Xofigo Treatment Guide PDF

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Available by prescription only.
Xofigo is used to treat prostate cancer that is resistant to
medical or surgical treatments that lower testosterone
and has spread to your bones with symptoms, but not
to other parts of your body
Patient Treatment Guide
Your physician has referred you for Xofigo therapy. Your healthcare provider will give you a brochure that explains more about Xofigo.
Over the course of your therapy, you will get up to 6 intravenous injections of Xofigo-1 injection every 4 weeks. Each injection of
Xofigo will be given over 1 minute. This document will help you keep track of some of the important steps in your treatment. Before
each injection of Xofigo, you will need to have a blood test so that your healthcare provider can be sure your blood counts are in the
appropriate range. If your blood counts are not in the appropriate range, your scheduled treatment may be postponed or suspended.
Injection 1
Injection 4
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Injection 2
Injection 5
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Your second treatment will take place at (location)
Your fifth treatment will take place at (location)
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Injection 3
Injection 6
Your blood test will be drawn at (location)
Your blood test will be drawn at (location)
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Your third treatment will take place at (location)
Your sixth treatment will take place at (location)
on (date/time)
For questions call
on (date/time)
For questions call
These projected dates are specific to only your Xofigo treatment. While being treated with Xofigo, you will continue to see the healthcare provider
who manages your cancer, just like you normally would. Please keep any additional appointments that your doctor requests.
Be sure to tell your healthcare provider about any signs of low blood cell counts. Signs of low blood cell counts include more bleeding or bruising
than usual after injury, catching more colds than usual, fever, shortness of breath, and tiredness.
IMPORTANT SAFETY INFORMATION
Before taking Xofigo, tell your healthcare provider if you:
• have bone marrow problems. Xofigo can cause your blood cells counts to go down, including
red blood cells, white blood cells, and/or platelets. In a clinical trial, some patients had to
permanently discontinue therapy because of bone marrow problems. In addition, there were
some deaths and blood transfusions that occurred due to severe bone marrow problems.
Your healthcare provider will do blood tests before and during treatment with Xofigo
Please see additional Important Safety Information on reverse side and accompanying
full Prescribing Information.
1 of 16
IMPORTANT SAFETY INFORMATION (continued)
Do not take Xofigo if you are pregnant or may become pregnant. Xofigo can harm your unborn baby.
Women who are pregnant or who may become pregnant should not come in contact with Xofigo without protection, such as
gloves.
Before taking Xofigo, tell your healthcare provider if you:
• are receiving any chemotherapy or another extensive radiation therapy
• have any other medical conditions
While you are on Xofigo:
• make sure you keep your blood cell count monitoring appointments and tell your healthcare provider about any symptoms
or signs of low blood cell counts. Report symptoms or signs of shortness of breath, tiredness, bleeding (such as bruising),
or infection (such as fever)
• stay well hydrated and report any signs of dehydration (such as dry mouth and increased thirst) or urinary or kidney
problems (such as burning when urinating)
• there are no restrictions regarding contact with other people after receiving Xofigo
• follow good hygiene practices in order to minimize radiation exposure from spills of bodily fluids to household members
and caregivers for a period of 1 week after each injection
• use condoms and make sure female partners who may become pregnant use highly effective birth control methods during
and for a minimum of 6 months after treatment with Xofigo
The most common side effects of Xofigo include:
• nausea
• diarrhea
• vomiting
• swelling of the arms or legs (peripheral edema)
• low blood cell counts
Tell your healthcare provider if you have any side effects.
You are encouraged to report negative side effects or quality complaints of prescription
drugs to the FDA. Visit http://www.fda.gov/medwatch or call 1-800-FDA-1088.
Xofigo is available by prescription only.
Please see accompanying full Prescribing Information.
For further information, please visit www.xofigo-us.com
© 2016 Bayer. All rights reserved.
BAYER, the Bayer Cross, and Xofigo are registered trademarks of Bayer.
PP-600-US-2082
04/16
HIGHLIGHTS OF PRESCRIBING INFORMATION
These highlights do not include all the information needed to use
XOFIGO safely and effectively. See full prescribing information for
XOFIGO.
