Laboratory Tests
Anagrelide therapy requires close clinical supervision of
the patient. While the platelet count is being lowered (usually during the
first two weeks of treatment), blood counts (hemoglobin, white blood cells),
liver function (SGOT, SGPT) and renal function (serum creatinine, BUN) should
be monitored.
In 9 subjects receiving a single 5 mg dose of anagrelide,
standing blood pressure fell an average of 22/15 mm Hg, usually accompanied by
dizziness. Only minimal changes in blood pressure were observed following a
dose of 2 mg.
Cessation of AGRYLIN® Treatment
In general, interruption of anagrelide treatment is followed
by an increase in platelet count. After sudden stoppage of anagrelide therapy,
the increase in platelet count can be observed within four days.
Carcinogenesis, Mutagenesis, Impairment of Fertility
In a two year rat carcinogenicity study a higher incidence of uterine adenocarcinoma,
relative to controls, was observed in females receiving 30mg/kg/day (at least
174 times human AUC exposure after a 1mg twice daily dose). Adrenal phaeochromocytomas
were increased relative to controls in males receiving 3mg/kg/day and above,
and in females receiving 10mg/kg/day and above (at least 10 and 18 times respectively
human AUC exposure after a 1mg twice daily dose). Anagrelide hydrochloride was
not genotoxic in the Ames test, the mouse lymphoma cell (L5178Y, TK+/-)
forward mutation test, the human lymphocyte chromosome aberration test, or the
mouse micronucleus test. Anagrelide hydrochloride at oral doses up to 240 mg/kg/day
(1,440 mg/m²/day, 195 times the recommended maximum human dose based on
body surface area) was found to have no effect on fertility and reproductive
performance of male rats. However, in female rats, at oral doses of 60 mg/kg/day
(360 mg/m²/day, 49 times the recommended maximum human dose based on body
surface area) or higher, it disrupted implantation when administered in early
pregnancy and retarded or blocked parturition when administered in late pregnancy.
Pregnancy
Pregnancy Category C.
Teratogenic Effects
Teratology studies have been performed in pregnant rats at
oral doses up to 900 mg/kg/day (5,400 mg/m²/day, 730 times the recommended
maximum human dose based on body surface area) and in pregnant rabbits at oral
doses up to 20 mg/kg/day (240 mg/m²/day, 32 times the recommended maximum human
dose based on body surface area) and have revealed no evidence of impaired
fertility or harm to the fetus due to anagrelide hydrochloride.
Nonteratogenic Effects
A fertility and reproductive performance study performed in
female rats revealed that anagrelide hydrochloride at oral doses of 60
mg/kg/day (360 mg/m²/day, 49 times the recommended maximum human dose based on
body surface area) or higher disrupted implantation and exerted adverse effect
on embryo/fetal survival.
A perinatal and postnatal study performed in female rats
revealed that anagrelide hydrochloride at oral doses of 60 mg/kg/day (360
mg/m²/day, 49 times the recommended maximum human dose based on body surface
area) or higher produced delay or blockage of parturition, deaths of
nondelivering pregnant dams and their fully developed fetuses, and increased
mortality in the pups born. There are however, no adequate and well controlled
studies with anagrelide hydrochloride in pregnant women. Because animal
reproduction studies are not always predictive of human response, anagrelide
hydrochloride should be used during pregnancy only if clearly needed.
Nonclinical toxicology
In the 2-year rat study, a significant increase in
non-neoplastic lesions were observed in anagrelide treated males and females in
the adrenal (medullary hyperplasia), heart (myocardial hypertrophy and chamber
distension), kidney (hydronephrosis, tubular dilation and urothelial
hyperplasia) and bone (femur enostosis). Vascular effects were observed in tissues
of the pancreas (arteritis/periarteritis, intimal proliferation and medial
hypertrophy), kidney (arteritis/periarteritis, intimal proliferation and medial
hypertrophy), sciatic nerve (vascular mineralization), and testes (tubular
atrophy and vascular infarct) in anagrelide treated males.
