Summary of the safety profile
The most common adverse reactions reported during therapy with deferiprone in clinical trials were nausea, vomiting, abdominal pain, and chromaturia, which were reported in more than 10% of patients. The most serious adverse reaction reported in clinical trials with deferiprone was agranulocytosis, defined as an absolute neutrophil count less than 0.5 x 109/l, which occurred in approximately 1% of patients. Less severe episodes of neutropenia were reported in approximately 5% of patients.
Tabulated list of adverse reactions
The adverse reactions are listed below by system organ class (SOC) and by frequency, with the following frequency grouping: 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 the order of decreasing seriousness.
| System organ class | Very common | Common | Frequency not known |
| Blood and lymphatic system disorders | | Agranulocytosis Neutropenia | |
| Immune system disorders | | | Hypersensitivity reactions |
| Metabolism and nutrition disorders | | Increased appetite | |
| Nervous system disorders | | Headache | |
| Gastrointestinal disorders | Vomiting Nausea Abdominal pain | Diarrhoea | |
| Skin and subcutaneous tissue disorders | | | Rash Urticaria |
| Musculoskeletal and connective tissue disorders | | Arthralgia | |
| Renal and urinary disorders | Chromaturia | | |
| General disorders and administration site conditions | | Fatigue | |
| Investigations | | Increased liver enzymes | |
Description of selected adverse reactions
The most serious adverse reaction reported in clinical trials with deferiprone is agranulocytosis (neutrophils <0.5 x 109/l), with an incidence of 1.1% (0.6 cases per 100 patient-years of treatment) (see section 4.4). Data from pooled clinical trials in patients with systemic iron overload show that 63% of the episodes of agranulocytosis occurred within the first six months of treatment, 74% within the first year and 26% after one year of therapy. The median time to onset of the first episode of agranulocytosis was 190 days (ranged 22 days - 17.6 years) and median duration was 10 days in clinical trials. A fatal outcome was observed in 8.3% of the reported episodes of agranulocytosis from clinical trials and post-marketing experience.
The observed incidence of the less severe form of neutropenia (neutrophils <1.5 x 109/l) is 4.9% (2.5 cases per 100 patient-years). This rate should be considered in the context of the underlying elevated incidence of neutropenia in thalassaemia patients, particularly in those with hypersplenism.
Episodes of diarrhoea, mostly mild and transient, have been reported in patients treated with deferiprone. Gastrointestinal effects are more frequent at the beginning of therapy and resolve in most patients within a few weeks without the discontinuation of treatment. In some patients it may be beneficial to reduce the dose of deferiprone and then scale it back up to the former dose. Arthropathy events, which ranged from mild pain in one or more joints to severe arthritis with effusion and significant disability, have also been reported in patients treated with deferiprone. Mild arthropathies are generally transient.
Increased levels of serum liver enzymes have been reported in some patients taking deferiprone. In the majority of these patients, the increase was asymptomatic and transient, and returned to baseline without discontinuation or decreasing the dose of deferiprone (see section 4.4).
Some patients experienced progression of fibrosis associated with an increase in iron overload or hepatitis C.
Low plasma zinc levels have been associated with deferiprone in a minority of patients. The levels normalised with oral zinc supplementation.
Neurological disorders (such as cerebellar symptoms, diplopia, lateral nystagmus, psychomotor slowdown, hand movements and axial hypotonia) have been observed in children who had been voluntarily prescribed more than 2.5 times the maximum recommended dose of 100 mg/kg/day for several years. Episodes of hypotonia, instability, inability to walk, and hypertonia with inability of limb movement have been reported in children in the post-marketing setting with standard doses of deferiprone. The neurological disorders progressively regressed after deferiprone discontinuation (see sections 4.4 and 4.9).
The safety profile of combination therapy (deferiprone and deferoxamine) observed in clinical trials, post-marketing experience or published literature was consistent with that characterised for monotherapy.
Data from the pooled safety database from clinical trials (1 343 patient-years exposure to deferiprone monotherapy and 244 patient-years exposure to deferiprone and deferoxamine) showed statistically significant (p<0.05) differences in the incidence of adverse reactions based on System Organ Class for “Cardiac disorders”, “Musculoskeletal and connective tissue disorders” and “Renal and urinary disorders”. The incidences of “Musculoskeletal and connective tissue disorders” and “Renal and urinary disorders” were lower during combination therapy than monotherapy, whereas the incidence of “Cardiac disorders” was higher during combination therapy than monotherapy. The higher rate of “Cardiac disorders” reported during combination therapy than monotherapy was possibly due to the higher incidence of pre-existing cardiac disorders in patients who received combination therapy. Careful monitoring of cardiac events in patients on combination therapy is warranted (see section 4.4).
Paediatric population
The incidences of adverse reactions experienced by 18 children and 97 adults treated with combination therapy were not significantly different between the two age groups except in the incidence of arthropathy (11.1% in children vs. none in adults, p=0.02). Evaluation of rate of reactions per 100 patient-years of exposure showed that only the rate of diarrhoea was significantly higher in children (11.1) than in adults (2.0, p=0.01).
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.