XOFIGO (radium Ra 223 dichloride) Injection, for intravenous use
Initial U.S. Approval: 2013
--------------------------- RECENT MAJOR CHANGES --------------------------Dosage and Administration (2.1)
3/2016
Dosage Forms and Strengths (3)
3/2016
--------------------------- INDICATIONS AND USAGE -------------------------Xofigo is an alpha particle-emitting radioactive therapeutic agent indicated for
the treatment of patients with castration-resistant prostate cancer, symptomatic
bone metastases and no known visceral metastatic disease. (1)
---------------------- DOSAGE AND ADMINISTRATION ---------------------The dose regimen of Xofigo is 55 kBq (1.49 microcurie) per kg body weight,
given at 4 week intervals for 6 injections. (2.1)
--------------------- DOSAGE FORMS AND STRENGTHS -------------------Single-use vial at a concentration of 1,100 kBq/mL (30 microcurie/mL) at the
reference date with a total radioactivity of 6,600 kBq/vial (178
microcurie/vial) at the reference date (3)
FULL PRESCRIBING INFORMATION: CONTENTS*
1 INDICATIONS AND USAGE
2 DOSAGE AND ADMINISTRATION
2.1 Recommended Dosage
2.2 Administration
2.3 Instructions for Use / Handling
3 DOSAGE FORMS AND STRENGTHS
4 CONTRAINDICATIONS
5 WARNINGS AND PRECAUTIONS
5.1 Bone Marrow Suppression
6 ADVERSE REACTIONS
6.1 Clinical Trials Experience
7 DRUG INTERACTIONS
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
8.3 Nursing Mothers
8.4 Pediatric Use
8.5 Geriatric Use
------------------------------ CONTRAINDICATIONS ----------------------------Pregnancy (4, 8.1)
----------------------- WARNINGS AND PRECAUTIONS ---------------------Bone Marrow Suppression: Measure blood counts prior to treatment initiation
and before every dose of Xofigo. Discontinue Xofigo if hematologic values do
not recover within 6 to 8 weeks after treatment. Monitor patients with
compromised bone marrow reserve closely. Discontinue Xofigo in patients
who experience life-threatening complications despite supportive care
measures. (5.1)
------------------------------ ADVERSE REACTIONS ----------------------------The most common adverse drug reactions ( 10%) in patients receiving
Xofigo were nausea, diarrhea, vomiting, and peripheral edema.
The most common hematologic laboratory abnormalities (≥ 10%) were
anemia, lymphocytopenia, leukopenia, thrombocytopenia, and neutropenia
(6.1).
To report SUSPECTED ADVERSE REACTIONS, contact Bayer
HealthCare Pharmaceuticals Inc. at 1-888-842-2937 or FDA at 1-800FDA-1088 or www.fda.gov/medwatch
SEE 17 FOR PATIENT COUNSELING INFORMATION
Revised: 3/2016
8.6 Patients with Hepatic Impairment
8.7 Patients with Renal Impairment
8.8 Males of Reproductive Potential
10 OVERDOSAGE
11 DESCRIPTION
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
12.2 Pharmacodynamics
12.3 Pharmacokinetics
12.6 Cardiac Electrophysiology
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
14 CLINICAL STUDIES
15 REFERENCES
16 HOW SUPPLIED/STORAGE AND HANDLING
17 PATIENT COUNSELING INFORMATION
*Sections or subsections omitted from the full prescribing information are not listed.
FULL PRESCRIBING INFORMATION
1 INDICATIONS AND USAGE
Xofigo is indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases
and no known visceral metastatic disease.
2 DOSAGE AND ADMINISTRATION
2.1 Recommended Dosage
The dose regimen of Xofigo is 55 kBq (1.49 microcurie) per kg body weight, given at 4 week intervals for 6 injections.
Safety and efficacy beyond 6 injections with Xofigo have not been studied.
The volume to be administered to a given patient should be calculated using the:

Patient’s body weight (kg)

Dosage level 55 kBq/kg body weight or 1.49 microcurie/kg body weight

Radioactivity concentration of the product (1,100 kBq/mL; 30 microcurie/mL) at the reference date
1

Decay correction factor to correct for physical decay of radium-223.
The total volume to be administered to a patient is calculated as follows:
Body weight in kg  55 kBq/kg body weight
Volume to be administered (mL)
=
Decay factor  1,100 kBq/mL
or
Body weight in kg  1.49 microcurie/kg body weight
Volume to be administered (mL)
=
Decay factor  30 microcurie/mL
Table 1: Decay Correction Factor Table
Days from Reference Date
-14
-13
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
Decay Factor
2.296
2.161
2.034
1.914
1.802
1.696
1.596
1.502
1.414
1.330
1.252
1.178
1.109
1.044
Days from Reference Date
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Decay Factor
0.982
0.925
0.870
0.819
0.771
0.725
0.683
0.643
0.605
0.569
0.536
0.504
0.475
0.447
0.420
The Decay Correction Factor Table is corrected to 12 noon Central Standard Time (CST). To determine the decay correction factor, count the
number of days before or after the reference date. The Decay Correction Factor Table includes a correction to account for the 7 hour time difference
between 12 noon Central European Time (CET) at the site of manufacture and 12 noon US CST, which is 7 hours earlier than CET.
Immediately before and after administration, the net patient dose of administered Xofigo should be determined by
measurement in an appropriate radioisotope dose calibrator that has been calibrated with a National Institute of Standards
and Technology (NIST) traceable radium-223 standard (available upon request from Bayer) and corrected for decay using
the date and time of calibration. The dose calibrator must be calibrated with nationally recognized standards, carried out at
the time of commissioning, after any maintenance procedure that could affect the dosimetry and at intervals not to exceed
one year.
2.2 Administration
Administer Xofigo by slow intravenous injection over 1 minute.
Flush the intravenous access line or cannula with isotonic saline before and after injection of Xofigo.