Five women became pregnant while on anagrelide treatment at
doses of 1 to 4 mg/day. Treatment was stopped as soon as it was realized that
they were pregnant. All delivered normal, healthy babies. There are no adequate
and well-controlled studies in pregnant women. Anagrelide hydrochloride should
be used during pregnancy only if the potential benefit justifies the potential
risk to the fetus. Anagrelide is not recommended in women who are or may become
pregnant. If this drug is used during pregnancy, or if the patient becomes
pregnant while taking this drug, the patient should be apprised of the
potential harm to the fetus. Women of child-bearing potential should be
instructed that they must not be pregnant and that they should use
contraception while taking anagrelide. Anagrelide may cause fetal harm when
administered to a pregnant woman.
Nursing Mothers
It is not known whether this drug is excreted in human milk.
Because many drugs are excreted in human milk and because of the potential for
serious adverse reaction in nursing infants from anagrelide hydrochloride, a
decision should be made whether to discontinue nursing or to discontinue the
drug, taking into account the importance of the drug to the mother.
Pediatric Use
Myeloproliferative disorders are uncommon in pediatric
patients and limited data are available in this population. An open label
safety and PK/PD study (see CLINICAL PHARMACOLOGY) was conducted in 17
pediatric patients 7-14 years of age (8 patients 7-11 years of age and 9
patients 11-14 years of age, mean age of 11 years; 8 males and 9 females) with
thrombocythemia secondary to ET as compared to 18 adult patients (mean age of
63 years, 9 males and 9 females). Prior to entry on to the study, 16 of 17 pediatric
patients and 13 of 18 adult patients had received anagrelide treatment for an
average of 2 years. The median starting total daily dose, determined by
retrospective chart review, for pediatric and adult ET patients who had
received anagrelide prior to study entry was 1mg for each of the three age
groups (7-11 and 11-14 year old patients and adults). The starting dose for 6
anagrelide-naive patients at study entry was 0.5 mg once daily. At study
completion, the median total daily maintenance doses were similar across age
groups, median of 1.75 mg for patients of 7-11 years of age, 2 mg in patients
11-14 years of age, and 1.5 mg for adults.
The study evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) profile
of anagrelide, including platelet counts (see CLINICAL
PHARMACOLOGY).
The frequency of adverse events observed in pediatric
patients was similar to adult patients. The most common adverse events observed
in pediatric patients were fever, epistaxis, headache, and fatigue during a
3-months treatment of anagrelide in the study. Adverse events that had been
reported in these pediatric patients prior to the study and were considered to
be related to anagrelide treatment based on retrospective review were
palpitation, headache, nausea, vomiting, abdominal pain, back pain, anorexia,
fatigue, and muscle cramps. Episodes of increased pulse rate and decreased
systolic or diastolic blood pressure beyond the normal ranges in the absence of
clinical symptoms were observed in some patients. Reported AEs were consistent
with the known pharmacological profile of anagrelide and the underlying
disease. There were no apparent trends or differences in the types of adverse
events observed between the pediatric patients compared with those of the adult
patients. No overall difference in dosing and safety were observed between
pediatric and adult patients. In another open-label study, anagrelide had been
used successfully in 12 pediatric patients (age range 6.8 to 17.4 years; 6 male
and 6 female), including 8 patients with ET, 2 patients with CML, 1 patient
with PV, and 1 patient with OMPD. Patients were started on therapy with 0.5 mg
qid up to a maximum daily dose of 10 mg. The median duration of treatment was
18.1 months with a range of 3.1 to 92 months. Three patients received treatment
for greater than three years. Other adverse events reported in spontaneous
reports and literature reviews include anemia, cutaneous photosensitivity and
elevated leukocyte count.
Geriatric Use
Of the total number of subjects in clinical studies of
AGRYLIN®, 42.1% were 65 years and over, while 14.9% were 75 years and over. No
overall differences in safety or effectiveness were observed between these
subjects and younger subjects, and other reported clinical experience has not
identified differences in response between the elderly and younger patients,
but greater sensitivity of some older individuals cannot be ruled out.
Last updated on RxList: 8/3/2009