Summary of the safety profile
Serious adverse reactions occurred in 59% of patients who received Enrylaze in a clinical trial. The most frequent serious adverse reactions were febrile neutropenia (29%), pyrexia (10%), vomiting (8%), sepsis (7%), medicinal product hypersensitivity (6%), nausea (6%), and pancreatitis (5%).
The most common adverse reactions were anaemia (52%), vomiting (49%), thrombocytopenia (42%), neutropenia (41%), nausea (38%), febrile neutropenia (32%), fatigue (32%), pyrexia (32%), decreased appetite (29%), transaminase increased (29%), abdominal pain (27%), white blood cell count decreased (27%), headache (25%), diarrhoea (22%), and lymphocyte count decreased (20%).
Tabulated list of adverse reactions
Adverse reactions reported in clinical trial are listed in Table 1 by system organ class and by frequency. The frequencies identified are from patients (n=228) who received 6 doses of Enrylaze, along with a multi-agent chemotherapeutic regimen. Certain adverse reactions listed below, such as reactions resulting from bone marrow suppression, and infections, are known to be associated with multi-agent chemotherapeutic regimens, and the contributory role of Enrylaze is not clear. In individual cases of adverse reactions, other medicinal products of the regimen may have contributed.
Frequencies are defined as: 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); not known (cannot be estimated from the available data). Within each frequency grouping, adverse reactions are presented in order of decreasing seriousness.
Table 1: Adverse reactions in patients receiving Enrylaze with multi-agent chemotherapy (Study JZP458-201)
| System organ class | Frequency | Adverse reaction |
| Infections and infestations | Common | Sepsis |
| Blood and lymphatic system disorders | Very common | Anaemia, Thrombocytopenia, Neutropenia, Febrile neutropenia |
| Immune system disorders | Very common | Drug hypersensitivity |
| Common | Anaphylactic reaction, Hypersensitivity |
| Metabolism and nutrition disorders | Very common | Decreased appetite, Hyperglycaemia, Hypoalbuminemia |
| Common | Hypertriglyceridemia, Hypoglycaemia, Hyperammonaemia |
| Psychiatric disorders | Very common | Anxiety |
| Common | Irritability |
| Nervous system disorders | Very common | Headache |
| Common | Dizziness |
| Uncommon | Superior sagittal sinus thrombosis |
| Vascular disorders | Common | Hypotension |
| Uncommon | Jugular vein thrombosis, Deep vein thrombosis |
| Respiratory, thoracic and mediastinal disorders | Common | Pulmonary embolism |
| Gastrointestinal disorders | Very common | Vomiting, Nausea, Abdominal pain, Diarrhoea |
| Common | Pancreatitis |
| Skin and subcutaneous tissue disorders | Common | Rash maculo-papular, Pruritus, Rash, Urticaria, Rash erythematous, |
| Musculoskeletal and connective tissue disorders | Very common | Pain in extremity |
| General disorders and administration site conditions | Very common | Fatigue, Pyrexia |
| Common | Injection site pain, Injection site reaction |
| Investigations | Very common | Transaminases increased, White blood cell count decreased, Lymphocyte count decreased, Weight decreased, Blood bilirubin increased |
| Common | Blood creatinine increased , Activated partial thromboplastin time prolonged, Blood fibrinogen decreased, Antithrombin III decreased |
| Injury, poisoning and procedural complications | Very common | Contusion |
| Common | Infusion-related reaction |
Description of selected adverse reactions
Hypersensitivity
Hypersensitivity reactions were reported adverse reactions in the Enrylaze clinical trial. The incidence of medicinal product hypersensitivity was 11% and it was severe in 8% of patients. The incidence of anaphylactic reaction was 2%, and it was severe in all patients. Overall hypersensitivity reactions observed more frequently in patients who received Enrylaze intravenously. The frequency of hypersensitivity reactions leading to discontinuation was 10% (see section 4.4).
Pancreatitis
Cases of pancreatitis including life threatening cases have been reported in the Enrylaze clinical trial. The incidence of pancreatitis was 7%; the incidence of serious events of pancreatitis was 5%; the incidence of life-threatening pancreatitis was 1%. One patient developed pancreatic pseudocyst after acute pancreatitis, which resolved without sequelae. The frequency of pancreatitis in Study JZP458‑201 which led to discontinuation was 5% (see section 4.4).
Adults and other special populations
Although the safety profile of adults above 25 years of age has not been studied, some adverse reactions, such as hepatotoxicity, thrombosis, and pancreatitis, have been reported more frequently in adults with acute lymphoblastic leukemia receiving other asparaginases than in paediatric patients.
Immunogencity
It has been reported that there is no to little cross reactivity between crisantaspase and other E. coli derived asparaginase.
As with all therapeutic proteins, there is a potential for immunogenicity. Immunogenicity assays are highly dependent on the sensitivity and specificity of the assay and may be influenced by several factors such as assay methodology, sample handling, timing of sample collection, concomitant treatment, and underlying disease. For these reasons, comparison of the incidence of antibodies to Enrylaze with the incidence of antibodies to other products may be misleading.
Analysis of patients receiving Enrylaze by either intramuscular injection (n=167) or intravenous infusion (n=61) showed that 116 of 228 (51%) patients had confirmed positive anti-drug antibodies (ADA) toward Enrylaze, 8 (7%) of these were ADA positive at pre dose 1.
A total of 23 (20%) patients who had ADAs experienced hypersensitivity reactions of which 6 (5%) had neutralising antibodies. Of the negative ADA patients 7/112 (6%) experienced a hypersensitivity reaction.
During the course of treatment 73 (63%) patients became ADA negative at least once.
Intravenous infusion
• A total of 34 (56%) patients were found to be ADA positive.
• 1 patient was ADA positive at pre dose 1.
• 33 patients developed ADA toward Enrylaze following administration of Enrylaze. 18 of these patients subsequently became ADA negative at least once during the study.
• 12 (35%) experienced hypersensitivity reactions during the study, and of these patients 2 had neutralising antibodies. Of the negative ADA patients 4/27 (15%) experienced a hypersensitivity reaction.
Intramuscular injection
• A total of 82 (49%) patients were found to be ADA positive.
• 7 patients were ADA positive at pre dose 1.
• 75 patients developed ADA toward Enrylaze following administration of Enrylaze. 55 of these patients subsequently became ADA negative at least once during the study.
• 11 (13%) patients experienced hypersensitivity reactions, and of these patients 4 had neutralising antibodies. Of the negative ADA positive patients 7/85 (8%) experienced a hypersensitivity reaction.
The presence of ADA does not appear to correlate with the occurrence of hypersensitivity reactions. SAA levels were not impacted for applicable ADA positive patients as they maintained SAA levels ≥ 0.1 U/mL at all available 48- and 72‑hour time points during Course 1. No impact on the pharmacokinetics of Enrylaze was observed and ADA status was not found to be a significant factor in population pharmacokinetic analysis.
Paediatric population
The majority of the patients in Study JZP458‑201 were children < 18 years old 197/228 (86%) and therefore a comparison of frequency and severity in adverse reactions versus other age groups is not suitable.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorization 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
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