2.3 Instructions for Use/Handling
General warning
Xofigo (an alpha particle-emitting pharmaceutical) should be received, used and administered only by authorized persons
in designated clinical settings. The receipt, storage, use, transfer and disposal Xofigo are subject to the regulations and/or
appropriate licenses of the competent official organization.
2
Xofigo should be handled by the user in a manner which satisfies both radiation safety and pharmaceutical quality
requirements. Appropriate aseptic precautions should be taken.
Radiation protection
The administration of Xofigo is associated with potential risks to other persons (e.g., medical staff, caregivers and
patient’s household members) from radiation or contamination from spills of bodily fluids such as urine, feces, or vomit.
Therefore, radiation protection precautions must be taken in accordance with national and local regulations.
For drug handling
Follow the normal working procedures for the handling of radiopharmaceuticals and use universal precautions for
handling and administration such as gloves and barrier gowns when handling blood and bodily fluids to avoid
contamination. In case of contact with skin or eyes, the affected area should be flushed immediately with water. In the
event of spillage of Xofigo, the local radiation safety officer should be contacted immediately to initiate the necessary
measurements and required procedures to decontaminate the area. A complexing agent such as 0.01 M ethylene-diaminetetraacetic acid (EDTA) solution is recommended to remove contamination.
For patient care
Whenever possible, patients should use a toilet and the toilet should be flushed several times after each use. When
handling bodily fluids, simply wearing gloves and hand washing will protect caregivers. Clothing soiled with Xofigo or
patient fecal matter or urine should be washed promptly and separately from other clothing.
Radium-223 is primarily an alpha emitter, with a 95.3% fraction of energy emitted as alpha-particles. The fraction emitted
as beta-particles is 3.6%, and the fraction emitted as gamma-radiation is 1.1%. The external radiation exposure associated
with handling of patient doses is expected to be low, because the typical treatment activity will be below 8,000 kBq (216
microcurie). In keeping with the As Low As Reasonably Achievable (ALARA) principle for minimization of radiation
exposure, it is recommended to minimize the time spent in radiation areas, to maximize the distance to radiation sources,
and to use adequate shielding. Any unused product or materials used in connection with the preparation or administration
are to be treated as radioactive waste and should be disposed of in accordance with local regulations.
The gamma radiation associated with the decay of radium-223 and its daughters allows for the radioactivity measurement
of Xofigo and the detection of contamination with standard instruments.
Instructions for preparation
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration,
whenever solution and container permit.
Xofigo is a ready-to-use solution and should not be diluted or mixed with any solutions. Each vial is for single use only.
Dosimetry
The absorbed radiation doses in major organs were calculated based on clinical biodistribution data in five patients with
castration-resistant prostate cancer. Calculations of absorbed radiation doses were performed using OLINDA/EXM
(Organ Level INternal Dose Assessment/EXponential Modeling), a software program based on the Medical Internal
Radiation Dose (MIRD) algorithm, which is widely used for established beta and gamma emitting radionuclides. For
radium-223, which is primarily an alpha particle-emitter, assumptions were made for intestine, red marrow and
bone/osteogenic cells to provide the best possible absorbed radiation dose calculations for Xofigo, considering its
observed biodistribution and specific characteristics.
The calculated absorbed radiation doses to different organs are listed in Table 2. The organs with highest absorbed
radiation doses were bone (osteogenic cells), red marrow, upper large intestine wall, and lower large intestine wall. The
calculated absorbed doses to other organs are lower.
3
Table 2: Calculated Absorbed Radiation Doses to Organs
Target Organ
Adrenals
Brain
Breasts
Gallbladder wall
LLI1 wall
Small intestine wall
Stomach wall
ULI2 wall
Heart wall
Kidneys
Liver
Lungs
Muscle
Ovaries
Pancreas
Red marrow
Osteogenic cells
Skin
Spleen
Testes
Thymus
Thyroid
Urinary bladder wall
Uterus
Whole body
Mean
(Gy/MBq)
Mean
(rad/mCi)
0.00012
0.00010
0.00005
0.00023
0.04645
0.00726
0.00014
0.03232
0.00173
0.00320
0.00298
0.00007
0.00012
0.00049
0.00011
0.13879
1.15206
0.00007
0.00009
0.00008
0.00006
0.00007
0.00403
0.00026
0.02311
0.44
0.37
0.18
0.85
171.88
26.87
0.51
119.58
6.40
11.86
11.01
0.27
0.44
1.80
0.41
513.51
4262.60
0.27
0.33
0.31
0.21
0.26
14.90
0.94
85.50
Coefficient of
Variation
(%)
56
80
120
14
83
45
22
50
42
36
36
90
41
40
43
41
41
79
54
59
109
96
63
28
16
1
LLI: lower large intestine
upper large intestine
2ULI:
3 DOSAGE FORMS AND STRENGTHS
Xofigo (radium Ra 223 dichloride injection) is available in single-use vials containing 6 mL of solution at a concentration
of 1,100 kBq/mL (30 microcurie/mL) at the reference date with a total radioactivity of 6,600 kBq/vial (178
microcurie/vial) at the reference date.
