or cold, cyanosis, and pallor. The majority of IARs were assessed as mild to moderate.
In the comparative study EFC14028/COMET study, fewer LOPD patients in the avalglucosidase alfa group reported at least 1 IAR (13/51 [25.5%]) in comparison to the alglucosidase alfa group (16/49 [32.7%]). Severe IARs were not reported in patients in the avalglucosidase alfa group and reported in 2 patients in the alglucosidase alfa group (dizziness, visual impairment, hypotension, dyspnoea, cold sweat, and chills). The most frequently reported treatment-emergent IARs (>2 patients) in the avalglucosidase alfa group were pruritus (7.8%) and urticaria (5.9%) and in the alglucosidase alfa group were nausea (8.2%), pruritus (8.2%), and flushing (6.1%). The majority of IARs reported in 7 (13.7%) patients were of mild severity in the avalglucosidase alfa group and 10 (20.4%) patients in the alglucosidase alfa group.
During the open-label extension period, IARs were reported in 12 (23.5%) patients continuing Nexviadyme treatment throughout the study; IARs reported in more than 1 patient were nausea, chills, erythema, pruritus, pyrexia, urticaria, rash, and ocular hyperaemia. IARs were reported in 22 (50%) patients who switched to Nexviadyme; IARs reported in more than 1 patient were pruritis, headache, rash, nausea, chills, fatigue, urticaria, respiratory distress, feeling cold, chest discomfort, erythema, rash erythematous, rash pruritic, skin plaque, burning sensation, lip swelling, and swollen tongue. The number of IARs in both groups decreased over time.
Immunogenicity
The incidence of ADA response to avalglucosidase alfa in Nexviadyme-treated patients with Pompe disease is shown in Table 3. The median time to seroconversion was 8.3 weeks.
In treatment-naïve adult patients, the occurrence of IARs was observed in both ADA-positive and ADA-negative patients. Increase in the incidence of IARs and hypersensitivity were observed with higher IgG ADA titres. In treatment-naïve patients, a trend for increases in the incidence of IARs was observed with increasing ADA titres, with the highest incidence of IARs (69.2%) reported in the high ADA peak titre range ≥12,800, compared with an incidence of 33.3% in patients with intermediate ADA titre 1,600-6,400, an incidence of 14.3% in those with low ADA titre 100-800 and an incidence of 33.3% in those who were ADA negative. In enzyme replacement therapy (ERT) experienced adult patients, the occurrences of IARs and hypersensitivity were higher in patients who developed treatment emergent ADA compared to patients who were ADA negative. One (1) treatment naïve patient and 2 treatment-experienced patients developed anaphylaxis. The occurrences of IARs were similar between paediatric patients with ADA positive and negative status. One treatment-experienced paediatric patient developed anaphylaxis (see section 4.4).
In clinical study EFC14028/COMET, 81 of 96 (84.4%) patients developed treatment-emergent ADA. Majority of patients developed ADA titre in the low to intermediate range, with 7 patients reported High Sustained Antibody Titres (HSAT) to Nexviadyme. Evaluation of ADA cross-reactivity at week 49 showed that three (5.9%) patients generated antibodies that were cross-reactive to alglucosidase alfa and Nexviadyme. Variable impact on PK, PD, and efficacy measures were observed among high titre patients, however, in most patients there was no clinically significant effect of ADA on efficacy (see section 5.2).
Table 3 – Treatment emergent ADA incidence in LOPD and IOPD patient population
| | Nexviadyme |
| Treatment-naïve patients Avalglucosidase alfa ADAa | Treatment-experienced patientsb Avalglucosidase alfa ADA |
| Adults 20 mg/kg every other week | Adults 20 mg/kg every other week | Paediatric 20 mg/kg every other week | Paediatric 40 mg/kg every other week |
| (N=62) N (%) | (N=58) N (%) | (N=6) N (%) | (N=16) N (%) |
| ADA at baseline | 2 (3.3) | 43 (74.1) | 1 (16.7) | 2 (12.5) |
| Treatment emergent ADA | 59 (95.2) | 36 (62.1) | 1 (16.6) | 9 (56.3) |
| Neutralizing antibody |
| Both NAb types | 14 (22.6) | 5 (8.6) | 0 | 0 |
| Inhibition enzyme activity, only | 5 (8.1) | 6 (10.3) | 0 | 0 |
| Inhibition of enzyme uptake, only | 12 (19.4) | 15 (25.9) | 0 | 2 (12.5%) |
a Includes two paediatric patients
b Treatment-experienced patients received alglucosidase alfa treatment before or during the clinical study within a range of 0.9-9.9 years for adult patients and 0.6-11.8 years for paediatric patients.
c Not determined
Paediatric population
Adverse drug reactions reported from clinical studies in the paediatric population (19 paediatric patients with IOPD between 1-12 years of age (mean age of 6.8) and two paediatric patients (9 and 16 years old) with LOPD) were similar to those reported 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 at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.