Myelosuppression
Severe bone marrow suppression, notably anaemia, thrombocytopenia and neutropenia, has been reported in patients treated with Fludara. In a Phase I intravenous study in adult solid tumour patients, the median time to nadir counts was 13 days (range 3 – 25 days) for granulocytes and 16 days (range 2 - 32 days) for platelets. Most patients had haematologic impairment at baseline either as a result of disease or as a result of prior myelosuppressive therapy.
Cumulative myelosuppression may be seen. While chemotherapy-induced myelosuppression is often reversible, administration of fludarabine phosphate requires careful haematologic monitoring.
Fludarabine phosphate is a potent antineoplastic agent with potentially significant toxic side effects. Patients undergoing therapy should be closely observed for signs of haematologic and non-haematologic toxicity. Periodic assessment of peripheral blood counts is recommended to detect the development of anaemia, neutropenia and thrombocytopenia.
Several instances of trilineage bone marrow hypoplasia or aplasia resulting in pancytopenia, sometimes resulting in death, have been reported in adult patients. The duration of clinically significant cytopenia in the reported cases has ranged from approximately 2 months to approximately 1 year. These episodes have occurred both in previously treated or untreated patients.
As with other cytotoxics, caution should be exercised with fludarabine phosphate, when further haematopoietic stem cell sampling is considered.
Autoimmune disorders
Irrespective of any previous history of autoimmune processes or Coombs test status, life-threatening and sometimes fatal autoimmune phenomena (see section 4.8) have been reported to occur during or after treatment with Fludara. The majority of patients experiencing haemolytic anaemia developed a recurrence in the haemolytic process after rechallenge with Fludara.
Patients treated with Fludara oral should be closely monitored for signs of haemolysis.
Discontinuation of therapy with Fludara is recommended in case of haemolysis. Blood transfusion (irradiated, see below) and adrenocorticoid preparations are the most common treatment measures for autoimmune haemolytic anaemia.
Neurotoxicity
The effect of chronic administration of Fludara on the central nervous system is unknown. However, patients tolerated the recommended intravenous dose, in some studies for relatively long treatment times (for up to 26 courses of therapy).
Patients should be closely observed for signs of neurologic effects.
When used at high doses in dose-ranging studies in patients with acute leukaemia, intravenous Fludara was associated with severe neurological effects, including blindness, coma and death. Symptoms appeared from 21 to 60 days from last dose. This severe central nervous system toxicity occurred in 36 % of patients treated intravenously with doses approximately four times greater (96 mg/m²/day for 5 - 7 days) than the recommended dose. In patients treated at doses in the range of the dose recommended for CLL, severe central nervous system toxicity occurred rarely (coma, seizures and agitation) or uncommonly (confusion) (see section 4.8)
In post-marketing experience neurotoxicity has been reported to occur earlier or later than in clinical trials.
Administration of Fludara can be associated with leukoencephalopathy (LE), acute toxic leukoencephalopathy (ATL) or reversible posterior leukoencephalopathy syndrome (RPLS). These may occur:
• at the recommended dose
o when Fludara is given following, or in combination with, medications known to be associated with LE, ATL or RPLS,
o or when Fludara is given in patients with other risk factors such as cranial or total body irradiation, Hematopoietic Cell Transplantation, Graft versus Host Disease, renal impairment, or hepatic encephalopathy.
• at doses higher than the recommended dose
LE, ATL or RPLS symptoms may include headache, nausea and vomiting, seizures, visual disturbances such as vision loss, altered sensorium, and focal neurological deficits. Additional effects may include optic neuritis, and papillitis, confusion, somnolence, agitation, paraparesis/ quadriparesis, muscle spasticity and incontinence.
LE/ ATL/ RPLS may be irreversible, life-threatening, or fatal.
Whenever LE, ATL or RPLS is suspected, fludarabine treatment should be stopped. Patients should be monitored and should undergo brain imaging, preferably utilizing MRI. If the diagnosis is confirmed, fludarabine therapy should be permanently discontinued.
Tumour lysis syndrome
Tumour lysis syndrome has been reported in CLL patients with large tumour burdens. Since Fludara can induce a response as early as the first week of treatment, precautions should be taken in those patients at risk of developing this complication, and hospitalisation may be recommended for these patients during the first course of treatment.
Transfusion-associated graft-versus-host disease
Transfusion-associated graft-versus-host disease (reaction by the transfused immunocompetent lymphocytes to the host) has been observed after transfusion of non-irradiated blood in Fludara treated patients. Fatal outcome as a consequence of this disease has been reported with a high frequency. Therefore, to minimise the risk of transfusion-associated graft-versus-host disease, patients who require blood transfusion and who are undergoing, or who have received treatment with Fludara should receive irradiated blood only.
Skin cancer
The worsening or flare up of pre-existing skin cancer lesions as well as new onset of skin cancer has been reported in some patients during or after Fludara therapy.
Impaired state of health
In patients with impaired state of health, Fludara should be given with caution and after careful risk/benefit consideration. This applies especially for patients with severe impairment of bone marrow function (thrombocytopenia, anaemia, and/or granulocytopenia), immunodeficiency or with a history of opportunistic infection.
Renal impairment
The total body clearance of the principle plasma metabolite 2-F-ara-A shows a correlation with creatinine clearance, indicating the importance of the renal excretion pathway for the elimination of the compound. Patients with reduced renal function demonstrated an increased total body exposure (AUC of 2F-ara-A). There are limited clinical data available in patients with impairment of renal function (creatinine clearance < 70 ml/min).
Fludara must be administered cautiously in patients with renal insufficiency. In patients with moderate impairment of renal function (creatinine clearance between 30 and 70 ml/min), the dose should be reduced by up to 50% and the patient should be monitored closely (see section 4.2). Fludara treatment is contraindicated if creatinine clearance is < 30ml/min (see section 4.3).
Older people
Since there are limited data for the use of Fludara in older people (> 75 years), caution should be exercised with the administration of Fludara in these patients.
In patients aged 65 years or older, creatinine clearance should be measured before start of treatment, see “Renal impairment” and section 4.2.
Pregnancy
Fludarabine phosphate has been shown to be genotoxic. Fludarabine phosphate has also been shown to be both embryotoxic and fetotoxic in rabbits and rats (see sections 5.3). Fludara may cause foetal harm when administered to pregnant females. Therefore, Fludara must not be used during pregnancy unless the potential benefit for the mother outweighs the potential risks to the foetus.
Females of childbearing potential receiving Fludara should be advised to avoid becoming pregnant, and to inform the treating physician immediately should this occur (see sections 4.6 and 5.3).
Contraception in males and females
Due to the genotoxic risk of fludarabine phosphate, females of child-bearing potential must take effective contraceptive measures during and at least for 6 months after cessation of therapy. Male patients must use effective methods of contraception and be advised to not father a child while receiving Fludara, and at least for 3 months following completion of treatment (see section 4.6).
Vaccination
During and after treatment with Fludara, vaccination with live vaccines should be avoided.
Retreatment options after initial Fludara treatment
A crossover from initial treatment with Fludara to chlorambucil for non responders to Fludara should be avoided because most patients who have been resistant to Fludara have shown resistance to chlorambucil.
Change to Fludara IV
The reported incidence of nausea/vomiting was higher with the oral than the i.v. formulation. If this presents a persistent clinical problem it is recommended to switch to the i.v. formulation.
Excipients
Each Fludara 10 mg film-coated tablet contains 74.75 mg lactose monohydrate. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Fludara 10 mg film-coated tablet contains sodium. This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially 'sodium-free'.