4 CONTRAINDICATIONS
Xofigo is contraindicated in pregnancy.
Xofigo can cause fetal harm when administered to a pregnant woman based on its mechanism of action. Xofigo is not
indicated for use in women. Xofigo is contraindicated 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, apprise the patient of the potential hazard to
the fetus [see Use in Specific Populations (8.1)].
4
5 WARNINGS AND PRECAUTIONS
5.1 Bone Marrow Suppression
In the randomized trial, 2% of patients on the Xofigo arm experienced bone marrow failure or ongoing pancytopenia
compared to no patients treated with placebo. There were two deaths due to bone marrow failure and for 7 of 13 patients
treated with Xofigo, bone marrow failure was ongoing at the time of death. Among the 13 patients who experienced bone
marrow failure, 54% required blood transfusions. Four percent (4%) of patients on the Xofigo arm and 2% on the placebo
arm permanently discontinued therapy due to bone marrow suppression.
In the randomized trial, deaths related to vascular hemorrhage in association with myelosuppression were observed in 1%
of Xofigo-treated patients compared to 0.3% of patients treated with placebo. The incidence of infection-related deaths
(2%), serious infections (10%), and febrile neutropenia (<1%) were similar for patients treated with Xofigo and placebo.
Myelosuppression; notably thrombocytopenia, neutropenia, pancytopenia, and leukopenia; has been reported in patients
treated with Xofigo. In the randomized trial, complete blood counts (CBCs) were obtained every 4 weeks prior to each
dose and the nadir CBCs and times of recovery were not well characterized. In a separate single-dose phase 1 study of
Xofigo, neutrophil and platelet count nadirs occurred 2 to 3 weeks after Xofigo administration at doses that were up to 1
to 5 times the recommended dose, and most patients recovered approximately 6 to 8 weeks after administration [see
Adverse Reactions (6)].
Hematologic evaluation of patients must be performed at baseline and prior to every dose of Xofigo. Before the first
administration of Xofigo, the absolute neutrophil count (ANC) should be ≥ 1.5 x 109/L, the platelet count ≥ 100 x 109/L
and hemoglobin ≥ 10 g/dL. Before subsequent administrations of Xofigo, the ANC should be ≥ 1 x 109/L and the platelet
count ≥ 50 x 109/L. If there is no recovery to these values within 6 to 8 weeks after the last administration of Xofigo,
despite receiving supportive care, further treatment with Xofigo should be discontinued. Patients with evidence of
compromised bone marrow reserve should be monitored closely and provided with supportive care measures when
clinically indicated. Discontinue Xofigo in patients who experience life-threatening complications despite supportive care
for bone marrow failure.
The safety and efficacy of concomitant chemotherapy with Xofigo have not been established. Outside of a clinical trial,
concomitant use with chemotherapy is not recommended due to the potential for additive myelosuppression. If
chemotherapy, other systemic radioisotopes or hemibody external radiotherapy are administered during the treatment
period, Xofigo should be discontinued.
6 ADVERSE REACTIONS
The following serious adverse reactions are discussed in greater detail in another section of the label:

Bone Marrow Suppression [see Warnings and Precautions (5.1)]
6.1 Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials
of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed
in practice.
In the randomized clinical trial in patients with metastatic castration-resistant prostate cancer with bone metastases, 600
patients received intravenous injections of 55 kBq/kg (1.49 microcurie/kg) of Xofigo and best standard of care and 301
patients received placebo and best standard of care once every 4 weeks for up to 6 injections. Prior to randomization, 58%
and 57% of patients had received docetaxel in the Xofigo and placebo arms, respectively. The median duration of
treatment was 20 weeks (6 cycles) for Xofigo and 18 weeks (5 cycles) for placebo.
5
The most common adverse reactions (≥ 10%) in patients receiving Xofigo were nausea, diarrhea, vomiting, and peripheral
edema (Table 3). Grade 3 and 4 adverse events were reported among 57% of Xofigo-treated patients and 63% of placebotreated patients. The most common hematologic laboratory abnormalities in Xofigo-treated patients (≥ 10%) were anemia,
lymphocytopenia, leukopenia, thrombocytopenia, and neutropenia (Table 4).
Treatment discontinuations due to adverse events occurred in 17% of patients who received Xofigo and 21% of patients
who received placebo. The most common hematologic laboratory abnormalities leading to discontinuation for Xofigo
were anemia (2%) and thrombocytopenia (2%).
Table 3 shows adverse reactions occurring in ≥ 2% of patients and for which the incidence for Xofigo exceeds the
incidence for placebo.
Table 3: Adverse Reactions in the Randomized Trial
System/Organ Class
Preferred Term
Xofigo (n=600)
Grades 1-4
Grades 3-4
%
%
Blood and lymphatic system disorders
Pancytopenia
2
Gastrointestinal disorders
Nausea
36
Diarrhea
25
Vomiting
19
General disorders and administration site conditions
Peripheral edema
13
Renal and urinary disorders
Renal failure and
3
impairment
Placebo (n=301)
Grades 1-4
Grades 3-4
%
%
1
0
0
2
2
2
35
15
14
2
2
2
2
10
1
1
1
1
Laboratory Abnormalities
Table 4 shows hematologic laboratory abnormalities occurring in > 10% of patients and for which the incidence for
Xofigo exceeds the incidence for placebo.
Table 4: Hematologic Laboratory Abnormalities
Hematologic
Xofigo (n=600)
Laboratory
Grades 1-4
Grades 3-4
Abnormalities
%
%
Anemia
93
6
Lymphocytopenia
72
20
Leukopenia
35
3
Thrombocytopenia
31
3
Neutropenia
18
2
Laboratory values were obtained at baseline and prior to each 4-week cycle.
Placebo (n=301)
Grades 1-4
Grades 3-4
%
%
88
6
53
7
10
<1
22
<1
5
<1
As an adverse reaction, grade 3-4 thrombocytopenia was reported in 6% of patients on Xofigo and in 2% of patients on
placebo. Among patients who received Xofigo, the laboratory abnormality grade 3-4 thrombocytopenia occurred in 1% of
docetaxel naïve patients and in 4% of patients who had received prior docetaxel. Grade 3-4 neutropenia occurred in 1% of
docetaxel naïve patients and in 3% of patients who have received prior docetaxel.
6
Fluid Status
Dehydration occurred in 3% of patients on Xofigo and 1% of patients on placebo. Xofigo increases adverse reactions such
as diarrhea, nausea, and vomiting which may result in dehydration. Monitor patients’ oral intake and fluid status carefully
and promptly treat patients who display signs or symptoms of dehydration or hypovolemia.
Injection Site Reactions
Erythema, pain, and edema at the injection site were reported in 1% of patients on Xofigo.
Secondary Malignant Neoplasms
Xofigo contributes to a patient’s overall long-term cumulative radiation exposure. Long-term cumulative radiation
exposure may be associated with an increased risk of cancer and hereditary defects. Due to its mechanism of action and
neoplastic changes, including osteosarcomas, in rats following administration of radium-223 dichloride, Xofigo may
increase the risk of osteosarcoma or other secondary malignant neoplasms [see Nonclinical Toxicology (13.1)]. However,
the overall incidence of new malignancies in the randomized trial was lower on the Xofigo arm compared to placebo
(<1% vs. 2%; respectively), but the expected latency period for the development of secondary malignancies exceeds the
duration of follow up for patients on the trial.
Subsequent Treatment with Cytotoxic Chemotherapy
In the randomized clinical trial, 16% patients in the Xofigo group and 18% patients in the placebo group received
cytotoxic chemotherapy after completion of study treatments. Adequate safety monitoring and laboratory testing was not
performed to assess how patients treated with Xofigo will tolerate subsequent cytotoxic chemotherapy.
7 DRUG INTERACTIONS
No formal clinical drug interaction studies have been performed.
Subgroup analyses indicated that the concurrent use of bisphosphonates or calcium channel blockers did not affect the
safety and efficacy of Xofigo in the randomized clinical trial.
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy Category X [see Contraindications (4)]
Xofigo can cause fetal harm when administered to a pregnant woman based on its mechanism of action. While there are
no human or animal data on the use of Xofigo in pregnancy and Xofigo is not indicated for use in women, maternal use of
a radioactive therapeutic agent could affect development of a fetus. Xofigo is contraindicated in women who are or may
become pregnant while receiving the drug. If this drug is used during pregnancy, or if the patient becomes pregnant while
taking this drug, apprise the patient of the potential hazard to the fetus and the potential risk for pregnancy loss. Advise
females of reproductive potential to avoid becoming pregnant during treatment with Xofigo.
8.3 Nursing Mothers
Xofigo is not indicated for use in women. It is not known whether radium-223 dichloride is excreted in human milk.
Because many drugs are excreted in human milk, and because of potential for serious adverse reactions in nursing infants
from Xofigo, a decision should be made whether to discontinue nursing, or discontinue the drug taking into account the
importance of the drug to the mother.
8.4 Pediatric Use
The safety and efficacy of Xofigo in pediatric patients have not been established.
7
In single- and repeat-dose toxicity studies in rats, findings in the bones (depletion of osteocytes, osteoblasts, osteoclasts,
fibro-osseous lesions, disruption/disorganization of the physis/growth line) and teeth (missing, irregular growth, fibroosseous lesions in bone socket) correlated with a reduction of osteogenesis that occurred at clinically relevant doses
beginning in the range of 22 – 88 kBq (0.59 - 2.38 microcurie) per kg body weight.
8.5 Geriatric Use
Of the 600 patients treated with Xofigo in the randomized trial, 75% were 65 years of age and over and while 33% were
75 years of age and over. No dosage adjustment is considered necessary in elderly patients. 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 responses between the elderly and younger patients, but greater sensitivity of some older
individuals cannot be ruled out.
8.6 Patients with Hepatic Impairment
No dedicated hepatic impairment trial for Xofigo has been conducted. Since radium-223 is neither metabolized by the
liver nor eliminated via the bile, hepatic impairment is unlikely to affect the pharmacokinetics of radium-223 dichloride
[see Clinical Pharmacology (12.3)]. Based on subgroup analyses in the randomized clinical trial, dose adjustment is not
needed in patients with mild hepatic impairment. No dose adjustments can be recommended for patients with moderate or
severe hepatic impairment due to lack of clinical data.
8.7 Patients with Renal Impairment
No dedicated renal impairment trial for Xofigo has been conducted. Based on subgroup analyses in the randomized
clinical trial, dose adjustment is not needed in patients with existing mild (creatinine clearance [CrCl] 60 to 89 mL/min) or
moderate (CrCl 30 to 59 mL/min) renal impairment. No dose adjustment can be recommended for patients with severe
renal impairment (CrCl less than 30 mL/min) due to limited data available (n = 2) [see Clinical Pharmacology (12.3)].
8.8 Males of Reproductive Potential
Contraception
Because of potential effects on spermatogenesis associated with radiation, advise men who are sexually active to use
condoms and their female partners of reproductive potential to use a highly effective contraceptive method during and for
6 months after completing treatment with Xofigo.
Infertility
There are no data on the effects of Xofigo on human fertility. There is a potential risk that radiation by Xofigo could
impair human fertility [see Nonclinical Toxicology (13.1)].
10 OVERDOSAGE
There have been no reports of inadvertent overdosing of Xofigo during clinical studies.
There is no specific antidote. In the event of an inadvertent overdose of Xofigo, utilize general supportive measures,
including monitoring for potential hematological and gastrointestinal toxicity, and consider using medical
countermeasures such as aluminum hydroxide, barium sulfate, calcium carbonate, calcium gluconate, calcium phosphate,
or sodium alginate.1
Single Xofigo doses up to 274 kBq (7.41 microcurie) per kg body weight were evaluated in a phase 1 clinical trial and no
dose-limiting toxicities were observed.
8
11 DESCRIPTION
Radium Ra 223 dichloride, an alpha particle-emitting pharmaceutical, is a radiotherapeutic drug.
Xofigo is supplied as a clear, colorless, isotonic, and sterile solution to be administered intravenously with pH between 6
and 8.
Each milliliter of solution contains 1,100 kBq radium-223 dichloride (30 microcurie), corresponding to 0.58 ng radium223, at the reference date. Radium is present in the solution as a free divalent cation.
Each vial contains 6 mL of solution (6,600 kBq (178 microcurie) radium-223 dichloride at the reference date). The
inactive ingredients are 6.3 mg/mL sodium chloride USP (tonicity agent), 7.2 mg/mL sodium citrate USP (for pH
adjustment), 0.2 mg/mL hydrochloric acid USP (for pH adjustment), and water for injection USP.
The molecular weight of radium-223 dichloride, 223RaCl2, is 293.9 g/mol.
Radium-223 has a half-life of 11.4 days. The specific activity of radium-223 is 1.9 MBq (51.4 microcurie)/ng.
The six-stage-decay of radium-223 to stable lead-207 occurs via short-lived daughters, and is accompanied predominantly
by alpha emissions. There are also beta and gamma emissions with different energies and emission probabilities. The
fraction of energy emitted from radium-223 and its daughters as alpha-particles is 95.3% (energy range of 5 - 7.5 MeV).
The fraction emitted as beta-particles is 3.6% (average energies are 0.445 MeV and 0.492 MeV), and the fraction emitted
as gamma-radiation is 1.1% (energy range of 0.01 - 1.27 MeV).
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
The active moiety of Xofigo is the alpha particle-emitting isotope radium-223 (as radium Ra 223 dichloride), which
mimics calcium and forms complexes with the bone mineral hydroxyapatite at areas of increased bone turnover, such as
bone metastases (see Table 2). The high linear energy transfer of alpha emitters (80 keV/micrometer) leads to a high
frequency of double-strand DNA breaks in adjacent cells, resulting in an anti-tumor effect on bone metastases. The alpha
particle range from radium-223 dichloride is less than 100 micrometers (less than 10 cell diameters) which limits damage
to the surrounding normal tissue.
12.2 Pharmacodynamics
Compared with placebo, there was a significant difference in favor of Xofigo for all five serum biomarkers for bone
turnover studied in a phase 2 randomized study (bone formation markers: bone alkaline phosphatase [ALP], total ALP
and procollagen I N propeptide [PINP], bone resorption markers: C-terminal crosslinking telopeptide of type I collagen
[S-CTX-I] and type I collagen crosslinked C-telopeptide [ICTP]).
12.3 Pharmacokinetics
The pharmacokinetics of radium-223 dichloride in blood was linear in terms of dose proportionality and time
independence in the dose range investigated (50 to 274 kBq [1.35 to 7.41 microcurie] per kg body weight).
Distribution
After intravenous injection, radium-223 is rapidly cleared from the blood and is distributed primarily into bone or is
excreted into intestine. Fifteen minutes post-injection, about 20% of the injected radioactivity remained in blood. At 4
hours, about 4% of the injected radioactivity remained in blood, decreasing to less than 1% at 24 hours after the injection.
At 10 minutes post-injection, radioactivity was observed in bone and in intestine. At 4 hours post-injection, the percentage
of the radioactive dose present in bone and intestine was approximately 61% and 49%, respectively. No significant uptake
9
was seen in other organs such as heart, liver, kidneys, urinary bladder, and spleen at 4 hours post-injection [see Dosage
and Administration (2.3)].
Metabolism
Radium-223 is an isotope that decays and is not metabolized.
Elimination
The whole body measurements indicated that approximately 63% of the administered radioactivity was excreted from the
body within 7 days after injection (after correcting for decay). Fecal excretion is the major route of elimination from the
body. At 48 hours after injection, the cumulative fecal excretion was 13% (range 0 - 34%), and the cumulative urine
excretion was 2% (range 1 - 5%). There was no evidence of hepato-biliary excretion based on imaging data.
The rate of elimination of radium-223 dichloride from the gastrointestinal tract is influenced by the high variability in
intestinal transit rates across the population. Patients with a slower intestinal transit rate could potentially receive a higher
intestinal radiation exposure. It is not known whether this will result in increased gastrointestinal toxicity.
Special Populations
Pediatric patients
Safety and effectiveness of Xofigo have not been established in children and adolescents below 18 years of age.
Patients with hepatic impairment
No dedicated pharmacokinetic study in patients with hepatic impairment has been conducted. However, since radium-223
is not metabolized and there is no evidence of hepato-biliary excretion based on imaging data, hepatic impairment is not
expected to affect the pharmacokinetics of radium-223 dichloride.
Patients with renal impairment
No dedicated pharmacokinetic study in patients with renal impairment has been conducted. However, since excretion in
urine is minimal and the major route of elimination is via the feces, renal impairment is not expected to affect the
pharmacokinetics of radium-223 dichloride.
12.6 Cardiac Electrophysiology
The effect of a single dose of 55 kBq/kg of radium-223 dichloride on the QTc interval was evaluated in a subgroup of 29
patients (21 received Xofigo and 8 received placebo) in the randomized clinical trial. No large changes in the mean QTc
interval (i.e., greater than 20 ms) were detected up to 6 hours post-dose. The potential for delayed effects on the QT
interval after 6 hours was not evaluated.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Animal studies have not been conducted to evaluate the carcinogenic potential of radium-223 dichloride. However, in
repeat-dose toxicity studies in rats, osteosarcomas, a known effect of bone-seeking radionuclides, were observed at
clinically relevant doses 7 to 12 months after the start of treatment. The presence of other neoplastic changes, including
lymphoma and mammary gland carcinoma, was also reported in 12- to 15-month repeat-dose toxicity studies in rats.
Genetic toxicology studies have not been conducted with radium-223 dichloride. However, the mechanism of action of
radium-223 dichloride involves induction of double-strand DNA breaks, which is a known effect of radiation.
Animal studies have not been conducted to evaluate the effects of radium-223 dichloride on male or female fertility or
reproductive function. Xofigo may impair fertility and reproductive function in humans based on its mechanism of action.
10
14 CLINICAL STUDIES
The efficacy and safety of Xofigo were evaluated in a double-blind, randomized, placebo-controlled phase 3 clinical trial
of patients with castration-resistant prostate cancer with symptomatic bone metastases. Patients with visceral metastases
and malignant lymphadenopathy exceeding 3 cm were excluded. The primary efficacy endpoint was overall survival. A
key secondary efficacy endpoint was time to first symptomatic skeletal event (SSE) defined as external beam radiation
therapy (EBRT) to relieve skeletal symptoms, new symptomatic pathologic bone fracture, occurrence of spinal cord
compression, or tumor-related orthopedic surgical intervention. There were no scheduled radiographic assessments
performed on study. All patients were to continue androgen deprivation therapy. At the cut-off date of the pre-planned
interim analysis, a total of 809 patients had been randomized 2:1 to receive Xofigo 55 kBq (1.49 microcurie)/kg
intravenously every 4 weeks for 6 cycles (n = 541) plus best standard of care or matching placebo plus best standard of
care (n = 268). Best standard of care included local EBRT, corticosteroids, antiandrogens, estrogens, estramustine or
ketoconazole. Therapy was continued until unacceptable toxicity or initiation of cytotoxic chemotherapy, other systemic
radioisotope, hemi-body EBRT or other investigational drug. Patients with Crohn’s disease, ulcerative colitis, prior
hemibody radiation or untreated imminent spinal cord compression were excluded from the study. In patients with bone
fractures, orthopedic stabilization was performed before starting or resuming treatment with Xofigo.
The following patient demographics and baseline disease characteristics were balanced between the arms. The median age
was 71 (range 44-94) with a racial distribution of 94% Caucasian, 4% Asian, 2% Black and <1% Other. Patients were
enrolled predominantly from Europe (85%) with 4% of patients enrolled from North America. ECOG performance status
was 0-1 in 86% of patients. Eighty-five percent of patients had 6 or more bone scan lesions and of those 40% had > 20
lesions or a superscan. Opiate pain medications were used for cancer-related pain in 54% of patients, non-opiate pain
medications in 44% of patients and no pain medications in 2% of patients. Patients were stratified by baseline ALP,
bisphosphonate use, and prior docetaxel exposure. Prior bisphosphonates were used by 41% of patients and 58% had
received prior docetaxel. During the treatment period, 83% of Xofigo patients and 82% of placebo patients received
gonadotropin-releasing hormone agonists and 21% of Xofigo patients and 34% of placebo patients received concomitant
antiandrogens. Use of systemic steroids (41%) and bisphosphonates (40%) was balanced between the arms.
The pre-specified interim analysis of overall survival revealed a statistically significant improvement in patients receiving
XOFIGO plus best standard of care compared with patients receiving placebo plus best standard of care. An exploratory
updated overall survival analysis performed before patient crossover with an additional 214 events resulted in findings
consistent with the interim analysis (Table 5).
11
Table 5: Overall Survival Results from the Phase 3 Clinical Trial
Xofigo
Placebo
541
268
Number of deaths
191 (35.3%)
123 (45.9%)
Censored
Median survival
(months) a
(95% CI)
p-valueb
350 (64.7%)
145 (54.1%)
14.0
(12.1, 15.8)
11.2
( 9.0, 13.2)
Interim Analysis
Subjects randomized
Hazard ratio (95% CI)
0.00185
c
0.695 (0.552, 0.875)
Updated Analysis
Subjects randomized
614
307
Number of deaths
333 (54.2%)
195 (63.5%)
Censored
Median survival
(months) a
(95% CI)
Hazard ratio (95% CI)c
281 (45.8%)
112 (36.5%)
14.9
(13.9, 16.1)
11.3
(10.4, 12.8)
0.695 (0.581, 0.832)
a
Survival time is calculated as months from date of randomization to date of death from any cause. Subjects who are not deceased at
time of analysis are censored on the last date subject was known to be alive or lost to follow-up.
b
p-value is from a log-rank test stratified by total ALP, current use of bisphosphonates, and prior use of docetaxel.
c
Hazard ratio is from a Cox proportional hazards model adjusted for total ALP, current use of bisphosphonates, and prior use of
docetaxel. Hazard ratio < 1 favors radium-223 dichloride.
12
The Kaplan-Meier curves for overall survival based on the updated survival results are shown in Figure 1.
Figure 1: Kaplan-Meier Overall Survival Curves from the Phase 3 Clinical Trial
The survival results were supported by a delay in the time to first SSE favoring the Xofigo arm. The majority of events
consisted of external beam radiotherapy to bone metastases.
15 REFERENCES
1. Radiation Emergency Medical Management. [REMM/National Library of Medicine Website.]
http://www.remm.nlm.gov/int_contamination.htm#blockingagents
16 HOW SUPPLIED/STORAGE AND HANDLING
Xofigo (radium Ra 223 dichloride injection) is supplied in single-use vials containing 6 mL of solution at a concentration
of 1,100 kBq/mL (30 microcurie/mL) with a total radioactivity of 6,600 kBq/vial (178 microcurie/vial) at the reference
date (NDC 50419-208-01).
Store at room temperature, below 40° C (104° F). Store Xofigo in the original container or equivalent radiation shielding.
This preparation is approved for use by persons under license by the Nuclear Regulatory Commission or the relevant
regulatory authority of an Agreement State.
Follow procedures for proper handling and disposal of radioactive pharmaceuticals [see Dosage and Administration
(2.3)].
13
17 PATIENT COUNSELING INFORMATION
Advise patients:




To be compliant with blood cell count monitoring appointments while receiving Xofigo. Explain the importance
of routine blood cell counts. Instruct patients to report signs of bleeding or infections.
To stay well hydrated and to monitor oral intake, fluid status, and urine output while being treated with Xofigo.
Instruct patients to report signs of dehydration, hypovolemia, urinary retention, or renal failure / insufficiency.
There are no restrictions regarding contact with other people after receiving Xofigo. Follow good hygiene
practices while receiving Xofigo and for at least 1 week after the last injection in order to minimize radiation
exposure from bodily fluids to household members and caregivers. Whenever possible, patients should use a toilet
and the toilet should be flushed several times after each use. Clothing soiled with patient fecal matter or urine
should be washed promptly and separately from other clothing. Caregivers should use universal precautions for
patient care such as gloves and barrier gowns when handling bodily fluids to avoid contamination. When handling
bodily fluids, wearing gloves and hand washing will protect caregivers.
Who are sexually active to use condoms and their female partners of reproductive potential to use a highly
effective method of birth control during treatment and for 6 months following completion of Xofigo treatment.
Manufactured for:
Bayer HealthCare Pharmaceuticals Inc.
Whippany, NJ 07981
Manufactured in Norway
Xofigo is a trademark of Bayer Aktiengesellschaft.
© 2013, Bayer HealthCare Pharmaceuticals Inc.
All rights reserved.
Revised: March 2016
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